Search

Background Ginseng, officially known as Panax ginseng Meyer, has been traditionally used as a medicinal herb, particularly in Asia. Ginseng is propagated from seeds; however, seed germination is challenging, especially in its natural environment on farms. The seeds typically exhibit morphophysiological dormancy and require release from both morphological and physiological dormancy before germination. Although some studies have proposed methods for increasing seed germination rates, the underlying mechanisms of its dormancy release process remain unclear. Here, we investigated metabolic alterations during dehiscence in P. ginseng to determine their potential roles in dormancy release. Methods We compared the ginseng seed metabolome before and after dehiscence and the ginsenoside and phytosterol compositions of the seeds in both periods in the presence of related enzymes. Results After seed dehiscence, the sugar, amino acid, and squalene concentrations were significantly altered, phytosterols associated with the stigmasterol biosynthesis pathway were increased, while ginsenoside and brassinosteroid levels were not significantly altered. In addition, squalene epoxidase, cycloartenol synthase, 24-methylenesterol C-methyltransferase, and the stigmasterol biosynthesis pathway were activated. Conclusion Overall, our findings suggest that morphological activities that facilitate ginseng seed growth are the primary phenomena occurring during the dehiscence process. This study improves the understanding of P. ginseng germination processes and promotes further research of its germination and cultivation.

Six Amaranthus species (A. cruentus, A. hybridus, A. hypochondriacus, A. muricatus, A. tuberculatus, and A. viridis) were collected in Italy (wild habitats) from crops and roadsides. Amaranth seed oil was extracted to obtain fractions rich in squalene. Squalene, free fatty acid, tocopherol, and sterol composition and content were investigated in detail. An analysis of variance and principal components was performed. The oil content in the seed ranged from 5.17% (A. muricatus) to 12.20% (A. tuberculatus). The quantity of squalene in the oil varied from 3.43% (A. muricatus) to 6.09% (A. hypochondriacus). The primary sterols were beta-sitosterol, brassicasterol, campesterol, and stigmasterol. The main tocopherols in all the samples were alfa-tocopherol, beta-tocopherol, and delta-tocopherol. Our results exhibited that the smallest seeds (A. tuberculatus) have the highest percentages of oil and squalene, whereas the largest seeds size (A. muricatus) show the lowest percentages. There is also evidence that the samples growing at lower altitudes show the highest concentration of fatty acids. According to our results, the six wild Amaranthus species exhibited similar characteristics to commercial species. This study confirms that the site of the collection has an impact on the oil and squalene content of the Amaranthus species.

Gusperimus is an anti-inflammatory drug that has shown to be effective in managing autoimmunity and preventing graft rejection. This is unstable and easily broken down into cytotoxic components. We encapsulated gusperimus binding it covalently to squalene obtaining squalene-gusperimus nanoparticles (Sq-GusNPs). These nanoparticles enhanced the immunosuppressive effect of gusperimus in both mouse macrophages and T cells. The half-maximal inhibitory concentration in macrophages was 9-fold lower for Sq-GusNPs compared with the free drug. The anti-inflammatory effect of the Sq-GusNPs was maintained over time without cytotoxicity. By studying nanoparticles uptake by cells with flow cytometry, we demonstrated that Sq-GusNPs are endocytosed by macrophages after binding to low-density lipoprotein receptors (LDLR). In presence of cathepsin B or D release of gusperimus is increased demonstrating the participation of proteases in the release process. Our approach may allow the application of Sq-GusNPs for effective management of inflammatory disorders including autoimmunity and graft rejection.

Santalenes and santalols from Santalum album are the main components of the valuable spice sandalwood essential oil, which also has excellent pharmacological activities such as antibacterial, anti-inflammatory, and antitumor. Firstly, we constructed biosynthesis pathways of santalenes by synthetic biology strategy. The assembled biosynthetic cassettes were integrated into the multiple copy loci of δ gene in S. cerevisiae BY4742 with assistance of pDi-CRISPR, and 94.6 mg/L santalenes was obtained by shake flask fermentation of engineered yeast. Secondly, a selected optimized P450-CPR redox system was integrated into the chromosome of the santalenes-producing strain with a single copy, and 24.6 mg/L santalols were obtained. Finally, the yields of santalenes and santalols were increased to 164.7 and 68.8 mg/L, respectively, by downregulating ERG9 gene. This is the first report on the de novo synthesis of santalols by P450-CPR chimera in S. cerevisiae. Meanwhile, the optimized chimeric CYP736A167opt-46tATR1opt exhibits higher activity to oxidize santalenes into santalols. It would provide a feasible solution for the optimal biosynthesis of santalols. KEY POINTS: • First-time de novo synthesis of santalols by P450-CPR chimera in S. cerevisiae. • Truncated 46tATR1 has higher activity than that of CPR2. • Yields of santalenes and santalols were increased by downregulating ERG9 gene.

