Search

Phenolic aldehydes are the major inhibitors from lignocellulose pretreatment. Previous studies show that oleaginous yeasts are difficult to survive in lignocellulosic hydrolysates even after the removal of furan aldehydes and organic acids inhibitors. This study investigated the cell viability, sugar consumption and lipid accumulation of the major oleaginous yeasts including Trichosporon cutaneum, Rhodosporidium toruloides, Rhodotorula glutinis, Yarrowia lipolytica in wheat straw hydrolysate containing only phenolic aldehydes after furan aldehydes and organic acids were selectively degraded by microorganisms. The results confirmed that the existence of residual phenolic aldehydes was the major reason for poor cell growth and metabolism of oleaginous yeasts. Only T. cutaneum demonstrated the higher tolerance by biodegrading phenolic aldehydes and the satisfactory cell growth and lipid production were obtained. This study revealed that T. cutaneum might be one of the promising cell factories for microbial lipid production from lignocellulosic feedstock.

The aim of this study was to assess the anesthetic efficacy and biochemical effects of citronellal on rainbow trout, Oncorhynchus mykiss. The fish were exposed to 200-800 µl/L citronellal to find the anesthesia induction and recovery times. The deep anesthesia stage was reached within 117-613 s, using 800-200 µl/L citronellal, respectively, and all fish recovered within 240-420 s. To assess biochemical responses, the fish were exposed to 200, 400, 600, and 800 µl/L of citronellal and blood-sampled after deep anesthesia. The results showed that anesthesia led to significant elevations in blood erythrocytes, hematocrit, hemoglobin, mean corpuscular volume, plasma lactate, and lactate dehydrogenase; these parameters exhibited increasing trends as citronellal concentration increased. These results along with significantly higher plasma lysozyme activity, cortisol, and glucose levels in 200 µl/L treatment suggest that an increase in citronellal concentration significantly mitigates hypoxia/stress responses in the fish. Significant elevations in plasma alkaline phosphatase activity and malondialdehyde level were observed in the 200 µl/L treatment, which suggests induction of hemolysis and oxidative stress in this treatment. There was a tendency to higher ammonia levels along with the increase in citronellal concentration, which might be due to early ammonia accumulation because of lower opercular movement in the fish. Except for blood hematocrit and mean corpuscular volume, there were no significant differences between the 600 and 800 µl/L citronellal treatments. In conclusion, high concentrations of citronellal are more suitable for trout anesthesia and blood sampling than low concentrations. Based on the present study, 600-800 µl/L citronellal is recommended for trout anesthesia.

BackgroundThe endoplasmic reticulum (ER) is a membranous organelle that maintains proteostasis and cellular homeostasis, controlling the fine balance between health and disease. Dysregulation of the ER stress response has been implicated in intestinal inflammation associated with inflammatory bowel disease (IBD), a chronic condition characterized by changes to the mucosa and alteration of the gut microbiota. While the microbiota and microbially derived metabolites have also been implicated in ER stress, examples of this connection remain limited to a few observations from pathogenic bacteria. Furthermore, the mechanisms underlying the effects of bacterial metabolites on ER stress signaling have not been well established.ResultsUtilizing an XBP1s-GFP knock-in reporter colorectal epithelial cell line, we screened 399 microbiome-related metabolites for ER stress pathway modulation. We find both ER stress response inducers (acylated dipeptide aldehydes and bisindole methane derivatives) and suppressors (soraphen A) and characterize their activities on ER stress gene transcription and translation. We further demonstrate that these molecules modulate the ER stress pathway through protease inhibition or lipid metabolism interference.ConclusionsOur study identified novel links between classes of gut microbe-derived metabolites and the ER stress response, suggesting the potential for these metabolites to contribute to gut ER homeostasis and providing insight into the molecular mechanisms by which gut microbes impact intestinal epithelial cell homeostasis.

The use of combinations of aroma compounds is common in many food and cosmetic applications. To investigate the binding behavior between high-amylose maize starch and binary aroma combinations of decanal and thymol, starch-aroma inclusion complexes (ICs) were prepared by a one-step or two-step method with different concentrations and orders of addition. The thymol molecule induced the starch chain to form a larger helical cavity and was more likely to form hydrogen bonds with solvents. The encapsulation efficiency and loading efficiency of starch-thymol ICs were always higher than those of starch-decanal ICs, independent of the aroma concentration and addition order in binary aroma ICs. However, starch-decanal ICs prepared in the presence of thymol encapsulated more decanal than in the absence of thymol. The V6I-type crystals formed by starch-decanal ICs and the V6III-type crystals formed by starch-thymol ICs were both present in binary aroma ICs, resulting in a less-ordered structure and lower thermal transition temperatures. In summary, the complexation between binary aroma compounds and starch exhibited both cooperative and competitive binding behaviors. The synergistic effects between decanal and thymol provide guidance in enhancing the aroma encapsulation in starch carriers.

Protein-based conjugates have been extensively utilized in various biotechnological and therapeutic applications. In order to prepare homogeneous conjugates, site-specific modification methods and efficient purification strategies are both critical factors to be considered. The development of general and facile conjugation and purification strategies is therefore highly desirable. Here, we apply a capture and release strategy to create protein conjugates based on Designed Ankyrin Repeat Proteins (DARPins), which are engineered antigen-binding proteins with prominent affinity and selectivity. In this case, DARPins that target the epithelial cell adhesion molecule (EpCAM), a diagnostic cell surface marker for many types of cancer, were employed. The DARPins were first genetically modified with a C-terminal CVIA sequence to install an enzyme recognition site and then labeled with an aldehyde functional group employing protein farnesyltransferase. Using a capture and release strategy, conjugation of the labeled DARPins to a TAMRA fluorophore was achieved with either purified proteins or directly from crude E. coli lysate and used in subsequent flow cytometry and confocal imaging analysis. DARPin-MMAE conjugates were also prepared yielding a construct manifesting an IC50 of 1.3 nM for cell killing of EpCAM positive MCF-7 cells. The method described here is broadly applicable to enable the streamlined one-step preparation of protein-based conjugates.

Enzymatic catalysis is a highly attractive approach to the DNA encoded library technology (DEL) that has not been widely explored. In this paper, we report an l-threonine aldolase (l-TA)-catalyzed on-DNA aldol reaction to form β-hydroxy-α-amino acids, and its diastereoselectivity determination. l-TAs from three species show good on-DNA aldehyde scope and complementary stereoselectivity. The formed aldol product can be further diversified via various reactions, which demonstrates the utility of this reaction in DEL.

The messenger RNA (mRNA) methylations in mammalian cells have been found to contain N6-methyladenosine (m6A), N6-2'-O-dimethyladenosine (m6Am), 7-methylguanosine (m7G), 1-methyladenosine (m1A), 5-methylcytosine (m5C), and 2'-O-methylation (2'-OMe). Their regulatory functions in control of mRNA fate and gene expression are being increasingly uncovered. To unambiguously understand the critical roles of mRNA methylations in physiological and pathological processes, mapping these methylations at single base resolution is highly required. Here, we will review the progresses made in methylation sequencing methodologies developed mainly in recent two years, with an emphasis on chemical labeling-assisted single base resolution methods, and discuss the problems and prospects as well.

