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Changes in the genome of an organism can cause changes in phenotype. Its phenotype can then determine how well-suited the organism is to its environment. The hologenome concept expands this view by suggesting instead, that it is not only the host genome at play in natural selection, but also the genome of endosymbiotic microorganisms (viruses, bacteria, and fungi) associated with their hosts. The concept is an area of growing interest. It directs the study of biology from an individual-centric approach to one that is more community-centric. This approach opens more opportunities to carefully examine host-community interactions and strategies to ensure a balance between counterparts. However, more intriguing is the potential that the hologenome concept may provide a glimpse into the biological mechanisms of speciation. This paper is a literature review presenting cases in endosymbiont interactions that affect reproductive competence of host and hence, may be an important mechanism of speciation. [ABSTRACT FROM AUTHOR]

Understanding the relative importance of reproductive isolating mechanisms across the speciation continuum remains an outstanding challenge in evolutionary biology. Here, we examine a common isolating mechanism, reproductive phenology, between plant sister taxa at different stages of adaptive divergence to gain insight into its relative importance during speciation. We study 17 plant taxa that have independently adapted to inhospitable serpentine soils, and contrast each with a nonserpentine sister taxon to form pairs at either ecotypic or species-level divergence. We use greenhouse-based reciprocal transplants in field soils to quantify how often flowering time (FT) shifts accompany serpentine adaptation, when FT shifts evolve during speciation, and the genetic versus plastic basis of these shifts. We find that genetically based shifts in FT in serpentine-adapted taxa are pervasive regardless of the stage of divergence. Although plasticity increases FT shifts in five of the pairs, the degree of plasticity does not differ when comparing ecotypic versus species-level divergence. FT shifts generally led to significant, but incomplete, reproductive isolation that did not vary in strength by stage of divergence. Our work shows that adaptation to a novel habitat may predictably drive phenological isolation early in the speciation process. [ABSTRACT FROM AUTHOR]

Hybrid lethality is a type of reproductive isolation in which hybrids die before maturation, due to the interaction between the two causative genes derived from each of the hybrid parents. The interspecific hybrid of Nicotiana suaveolens × Nicotiana tabacum is a model plant used in studies on hybrid lethality. While most of the progeny produced from such a cross die, some individuals grow normally and mature. Separately, a technique for producing mature hybrids by artificial culture has been developed. However, the mechanism by which hybrids overcome lethality, either spontaneously or by artificial culture, remains unclear. In the present study, we found that some hybrids that overcome lethality, either spontaneously or by artificial culture, lack the distal part of the Q chromosome, a region that includes the gene responsible for lethality. Quantitative polymerase chain reaction results suggested that the distal deletion of the Q chromosome, detected in some hybrid seedlings that overcome lethality, is caused by reciprocal translocations between homoeologous chromosomes. The results showed that chromosomal instability during meiosis in amphidiploid N. tabacum as well as during artificial culturing of hybrid seedlings is involved in overcoming hybrid lethality in interspecific crosses of the genus Nicotiana. [ABSTRACT FROM AUTHOR]

Many recent studies have addressed the mechanisms operating during the early stages of speciation, but surprisingly few studies have tested theoretical predictions on the evolution of strong reproductive isolation (RI). To help address this gap, we first undertook a quantitative review of the hybrid zone literature for flowering plants in relation to reproductive barriers. Then, using Populus as an exemplary model group, we analysed genome-wide variation for phylogenetic tree topologies in both early- and late-stage speciation taxa to determine how these patterns may be related to the genomic architecture of RI. Our plant literature survey revealed variation in barrier complexity and an association between barrier number and introgressive gene flow. Focusing on Populus, our genome-wide analysis of tree topologies in speciating poplar taxa points to unusually complex genomic architectures of RI, consistent with earlier genome-wide association studies. These architectures appear to facilitate the 'escape' of introgressed genome segments from polygenic barriers even with strong RI, thus affecting their relationships with recombination rates. Placed within the context of the broader literature, our data illustrate how phylogenomic approaches hold great promise for addressing the evolution and temporary breakdown of RI during late stages of speciation. [ABSTRACT FROM AUTHOR]

Polyploid speciation entails substantial and rapid postzygotic reproductive isolation of nascent species that are initially sympatric with one or both parents. Despite strong postzygotic isolation, ecological niche differentiation has long been thought to be important for polyploid success. Using biogeographic data from across vascular plants, we tested whether the climatic niches of polyploid species are more differentiated than their diploid relatives and if the climatic niches of polyploid species differentiated faster than those of related diploids. We found that polyploids are often more climatically differentiated from their diploid parents than the diploids are from each other. Consistent with this pattern, we estimated that polyploid species generally have higher rates of multivariate niche differentiation than their diploid relatives. In contrast to recent analyses, our results confirm that ecological niche differentiation is an important component of polyploid speciation and that niche differentiation is often significantly faster in polyploids. [ABSTRACT FROM AUTHOR]

Highlights • Nitzschia laevis was a promising resource to develop fucoxanthinol and fucoxanthin production. • A simple two-step method was mediated with SPE and TLC techniques. • This exploited approach could effectively purified fucoxanthinol and fucoxanthin. • The purities of the two purified compounds were over 95%. Abstract In this study, the microalga Nitzschia laevis (N. laevis) can accumulate a marine carotenoid fucoxanthinol. In particular, fucoxanthinol was firstly isolated from microalgae, accompanied by its derivative fucoxanthin. The identification and quantification of fucoxanthinol and fucoxanthin were determined by ultra-performance liquid chromatography coupled to photodiode array detector-quadrupole/travelling-wave ion mobility mass spectrometry/time-of-flight mass spectrometry (UPLC-PDA-TWIMS-QTOF-MS). Furthermore, a cost-effective approach mediated with solid-phase extraction (SPE) and thin-layer chromatography (TLC) technique was used to isolate and purify fucoxanthinol and fucoxanthin from the extracts of N. laevis. This two-step method can obtain 98% fucoxanthinol and 95% fucoxanthin, with the recovery efficiencies of around 85% for fucoxanthinol and 70% for fucoxanthin, respectively. Moreover, 1H and 13C nuclear magnetic resonance (NMR) techniques were adopted to record the purified compounds for supporting the above results. In all, the developed method has a promising potential to purify fucoxanthinol and fucoxanthin of microalgae for food and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Recently diverged species often show incomplete reproductive isolation and subsequently experience hybridization and introgression. The plant genus Mimulus includes many such examples of closely related taxa that prove useful for studying incipient speciation. However, Sandstedt et al. show that in contrast to other Mimulus species, species of the M. tilingii complex are characterized by strong postzygotic isolation mediated by multiple barriers. This finding highlights the diverse speciation histories of related plant groups. [ABSTRACT FROM AUTHOR]