Harnessing mitochondria is considered as a promising method for biosynthesis of terpenes due to the adequate supply of acetyl-CoA and redox equivalents in mitochondria. However, mitochondrial engineering often causes serious metabolic burden indicated by poor cell growth. Here, we systematically analyzed the metabolic burden caused by the compartmentalization of the MVA pathway in yeast mitochondria for squalene synthesis. The phosphorylated intermediates of the MVA pathway, especially mevalonate-5-P and mevalonate-5-PP, conferred serious toxicity within mitochondria, which significantly compromised its possible advantages for squalene synthesis and was difficult to be significantly improved by routine pathway optimization. These phosphorylated intermediates were converted into ATP analogues, which strongly inhibited ATP-related cell function, such as mitochondrial oxidative respiration. Fortunately, the introduction of a partial MVA pathway from acetyl-CoA to mevalonate in mitochondria as well as the augmentation of the synthesis of mevalonate in cytosol could significantly promote the growth of yeasts. Accordingly, a combinatorial strategy of cytoplasmic and mitochondrial engineering was proposed to alleviate the metabolic burden caused by the compartmentalized MVA pathway in mitochondria and improve cell growth. The strategy also displayed the superimposed effect of cytoplasmic engineering and mitochondrial engineering on squalene production. Through a two-stage fermentation process, the squalene titer reached 21.1 g/L with a specific squalene titer of 437.1 mg/g dcw, which was the highest at present. This provides new insight into the production of squalene and other terpenes in yeasts based on the advantages of mitochondrial engineering.

Transcriptional downregulation is widely used for metabolic flux control. Here, marO, a cis-element of Escherichia coli mar operator, was explored to engineer promoters of Saccharomyces cerevisiae for downregulation. First, the ADH1 promoter (PADH1) and its enhanced variant PUADH1 were engineered by insertion of marO into different sites, which resulted in decrease in both gfp5 transcription and GFP fluorescence intensity to various degrees. Then, marO was applied to engineer the native ERG1 and ERG11 promoters due to their importance for accumulation of value-added intermediates squalene and lanosterol. Elevated squalene content (4.9-fold) or lanosterol content (4.8-fold) and 91 or 28% decrease in ergosterol content resulted from the marO-engineered promoter PERG1(M5) or PERG11(M3), respectively, indicating the validity of the marO-engineered promoters in metabolic flux control. Furthermore, squalene production of 3.53 g/L from cane molasses, a cheap and bulk substrate, suggested the cost-effective and promising potential for squalene production.

Heavy metal toxicity and drought stresses are two growing concerns of the global population as these have a disastrous effect on the agriculture sector, creating oxidative stress in plants and leads to deleterious effects, which end up causing a major decline in yield. Hence, carving out the best candidate for combating both these stresses have become the prime objective of researchers. Plectranthus amboinicus (Lour.) Spreng., a medicinal plant, is regarded as one such candidate that can tolerate both drought and zinc stressors by the elicitation of metabolic changes. Variation in the composition of primary and secondary metabolites of P. amboinicus was evaluated in the leaf tissues of the plants subjected to drought and ZnSO4 (4 mM) treatments. Drought stress resulted in the accumulation of amino acids and sugars in the leaves of plants exposed to this stress. Similarly, zinc stress exhibited a remarkable impact on the synthesis of secondary metabolites like alkaloids, phenols, and flavonoids. Further, on carrying out GC–MS profiling, the compositional variation of secondary metabolites produced in P. amboinicus implicated its inherent potential to survive environments of these two stresses. Compounds like 2-methoxy-4-ethyl-6-methylphenol, gamma-sitosterol, hexadecanoic acid, alpha-amyrin, and ethyl linalool were some of the major secondary metabolites developed in leaves of plants under drought, whereas during ZnSO4 treatment, the major compounds developed were trans-alpha-bergamotene, squalene, 1,5-dimethyl-1-vinyl-4-hexenyl isovalerate, and spathulenol. This in turn makes the plant more compatible with the stressful environmental conditions, aiding it with better survival and protection. At the same time, the enhancement in the content of these metabolites in this medicinal plant under the influence of these stressors may have applications in the pharmaceutical industry, necessary for the development of novel drugs.