Aldehyde oxidase (AOX) is a soluble, cytosolic enzyme that metabolizes various N-heterocyclic compounds and organic aldehydes. It has wide tissue distribution with highest levels found in liver, kidney, and lung. Human clearance projections of AOX substrates by in vitro assessments in isolated liver fractions (cytosol, S9) and even hepatocytes have been largely underpredictive of clinical outcomes. Various hypotheses have been suggested as to why this is the case. One explanation is that extrahepatic AOX expression contributes measurably to AOX clearance and is at least partially responsible for the often observed underpredictions. Although AOX expression has been confirmed in several extrahepatic tissues, activities therein and potential contribution to overall human clearance have not been thoroughly studied. In this work, the AOX enzyme activity using the S9 fractions of select extrahepatic human tissues (kidney, lung, vasculature, and intestine) were measured using carbazeran as a probe substrate. Measured activities were scaled to a whole-body clearance using best-available parameters and compared with liver S9 fractions. Here, the combined scaled AOX clearance obtained from the kidney, lung, vasculature, and intestine is very low and amounted to

p53, the major tumor suppressor, is frequently mutated in many cancers, and up to 84% of human melanomas harbor wild-type p53, which is considered to be an ideal target for melanoma therapy. Here, we evaluated the antitumor activity of a carbazole derivative, 9-ethyl-9H-carbazole-3-carbaldehyde (ECCA), on melanoma cells. ECCA had a selectively strong inhibitory activity against the growth of BRAF-mutated and BRAF-wild-type melanoma cells but had little effect on normal human primary melanocytes. ECCA inhibited melanoma cell growth by increasing cell apoptosis, which was associated with the upregulation of caspase activities and was significantly abrogated by the addition of a caspase inhibitor. In vivo assays confirmed that ECCA suppressed melanoma growth by enhancing cell apoptosis and reducing cell proliferation, and importantly ECCA did not have any evident toxic effects on normal tissues. RNA-Seq analysis identified several pathways related to cell apoptosis that were affected by ECCA, notably, activation of the p53 signaling pathway. Biochemical assays demonstrated that ECCA enhanced the phosphorylation of p53 at Ser15 in melanoma cells harboring wild-type p53, and importantly, the knockdown or deletion of p53 in those cells counteracted the ECCA-induced apoptosis, as well as senescence. Further investigations revealed that ECCA enhanced the phosphorylation of p38-MAPK and c-Jun N-terminal kinase (JNK), and treatment with either a p38-MAPK or a JNK inhibitor rescued the cell growth inhibition elicited by ECCA, which depended on the expression of the p53 gene. Finally, the combination of ECCA with a BRAF inhibitor significantly enhanced the growth inhibition of melanoma cells. In summary, our study demonstrates that the carbazole derivative, ECCA, induces melanoma cell apoptosis and senescence through the activation of p53 to significantly and selectively suppress the growth of melanoma cells without affecting normal human melanocytes, suggesting its potential to develop a new drug for melanoma therapy.

The chalcone derivatives of 20-oxo-lupanes have been synthesised and screened for some types of biological activity. Ozonolysis of lupanes afforded 20-oxo-derivatives with the following condensation using different aromatic aldehydes by Claisen‒Schmidt reaction to the target compounds. The

Investigation into plant-fungal pathogen interactions is one of the most interesting fields in plant sciences. However, the roles of plant volatile organic compounds in the arms race are still largely unknown. Based on precise quantification of plant volatiles, we discovered that the plant volatile organic compound (E)-2-hexenal, at concentrations that were similar to or lower than those in tissues of strawberry and tomato fruits, upregulates sulfate assimilation in spores and hyphae of the phytopathogenic fungus Botrytis cinerea. This upregulation is independent of the types of sulfur sources in the plant and can be achieved in the presence of inorganic sulfate and organic sulfur sources. Using the fungal deletion mutants, we further found that sulfate assimilation is involved in the infection of tomato and strawberry fruits by B. cinerea, and that the severity of the disease is proportional to the sulfate content in the fruits. Both before and during the infection, (E)-2-hexenal induced utilisation of plant sulfate by B. cinerea facilitates its pathogenesis through enhancing its tolerance to oxidative stress. This work provides novel insights into the role of plant volatiles in plant-fungal pathogen interaction and highlights the importance of sulfur levels in the host in the prevention of grey mould disease.

Hexanal, a natural volatile organic compound, exerts antifungal activity against Aspergillus flavus; however, the mechanisms underlying these effects are unclear. In this study, we found that the growth of A. flavus mycelium was completely inhibited following exposure to 0.4 μL/mL hexanal (minimal inhibitory concentration). A detailed metabolomics survey was performed to identify changes in metabolite production by A. flavus cells after exposure to 1/2 the minimal inhibitory concentration of hexanal for 6 h, which revealed significant differences in 70 metabolites, including 20 upregulated and 50 downregulated metabolites. Among them, levels of L-malic acid, α-linolenic acid, phosphatidylcholine, D-ribose, riboflavin, D-mannitol, D-sorbitol, and deoxyinosine were significantly reduced. The metabolomics results suggest that the metabolites are mainly involved in the tricarboxylic acid cycle (TCA), ABC transport system, and membrane synthesis in A. flavus cells. Hexanal treatment reduced succinate dehydrogenase and mitochondrial dehydrogenase activity and stimulated superoxide anion and hydrogen peroxide accumulation in A. flavus mycelia. Increases in the electric conductivity and A260nm of the culture supernatant indicated cell membrane leakage. Therefore, hexanal appears to disrupt cell membrane synthesis, induce mitochondrial dysfunction, and increase oxidative stress in A. flavus mycelia. KEY POINTS: • Metabolite changes of A. flavus mycelia were identified after hexanal treatment. • Most differential metabolites were downregulated in hexanal-treated A. flavus. • An antifungal model of hexanal against A. flavus was proposed.

A novel series of peptidomimetic aldehydes was designed and synthesized to target 3C protease (3Cpro) of enterovirus 71 (EV71). Most of the compounds exhibited high antiviral activity, and among them, compound 18p demonstrated potent enzyme inhibitory activity and broad-spectrum antiviral activity on a panel of enteroviruses and rhinoviruses. The crystal structure of EV71 3Cpro in complex with 18p determined at a resolution of 1.2 Å revealed that 18p covalently linked to the catalytic Cys147 with an aldehyde group. In addition, these compounds also exhibited good inhibitory activity against the 3CLpro and the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), especially compound 18p (IC50 = 0.034 μM, EC50 = 0.29 μM). According to our previous work, these compounds have no reasons for concern regarding acute toxicity. Compared with AG7088, compound 18p also exhibited good pharmacokinetic properties and more potent anticoronavirus activity, making it an excellent lead for further development. ispartof: JOURNAL OF MEDICINAL CHEMISTRY vol:65 issue:4 pages:2794-2808 ispartof: location:United States status: published

Aldehydes are ubiquitous electrophilic compounds that ferment microorganisms including Saccharomyces cerevisiae encounter during the fermentation processes to produce food, fuels, chemicals, and pharmaceuticals. Aldehydes pose severe toxicity to the growth and metabolism of the S. cerevisiae through a variety of toxic molecular mechanisms, predominantly via damaging macromolecules and hampering the production of targeted compounds. Compounds with aldehyde functional groups are far more toxic to S. cerevisiae than all other functional classes, and toxic potency depends on physicochemical characteristics of aldehydes. The yeast synthetic biology community established a design-build-test-learn framework to develop S. cerevisiae cell factories to valorize the sustainable and renewable biomass, including the lignin-derived substrates. However, thermochemically pretreated biomass-derived substrate streams contain diverse aldehydes (e.g., glycolaldehyde and furfural), and biological conversions routes of lignocellulosic compounds consist of toxic aldehyde intermediates (e.g., formaldehyde and methylglyoxal), and some of the high-value targeted products have aldehyde functional group (e.g., vanillin and benzaldehyde). Numerous studies comprehensively characterized both single and additive effects of aldehyde toxicity via systems biology investigations, and novel molecular approaches have been discovered to overcome the aldehyde toxicity. Based on those novel approaches, researchers successfully developed synthetic yeast cell factories to convert lignocellulosic substrates to valuable products, including aldehyde compounds. In this mini-review, we highlight the salient relationship of physicochemical characteristics and molecular toxicity of aldehydes, the molecular detoxification and macromolecules protection mechanisms of aldehydes, and the advances of engineering robust S. cerevisiae against complex mixtures of aldehyde inhibitors. KEY POINTS: • We reviewed structure-activity relationships of aldehyde toxicity on S. cerevisiae. • Two-tier protection mechanisms to alleviate aldehyde toxicity are presented. • We highlighted the strategies to overcome the synergistic toxicity of aldehydes.