Members of the genus Dickeya are plant pathogens that mostly cause soft‐rot diseases. Diversity within the genus has led to the recent description of three novel species (i.e. a mainly clonal D. solani of economic consequence in potatoes, D. aquatica from water samples and D. fangzhongdai isolated from necrotic pear trees in China). However, multilocus sequence analysis (MLSA) has highlighted the occurrence of seven isolates not related to the defined Dickeya species. These include a previously unclassified group of Dickeya strains isolated from monocotyledonous plants, Dickeya sp. S1, Dickeya sp. B16, and Dickeya sp. NCPPB 3274, as well as Dickeya sp. MK7, a strain isolated from water, and misassigned strains D. solani ND14, D. solani M005 and D. chrysanthemi M074. Here, it is reported that these isolates can be classified as D. fangzhongdai by using average nucleotide identity analysis and MLSA. However, variations in phenotypic characterization featuring colony morphology and carbon utilization assays revealed a diversity of bacterial isolates classified as D. fangzhongdai. Based on the results of the genomic analysis, the classification of Dickeya sp. S1, Dickeya sp. B16, Dickeya sp. MK7, Dickeya sp. NCPPB 3274 to D. fangzhongdai is proposed as well as the reclassification of D. solani ND14, D. solani M005 and D. chrysanthemi M074 to D. fangzhongdai. [ABSTRACT FROM AUTHOR]

Gene flow is one of the main factors shaping genetic diversity within and among tree populations, and occurs through pollen and seed dispersal. Recent findings of pollen-release asynchronies in distant populations of Scots pine (Pinus sylvestris L.) within Scotland suggest that gene dispersal among more distant populations might be less effective than previously thought. Limited gene dispersal is one of the major factors causing genetic structure for neutral markers, and pollen-release asynchrony could have driven isolation by distance (IBD) among Scottish populations. Previous studies of neutral markers found little differentiation among Scottish populations of Scots pine, however they did not consider IBD over the full Scottish range. We analysed data from 6 nuclear simple sequence repeats (SSR) and 5 chloroplast SSR loci in a total of 540 individuals of Scots pine from 18 populations across Scotland. Our aim was to assess contemporary levels and distribution of genetic variation and to test if the distribution of genetic diversity was consistent with IBD. We also analysed patterns of gene flow that could have contributed to the observed patterns of variation. Levels of genetic diversity were high, for both nuclear and chloroplast markers within populations, and there was no significant differentiation among populations. A weak signal of IBD was present. We found an increase in nuclear diversity towards the East along with greater gene flow in a West-East direction commensurate with the prevailing winds. Our findings suggest that this wind-driven gene flow is dominant over genetic drift and prevents differentiation among the Scottish populations. It may also counteract any pollen-release asynchronies among populations. [ABSTRACT FROM AUTHOR]

Background: Biological methods of polycyclic aromatic hydrocarbons (PAH) contamination elimination typically involve the transformation of contaminants to non-toxic materials by microorganisms and plants and appear to be the most effective methods available. Methods: In this study, Bacillus licheniformis and Bacillus mojavensis isolated from oil-contaminated soils were inoculated onto Festuca arundinacea seeds before planting in the pot and 3 weeks after planting by syringe injection into the rhizospheric zone in order to study the elimination of PAHs from Festuca’s rhizosphere in the greenhouse. Some physical and chemical properties of the soil, PAH concentrations, seeds germination percentage, root and shoot biomasses of the treated samples were examined. Results: The results showed that the treated samples inoculated with both bacteria had a significantly higher percentage of seed germination and root and shoot biomass compared to other treatments. The concentration of some PAHs reduced significantly (Pvalue < 0.05) in the rhizosphere of the treated samples inoculated with both bacteria compared to in contaminated soils. Concentrations of some PAHs (eg. Naphthalene, Phenanthrene, Benzo[a]anthracene and Dibenzo[a,h]anthracene) even reached below the detection limit of the method. The PAHs concentrations in the treated samples inoculated with bacteria was decreased significantly (Pvalue < 0.05). Therefore, the results showed the high efficiency of the Festuca and bacterial inoculation in eliminating PAHs from the soil. Conclusion: According to the results, the partnership of Festuca with B. licheniformis and B. mojavensis isolates displayed positive effect on PAHs dissipation and can be effective cleanup technology with high performance. [ABSTRACT FROM AUTHOR]

Black rot of sweetpotato, caused by Ceratocystis fimbriata, has recently reemerged as a significant threat to sweetpotato production in North Carolina and other states across the United States. This disease has historically been controlled largely through cultural management strategies and. in some cases, fungicide application. The sudden and destructive reemergence of this disease in 2015 created the need for rapidly evaluating disease control strategies. Genetic diversity of current C. fimbriata isolates infecting sweetpotato in North Carolina was assessed using ITS, TEF, and MAT-2 sequences. All 50 tested isolates were confirmed to be of a single mating type, MAT-2, based on PCR amplification. Alignment of ITS, TEF, and MAT-2 sequences revealed all isolates were identical at each locus. Fourteen common sweetpotato cultivars and advanced breeding lines were screened for black rot resistance using two isolates. None of the cultivars were completely resistant to the disease and most were equally susceptible. 'Stokes Purple' and 'Covington' were the least susceptible, but significantly (P < 0.05) differed only from 'Bellevue', the most susceptible cultivar. Sensitivity of 50 C. fimbriata isolates to difenoconazole, fludioxonil, thiabendazole, dicloran, azoxystrobin, pyraclostrobin, fenamidone, and fluazinam was evaluated in vitro. Difenoconazole, thiabendazole, and fluazinam were most effective in reducing mycelia growth. Postharvest fungicide application on black rot-infected roots provided similar results. Low efficacy of dicloran, as well as a range of EC5() values among isolates, suggests potential resistance to this commonly applied fungicide. Results obtained in this study provide current and useful information so that improved recommendations can be made to reduce losses in sweetpotato to black rot. [ABSTRACT FROM AUTHOR]