PURPOSE: The enzyme Cyclooxygenases (COX-1 and COX-2) catalyze the formation of prostaglandin, a mediator of the inflammatory pathway. Inflammation related pathological conditions may be alleviated by targeting the Cox enzymes.COX-2 inhibitors that are currently available in the market causes undesirable side effects. Our present study focuses on the in-silico inhibition of COX -2 enzyme by the phytocompounds from Albizia amara and Phyla nodiflora. METHODS: The phytochemicals present in Albizia amara and Phyla nodiflora were analyzed for their COX-2 inhibition potential. Eight compounds from Albizia amara and eleven compounds from Phyla nodiflora obtained from GC–MS analysis was used for the current study. Molecular docking was performed using AutoDock vina. The crystal structure of COX-2 (PDB ID: 5IKR) was obtained from Protein data bank. PyMol was used to remove any solvent, organic and inorganic molecules. Energy minimization of the protein was carried out using SPDBV software. Geometrical optimizations of the ligands were performed using Avogadro software. Celecoxib was used as the positive control. ADMET properties of the compounds were analyzed using SwissADME and ProtoxII online servers. Molecular mechanics/generalized born surface area (MM/GBSA) calculations were performed to evaluate the binding efficiency. Molecular dynamics of the protein and protein–ligand complex was studied for about 100 ns using Desmond package of Schrodinger suite. RESULTS: Among the eighteen compounds, Squalene present in both the plants showed a better binding energy of -7.7 kcal/mol, when compare to other phytocompounds present in the extract. The control celecoxib showed a binding energy of about – 9.4 kcal/mol. The toxicity and ADMET properties of squalene indicated that it is non-toxic and followed Lipinski’s rule. Molecular Dynamics (MD) analysis showed that the binding of squalene to the enzyme was stable. CONCLUSION: Squalene could potentially inhibit COX2 and o wing to its properties, squalene can be formulated in gels/creams and could be possibly used for external edema and inflammation GRAPHICAL ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40199-021-00408-6.

Background Clerodendrum serratum Linn commonly known as Bharangi in India has wide applications in the Ayurveda and Siddha system of medicine which has been attributed to the treatment of various diseases like asthma, cough, fever, rheumatism, and cephalalgia ophthalmia. Squalene has nutritional, medicinal, and pharmaceutical health benefits, hence possess antioxidant and cytoprotective effects. Method The study presents the GC-MS analysis of phytoconstituents present in the Clerodendrum serratum roots and further estimation of one of the constituents, i.e., squalene which is ought to be present in the roots as per mass spectral data obtained. Squalene was determined from the ethanolic extract of C. serratum roots using GC-FID without derivatization. Results Four major constituents, i.e., squalene, methyl palmitate, hexadecenoic acid, and stigmasterol were detected by GC-MS. Squalene from the extract was eluted at 17.5min which was confirmed with the standard squalene peak eluted at the same retention time. The linearity range chosen was 5–30ug/mL, and the method was found to be pretty linear (R=0.995), accurate with satisfactory repeatability. Hence, the phytochemical compounds were detected by GC-MS and the squalene was determined and validated according to the ICH guidelines. Conclusion Thus, the green gas chromatographic method can be used for quantification and qualification of active constituents in the roots of ethanolic extract of C. serratum. In addition, the presence of metabolite squalene by the GC-FID method was developed for the extract which is simple, fast, and environmentally friendly.