A study to determine the volatile fraction of distillates with added 50% and 70% ethanol extracts of donkey thistle (Onopordum acanthium L.) was conducted. The extracts were added to the pure distillate from the grapes of Melnik-55 grapevine variety in amounts of 20, 50, 80, 100, 200, 400 and 600 ml. The remaining amount to liter was a pure distillate. A distillate of Melnik-55 grapes (without extracts) was used as a control. The addition of 50% ethanol extract of Onopordum acanthium L. increased the total volatile composition of variants 1000:20 and 1000:50, in comparison to the control sample. Higher levels of esters and higher alcohols were found in the same variants. Incorporation of the 50% and 70% ethanol extracts of donkey thistle resulted in increased final total terpene content of the distillates. By increasing the amount of the added 50% ethanol extract, a reduction in the concentrations of acetaldehyde and ethyl acetate was found in the distillates. The basic ester in all the distillates analyzed was ethyl acetate, and the major higher alcohols were 2-methyl-1-butanol, 3-methyl-1-butanol, 1-propanol and 2-butanol. By applying of 50% and 70% ethanol extracts of the plant, a reduction in methanol content in the final distillates was observed. A prospect was the application of 50% ethanol extracts of Onopordum acanthium L, especially variants 1000:20 and 1000:50. This two variants showed higher final levels of aromatic compounds (beverage quality) and slightly higher final levels of terpenes (biological value) compared to the control. The other variants of this group had proven lower levels of methanol (improved toxicological quality) compared to the control., Проведено е изследване за определяне на летливата фракция на дестилат с добавени 50% и 70% етанолни екстракти на магарешки бодил (Onopordum acanthinum L.). Екстрактите са добавени в чист дестилат от грозде на сорта Мелник-55 в количества 20, 50, 80, 100, 200, 400 и 600 ml. Останалото количество до литър е дестилат. Като контрола служи чистия дестилат (без екстракти) на грозде от сорта Мелник-55. Установено е, че добавянето на 50% етанолен екстракт на Onopordum acanthinum L. повишава общия летлив състав на варианти 1000:20 и 1000:50, значително над установеното в контролата. Прилагането на 50% и 70% етанолни екстракти на магарешки бодил води до повишаване на финалното общо терпеново съдържание на дестилатите. С увеличаване количеството на добавен 50% етанолен екстракт е установено редуциране в концентрациите на ацеталдехид и етилацетат в дестилатите. Основен естер във всички анализирани дестилати е етилацетат, а основни висши алкохоли са 2-метил-1-бутанол, 3-метил-1-бутанол, 1-пропанол и 2-бутанол. При прилагане на 50% и 70% етанолни екстракти на растението, се констатира редуциране на метанолното съдържание в дестилатите. Перспектива представлява прилагането на 50% етанолни екстракти на Onopordum acanthium L, особено варианти 1000:20 и 1000:50. В тези два варианта се установяват високи крайни нива на ароматичн съединения (качество на напитката) и малко по-високи крайни нива на терпени (биологична стойност), в сравнение с контролата. Останалите варианти на тази група са с доказани по-ниски нива на метанол (подобрено токсикологично качество), в сравнение с контролата.

In dual culture confrontation assays, basidiomycete Irpex lacteus efficiently antagonized Fusarium spp., Colletotrichum spp., and Phytophthora spp. phytopathogenic strains, with growth inhibition percentages between 16.7–46.3%. Antibiosis assays evaluating the inhibitory effect of soluble extracellular metabolites indicated I. lacteus strain inhibited phytopathogens growth between 32.0–86.7%. Metabolites in the extracellular broth filtrate, identified by UPLC-QTOF mass spectrometer, included nine terpenes, two aldehydes, and derivatives of a polyketide, a quinazoline, and a xanthone, several of which had antifungal activity. I. lacteus strain and its extracellular metabolites might be valuable tools for phytopathogenic fungi and oomycete biocontrol of agricultural relevance.

Premature placental senescence is a hallmark of pregnancy-related disorders such as intrauterine growth restriction (IUGR) and preeclampsia (PE), two major cause of maternal and neonatal morbidity and mortality. Oxidative stress and lipid peroxidation are involved in the pathogenesis of PE and IUGR, and may play a role in placental aging. In this study, we investigated whether 4-hydroxy-2-nonenal (HNE), a lipid peroxidation-derived aldehyde present in preeclamptic placentas, may contribute to premature senescence in placenta-related complications. Placentas from PE-affected women, exhibited several senescence patterns, such as an increased expression of phosphorylated (serine-139) histone γH2AX, a sensitive marker of double-stranded DNA breaks, the presence of lipofuscin granules, and an accumulation of high molecular weight cross-linked and ubiquitinated proteins. PE placentas showed an accumulation of acetylated proteins consistent with the presence of HNE-adducts on sirtuin 1 (SIRT1). Likewise, oxidative stress and senescence markers together with SIRT1 modification by HNE, were observed in murine placentas from mice treated with lipopolysaccharide during gestation and used as models of IUGR. The addition of HNE and ONE (4-oxo-2-nonenal), to cultured HTR-8/SVneo human trophoblasts activated the senescence-associated- β-galactosidase, and generated an accumulation of acetylated proteins, consistent with a modification of SIRT1 by HNE. Altogether, these data emphasize the role of HNE and lipid peroxidation-derived aldehydes in premature placental senescence in PE and IUGR, and more generally in pathological pregnancies.

Grain commodities in postharvest storage often deteriorate because of fungal and insect attacks. With the green consumption requirements of consumers, ecofriendly and safe pesticides are needed for grain storage. The current study investigated the efficacy of the plant volatile compound trans-2-hexenal against the storage insect pest Tribolium castaneum (Herbst) and three commonly occurring storage fungi, viz., Fusarium graminearum, Aspergillus flavus, and Aspergillus niger, to recommend its application as a botanical fumigant for grain commodities. trans-2-Hexenal weakly repels T. castaneum but has favorable insecticidal activity against multiple developmental stages of T. castaneum, ranging in sensitivity as follows: eggs (LC50 = 14.3 µl/l) > adults (31.6 µl/l) > young larvae (42.1 µl/l) > mature larvae (64.5 µl/l) > pupae (70.5 µl/l). Moreover, trans-2-hexenal caused a high malformation rate and high mortality in adults developed from fumigated pupae. In a 7-d grain, trans-2-hexenal at 0.8 µl/ml provided an appreciable efficacy (81.3%), and concentrations ≥ 0.1 µl/ml completely inhibited the offspring of T. castaneum. trans-2-Hexenal was nonphytotoxic to the seed germination and seedling growth of wheat seeds. Furthermore, trans-2-hexenal completely inhibited the growth of A. flavus, F. graminearum, and A. niger at 5, 10, and 10 µl/l, respectively. The favorable biological activity of trans-2-hexenal against T. castaneum and three frequently occurring mycotoxigenic storage fungi indicated the potential of trans-2-hexenal for simultaneously controlling pests and pathogens, which could reduce its application frequency in grains and decrease pesticide resistance risks.

This work aimed to determine the formation over time of 3-methylbutanal and 3-methylbutan-1-ol recognized as malty during the manufacture of Raclette-type cheese and the fermention of reconstituted skim milk, and filter-sterilized MRS broth. Using dynamic headspace-vacuum transfer in trap extraction followed by gas chromatography coupled with mass spectrometry-olfactometry (DHS-VTT-GC-MS-O) as a screening method for the malty compounds, five compounds (2-methylpropanal, 2- and 3-methylbutanal, and 2- and 3-methylbutan-1-ol) were identified as potential compounds causing the malty aroma in starter culture development and Raclette-type cheeses. Focus on compounds having a predominant sensorial effect (3-methylbutanal and 3-methylbutan-1-ol), spikings of leucine, 13C-labeled leucine, α-ketoisocaproic acid, and α-ketoglutaric acid provided a better understanding of their formation pathway. This study highlighted the discrepancies in the formation of 3-methylbutanal and 3-methylbutan-1-ol between the growth media; namely, despite the presence of free leucine available in MRS and the addition of an excess, no increase of the target compounds was observed. The concentration of these compounds in MRS increased only when α-ketoglutaric acid or α-ketoisocaproic acid was added, and a preference for the pathway to α-hydroxyisocaproic acid instead of 3-methylbutanal was shown. In addition, a formation of 3-methylbutanal when the bacteria were not yet active was observed when spiking α-ketoisocaproic acid, which potentially indicates that this part of the metabolism could take place extracellularly. These results could potentially unveil other, not-yet-identified reactants, directly influencing the production of compounds responsible for the malty aroma in Raclette cheese.