Eight fungal isolates (ELRF I to 8) were recovered from necrotic roots of Easter lilies, Lilium longiflorum cv. Nellie White, grown in a field in the U.S. Pacific Northwest. The eight fungal isolates were identified by sequencing and molecular phylogenetic analyses based on their ITS i DNA region. Five isolates were identified as Fusarium oxysporum, two as F. tricinctum, and one as Rhizoctonia sp. AG-I. This constitutes the first report of Rhizoctonia sp. AG-I infecting lilies worldwide and the first report of F. tricinctum infecting lilies in the United States. To study and validate their pathogenicity, pure cultures of each isolate were used to infect the roots of Easter lily plants growing in vitro. In addition, Easter lily plants growing in vitro were infected either with or without Pratylenchus penetrans, the root lesion nematode, prior to placing a culture plug of fungus 1 cm from a lily root. Pratylenchus penetrans is a nematode species commonly found in the sampled fields. The presence of both nematode and Rhizoctonia sp. AG-1 isolate ELRF 3 in infected lilies was evaluated by molecular analyses, confirming the infection of roots 3 days after inoculation, prior to development of disease symptoms. Necrosis and root rot developed more rapidly with all eight fungal isolates when there had been prior infection with P. penetrans, the major nematode parasitizing Easter lily roots in the field in Oregon. [ABSTRACT FROM AUTHOR]

The hop cultivar Cascade has been grown in the Pacific Northwestern U.S. and elsewhere with minimal input for management of powdery mildew (Podosphaera macularis) for nearly 15 years due to the putatively quantitative resistance in this cultivar. While partial resistance is generally thought to be more durable than qualitative resistance, in 2012, powdery mildew was reported on Cascade in Washington State. Field surveys conducted during 2013 to 2016 indicated increasing prevalence of powdery mildew on Cascade, as well as an increasing number of fungicide applications applied to this cultivar in Washington State. Nearly all isolates of P. macularis tested were able to infect Cascade in laboratory inoculations. However, the greatest number of colonies, most conidia produced, and the shortest latent period was only observed with isolates derived originally from Cascade, as compared with other isolates derived from other cultivars. Further, the enhanced aggressiveness of these isolates was only manifested on Cascade and not six other susceptible cultivars, further indicating a specific adaptation to Cascade by the isolates. There was no evidence of a known major R-gene in Cascade, as seven isolates of P. macularis with contrasting virulence all infected Cascade. Among 158 isolates obtained from hop yards planted to Cascade, only two (1.3%) were able to infect the cultivar Nugget, which possesses the resistance factor termed R6, indicating that isolates of P. macularis virulent on Nugget are largely distinct from those adapted to Cascade. Further, race characterization indicated Cascadeadapted isolates of P. macularis were able to overcome R-genes Rb, R3, and R5, but not other known R-genes. Therefore, multiple R-genes and other sources of partial resistance are expected to provide resistance to Cascadeadapted strains of the fungus. Given the plasticity of the powdery mildew fungus, breeding strategies for powdery mildew need to consider the potential for adaptation to both qualitative and partial resistance in the host. [ABSTRACT FROM AUTHOR]

The C-repeat binding factors (CBFs), also termed dehydration-responsive element-binding protein 1 (DREB1) family members, play crucial roles in the acquisition of stress tolerance, but in trees, the underlying mechanisms of stress tolerance remain elusive. To gain insight into these mechanisms, we isolated five CBF1 orthologs from four poplar sections (Populus spp.) and assessed their expression under drought, cold, heat and salt stress conditions. Globally induced expression in response to cold suggested a correlation between poplar CBF1 expression and the acquisition of cold tolerance. Responses that varied between sections may reflect section-specific stress tolerance mechanisms, suggesting an effect of ecological context on the development of CBF1- mediated stress tolerance in poplar. We then used a genome-wide search strategy in Populus trichocarpa to predict 2263 putative CBF target genes; the identified genes participate in multiple biological processes and pathways. Almost all of the putative target genes contained multiple cis-acting elements that mediate responses to various environmental and endogenous signals, consistent with an important role of CBF1s in an integrated cold regulatory network. Finally, analysis of an association population of 528 individuals of Populus simonii identified six single-nucleotide polymorphisms (false discovery rate Q < 0.10) significantly (P < 0.005) associated with malondialdehyde production and electrolyte leakage, suggesting the potential importance of PsCBF1 in the regulation of some membrane-related functions. Our findings provide new insights into the function of PsCBF1 and shed light on the CBF-mediated regulatory network in poplar. [ABSTRACT FROM AUTHOR]

Transposable elements are key players in eukaryotic genomic diversity. Due to their high abundance, great heterogeneity, and replicative transposition, long terminal repeat (LTR) retrotransposons are well suited as molecular markers for breeding and biodiversity studies, whereas their utilities in non-model organisms have been hindered by the lack of prior sequence knowledge. In this study, a putative complete (5362 bp) LTR retrotransposon was isolated and characterized in the mangrove species Kandelia candel (named KCRE1), and its transcription, insertional polymorphisms and copy number variations were also investigated. KCRE1 has all the features of a typical copia retroelement, and its transcription initiation and termination sites were identified by 5′ and 3′ rapid amplification of cDNA ends (RACE), respectively. KCRE1 exhibits high sequence similarity with the tomato retroelement Rider and is constitutively expressed in the leaf, root, flower, and hypocotyl tissues of K. candel. Based on KCRE1, sequence-specific amplification polymorphism (SSAP) markers were developed to explore genetic diversity across 30 individuals from three natural populations of K. candel in China. Six primer combinations yielded a total of 204 SSAP bands with an averaged percentage of polymorphic loci of 55.37 and 41.35 % at the species and population levels, respectively. Each individual had a distinct SSAP phenotype, and 14-23 unique bands were observed for each population. Accordingly, KCRE1 was highly abundant in the genome of K. candel and showed considerable copy number variation among the three populations. In conclusion, KCRE1 is the first transcriptionally active retrotransposon reported in K. candel, providing a useful tool for the elucidation of untapped genetic diversity in mangrove genomes. [ABSTRACT FROM AUTHOR]

Filamentous cyanobacterium (strain NE-PS) isolated from a freshwater body in Pune, India, is being described as new species of the polyphyletic genus Nostoc. Phenotypic and molecular characterizations were performed, and the combined results validated the strain as a new species. Careful observations of the filaments, the presence of a distinct sheath throughout the length of the trichome, prominent differences in the shape and dimensions of the vegetative cells, heterocytes and the akinetes provided reliable morphological signals that the strain differed from rest of the closely related species. Sequencing of the 16S rRNA gene showed 98.66 % sequence similarity with Nostoc linckia, while rbcL and psbA sequencing showed 97 and 94 % similarities with Nostoc sp. PCC 7906 and Nostoc punctiforme PCC 73102, respectively, while the nifD gene sequence similarity was found to be 96 % with N. punctiforme Ind35 and Desmonostoc muscorum. The PC-IGS region was sequenced and concatenated cpcB, IGS and cpcA regions indicated the closest similarity with Nostoc linckia PACC 5085 at 96 %. Subsequent phylogenetic analyses gave a strong pattern of distinct clustering in case of all the molecular markers. The phenotypic, genetic and phylogenetic observations prove conclusively that the strain NE-PS is a new species in the genus Nostoc with the name proposed being Nostoc punensis, sp. nov. [ABSTRACT FROM AUTHOR]