Clerodendrum inerme is a perennial shrub belonging to the family Lamiaceae and is used in many of the herbal preparations of Siddha and Ayurveda in India. Ethnomedicinally, the leaves of this plant are used to cure various ailments. In spite of enormous ethnomedicinal implications, proper chemical profiling and characterization of isolated compounds of C. inerme still remains unaddressed. Present study involves the characterization and chemical profiling of phytoconstituents from leaf extract which promise to be of immense therapeutic significance. Two compounds namely squalene and linolenic acid methyl ester were isolated from the leaves of C. inerme employing column chromatography technique. The structures were elucidated by spectroscopic methods including FTIR, 1H NMR and 13C NMR. Subsequently, antioxidant and antimicrobial activities of the isolated compounds were estimated in-vitro. Pertaining results were validated with in silico molecular docking-based investigations which revealed that both the compounds displayed high binding affinities with the target proteins of the antioxidant pathway commonly targeted for drug development.

The constituent and fatty-acid compositions of neutral lipids (NL), glyco-, and phospholipids and the squalene contents in seeds and the aerial part of Amaranthus retroflexus were studied for the first time. Elaidic acid was observed in all lipid groups. The squalene content was 4.3% of the NL mass in seeds and 3.15% in the aerial part. Preliminary wetting of wheat and cucumber seeds in unsaponified substances, fatty acids, and their methyl esters obtained from A. retroflexus seeds at concentrations 0.001 and 0.0001% was found to reduce the inhibiting action of salt stress. Neutral lipids did not exhibit a protective effect.

The oil palm (Elaeis guineensis) fruit is a source of vegetable oil and various phytonutrients. Phytochemical compounds present in palm oil include tocotrienols, carotenoids, phytosterols, squalene, coenzyme Q10, and phospholipids. Being a fruit, the oil palm is also a rich source of water-soluble phytonutrients, including phenolic compounds. Extraction of phytonutrients from the oil palm vegetation liquor of palm oil milling results in a phenolic acid-rich fraction termed Water-Soluble Palm Fruit Extract (WSPFE). Pre-clinical in vitro, ex vivo, and in vivo studies carried out using various biological models have shown that WSPFE has beneficial bioactive properties, while clinical studies in healthy volunteers showed that it is safe for human consumption and confers antioxidant and anti-inflammatory effects. The composition, biological properties, and relevant molecular mechanisms of WSPFE discovered thus far are discussed in the present review, with a view to offer future research perspectives on WSPFE for health and non-health applications.

Red-skin disease (RSD) is a common soil-borne disease encountered during ginseng cultivation. We found that RSD was closely related to soil properties such as soil acidification and metal stress. The levels of active ingredients, especially ginsenoside, in RSD ginseng were reduced, thereby reducing its medicinal value. We investigated the inducing factors and pathological processes leading to RSD in ginseng and the soil properties responsible for the inhibition of ginsenoside biosynthesis. Healthy and RSD ginseng were compared for properties including the planting slope, soil moisture, soil pH, and metal content. Changes in metal absorption and ginsenoside synthesis at different pH were screened as inducers of RSD using ginseng cells. The activities of nitrate reductase, glutamate dehydrogenase, glutamate synthase, glutamine synthase, and squalene synthase were determined using enzyme-linked immunosorbent assay. The effect of nitrogen on ginsenoside synthesis was analyzed by culturing ginseng cells in a nitrogen-deficient environment. Field data showed that RSD ginseng grew at a slope of about 13 degrees and at a slower rate than healthy ginseng. RSD was caused when ginseng was grown in soils having higher water content and acidity. Acidic conditions inhibited the ginsenoside biosynthesis, whereas an increase in the pH of the medium could alleviate this inhibition. The overabsorption of aluminum ions in ginseng cells in acidic conditions was most significant. Aluminum stress not only inhibited the ginsenoside synthesis but also decreased the levels of nitrogen-containing compounds and enzyme activities related to nitrogen metabolism. Moreover, nitrogen concentration was positively correlated with ginsenoside content and squalene synthase activity. Our findings indicated that RSD was observed in ginseng when the planting slope was slow, there was water accumulation in the soil, and when the soil was acidic. Acidic conditions appeared to promote aluminum overabsorption in ginseng cells. The interference in aluminum stress-induced nitrogen uptake was found to inhibit ginsenoside synthesis in RSD. Our findings may contribute to a better understanding of the susceptibility factors and pathological processes in the RSD of ginseng.