Aldehydes are the main inhibitors generated during the pretreatment of lignocellulosic biomass, which can inhibit cell growth and disturb subsequent fermentation. Saccharomyces cerevisiae has the intrinsic ability to in situ detoxify aldehydes to their less toxic or nontoxic alcohols by numerous aldehyde dehydrogenases/reductases during the lag phase. Herein, we report that an uncharacterized open reading frame YMR152W from S. cerevisiae encodes a novel aldehyde reductase with catalytic functions for reduction of at least six aldehydes, including two furan aldehydes (furfural and 5-hydroxymethylfurfural), three aliphatic aldehydes (acetaldehyde, glycolaldehyde, and 3-methylbutanal), and an aromatic aldehyde (benzaldehyde) with NADH or NADPH as the co-factor. Particularly, Ymr152wp displayed the highest specific activity (190.86 U/mg), and the best catalytic rate constant (Kcat), catalytic efficiency (Kcat/Km), and affinity (Km) when acetaldehyde was used as the substrate with NADH as the co-factor. The optimum pH of Ymr152wp is acidic (pH 5.0–6.0), but this enzyme is more stable in alkaline conditions (pH 8.0). Metal ions, chemical protective additives, salts, and substrates could stimulate or inhibit enzyme activities of Ymr152wp in varying degrees. Ymr152wp was classified into the quinone oxidoreductase (QOR) subfamily of the medium-chain dehydrogenase/reductase (MDR) family based on the results of amino acid sequence analysis and phylogenetic analysis. Although Ymr152wp was grouped into the QOR family, no quinone reductase activity was observed using typical quinones (9,10-phenanthrenequinone, 1,2-naphthoquinone, and p-benzoquinone) as the substrates. This study provides guidelines for exploring more uncharacterized aldehyde reductases in S. cerevisiae for in situ detoxification of aldehyde inhibitors derived from lignocellulosic hydrolysis.

Rationale: The activity of aldehyde dehydrogenase 7A1 (ALDH7A1), an enzyme that catalyzes the lipid peroxidation of fatty aldehydes was found to be upregulated in pancreatic ductal adenocarcinoma (PDAC). ALDH7A1 knockdown significantly reduced tumor formation in PDAC. We raised a question how ALDH7A1 contributes to cancer progression. Methods: To answer the question, the role of ALDH7A1 in energy metabolism was investigated by knocking down and knockdown gene in mouse model, because the role of ALDH7A1 has been reported as a catabolic enzyme catalyzing fatty aldehyde from lipid peroxidation to fatty acid. Oxygen consumption rate (OCR), ATP production, mitochondrial membrane potential, proliferation assay and immunoblotting were performed. In in vivo study, two human PDAC cell lines were used for pre-clinical xenograft model as well as spontaneous PDAC model of KPC mice was also employed for anti-cancer therapeutic effect. Results: ALDH7A1 knockdown significantly reduced tumor formation with reduction of OCR and ATP production, which was inversely correlated with increase of 4-hydroxynonenal. This implies that ALDH7A1 is critical to process fatty aldehydes from lipid peroxidation. Overall survival of PDAC is doubled by cross breeding of KPC (KrasG12D; Trp53R172H; Pdx1-Cre) and Aldh7a1-/- mice. Conclusion: Inhibitions of ALDH7A1 and oxidative phosphorylation using gossypol and phenformin resulted in a regression of tumor formation in xenograft mice model and KPC mice model.

Dee are a unique and rapidly growing part of the global snack food market and are recognised as having distinct sensory properties (taste and texture). In this study, the development of important volatile aroma compounds over storage was evaluated and their chemical origin explained. Sweet potatoes were batch fried in high oleic sunflower oil (HOSO) and subjected to accelerated shelf life testing. Headspace volatiles were analysed using SPME GC-MS and correlated with sensory perception. All the components (sweet potatoes, oil and β-carotene) showed significant degradation after 3 weeks of storage at accelerated conditions (equivalent to 12 weeks in real-time at 25 °C). Marker volatiles associated with lipid oxidation such as hexanal, octanal, pentanal were identified, in addition to norisoprenoids from β-carotene degradation such as β-ionon, 5,6-epoxy-β-ionone, dihydroactinidiolide (DHA) and β-cyclocitral. The most prominent marker of lipid oxidation (hexanal) rapidly increased at week 1, whereas the carotene degradation makers did not rapidly increase until week 3 suggesting a delayed response. The frying temperature during the batch frying process of SPC was also shown to play a significant role in the sensory perception of the product over the shelf life. Overall, the results suggest that tight control of process variables and raw material design may enable extended shelf life and potentially enhanced health credentials for the product. These findings are unique to SPC, but also of value to the wider food industry., Lipid oxidation markers, degradation markers of β-carotene and changes in sensory properties were tracked in fried sliced sweet potatoes over shelf life and under different frying conditions.

Rationale: Aldehyde dehydrogenase (ALDH) enzymes are often upregulated in cancer cells and associated with therapeutic resistance. ALDH enzymes protect cells by metabolizing toxic aldehydes which can induce DNA double stand breaks (DSB). We recently identified a novel ALDH1A family inhibitor (ALDHi), 673A. We hypothesized that 673A, via inhibition of ALDH1A family members, could induce intracellular accumulation of genotoxic aldehydes to cause DSB and that ALDHi could synergize with inhibitors of the ATM and ATR, proteins which direct DSB repair. Methods: We used immunofluorescence to directly assess levels of the aldehyde 4-hydroxynonenal and comet assays to evaluate DSB. Western blot was used to evaluate activation of the DNA damage response pathways. Cell counts were performed in the presence of 673A and additional aldehydes or aldehyde scavengers. ALDH inhibition results were confirmed using ALDH1A3 CRISPR knockout. Synergy between 673A and ATM or ATR inhibitors was evaluated using the Chou-Talalay method and confirmed in vivo using cell line xenograft tumor studies. Results: The ALDHi 673A cellular accumulation of toxic aldehydes which induce DNA double strand breaks. This is exacerbated by addition of exogenous aldehydes such as vitamin-A (retinaldehyde) and ameliorated by aldehyde scavengers such as metformin and hydralazine. Importantly, ALDH1A3 knockout cells demonstrated increased sensitivity to ATM/ATR inhibitors. And, ALDHi synergized with inhibitors of ATM and ATR, master regulators of the DSB DNA damage response, both in vitro and in vivo. This synergy was evident in homologous recombination (HR) proficient cell lines. Conclusions: ALDHi can be used to induce DNA DSB in cancer cells and synergize with inhibitors the ATM/ATR pathway. Our data suggest a novel therapeutic approach to target HR proficient ovarian cancer cells.

Drought is the most devastating stress for crops. Intensity and duration of drought determine the magnitude of plant damage; similarly, plant ability to counteract drought determines its tolerance capacity. Recent studies revealed that exogenous apocarotenoid treatment confers abiotic stress tolerance to plants. However, much less is known about the role of β-cyclocitral (βCC), the major apocarotenoid, in drought tolerance. Here, we demonstrate βCC's role in improving plants' tolerance against drought stress. Tomato (Solanum lycopersicum L.) plants were independently treated with water and βCC and grown under either water-limited or irrigated conditions. The βCC-treated drought-exposed (BD) and βCC-treated irrigated (BH) plants were analysed for the major drought tolerance associated traits; water-treated drought-exposed (CD) and water-treated irrigated plants (CH) were used as controls. On exposure to drought, unlike controls, βCC-treated plants showed no wilting, higher RWC and stomatal conductance, unchanged ABA levels and stomatal closure. The BD plants had increased photosynthesis, chlorophyll content and enhanced root, but not shoot, growth. In addition, βCC treatment enhanced proline accumulation and activity of SOD in both drought-exposed and well irrigated plants. Taken together, βCC was identified as a potential candidate that improves tomato osmolyte accumulation and superoxide elimination, independent of ABA, and prepares the plant for upcoming drought stress. Our results suggest that βCC can be used to prime crops against drought stress.