Published protocols for chloroplast and mitochondrial DNA enrichment are based on large samples (more than 5 g) which imply high costs and plenty of sample material. Reduction of tissue sample and reagent quantities is possible and convenient. This work describes an efficient miniprep for chloroplast and mitochondria DNA enrichment and extraction from 500 mg of pericarp samples of Manzano chili fruits (Capsicum pubescens R. & P.). Extraction efficiency from fresh fruit samples was 20 μg DNA g-1 for choloroplasts and 33 μg DNA g-1 for mitochondria. Isolation using the recommended miniprep resulted in costs reduction of 160x for chloroplast and up to 8x for mitochondria. PCR amplification of reference marker genes for chloroplast (rbcL, Rubisco large subunit) and mitochondria (cox1, Cytochrome oxidase) confirmed DNA identity of each extraction. [ABSTRACT FROM AUTHOR]

Reinforcement is the process by which selection favors traits that decrease mating between two incipient species in response to costly mating or the production of maladapted hybrids, causing the evolution of greater reproductive isolation between emerging species. I have studied a pair of orchids, Neotinea tridentata and N. ustulata, to examine the level of postmating pre- and post-zygotic isolating mechanisms that maintain these species, and the degree to which the boundary may still be permeable to gene flow. In this study, I performed pollen tube growth rate experiments and I investigated pre- and post-zygotic barriers by performing hand pollination experiments in order to evaluate fruit set, embryonate seed set and seed germination rates by intra- and interspecific crosses. Fruit set, the percentage of embryonate seeds and germinability of interspecific crosses were reduced compared to intraspecific pollinations, showing significant differences between sympatric and allopatric populations. While in allopatric populations the post-pollination isolation index ranged between 0.40 and 0.11, in sympatric populations orchid pairs showed total isolation due to post-pollination prezygotic barriers, guaranteed at the level of pollen-stigma interactions. Indeed, in sympatric populations, pollen tubes reached the ovary after 24 h in only 8 out of 45 plants; in the remaining cases, the pollen tubes did not enter the ovary, and thus no fruit set occurred. This pair of orchids is characterized by postmating pre-zygotic reproductive isolation in sympatric populations that prevents the formation of hybrids. This mechanism of speciation, starting in allopatry and triggering the reinforcement mechanisms of reproductive isolation in secondary sympatry, is the most likely explanation for the pattern of evolutionary transitions found in this pair of orchids. [ABSTRACT FROM AUTHOR]

Using various chromatographic methods, three new megastigmane glycosides, docynicasides A - C ( 1 - 3) and ten known, (6 S,9 R)-vomifoliol 9- O- β- d-xylopyranosyl-(1′′→6′)- O- β- d-glucopyranoside ( 4), hyperin ( 5), quercitrin ( 6), quercetin 3- α- l-arabinofuranoside ( 7), naringenin 7- O- β- d-glucopyranoside ( 8), phloridzin ( 9), phloretin 2′- O- β- d-xylopyranosyl-(1→6)- β- d-glucopyranoside ( 10), pinosylvin 3- O- β- d-glucopyranoside ( 11), tormentic acid ( 12), and chlorogenic acid methyl ester ( 13) were isolated from the fruits of Docynia indica. Their chemical structures were elucidated by physical and chemical methods. All the isolated compounds were evaluated for the inhibitory activity on NO production in LPS-stimulated BV2 cells. As the results, compounds 3 - 5 showed significant inhibitory activity on LPS-stimulated NO production in BV2 cells with the IC50 values ranging from 21.0 to 29.3 μ m. [ABSTRACT FROM AUTHOR]

In flowering plants, F1 hybrid seed lethality is a common outcome of crosses between closely related diploid species, but the genetic basis of this early-acting and potentially widespread form of postzygotic reproductive isolation is largely unknown., We intercrossed two closely related species of monkeyflower, Mimulus guttatus and Mimulus tilingii, to characterize the mechanisms and strength of postzygotic reproductive isolation. Then, using a reciprocal backcross design, we performed high-resolution genetic mapping to determine the genetic architecture of hybrid seed lethality and directly test for loci with parent-of-origin effects., We found that F1 hybrid seed lethality is an exceptionally strong isolating barrier between Mimulus species, with reciprocal crosses producing < 1% viable seeds. This form of postzygotic reproductive isolation appears to be highly polygenic, indicating that multiple incompatibility loci have accumulated rapidly between these closely related Mimulus species. It is also primarily caused by genetic loci with parent-of-origin effects, suggesting a possible role for imprinted genes in the evolution of Mimulus hybrid seed lethality., Our findings suggest that divergence in loci with parent-of-origin effects, which is probably driven by genomic coevolution within lineages, might be an important source of hybrid incompatibilities between flowering plant species. [ABSTRACT FROM AUTHOR]

Technological properties of two strains of Lactobacillus plantarum (B3 and B11) and one of Lactobacillus pentosus (B4), previously isolated from natural fermented green olives, have been studied in vitro. Acidifying ability, salt, temperature, and pH tolerances of all strains were found in the range reported for similar strains produced in Italy and optimal growth conditions were found to be 6.0-8.0 pH, 15-30°C temperature, and less than 6% NaCl. Moreover, all strains showed very good tolerance to common olive phenol content (0.3% total phenol) and high oleuropein-degrading capability. It was found that medium composition affected the bacterial oleuropein degradation. B11 strain grown in a nutrient-rich medium showed a lower oleuropein-degrading action than when it was cultivated in nutrient-poor medium. Furthermore, enzymatic activity assays revealed that oleuropein depletion did not correspond to an increase of hydroxytyrosol, evidencing that bacterial strains could efficiently degrade oleuropein via a mechanism different from hydrolysis. [ABSTRACT FROM AUTHOR]