Panax quinquefolius L., a medicinal plant of Araliaceae family, is used in traditional Chinese medicine. Arbuscular mycorrhizal fungi (AMF) has been shown to promote plant growth and the accumulation of secondary metabolites in many plants. Our group has found a significant positive correlation between AMF infection rate and the accumulation of ginsenoside, while the effects and underlying mechanism of AMF on the growth and accumulation of ginsenoside in P. quinquefolius have been poorly studied. In this study, the effects on the biomass, photosynthesis and expressions of genes involved in biosynthesis of ginsenoside: hydroxymethylglutaryl-CoA reductase (HMGR), geranylgeranyl pyrophosphate synthase (GPS), farnesyl diphosphate synthase (FPS), squalene synthase (SS), squalene epoxidase (SE), dammarendiol synthase (DS) and cytochrome P450 enzyme (CYP716A47, CYP716A53v2) in P. quinquefolius during AMF inoculation were investigated. Plant biomass and photosynthesis of P. quinquefolius were stimulated by AMF treatment. Chlorophyll concentration in P. quinquefolius leaves treated by R. intraradices was higher than those in non-inoculated leaves. The concentration of Rb1 and Re was markedly increased by 26.15% and 22.38% (P

Steroid and hopanoid biomarkers can be found in ancient rocks and, in principle, can give a glimpse of what life was present at that time. Sterols and hopanoids are produced by two related enzymes, though the evolutionary history of this protein family is complicated by losses and horizontal gene transfers, and appears to be widely misinterpretted. Here, I have added sequences from additional key species, and re-analysis of the phylogeny of SHC and OSC indicates a single origin of both enzymes among eukaryotes. This pattern is best explained by vertical inheritance of both enzymes from a bacterial ancestor, followed by widespread loss of SHC, and two subsequent HGT events to ferns and ascomycetes. Thus, the last common ancestor of eukaryotes would have been bifunctional for both sterol and hopanoid production. Later enzymatic innovations allowed diversification of sterols in eukaryotes. Contrary to previous interpretations, the LCA of eukaryotes potentially would have been able to produce hopanoids as a substitute for sterols in anaerobic conditions. Without invoking any other metabolic demand, the LCA of eukaryotes could have been a facultative aerobe, living in unstable conditions with respect to oxygen level.

Previous studies suggest that squalene (SQ) in sebum is oxidized by a photooxidation mechanism (i.e., singlet oxygen oxidation) to create SQ hydroperoxide (SQOOH), a compound that causes adverse skin conditions. However, oxidation of other lipids in sebum, such as linoleic acid (LA), has not been fully understood. Elucidating their oxidation, especially its mechanisms, may lead to a further understanding of the relationship between sebum oxidation and skin conditions. In this study, using HPLC-MS/MS, we aimed to detect LA hydroperoxide (LAOOH) directly from sebum and identify the oxidation mechanism of LA in sebum through analysis of LAOOH isomers. We developed extraction and HPLC-MS/MS analysis conditions that can sufficiently quantify each LAOOH isomer in sebum. Using this method, LAOOH was detected in samples from healthy individuals, demonstrating the presence of LAOOH in human sebum. Moreover, isomer analysis of LAOOH and SQOOH indicated that LA and SQ are oxidized in sebum by discrete oxidation mechanisms (LA oxidized by free radical oxidation, whereas SQ oxidized by singlet oxygen oxidation). Such results may further lead to the development of mechanism-specific ways to prevent oxidation of sebum via a selection of appropriate antioxidants, ultimately leading to the promotion of skin health.