AimsE-cigarette aerosol containing aldehydes, including acetaldehyde, are metabolized by the enzyme aldehyde dehydrogenase 2 (ALDH2). However, little is known how aldehyde exposure from e-cigarettes, when coupled with an inactivating ALDH2 genetic variant, ALDH2*2 (present in 8% of the world population), affects cardiovascular oxidative stress. The aim of this study was to determine how e-cigarette aerosol exposure, when coupled with genetics, impacts cardiovascular oxidative stress in wild type ALDH2 and ALDH2*2 knock-in mice.Methods and ResultsUsing selective ion flow mass spectrometry, we determined that e-cigarette aerosol contains acetaldehyde that are 10-fold higher than formaldehyde or acrolein. Next, using wild type ALDH2 and ALDH2*2 knock-in rodents, we identified organ-specific differences in ALDH2 with the heart having ~1.5-fold less ALDH2 enzyme activity relative to the liver and lung. In isolated cardiac myocytes, acetaldehyde exposure (30 seconds, 0.1-1 μM) caused a 4-fold greater peak in calcium levels for ALDH2*2 relative to ALDH2 cardiomyocytes. ALDH2*2 cardiomyocytes exposed to acetaldehyde also demonstrated a 2-fold increase in ROS production and 2.5-fold increase in 4HNE protein adducts relative to ALDH2 cardiomyocytes. For intact rodents, ALDH2*2 knock-in mice exposed to e-cigarette aerosol had an increased heart rate beginning 5 days after exposure compared to wild type ALDH2 mice (775±30 bpm versus 679±33 bpm, respectively, *pConclusionsThe increased oxidative stress from e-cigarette aerosol aldehydes triggers the proinflammatory NF-κB pathway. As ALDH2 expression and activity is lower in the heart relative to the lung, the heart could be more susceptible to increases in cardiovascular oxidative stress from e-cigarette aerosol; particularly for those carrying an ALDH2*2 genetic variant which limits acetaldehyde metabolism.Graphical AbstractE-cigarette aerosol exposure triggers increases in ROS that lead to increased protein carbonylation, MDA production, and elevates phosphorylated NF-kB. This exposure to e-cigarette aerosol leads to increases in cardiovascular oxidative stress. For the ALDH2*2 variant, there is limited ability to metabolize the reactive aldehydes from e-cigarette aerosol and with increased levels of oxidative stress at baseline relative to wild type ALDH2, e-cigarette aerosol increased oxidative stress, protein carbonylation, and phosphorylation of NF-kB relative to wild type ALDH2 rodents.

The participation of reactants undergoing a polarity inversion along a multicomponent reaction allows the continuation of the transformation with productive domino processes. Thus, indole aldehydes in Groebke-Blackburn-Bienaymé reactions lead to an initial adduct which spontaneously triggers a series of events leading to the discovery of novel reaction pathways together with direct access to a variety of linked, fused, and bridged polyheterocyclic scaffolds. Indole 3- and 4-carbaldehydes with suitable isocyanides and aminoazines afford fused adducts through oxidative Pictet-Spengler processes, whereas indole 2-carbaldehyde yields linked indolocarbazoles under mild conditions, and a bridged macrocycle at high temperature. These novel structures are potent activators of the human aryl hydrocarbon receptor signaling pathway.

Metabolic alterations in cancer represent convergent effects of oncogenic mutations. We hypothesized that a metabolism-restricted genetic screen, comparing normal primary mouse hematopoietic cells and their malignant counterparts in an ex vivo system mimicking the bone marrow microenvironment, would define distinctive vulnerabilities in acute myeloid leukemia (AML). Leukemic cells, but not their normal myeloid counterparts, depended on the aldehyde dehydrogenase 3a2 (Aldh3a2) enzyme that oxidizes long-chain aliphatic aldehydes to prevent cellular oxidative damage. Aldehydes are by-products of increased oxidative phosphorylation and nucleotide synthesis in cancer and are generated from lipid peroxides underlying the non–caspase-dependent form of cell death, ferroptosis. Leukemic cell dependence on Aldh3a2 was seen across multiple mouse and human myeloid leukemias. Aldh3a2 inhibition was synthetically lethal with glutathione peroxidase-4 (GPX4) inhibition; GPX4 inhibition is a known trigger of ferroptosis that by itself minimally affects AML cells. Inhibiting Aldh3a2 provides a therapeutic opportunity and a unique synthetic lethality to exploit the distinctive metabolic state of malignant cells.

Myeloperoxidase (MPO)-derived hypochlorous (HOCl) reacts with membrane plasmalogens to yield α-chlorofatty aldehydes such as 2-chlorofatty aldehyde (2-ClFALD) and its metabolite 2-chlorofatty acid (2-ClFA). Recent studies showed that 2-ClFALD and 2-ClFA serve as mediators of the inflammatory responses to sepsis by as yet unknown mechanisms. Since no scavenger for chlorinated lipids is available and on the basis of the well-established role of the MPO/HOCl/chlorinated lipid axis in inflammatory responses, we hypothesized that treatment with MPO inhibitors (N-acetyl lysyltyrosylcysteine amide or 4-aminobenzoic acid hydrazide) would inhibit inflammation and proinflammatory mediator expression induced by cecal ligation and puncture (CLP). We used intravital microscopy to quantify in vivo inflammatory responses in Sham and CLP rats with or without MPO inhibition. Small intestines, mesenteries, and lungs were collected to assess changes in MPO-positive staining and lung injury, respectively, as well as free 2-ClFA and proinflammatory mediators levels. CLP caused neutrophil infiltration, 2-ClFA generation, acute lung injury, leukocyte-/platelet-endothelium interactions, mast cell activation (MCA), plasminogen activator inhibitor-1 (PAI-1) production, and the expression of several cytokines, chemokines, and vascular endothelial growth factor, changes that were reduced by MPO inhibition. Pretreatment with a PAI-1 inhibitor or MC stabilizer prevented CLP-induced leukocyte-endothelium interactions and MCA, and abrogated exogenous 2-ClFALD-induced inflammatory responses. Thus, we provide evidence that MPO instigates these inflammatory changes in CLP and that chlorinated lipids may serve as a mechanistic link between the enzymatic activity of MPO and PAI-1- and mast cell-dependent adhesive interactions, providing a rationale for new therapeutic interventions in sepsis. NEW & NOTEWORTHY Using two distinct myeloperoxidase (MPO) inhibitors, we show for the first time that MPO plays an important role in producing increases in free 2-chlorofatty aldehyde (2-ClFALD)—a powerful proinflammatory chlorinated lipid in plasma and intestine—a number of cytokines and other inflammatory mediators, leukocyte and platelet rolling and adhesion in postcapillary venules, and lung injury in a cecal ligation and puncture model of sepsis. In addition, the use of a plasminogen activator inhibitor-1 (PAI-1) inhibitor or a mast cell stabilizer prevented inflammatory responses in CLP-induced sepsis. PAI-1 inhibition also prevented the proinflammatory responses to exogenous 2-ClFALD superfusion. Thus, our study provides some of the first evidence that MPO-derived free 2-ClFA plays an important role in CLP-induced sepsis by a PAI-1- and mast cell-dependent mechanism.

Iturin A is a natural antifungal agent that is widely used in the agriculture and food industries. In the present study, a new modified chitosan sub-micron, succinaldehydic acid (SAC) - chitosan (CS) system was synthesised by microwave irradiation and then as a carrier for capsulation of Iturin A (SAC-CS-IA). The structures of SAC-CS and SAC-CS-IA were characterised by SEM, NMR and FTIR. The size distribution suggested that the average size of SAC-CS and SAC-CS-IA was from 1.5 to 2.5 μm. An encapsulation efficiency of 92.02% under an adaptive pH (pH = 5) and time (5.5 h) was used. The study of release kinetics shows that about 80% of Iturin A was released in 25 days. An antifungal activity assay indicated that SAC-CS-IA exhibited higher antifungal activity against Ceratocystis fimbriata and Rhizopus strolonifer with 75.05 ± 3.24% and 80.54 ± 2.65%, respectively. The results indicate that the SAC-CS can improve the stability of IA on heat and pH with a wide range and tolerance most of enzymes. Actual tuber storage suggested that SAC-CS-IA can significantly inhibit pathogen fungal infection and reduce toxin product. Meanwhile, SAC-CS-IA could retain the water, starch, and soluble sugar contents. Low residue assay indicated that SAC-CS-IA could be used as an antifungal and anti-rotting agent in agriculture and food applications.