Incompletely isolated species provide an opportunity to investigate the genetic mechanisms and evolutionary forces that maintain distinct species in the face of ongoing gene flow. Here, we use field surveys and reduced representation sequencing to characterize the patterns of reproductive isolation, admixture and genomic divergence between populations of the outcrossing wildflower Mimulus guttatus and selfing M. nasutus. Focusing on a single site where these two species have come into secondary contact, we find that phenological isolation is strong, although incomplete, and is likely driven by divergence in response to photoperiod. In contrast to previous field studies, which have suggested that F1-hybrid formation might be rare, we discover patterns of genomic variation consistent with ongoing introgression. Strikingly, admixed individuals vary continuously from highly admixed to nearly pure M. guttatus, demonstrating ongoing hybridization and asymmetric introgression from M. nasutus into M. guttatus. Patterns of admixture and divergence across the genome show that levels of introgression are more variable than expected by chance. Some genomic regions show a reduced introgression, including one region that overlaps a critical photoperiod QTL, whereas other regions show elevated levels of interspecific gene flow. In addition, we observe a genome-wide negative relationship between absolute divergence and the local recombination rate, potentially indicating natural selection against M. nasutus ancestry in M. guttatus genetic backgrounds. Together, our results suggest that Mimulus speciation is both ongoing and dynamic and that a combination of divergence in phenology and mating system, as well as selection against interspecific alleles, likely maintains these sympatric species. [ABSTRACT FROM AUTHOR]

Natural hybrid zones have proven to be precious tools for understanding the origin and maintenance of reproductive isolation ( RI) and therefore species. Most available genomic studies of hybrid zones using whole- or partial-genome resequencing approaches have focused on comparisons of the parental source populations involved in genome admixture, rather than exploring fine-scale patterns of chromosomal ancestry across the full admixture gradient present between hybridizing species. We have studied three well-known European 'replicate' hybrid zones of Populus alba and P. tremula, two widespread, ecologically divergent forest trees, using up to 432 505 single-nucleotide polymorphisms ( SNPs) from restriction site-associated DNA ( RAD) sequencing. Estimates of fine-scale chromosomal ancestry, genomic divergence and differentiation across all 19 poplar chromosomes revealed strikingly contrasting results, including an unexpected preponderance of F1 hybrids in the centre of genomic clines on the one hand, and genomically localized, spatially variable shared variants consistent with ancient introgression between the parental species on the other. Genetic ancestry had a significant effect on survivorship of hybrid seedlings in a common garden trial, pointing to selection against early-generation recombinants. Our results indicate a role for selection against recombinant genotypes in maintaining RI in the face of apparent F1 fertility, consistent with the intragenomic 'coadaptation' model of barriers to introgression upon secondary contact. Whole-genome resequencing of hybridizing populations will clarify the roles of specific genetic pathways in RI between these model forest trees and may reveal which loci are affected most strongly by its cyclic breakdown. [ABSTRACT FROM AUTHOR]

Kadcoccinin A (1), a cage-like sesquiterpenoid possessing a tricyclo[4.4.0.03,10]decane scaffold, and the biosynthetically related kadcoccinin B (2) were isolated from the stems of Kadsura coccinea. Their structures and absolute configurations were determined from extensive spectroscopic analysis and quantum chemical calculations. Additionally, their cytotoxic and antifungal effects were initially evaluated, and a plausible biosynthetic pathway was proposed. [ABSTRACT FROM AUTHOR]

Seven filicinic acid-based meroterpenoids (1-7), possessing 6/6/11, 6/6/7/5, or 6/6/10 ring systems, were isolated from Hypericum japonicum. All of them have novel skeletons with the incorporation of sesquiterpenoid moieties to an acylated filicinic acid. Compounds 2a and 4 exhibited significant efficacy on anti-Epstein-Barr virus, with EC50 values of 0.57 and 0.49 μM, respectively. Furthermore, compounds 2a and 4 were well accommodated to the binding pocket of 2GV9 predicted by the molecular docking. On May 6, 2016, the figure of HRESIMS of compound 1a/1b in the Supporting Information was corrected. [ABSTRACT FROM AUTHOR]

Euphorbia peplus has been used in traditional medicine to treat asthma and psoriasis. Three highly modified diterpenoids, namely, pepluacetal (1) and pepluanol A-B (2-3), have been isolated and identified from this plant. Compounds 1-3 exhibit unprecedented 5/4/7/3, 5/6/7/3, and 5/5/8/3 ring systems, respectively. Their structures with absolute configurations were determined by spectroscopic analyses, X-ray crystallography, and electronic circular dichroism calculations. Since Kv1.3 is a validated target for the treatment of autoimmune diseases, such as multiple sclerosis, type-1 diabetes, asthma, and psoriasis, Kv1.3 was studied in terms of its response to the new compounds. All three compounds inhibit Kv1.3, with compound 3 being the most effective with an IC50 value of 9.50 μM. [ABSTRACT FROM AUTHOR]

Plants in the Meliaceae family are known to possess interesting biological activities, such as antimalaral, antihypertensive and antitumour activities. Previously, our group reported the plant-derived compound cycloart-24-ene-26-ol-3-one isolated from the hexane extracts of Aglaia exima leaves, which shows cytotoxicity towards various cancer cell lines, in particular, colon cancer cell lines. In this report, we further demonstrate that cycloart-24-ene-26-ol-3-one, from here forth known as cycloartane, reduces the viability of the colon cancer cell lines HT-29 and CaCO-2 in a dose- and time-dependent manner. Further elucidation of the compound’s mechanism showed that it binds to tumour necrosis factor-receptor 1 (TNF-R1) leading to the initiation of caspase-8 and, through the activation of Bid, in the activation of caspase-9. This activity causes a reduction in mitochondrial membrane potential (MMP) and the release of cytochrome-C. The activation of caspase-8 and -9 both act to commit the cancer cells to apoptosis through downstream caspase-3/7 activation, PARP cleavage and the lack of NFkB translocation into the nucleus. A molecular docking study showed that the cycloartane binds to the receptor through a hydrophobic interaction with cysteine-96 and hydrogen bonds with lysine-75 and -132. The results show that further development of the cycloartane as an anti-cancer drug is worthwhile. [ABSTRACT FROM AUTHOR]