Methotrexate (MTX), an antifolate drug, is extensively prescribed for patients suffering from diseases like cancer, psoriasis, neoplasms, and rheumatoid arthritis. Despite its effectiveness, MTX sometimes finds limited application because its undesirable side effects, including hepatic or renal impairment, bone marrow toxicity and gastrointestinal mucosal injury. Squalene, a highly unsaturated isoprenoid compound, isolated from shark liver oil has great potential in neutralizing the damaging effects triggered by free radicals. Therefore, in this study, the protective role of dietary squalene supplementation on oxidative stress induced by methotrexate in experimental rats was evaluated. A significant reduction was displayed in the activities of catalase (CAT) and superoxide dismutase (SOD) in MTX-intoxicated groups compared to other groups. Similarly, the activities of glutathione dependant enzymes (GPx and GST) and reduced glutathione (GSH) in MTX-induced groups were shown to be lower compared to the untreated control. Increased LPO (lipid peroxide) level was found in MTX-intoxicated groups compared to other groups. In addition, alterations in the levels of liver marker enzymes like AST, ALP, ALT, and LDH were noticed in MTX intoxicated groups compared to other groups. Biochemical results were confirmed by the histopathological examination of liver sections. In conclusion, the result obtained in the present study proposes that squalene exerts antioxidant activity and is capable of ameliorating oxidative stress and liver injury induced by MTX.

Azadirachta indica is used to insects repellent, control diabetes, and combat with cancer. In this study, the effect of different concentrations of chitosan and sampling times on cell suspension culture and SQS1 and MOF1 genes expression were studied and response surface methodology was used to construct the prediction models for azadirachtin, mevalonic acid and squalene accumulation and production. The highest fresh and dry cell weight and azadirachtin accumulation were 726.21 g/L, 20.76 g/L, and 11.74 mg/g DW obtained 6 days after using 50 mg/L chitosan, respectively. The highest azadirachtin production was 165.50 mg/L achieved by using 50 mg/L chitosan for 8 days. Maximum mevalonic acid accumulation (1.87 mg/g DW) and production (22.50 mg/L) were observed 2 and 4 days after the addition of 50 mg/L chitosan and control condition, respectively. The highest amount of squalene accumulation (0.319 mg/g DW) and production (3.56 mg/L) were obtained 10 days after using 50 mg/L chitosan. Also, the prediction results showed the highest azadirachtin accumulation (10.76 mg/g DW) and production (136.83 mg/L), mevalonic acid accumulation (1.869 mg/g DW) and production (20.576 mg/L) and squalene accumulation (0.217 mg/g DW) and production (2.23 mg/L) by using 71.50 mg/L chitosan for 5.24 days, 66.25 mg/L chitosan for 9.1 days, 2.5 mg/L chitosan for 2 days, without chitosan for 2 days, 98.50 mg/L chitosan for 2 days and 80.25 mg/L chitosan for 6.08 days, respectively. The qRT-PCR analysis indicated the maximum relative expression of SQS1 and MOF1 genes by using 25 and 50 mg/L chitosan for 6 days. For the first time, chitosan concentrations and sampling times optimized by response surface methodology for azadirachtin, mevalonic acid and squalene accumulation and production and investigated SQS1 and MOF1 genes expression.

Human skin oils are significant scavengers of atmospheric oxidants in occupied indoor environments, and squalene is a major ozone-active constituent. Here, we present a combined spectroscopic and atomistic modeling approach to elucidate the conformational and orientational preferences of squalene at the air/oil interface and their implications for reactions with ozone. We find that squalene chains have a tendency to align with the surface normal, resulting in different concentrations of the various types of its double bonds and thus different reactivities. We also observe the presence of water at the surface of this hydrophobic compound. Both findings have possible implications for the design and outcomes of kinetic models describing this important aspect of indoor air chemistry.

Background Wrightia tinctoria R.Br. (Apocyanaceae) is known as a biologically effective plant for the treatment of jaundice in the Indian traditional system of medicine. It is a wild medicinal tree possessing anti-inflammatory, antidiabetic, antinociceptive, hepatoprotective, antibacterial, antifungal, antiviral, antipsoriatic, anticancerous, anthelmintic, aphrodisiac, analgesic, and antipyretic activities. Its constituents are of utmost interest to pharmaceutical industries owing to their many actions and biological activities. Method Methanolic extract of W. tinctoria (MEWT) was investigated by gas chromatography-mass spectroscopy and provided affirmative results assisting in the identification and characterization of therapeutic claims regarding this species in the traditional system. The antioxidant activity of MEWT was determined by the most suitable DPPH method. Results The basic compounds found in MEWT were β-caryophyllene (0.22%), mome inositol (12.02%), neophytadiene (1.61%), eicosanoic acid methyl ester (0.32%), 8,11,14-eicosatrienoic acid methyl ester (0.60%), phytol (0.94%), phytol palmitate (1.37%), squalene (1.57%), flavone 4-OH, 5-OH, 7-di-O-glucoside (29.34%), γ-tocopherol (0.49%), stigmast-5-en-3-ol (3.14%), methyl commate B (1.76%), methyl commate A (5.20%), and 24-norursa-3,12-diene (20.36%). The obtained results in the analysis of antioxidant activity of MEWT exhibited considerable free radical scavenging capacity against DPPH-generated free radicals. Conclusions This study expands the knowledge of MEWT chemical composition and provides evidence to substantiate ethno-medicinal use of the plant by exploring antioxidant activity. The substantial antioxidant activity of MEWT could be due to presence of terpenes, flavonoids, vitamin E, and other reported compounds. Highlights This study includes identification of phytochemicals and antioxidant potential of methanolic extract of Wrightia tinctoria, assisting in therapeutic claims regarding this species in the traditional system.