Shikonin derivatives are red naphthoquinone pigments produced by several boraginaceous plants, such as Lithospermum erythrorhizon. These compounds are biosynthesized from p-hydroxybenzoic acid and geranyl diphosphate. The coupling reaction that yields m-geranyl-p-hydroxybenzoic acid has been actively characterized, but little is known about later biosynthetic reactions. Although 3″-hydroxy-geranylhydroquinone produced from geranylhydroquinone by CYP76B74 has been regarded as an intermediate of shikonin derivatives, the next intermediate has not yet been identified. This study describes a novel alcohol dehydrogenase activity in L. erythrorhizon cell cultures. This enzyme was shown to oxidize the 3″-alcoholic group of (Z)-3″-hydroxy-geranylhydroquinone to an aldehyde moiety concomitant with the isomerization at the C2′–C3′ double bond from the Z-form to the E-form. An enzyme oxidizing this substrate was not detected in other plant cell cultures, suggesting that this enzyme is specific to L. erythrorhizon. The reaction product, (E)-3″-oxo-geranylhydroquinone, was further converted to deoxyshikonofuran, another meroterpenoid metabolite produced in L. erythrorhizon cells. Although nonenzymatic cyclization occurred slowly, it was more efficient in the presence of crude enzymes of L. erythrorhizon cells. This activity was detected in both shikonin-producing and nonproducing cells, suggesting that the aldehyde intermediate at the biosynthetic branch point between naphthalene and benzo/hydroquinone ring formation likely constitutes a key common intermediate in the synthesis of shikonin and benzoquinone products, respectively.

Specific inhalation challenge (SIC) is the reference standard for the diagnosis of occupational asthma. Current guidelines for identifying late asthmatic reactions are not evidence based.ObjectivesTo identify the fall in forced expiratory volume in 1 s (FEV1) required following SIC to exceed the 95% CI for control days, factors which influence this and to show how this can be applied in routine practice using a statistical method based on the pooled SD for FEV1 from three control days.MethodsFifty consecutive workers being investigated for occupational asthma were asked to self-record FEV1 hourly for 2 days before admission for SIC. These 2 days were added to the in-hospital control day to calculate the pooled SD and 95% CI.Results45/50 kept adequate measurements. The pooled 95% CI was 385 mL (SD 126), or 14.2% (SD 6.2) of the baseline FEV1, but was unrelated to the baseline FEV1 (r=0.06, p=0.68), or gender, atopy, smoking, non-specific reactivity or treatment before or during SIC. Thirteen workers had a late asthmatic reaction with ≥2 consecutive FEV1 measurements below the 95% CI for pooled control days, 4/13 had 15% late fall from baseline. The four workers with ≥2 values below the 95% CI all had independent evidence of occupational asthma.ConclusionThe pooled SD method for defining late asthmatic reactions has scientific validity, accounts for interpatient spirometric variability and diurnal variation and can identify clinically relevant late asthmatic reactions from smaller exposures. For baseline FEV1

Microbial communities comprised of phototrophs and heterotrophs hold great promise for sustainable biotechnology. Successful application of these communities relies on the selection of appropriate partners. Here we construct four community metabolic models to guide strain selection, pairing phototrophic, sucrose-secreting Synechococcus elongatus with heterotrophic Escherichia coli K-12, Escherichia coli W, Yarrowia lipolytica, or Bacillus subtilis. Model simulations reveae metabolic exchanges that sustain the heterotrophs in minimal media devoid of any organic carbon source, pointing to S. elongatus-E. coli K-12 as the most active community. Experimental validation of flux predictions for this pair confirms metabolic interactions and potential production capabilities. Synthetic communities bypass member-specific metabolic bottlenecks (e.g. histidine- and transport-related reactions) and compensate for lethal genetic traits, achieving up to 27% recovery from lethal knockouts. The study provides a robust modelling framework for the rational design of synthetic communities with optimized growth sustainability using phototrophic partners., Successful application of microbial community for bioproduction relies on the selection of appropriate heterotroph and phototroph partners. Here, the authors construct community metabolic models to guide strain selection and experimentally validate metabolic exchanges that sustain the heterotrophs in minimal media.

Despite their ubiquitous expression, the inheritance of monoallelic germline mutations in breast cancer susceptibility gene type 1 or 2 (BRCA1/2) poses tissue-specific variations in cancer risks and primarily associate with familial breast and ovarian cancers. The molecular basis of this tissue-specific tumor incidence remains unknown and intriguing to cancer researchers. A plethora of recent reports support the idea that several nongenetic factors present in the tissue microenvironment could induce tumors in the mutant BRCA1/2 background. This Opinion article summarizes the recent advances on tissue-specific carcinogens and their complex crosstalk with the compromised DNA repair machinery of BRCA1/2-mutant cells. Finally, we present our perspective on the therapeutic and chemopreventive interpretations of these developments.

2-Nonenal is a long-chain aliphatic aldehyde containing nine carbons and an unsaturated bond. 2-Nonenal is the primary cause of odor associated with aging, with an unpleasant greasy and grassy odor. Lysosome, mitochondria, and peroxisome are significant organelles in eukaryotic cells that contain various hydrolases that degrade biomolecules. Proteins in mitochondria and peroxisome also contain aldehyde dehydrogenase. We performed trans-2-nonenal treatment using lysosomal-related enzymes extracted from hen egg white (HEW). As trans-2-nonenal is more structurally stable than cis-2-nonenal, it was selected as the target aldehyde. HEW contains various biologically active proteins and materials such as albumin, ovotransferrin, lysosome, peroxisome, and mitochondria. Here, complementary experiments were conducted to evaluate the role of lysosomal-related enzymes in the treatment of trans-2-nonenal. The activity of lysosomal-related enzymes was confirmed via antimicrobial test against E. coli. HPLC analysis was used to determine the reduction of trans-2-nonenal. The trans-2-nonenal treatment depended on the reaction time and enzyme concentration. Materials considered as an intermediate from trans-2-nonenal treatment were detected by GC/MS spectrometer. Under acidic conditions (pH 6), lysosomal-related enzymes were the most efficient in the treatment of trans-2-nonenal. Furthermore, based on differential pH testing, we found the conditions under which all the 50 ppm trans-2-nonenal was removed. Therefore, our results suggest that the lysosomal-related enzymes reduced trans-2-nonenal, suggesting clinical application as anti-aging deodorants.

At least 24 aldehyde reductases from Saccharomyces cerevisiae have been characterized and most function in in situ detoxification of lignocellulosic aldehyde inhibitors, but none is classified into the polyol dehydrogenase (PDH) subfamily of the medium-chain dehydrogenase/reductase (MDR) superfamily. This study confirmed that two (2R,3R)-2,3-butanediol dehydrogenases (BDHs) from industrial (denoted Y)/laboratory (denoted B) strains of S. cerevisiae, Bdh1p(Y)/Bdh1p(B) and Bdh2p(Y)/Bdh2p(B), were members of the PDH subfamily with an NAD(P)H binding domain and a catalytic zinc binding domain, and exhibited reductive activities towards lignocellulosic aldehyde inhibitors, such as acetaldehyde, glycolaldehyde, and furfural. Especially, the highest enzyme activity towards acetaldehyde by Bdh2p(Y) was 117.95 U/mg with cofactor nicotinamide adenine dinucleotide reduced (NADH). Based on the comparative kinetic property analysis, Bdh2p(Y)/Bdh2p(B) possessed higher specific activity, substrate affinity, and catalytic efficiency towards glycolaldehyde than Bdh1p(Y)/Bdh1p(B). This was speculated to be related to their 49% sequence differences and five nonsynonymous substitutions (Ser41Thr, Glu173Gln, Ile270Leu, Ile316Met, and Gly317Cys) occurred in their conserved NAD(P)H binding domains. Compared with BDHs from a laboratory strain, Bdh1p(Y) and Bdh2p(Y) from an industrial strain displayed five nonsynonymous mutations (Thr12, Asn61, Glu168, Val222, and Ala235) and three nonsynonymous mutations (Ala34, Ile96, and Ala369), respectively. From a first analysis with selected aldehydes, their reductase activities were different from BDHs of laboratory strain, and their catalytic efficiency was higher towards glycolaldehyde and lower towards acetaldehyde. Comparative investigation of kinetic properties of BDHs from S. cerevisiae as aldehyde reductases provides a guideline for their practical applications in in situ detoxification of aldehyde inhibitors during lignocellulose bioconversion. Key Points • Two yeast BDHs have enzyme activities for reduction of aldehydes. • Overexpression of BDHs slightly improves yeast tolerance to acetaldehyde and glycolaldehyde. • Bdh1p and Bdh2p differ in enzyme kinetic properties. • BDHs from strains with different genetic backgrounds differ in enzyme kinetic properties.