Sweet potato [ Ipomoea batatas (L.) Lam.], the world's seventh most important food crop, is also a major industrial raw material for starch and ethanol production. In the plant starch biosynthesis pathway, ADP-glucose pyrophosphorylase (AGPase) catalyzes the first, rate-limiting step and plays a pivotal role in regulating this process. In spite of the importance of sweet potato as a starch source, only a few studies have focused on the molecular aspects of starch biosynthesis in sweet potato and almost no intensive research has been carried out on the AGPase gene family in this species. In this study, cDNAs encoding two small subunits (SSs) and four large subunits (LSs) of AGPase isoforms were cloned from sweet potato and the genomic organizations of the corresponding AGPase genes were elucidated. Expression pattern analysis revealed that the two SSs were constitutively expressed, whereas the four LSs displayed differential expression patterns in various tissues and at different developmental stages. Co-expression of SSs with different LSs in Escherichia coli yielded eight heterotetramers showing different catalytic activities. Interactions between different SSs and LSs were confirmed by a yeast two-hybrid experiment. Our findings provide comprehensive information about AGPase gene sequences, structures, expression profiles, and subunit interactions in sweet potato. The results can serve as a foundation for elucidation of molecular mechanisms of starch synthesis in tuberous roots, and should contribute to future regulation of starch biosynthesis to improve sweet potato starch yield. [ABSTRACT FROM AUTHOR]

Genetic hybridization analysis revealed that industrially important species Komagataella kurtzmanii has reproductive postzygotic isolation from K. pastoris, K. phaffii, K. populi, K. pseudopastoris, and K. ulmi. Therefore, it represents a new biological species of the genus Komagataella. The genetic data are in perfect agreement with the molecular taxonomy of the genus Komagataella. [ABSTRACT FROM AUTHOR]

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The bark of Mimosa tenuiflora (Willd.) Poiret (Leguminosae family), popularly known as “jurema preta” in Brazil, is used by the population of Contendas of Sincorá (Bahia State, Brazil) for the treatment of coughs and wound healing. Thus, the aim of this study was to evaluate the antinociceptive and anti-inflammatory activities of the bark ethanol extract (EEMT) and solvent soluble fractions (hexane—H, DCM—D, EtOAc—E and BuOH—B) of the extract in vivo. Additionally, we synthesized 5,7-dihidroxy-4’-methoxyflavanone (isosakuranetin) and isolated the compound sakuranetin, and both compounds were also tested. The anti-inflammatory and antinociceptive assays performed were: writhing test; nociception induced by intraplantar formalin injection; leukocyte recruitment to the peritoneal cavity; evaluation of vascular permeability (Evans blue test); and evaluation of mechanical hypernociception (von Frey test). Production of TNF-α, IL-10, myeloperoxidase and the expression of ICAM-1 were also evaluated. Statistical analysis was performed by one-way ANOVA followed by the Bonferroni post-test (n = 8), with P < 0.05. The EEMT showed antinociceptive activities in writhing test (100–200 mg/kg), in the second phase of the formalin test (50–200 mg/kg), and in mechanical hypernociception (100 mg/kg). EEMT showed an anti-inflammatory effect by reducing neutrophil migration to the peritoneal cavity and in the plantar tissue detected by the reduction of myeloperoxidase activity (100 mg/kg), reduction of IL-10 levels and expression of ICAM-1 in the peritoneal exudate and the mesentery (100 mg/kg), respectively. The four soluble EEMT fractions showed good results in tests for antinociceptive (H, D, E, B) and anti-inflammation (H, D, E). Only sakuranetin showed reduction of the writhing and neutrophil migration (200 mg/kg). Thus, the EEMT and soluble fractions of M. tenuiflora bark demonstrated great antinociceptive and anti-inflammatory activities, as also sakuranetin. More studies should be conducted to elucidate the mechanism of action of this compound. To the best of our knowledge, this is the first report on the antinociceptive activity of the M. tenuiflora fractions and the bioactive isolated compound sakuranetin in vivo. [ABSTRACT FROM AUTHOR]

Eleven new furostanol saponins, typaspidosides B-L (1–11), one new spirostanol saponin, typaspidoside M (12), and five known spirostanol saponins, 25S-atropuroside (13), neoaspidistrin (14), (25S)-pratioside D1 (15), 25S-aspidistrin (16) and 25S-neosibiricoside (17) were isolated from the rhizomes of Aspidistra typica Baill. The structures of the new compounds were established using 1D and 2D NMR (1H-1H COSY, HMQC, HMBC and ROESY) spectroscopy, high resolution mass spectrometry, and chemical methods. The aglycones of 1–3 (unusual furostanol saponins with opened E ring type), 9 and 10 (the methoxyl substituent at C-23 position) were found, identified from natural products for the first time. Moreover, the anti-HIV activities of the isolated steroidal glycosides were assessed, and compounds 13, 14, 16 and 17 exhibited high active against HIV-1. [ABSTRACT FROM AUTHOR]

The aim of this work was to study the processes taking place during the enzymatic hydrolysis of seed globulins isolated from narrow-leaf (var. Zeus and Bojar) and yellow (var. Lord and Parys) lupin seeds species cultivated in Poland. In lupin seed globulins hydrolysis studies, there were used enzymes typical for the human gastrointestinal tract, such as: pepsin, pancreatin, trypsin and chymotrypsin. The obtained hydrolysates were assessed based on the results of electrophoretic, immunoblotting, as well as chromatographic separations. The evaluation of lupin seed globulins digestion susceptibility was supported by the bioinformatics analyses. Analysis of hydrolysates showed that the proteins present in globulins are completely hydrolysed by: pepsin, double digestion model (pepsin followed by pancreatin) or chymotrypsin. The high specificity of pancreatin and trypsin action results in limited lupin globulins hydrolysis. Protein fraction resistant to the action of these enzymes was γ-conglutin which also retains its antigenic properties. Its insensitivity to the hydrolysis might be associated with the formation of complexes with flavonoids which were released from other protein connections during digestion, as well as with relatively low number of cleavage sites for trypsin. The analysis of the three-dimensional structure of γ-conglutin enabled a very accurate description of the amino acid residues localisation, at which trypsin hydrolysis should occur. [ABSTRACT FROM AUTHOR]

The aim of this work is to study alternative biotechnological procedures to prepare green table olives. Specifically, by working on laboratory-scale system and under controlled conditions, the technological potential of enzymes from olive leaf and/or Lactobacillus plantarum strain (TB38) isolated from wine were assayed on green olives in comparison with spontaneous fermentation and 3 % NaOH treatment. The fermentation process (microbial count, pH, ethyl alcohol and the lactic and acetic acids, in the cover liquid medium) and the changes of phenolic fraction (total phenols, oleuropein and hydroxytyrosol, in the olive fruits) were checked weekly for 30 days. In the first week, olive leaf enzymes showed to be very effective in degrading the oleuropein; conversely, their action showed a decline in the subsequent days. Also the TB38 LAB strain showed a good oleuropeinolytic activity and acidifying capacity. However, the presence of undissolved olive leaf solid residue inhibited clearly the metabolism of LAB. [ABSTRACT FROM AUTHOR]

