Project description:A phytochemical investigation of the roots of Swietenia macrophylla led to the isolation of seven polyacetylenes, including five new compounds (1-5) and two known ones (6-7). Their structures were elucidated by extensive spectroscopic analysis and detailed comparison with reported data. All the isolates were tested for their cytotoxicity against the human hepatocellular carcinoma cell line BEL-7402, human myeloid leukemia cell line K562, and human gastric carcinoma cell line SGC-7901. Compounds 1 and 6 showed moderate cytotoxicity against the above three human cancer cell lines with IC50 values ranging from 14.3 to 45.4 μM. Compound 4 displayed cytotoxicity against the K562 and SGC-7901 cancer cell lines with IC50 values of 26.2 ± 0.4 and 21.9 ± 0.3 μM, respectively.
Project description:The title compound, C(31)H(38)O(10) [systematic name: (αR,4R,4aR,6aS,7R,8S,10R,11S)-methyl α,10-di-acet-oxy-4-(3-furyl)-4a,7,9,9-tetra-methyl-2,13-dioxo-1,4,4a,5,6,6a,7,8,9,10,11,12-dodeca-hydro-7,11-methano-2H-cyclo-octa-[f][2]benzo-pyran-8-acetate], was isolated from the seeds of Swietenia macrophylla. The mol-ecule contains four six-membered rings connected together in the shape of a bowl; one of the inner rings adopts a twisted chair conformation owing to the carbon-carbon double bond. The furyl substitutent is connected to an outer ring, and it points away from the bowl cavity.
Project description:Mahogany species (family Meliaceae) are highly valued for their aesthetic and durable wood. Despite their economic and ecological importance, genomic resources for mahogany species are limited, hindering genetic improvement and conservation efforts. Here we perform chromosome-scale genome assemblies of two commercially important mahogany species: Swietenia macrophylla and Khaya senegalensis. By combining 10X sequencing and Hi-C data, we assemble high-quality genomes of 274.49 Mb (S. macrophylla) and 406.50 Mb (K. senegalensis), with scaffold N50 lengths of 8.51 Mb and 7.85 Mb, respectively. A total of 99.38% and 98.05% of the assembled sequences are anchored to 28 pseudo-chromosomes in S. macrophylla and K. senegalensis, respectively. We predict 34,129 and 31,908 protein-coding genes in S. macrophylla and K. senegalensis, respectively, of which 97.44% and 98.49% are functionally annotated. The chromosome-scale genome assemblies of these mahogany species could serve as a vital genetic resource, especially in understanding the properties of non-model woody plants. These high-quality genomes could support the development of molecular markers for breeding programs, conservation efforts, and the sustainable management of these valuable forest resources.
Project description:In this day and age, the expectation of cosmetic products to effectively slow down skin photoaging is constantly increasing. However, the detrimental effects of UVB on the skin are not easy to tackle as UVB dysregulates a wide range of molecular changes on the cellular level. In our research, irradiated keratinocyte cells not only experienced a compromise in their redox system, but processes from RNA translation to protein synthesis and folding were also affected. Aside from this, proteins involved in various other processes like DNA repair and maintenance, glycolysis, cell growth, proliferation, and migration were affected while the cells approached imminent cell death. Additionally, the collagen degradation pathway was also activated by UVB irradiation through the upregulation of inflammatory and collagen degrading markers. Nevertheless, with the treatment of Swietenia macrophylla (S. macrophylla) seed extract and fractions, the dysregulation of many genes and proteins by UVB was reversed. The reversal effects were particularly promising with the S. macrophylla hexane fraction (SMHF) and S. macrophylla ethyl acetate fraction (SMEAF). SMHF was able to oppose the detrimental effects of UVB in several different processes such as the redox system, DNA repair and maintenance, RNA transcription to translation, protein maintenance and synthesis, cell growth, migration and proliferation, and cell glycolysis, while SMEAF successfully suppressed markers related to skin inflammation, collagen degradation, and cell apoptosis. Thus, in summary, our research not only provided a deeper insight into the molecular changes within irradiated keratinocytes, but also serves as a model platform for future cosmetic research to build upon. Subsequently, both SMHF and SMEAF also displayed potential photoprotective properties that warrant further fractionation and in vivo clinical trials to investigate and obtain potential novel bioactive compounds against photoaging.
Project description:Numerous documented ethnopharmacological properties have been associated with Swietenia macrophylla (Meliaceae), with its seed extract reported to display anti-hypoglycemic activities in diabetic rats. In the present study, three compounds isolated from the seeds of S. macrophylla were tested on a modified ELISA binding assay and showed to possess PPAR? ligand activity. They were corresponded to PPAR?-mediated cellular response, stimulated adipocyte differentiation but produced lower amount of fat droplets compared to a conventional anti-diabetic agent, rosiglitazone. The up-regulation of adipocytes was followed by increased adipocyte-related gene expressions such as adiponectin, adipsin, and PPAR?. The S. macrophylla compounds also promoted cellular glucose uptake via the translocation of GLUT4 glucose transporter.
Project description:Polyploidization events are known to trigger extensive epigenetic and transcriptional alteration of the duplicated or merged genomes, accompanied by small- and large-scale conformational changes. The genome of modern hexaploid wheat (Triticum aestivum L.; 2n = 6x = 42) is the product of two rounds of interspecific hybridization between three closely related diploid species, resulting in the presence of distinct but highly syntenic sub-genomes (AA, BB and DD). We examined the large-scale chromatin architecture of the nucleus of wheat using Hi-C, a genome-wide chromatin conformation capture (3C) method and GISH, (genomic in situ hybridization). We found evidence that physical interactions occur with significantly higher frequency within sub genomes (A with A, B with B or D with D) than between sub genomes (A with B or D, etc. ...), defining sub-nuclear “genomic territories”. In addition, we observed a polarized distribution of facultative and constitutive heterochromatin that suggests a functional compartmentalization within the nucleus. On a local scale, we found that genes tend to interact mainly with other genes over long-distance “loops” that are especially established between genes presenting similar expression levels and bearing the same histone marks. Moreover, gene pairs in spatial proximity show similar changes in expression levels between shoots and roots. Consistently, we found that physical contact between genes is mediated by RNA polymerase II (RNAPII). Immunofluorescence assays with anti RNAP2 antibodies revealed the presence of “transcription factories” in which multiple interacting genes are co-transcribed. This indicates that local-scale topology is an important factor for transcriptional regulation as it determines the micro-compartimentalization of active genes within the nucleus.Our results provide a framework for understanding the physical organization of wheat genome and highlight the interplay between chromosome conformation and gene expression in wheat.