Supplemental Digital Content is Available in the Text. ALDH2 activity influences endometriosis and its associated pain., Endometriosis affects ∼176 million women worldwide, yet on average, women experience pain ∼10 years from symptom onset before being properly diagnosed. Standard treatments (drugs or surgery) often fail to provide long-term pain relief. Elevated levels of reactive aldehydes such as 4-hydroxynonenal (4-HNE) have been implicated in the peritoneal fluid of women with endometriosis and upon accumulation, reactive aldehydes can form protein-adducts and/or generate pain. A key enzyme in detoxifying reactive aldehydes to less reactive forms is the mitochondrial enzyme aldehyde dehydrogenase-2 (ALDH2). Here, we tested the hypothesis that aberrant reactive aldehyde detoxification by ALDH2 underlies endometriosis and its associated pain. We determined, in the eutopic and ectopic endometrium of women with severe (stage IV) peritoneal endometriosis, that ALDH2 enzyme activity was decreased, which was associated with decreased ALDH2 expression and increased 4-HNE adduct formation compared to the eutopic endometrium of controls in the proliferative phase. Using a rodent model of endometriosis and an ALDH2*2 knock-in mouse with decreased ALDH2 activity, we determined that increasing ALDH2 activity with the enzyme activator Alda-1 could prevent endometriosis lesion development as well as alleviate pain-associated behaviors in proestrus. Overall, our findings suggest that targeting the ALDH2 enzyme in endometriosis may lead to better treatment strategies and in the proliferative phase, that increased 4-HNE adduct formation within the endometrium may serve as a less invasive diagnostic biomarker to reduce years of suffering in women.

A study for determination of the volatile composition of distillates with the addition of 50% and 70% ethanol extracts of St. John's wort (Hypericum perforatym L) was conducted. The extracts were added in amounts of 20, 80, 100, 200, 400 and 600 ml. The remaining amount to liter was pure distillate obtained from the grapes of the variety “Melnik-55”. Gas chromatographic (GC-FID) analysis for identification and quantification of the volatile components in the distillates obtained was performed. Various compounds from the groups of esters, higher alcohols, aldehydes and terpene alcohols have been identified. The methanol levels were found to be highest in the control sample (364.74 ± 0.32 mg/dm3) and proportionally decreased with increasing of the fraction of added extract in the experimental variants. This contributed to obtained of the alcoholic distillate with decreased methanol content. A similar decrease in the amounts of acetaldehyde and ethyl acetate was observed. This reduced the harmful aromatic nuances that these compounds impart when they were in higher amounts. Four major higher alcohols have been identified - 3-methyl-1-butanol, 2-methyl-1-butanol, 2-butanol and 1-propanol. The ester composition was diverse, quantitatively dominated by the presence of ethyl acetate. A higher total terpene content was detected in the samples with the addition of Hypericum perforatym L extract compared to the control. This indicated increased final concentrations in the distillates (a consequence of the terpene composition of the herb), which may intensify its biological effect. The produced distillates with added extracts of Hypericum perforatym L can be used for obtaining of new higher alcoholic beverages with added medicinal herb extracts.

Aldehyde-alcohol dehydrogenase (AdhE) is an enzyme responsible for converting acetyl-CoA to ethanol via acetaldehyde using NADH. AdhE is composed of two catalytic domains of aldehyde dehydrogenase (ALDH) and alcohol dehydrogenase (ADH), and forms a spirosome architecture critical for AdhE activity. Here, we present the atomic resolution (3.43 Å) cryo-EM structure of AdhE spirosomes in an extended conformation. The cryo-EM structure shows that AdhE spirosomes undergo a structural transition from compact to extended forms, which may result from cofactor binding. This transition leads to access to a substrate channel between ALDH and ADH active sites. Furthermore, prevention of this structural transition by crosslinking hampers the activity of AdhE, suggesting that the structural transition is important for AdhE activity. This work provides a mechanistic understanding of the regulation mechanisms of AdhE activity via structural transition, and a platform to modulate AdhE activity for developing antibiotics and for facilitating biofuel production., Using cryo-EM, Kim et al. show that aldehyde-alcohol dehydrogenase (AdhE) spirosomes undergo structural transition from compact to extended conformation from substrate binding. This transition opens up the substrate channel that transports the reaction intermediates to the next catalytic site.

Folic acid a synthetic form of folate, is the oxidized form of folate which acts as a coenzyme in one carbon transfer reactions required in the biosynthesis of DNA and RNA and its deficiency could be related to diseases such as neural tube defects, Alzheimer's disease, pregnancy complications and cancer. Inulin is a polydisperse polysaccharide comprising mostly of fructosyl fructose units. An oxidized derivative of this inulin was prepared and used as a complexing agent for folic acid to obtain a polysaccharide bound folic acid conjugate. The aldehyde content and degree of oxidation of the oxidized inulin were determined by acid-base titrations. All the products were characterized by sophisticated spectroscopic and thermal methods of analysis. Release studies of folic acid from conjugates were carried out in different pH media and the results demonstrate the pH-sensitive behavior of the inulin-based delivery system towards the controlled release of folic acid.

The epidermal surface of bread wheat (Triticum aestivum) is coated with a hydrophobic cuticular wax layer that protects plant tissues against environmental stresses. However, the regulatory mechanism of cuticular wax biosynthesis remains to be uncovered in bread wheat. Here, we identified wheat Enoyl-CoA Reductase (TaECR) as a core component responsible for biosynthesis of wheat cuticular wax. Silencing of TaECR in bread wheat resulted in a reduced cuticular wax load and attenuated conidia germination of the adapted fungal pathogen powdery mildew (Blumeria graminis f.sp. tritici). Furthermore, we established that TaECR genes are direct targets of TaECR promoter-binding MYB transcription factor1 (TaEPBM1), which could interact with the adapter protein Alteration/Deficiency in Activation2 (TaADA2) and recruit the histone acetyltransferase General Control Nonderepressible5 (TaGCN5) to TaECR promoters. Most importantly, we demonstrated that the TaEPBM1-TaADA2-TaGCN5 ternary protein complex activates TaECR transcription by potentiating histone acetylation and enhancing RNA polymerase II enrichment at TaECR genes, thereby contributing to the wheat cuticular wax biosynthesis. Finally, we identified very-long-chain aldehydes as the wax signals provided by the TaECR-TaEPBM1-TaADA2-TaGCN5 circuit for triggering B. graminis f.sp. tritici conidia germination. These results demonstrate that specific transcription factors recruit the TaADA2-TaGCN5 histone acetyltransferase complex to epigenetically regulate biosynthesis of wheat cuticular wax, which is required for triggering germination of the adapted powdery mildew pathogen.