Astragaloside VII (AST-VII), a major cycloartane saponin isolated from Turkish Astragalus species, turned out to be one of the most active metabolites demonstrating Th1/Th2 balanced immune response. As Quillaja saponins are extensively used in adjuvant systems, this study made an attempt to improve AST-VII based adjuvant systems by using different immunostimulatory/delivery agents (monophosphoryllipid A (MPL), Astragalus polysaccharide (APS) and squalene) and to induce cellular and humoral immune response against a viral vaccine. For this purpose, Newcastle Disease vaccine (NDV) was chosen as a model vaccine. Swiss albino mice were immunized subcutaneously with LaSota vaccines in the presence/absence of AST-VII or developed adjuvant systems. AST-VII administration both in live/inactivated LaSota vaccines induced neutralizing and NDV specific IgG, IgG1 and IgG2b antibodies response as well as IL-2 and IL-4 production. APS based delivery systems enhanced the production of neutralizing antibody and the minor augmentation of IFN-? and IL-2 levels. Squalene emulsion (SE) alone or combined with AST-VII were effective in NDV restimulated splenocyte proliferation. As a conclusion, AST-VII and AST-VII containing adjuvant systems demonstrated Th1/Th2 balanced antibody and cellular immune responses in NDV vaccines. Thus, these systems could be developed as vaccine adjuvants in viral vaccines as alternative to saponin-based adjuvants. © 2021 International Alliance for Biological Standardization, 1139B411402292 Türkiye Bilimsel ve Teknolojik Araştirma Kurumu, TÜBITAK, This study partially supported by The Scientific and Technological Research Council of Turkey (TUBITAK) under Grant 1139B411402292 .

Background Rhodosporidium strain, a well-known oleaginous yeast, has been widely used as a platform for lipid and carotenoid production. However, the production of squalene for application in lipid-based biofuels is not reported in this strain. Here, a new strain of Rhodosporidium sp. was isolated and identified, and its potential was investigated for production of squalene under various cultivation conditions. Results In the present study, Rhodosporidium sp. DR37 was isolated from mangrove ecosystem and its potential for squalene production was assessed. When Rhodosporidium sp. DR37 was cultivated on modified YEPD medium (20 g/L glucose, 5 g/L peptone, 5 g/L YE, seawater (50% v/v), pH 7, 30 °C), 64 mg/L of squalene was produced. Also, squalene content was obtained as 13.9% of total lipid. Significantly, use of optimized medium (20 g/L sucrose, 5 g/L peptone, seawater (20% v/v), pH 7, 25 °C) allowed highest squalene accumulation (619 mg/L) and content (21.6% of total lipid) in Rhodosporidium sp. DR37. Moreover, kinetic parameters including maximum specific cell growth rate (μmax, h−1), specific lipid accumulation rate (qp, h−1), specific squalene accumulation rate (qsq, h−1) and specific sucrose consumption rate (qs, h−1) were determined in optimized medium as 0.092, 0.226, 0.036 and 0.010, respectively. Conclusions This study is the first report to employ marine oleaginous Rhodosporidium sp. DR37 for accumulation of squalene in optimized medium. These findings provide the potential of Rhodosporidium sp. DR37 for production of squalene as well as lipid and carotenoids for biofuel applications in large scale. Graphic abstract