Stromules are stroma-containing tubules that have been observed to emanate from the main plastidic body in vivo. These structures have been shown to require cytoskeletal components for movement. Though numerous studies have shown a close association with the endoplasmic reticulum, nucleus, mitochondria, and other plastids, the mechanism of formation and their overall function remain unknown. A limiting factor in studying these structures has been the lack of a reconstituted system for in vitro stromule formation. In this study, stromule formation was induced in vitro by adding a plant extract fraction that is greater than 100 kDa to a population of isolated chloroplasts. Kinetic measurements show that stromule formation occurs within ~10 seconds after the addition of the plant extract fraction. Heat inactivation and apyrase treatment reveal that the stromule stimulating compound found in the extract fraction is a protein or protein complex 100 kDa or greater. The formation of the stromules in vitro with isolated chloroplasts and a concentrated fraction of cell extract opens an avenue for the biochemical dissection of this process that has heretofore been studied only in vivo. [ABSTRACT FROM AUTHOR]

NAD(H) kinase (NADK) is a key enzyme for maintaining the cellular NAD(H)/NADP(H) balance and for NADP(H)-based metabolic pathways. We identified four NADK homologs, NADK1-4, from three major cereal crops, wheat, rice and maize, based on their phylogenetic relationships and gene structures. Four of the 11 NADK genes isolated from the wheat genome ( TaNADK1-4) were cloned. Subcellular localization analysis showed that TaNADK1 and 2 are located in the cytosol, TaNADK3 in chloroplasts and TaNADK4 in peroxisomes. The genes of wheat NADKs were expressed in all tissues examined and throughout development, with the same tissue specificity and developmental stage dominance. Although we found some species specificities between the orthologous and/or paralogous genes of the cereal NADKs, transcripts of these genes in wheat, rice and maize were all notably affected in the presence of one of several abiotic stresses or hormonal treatments, demonstrating their crucial roles in the abiotic stress response and hormone signaling regulation. The cereal NADKs might function in cellular NAD(H)/NADP(H) balance and NADP(H) production for redox-based enzymatic processes in plants and therefore contribute to plant stress tolerance and developmental regulation. The compartmentalization of different NADKs might play a fundamental role in the regulation of multiple biological processes. [ABSTRACT FROM AUTHOR]

Heat shock transcription factor (HSF) plays an essential role on the increased tolerance against heat stress by regulating the expression of heat-responsive genes. In this study, a HSF gene, CarHSFB2, was isolated and characterized in chickpea. CarHSFB2 was a nuclear protein with a predicted polypeptide of 267 amino acids and encoded by a single/low copy genes. Phylogenetic analysis showed that CarHSFB2 belonged to the class B HSFs. It had little or no any transcription activation activity due to lack of aromatic, hydrophobic, and acidic amino acid (AHA) motifs. CarHSFB2 showed different expression patterns among different developmental processes (leaf senescence, developing seed, and embryo of germinating seed). It was induced by the stress of heat, salt, wound and drought, and the treatment of HO, IAA, and GA3, respectively, while inhibited by 6-BA. However, the other stress and chemical treatments (cold, ABA, MeJA, Et, and SA) had no obvious effect on its expression. Overexpression of CarHSFB2 in Arabidopsis seedlings showed the increased tolerance to drought and heat stress. Additionally, stress-responsive genes, RD22, RD26, and RD29A, showed significantly higher expression levels in transgenic Arabidopsis seedlings than in the wild type (WT) under drought stress, whereas HsfA2, HsfB2a, and HsfA7a in transgenic Arabidopsis seedlings were markedly accumulated in transcript level than in the WT under heat stress. All these results indicate that CarHSFB2, a class B HSF, positively functions in different developmental processes and various stress responses, especially in positive response to heat and drought stresses, in chickpea. [ABSTRACT FROM AUTHOR]

A dimeric acylphenol and a potent α-glucosidase inhibitor, giganteone D (IC 50 5.05 μM), was isolated and characterized from the bark of Myristica cinnamomea King. The bark also yielded an acylphenol with an unprecedented skeleton for which the name cinnamomeone A (IC 50 358.80 μM) was proposed. Their structures were established by means of NMR and MS spectrometric analyses. The Lineweaver–Burk plot of giganteone D indicated that it was a mixed-type inhibitor. This is the first report on the α-glucosidase inhibiting potential of acylphenols. [ABSTRACT FROM AUTHOR]

Eleven benzofuran dimers, (+)-dieupachinins A–E, (−)-dieupachinins A–E and dieupachinin F, a benzofuran trimer trieupachinin A, as well as seven known compounds were isolated from the roots of Eupatorium chinense . The enantiomers of racemates dieupachinins A–E were separated by chiral HPLC. The structures with absolute configurations were elucidated on the basis of spectroscopic data, X-ray diffraction analysis, and circular dichroism experiments. The isolated compounds were evaluated for their in vitro antiviral activities against respiratory syncytial virus (RSV). [ABSTRACT FROM AUTHOR]

Investigation of the fungus Phoma herbarum PSU-H256 isolated from a leaf of Hevea brasiliensis resulted in the isolation of eight terezine derivatives (E–L) together with four known compounds. Their structures were established by analysis of spectroscopic evidence. For terezines E and H, their structures were confirmed by single-crystal X-ray diffraction crystallography. In addition, the absolute configuration at C-7 in terezine E was established by Mosher’s method. Terezines K and L were tested for antibacterial, antimalarial, antimycobacterial and cytotoxic activities, but were inactive. [ABSTRACT FROM AUTHOR]

Phytochemical investigation of the aerial parts of Chimonanthus salicifolius resulted in the isolation of two sesquiterpenoids, 8 α -hydroxy-T-muurolol and (1 α ,6 β ,7 β )-cadinane-4-en-8 α ,10 α -diol, together with 13 known compounds. The 15 structures were established by means of 1D and 2D NMR spectroscopy. The relative and absolute configurations of 8 α -hydroxy-T-muurolol and 8 α ,11-elemodiol were achieved by NOESY experiments and X-ray crystallography using CuK α radiation. 8 α -hydroxy-T-muurolol and (1 α ,6 β ,7 β )-cadinane-4-en-8 α ,10 α -diol showed immunosuppressive activities in a dose-dependent manner. [ABSTRACT FROM AUTHOR]