BACKGROUND The insect olfactory system can recognize odorants for feeding, courtship, oviposition and avoiding natural enemies. Odorant cues from host plants play important roles in insect behaviours. Tobacco (Nicotiana tabacum) is the main cultivated host of the oriental tobacco budworm Helicoverpa assult. Volatiles of tobacco plants attract and stimulate oviposition in female moths. However, it is still not known how female H. assulta recognize tobacco volatiles and which odorant compounds are used as oviposition cues. RESULTS We detected 14 volatile compounds emitted from a tobacco plant during vegetative growth, using gas chromatography–mass spectrometry. Electroantennogram tests indicated that eight of the 14 compounds induced responses in female H. assulta. Among these eight volatiles, nonanal greatly increased oviposition preference. Single‐sensillum recording (SSR) results showed that many neurons housed in three types of short basiconic sensilla and four types of long basiconic sensilla responded to nonanal and heptanal as its structural analogue. The responses to nonanal were significantly stronger than those to the other compounds. Nonanal was the main ligand of OR67, an odorant receptor from H. assulta. This was demonstrated using an in vitro Xenopus oocytes expression system that supported the SSR results. CONCLUSION Nonanal is a key signal volatile of tobacco plants that attracts female H. assulta moths to oviposit. © 2020 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry., The main cultivated host of the oligophage oriental tobacco budworm Helicoverpa assulta is tobacco (Nicotiana tabacum). Volatiles of tobacco plants attract and stimulate oviposition in female moths.

In aquaculture, fish species may experience stressful episodes caused by poor farming conditions. The exponential increase of global aquaculture has raised the number of research studies aimed at demonstrating the sensitivity of aquatic animals in confined environments. The development of a real-time PCR and immunohistochemistry methods were investigated to evaluate the presence, localization, and quantity of biomarkers of oxidative stress in European sea bass (Dicentrarchus labrax). In particular, stress tests such as manipulation and temperature changes were conducted through molecular methods to identify the expression level of heat shock protein 70 (HSP70) in stressed animals compared with a control group. The immunohistochemical technique was also applied to locate and study the trends-levels of nitrotyrosine (NT), heat shock protein 70 (HSP70), malondialdehyde (MDA), and 4-hydroxy-2-nonenal (HNE) in different tissues from stressed animals and control group. The presence of the rodlet cell (RCs) was evaluated by histology in both a control and stressed group. Our results show that the real-time PCR method developed is specific for the evaluated target gene and that manipulation and temperature increase are strong stressors for animals. Relative quantification data revealed a gene expression increase of HSP70 in the stressed group of animals compared to the control group. The antibodies used for the immunohistochemical staining were efficient, and it was possible to appreciate the increase of immunoprecipitates in European sea bass either manipulated or stressed by temperature increase. The present study can be a starting point to allow the quantification of HSP70 and the identification of other stress biomarkers in D. labrax.

Biomass pretreatments represent a necessary route to overcome the natural physico-chemical barriers of recalcitrant feedstocks. However, current biomass pretreatments generally result in generation of various inhibitors (such as furfural derived from pentose), which could inhibit cell growth and decrease biofuel productivity. This study aims to understand the impact of furfural on hydrogen-producing Enterobacter aerogenes in dark fermentation of glucose. When adding 5 mM furfural in fermentation, hydrogen yield unexpectedly increased to 193.7 mL/g compared to 163.5 mL/g (in the absence of furfural); and the associated peak hydrogen production rate increased by 126%. This phenomenon from a thermodynamic perspective was due to the fact that furfural at a low concentration contributes to hydrogen production. A higher concentration of furfural (30 mM) significantly decreased hydrogen yield to 109.1 mL/g owing to severe cell membrane damage. The indicator of half-maximal inhibitory concentration was calculated as 32.5 mM. A postulated metabolic response of E. aerogenes to furfural is that the degradation of low concentrations of furfural (5 mM) involved a reduction reaction of furfural to hydrogen and furfuryl alcohol. However, a high concentration of furfural (30 mM) caused significant cell disfunction in normal metabolism, causing increased deformation degree in bacterial surface.

Volatile components in fresh leaves are involved in the regulation of many stress responses, such as insect damage, fungal infection and high temperature. However, the potential function of volatile components in hyperosmotic response is largely unknown. Here, we found that 7-day hyperosmotic treatment specifically led to the accumulation of (Z)-3-hexen-1-ol, (E)-2-hexenal and methyl salicylate. Transcriptome and qRT-PCR analyses suggested the activation of linolenic acid degradation and methyl salicylate processes. Importantly, exogenous (Z)-3-hexen-1-ol pretreatment dramatically enhanced the hyperosmotic stress tolerance of tea plants and decreased stomatal conductance, whereas (E)-2-hexenal and methyl salicylate pretreatments did not exhibit such a function. qRT-PCR analysis revealed that exogenous ABA induced the expressions of related enzyme genes, and (Z)-3-hexen-1-ol could up-regulate the expressions of many DREB and RD genes. Moreover, exogenous (Z)-3-hexen-1-ol tremendously induced the expressions of specific LOX and ADH genes within 24 h. Taken together, hyperosmotic stress induced (Z)-3-hexen-1-ol accumulation in tea plant via the activation of most LOX, HPL and ADH genes, while (Z)-3-hexen-1-ol could dramatically enhance the hyperosmotic stress tolerance via the decrease of stomatal conductance and MDA, accumulation of ABA and proline, activation of DREB and RD gene expressions, and probably positive feedback regulation of LOXs and ADHs. KEY MESSAGE: Hyperosmotic stress induced (Z)-3-hexen-1-ol accumulation in Camellia sinensis via the up-regulation of most LOX, HPL and ADH genes, while (Z)-3-hexen-1-ol could dramatically enhance the hyperosmotic stress tolerance via the decrease of stomatal conductance, accumulation of proline, activation of DREB and RD gene expressions, and probably positive feedback regulation of LOXs and ADHs.

Transcription is a highly dynamic process that generates single-stranded DNA (ssDNA) in the genome as ‘transcription bubbles’. Here we describe a kethoxal-assisted single-stranded DNA sequencing (KAS-seq) approach, based on the fast and specific reaction between N3-kethoxal and guanines in ssDNA. KAS-seq allows rapid (within 5 min), sensitive and genome-wide capture and mapping of ssDNA produced by transcriptionally active RNA polymerases or other processes in situ using as few as 1,000 cells. KAS-seq enables definition of a group of enhancers that are single-stranded and enrich unique sequence motifs. These enhancers are associated with specific transcription-factor binding and exhibit more enhancer–promoter interactions than typical enhancers do. Under conditions that inhibit protein condensation, KAS-seq uncovers a rapid release of RNA polymerase II (Pol II) from a group of promoters. KAS-seq thus facilitates fast and accurate analysis of transcription dynamics and enhancer activities simultaneously in both low-input and high-throughput manner. KAS-seq applies N3-kethoxal to label guanines along single-stranded DNA in live cells, enabling characterization of ssDNA-involved transcription dynamics with as little as 1,000 cells.

The organic synthesis has been driven by the need of sustainable processes, which also requires efficiency and cost-effectiveness. In this work, we described the synthesis of nine Knoevenagel adducts between cyanoacetamide and aromatic aldehydes ((E)-2-cyano-3-(phenyl)acrylamide derivatives), employing triethylamine as catalyst under microwave irradiation in 30 min with excellent yields (93-99% yield). Then, these adducts were employed in the C-C double bond bioreduction by the marine-derived fungus Cladosporium sp. CBMAI 1237 for obtention of 2-cyano-3-phenylpropanamide derivatives in mild conditions and short reaction time for a whole-cells reduction (phosphate buffer pH 7.0, 32 °C, 130 rpm, 8 h) with good yields (48-90%). It is important to emphasize that the experimental conditions, especially the reaction time, should be carefully evaluated for the obtention of high yields. Since a biodegradation process consumed the obtained product in extended periods, probably due to the use of the substrate as carbon and nitrogen source. This approach showed that the use of coupled and greener catalysis methods such as microwave irradiation and biocatalytic reduction, which employs unique biocatalysts like marine-derived fungi, can be an interesting tool for the obtention of organic molecules.

The ability to catalyse a reaction acting on different substrates, known as “broad-specificity” or “multi-specificity”, and to catalyse different reactions at the same active site (“promiscuity”) are common features among the enzymes. These properties appear to go against the concept of extreme specificity of the catalytic action of enzymes and have been re-evaluated in terms of evolution and metabolic adaptation. This paper examines the potential usefulness of a differential inhibitory action in the study of the susceptibility to inhibition of multi-specific or promiscuous enzymes acting on different substrates. Aldose reductase is a multi-specific enzyme that catalyses the reduction of both aldoses and hydrophobic cytotoxic aldehydes and is used here as a concrete case to deal with the differential inhibition approach.