Investigation of the hydrophobic extract of Rabdosia serra (Lamiaceae) led to the isolation of seven ent -6,7-secokaurane diterpenoids rabdosins E–K, along with twelve known ent -kaurane diterpenoids. Their structures were established by extensive spectroscopic analysis. The absolute configurations of rabdosins E, F, H and I were determined by single-crystal X-ray diffraction, with rabdosin E having a 3,20-epoxy group. These diterpenoids could be divided into two types according to their skeletons: rabdosins E–J are ent -6,20-epoxy-6,7-secokaur-1,7-olides, and rabdosin K is an ent -6,7-secokaur-7,20-olide. Cytotoxicity evaluation showed that serrin B, serrin A, isodocarpin and lushanrubescensin J exhibited weak to moderate cytotoxic activities (IC 50 < 10 μM) against two human cancer cell lines. [ABSTRACT FROM AUTHOR]

Ten diterpenoids, named macrorilone A–B, macroripremyrsinone A, macrorilathyrone A–B, macrorieuphorone A–B and macroricasbalone A–C, together with ten known diterpenoids, jatrophalone, sikkimenoids A–D, jatrophodione A, latilagascenes F, jolkinol B, 15β- O -benzoyl-5α-hydroxyisolathyrol and jatrophalactone were isolated from the whole plant of Euphorbia macrorrhiza C.A. Mey. These diterpenoids belong to six skeleton-types, including jatropholane, premyrsinane, lathyrane, euphoractin, casbene and rhamnofolane diterpenoids. Their structures were elucidated by extensive analysis of 1D, 2D NMR and HRESIMS spectroscopic data. The absolute configurations of macrorilone B, macroripremyrsinone A and macrorilathyrone A were established by comparing their experimental and calculated electronic circular dichroism (ECD) spectra. Several of the isolated compounds exhibited weak cytotoxicity against the KB and KBv200 cell lines with IC 50 values ranging from 21.19 to 47.87 μM. Some also showed multidrug resistance (MDR) reversal activity, among which macrorilathyrone B exhibited a remarkable inhibitory effect on P-gp-mediated drug exclusion. [ABSTRACT FROM AUTHOR]

Three dimeric acylphloroglucinols, austrobrasilol A, austrobrasilol B and isoaustrobrasilol B were isolated from the flowers of Hypericum austrobrasiliense (Hypericaceae, section Trigynobrathys ). Their structures were elucidated using mass spectrometry and NMR experiments (1D and 2D), and by comparison with previously reported data for other dimeric acylphloroglucinols isolated from Hypericum and Elaphoglossum genera. The three compounds were orally administered in mice at equimolar doses to uliginosin B (15 mg/kg, p.o.) displaying antinociceptive activity in the hot-plate test. The compounds did not induce motor impairment in the rotarod apparatus. [ABSTRACT FROM AUTHOR]

The phytochemical investigation of the methanolic extract of Uvaria flexuosa (Annonaceae) leaves led to the isolation of seven compounds including, 3-methyl-4,5-dihydro-oxepine (flexuvaroxepine A), four polyoxygenated seco-cyclohexene (flexuvarin A–D) and two polyoxygenated cyclohexene (flexuvarol A–B) derivatives, together with four known flavones. The structures of the isolated compounds were elucidated using different spectroscopic techniques. A plausible biogenetic route of the new compounds was discussed. The anti-inflammatory activity of the isolated compounds was evaluated by superoxide anion generation and elastase release assays. Among the tested compounds, flexuvarol B and chrysin showed the most potent anti-inflammatory effect by inhibiting superoxide anion generation and elastase release from human neutrophils in response to fMLP with IC 50 2.25–5.55 μM. Moreover, 5-hydroxy-6,7-dimethoxy-flavone showed selective inhibitory activity on superoxide anion generation (IC 50 = 1.19 ± 0.34 μM). [ABSTRACT FROM AUTHOR]

Twelve metabolites, including five highly oxygenated azaphilones, geumsanols A–E, along with seven known analogues were isolated from Penicillium sp. KCB11A109, a fungus derived from a ginseng field. Their structures were assigned by spectroscopic means (NMR and MS), and stereochemistries were determined by extensive spectroscopic analyses ( 1 H– 1 H coupling constants, NOESY, and HETLOC) and chemical derivatizations (modified Mosher’s method and acetonide formation). The isolates were evaluated for their anticancer, antimicrobial, antimalarial activities, and phenotypic effects in zebrafish development. Of these compounds possessing no pyranoquinone core, only geumsanol E exhibited cytotoxic activities and toxic effects on zebrafish embryos, suggesting that a double bond at C-11 and C-12 is important for biological activity. [ABSTRACT FROM AUTHOR]

A cycloartane gardurvilleic acid, three 3,4- seco - cycloartanes securvienol, secodienurvilleic acid, securvitriol, a 3,4;9,10- seco -cycloartane gardheptlactone, two dammaranes urvilone, urvilol, along with eight known cycloartanes and 3,4- seco -cycloartanes and four known dammaranes have been isolated from the bud exudate of Gardenia urvillei , an endemic tree to the New Caledonian dry forest. Two other dammarane derivatives have been obtained by semisynthesis. The structures of the original compounds were determined by spectroscopic methods and chemical correlations. In association with previously published data, the description of oxidized side-chains in position 17 are now available for two couples of diastereoisomers. Evaluation of anti-parasite activity and cytotoxicity has shown noticeable results for some of the isolated triterpenes. [ABSTRACT FROM AUTHOR]

Eight structurally diverse cassane diterpenes named tomocins A–H were isolated from the seed kernels of Vietnamese Caesalpinia sappan Linn. Their structures were determined by extensive NMR and CD spectroscopic analysis. Among the isolated compounds, tomocin A, phanginin A, F, and H exhibited mild preferential cytotoxicity against PANC-1 human pancreatic cancer cells under nutrition-deprived condition without causing toxicity in normal nutrient-rich conditions. [ABSTRACT FROM AUTHOR]

Six diterpenoids [crassifolin J, K, L, M, N and O] along with eleven known ones were isolated from the supercritical fluid extract (SFE) of the roots of Croton crassifolius (Euphorbiaceae). Their structures were elucidated using spectroscopic methods (IR, UV, HRESIMS, 1D and 2D NMR). The structure and stereochemistry of crassifolin J was confirmed by single-crystal X-ray diffraction analysis, and the absolute configurations of crassifolin K–M were determined by CD spectra. Twenty-three diterpenoids from this plant were screened for their anti-angiogenic activity using a wild-type zebrafish in vivo model. Four of the known compounds were active, of which penduliflaworosin possessed the best activity relative to the positive control (SU5416). Further study demonstrated that penduliflaworosin could inhibit vessel formation on Tg(fli1a:EGFP)y1 -type zebrafish embryos. [ABSTRACT FROM AUTHOR]