Meliasanines A-L, tirucallane-type triterpenoids from Melia toosendan with anti-inflammatory properties via NF-κB signaling pathway.

Meliasanines A-L, twelve previously unreported tirucallane-type triterpenoids, together with fifteen known ones, have been isolated from the stem bark of Melia toosendan. Their structures and absolute configurations were determined based on HRESIMS, and NMR, combined with calculated ECD and single-crystal X-ray diffraction analyses. Subsequently, all compounds except 10 were evaluated for their inhibitory effect on the production of nitric oxide induced by lipopolysaccharide in RAW264.7 macrophage cells. The results indicated that seven compounds (1, 13, 14, 16, 20, 22, and 23) exhibited significant NO inhibitory effects, with IC50 values ranging from 1.35 to 5.93 µM, which were more effective than the positive control indomethacin (IC50 = 13.18 µM). Moreover, the corresponding results of Western blot analysis revealed that meliasanine A (1) can significantly suppress the protein expression of inducible nitric oxide synthase and cyclooxygenase 2 in a concentration-dependent manner. The mechanism study suggested that meliasanine A exerts an anti-inflammatory effect via the nuclear factor-κB signaling pathway by suppressing phosphorylation of P65 and IκBα.

Synthesis and in†vitro Anti-Inflammatory Activity of Novel Dendrobine Amide/Sulfonamide Derivatives.

A traditional Chinese medicine ingredient, dendrobine, has been demonstrated to have anti-inflammatory properties. However, due to its poor anti-inflammatory properties, its clinical use is limited. Consequently, we have designed and synthesized 32 new amide/sulfonamide dendrobine derivatives and screened their anti-inflammatory activities in vitro. Experiments showed that nitric oxide (NO) generation in lipopolysaccharide (LPS)-induced RAW264.7 cells was strongly reduced by derivative 14, with an IC50 of 2.96 µM. Western blot research revealed that 14 decreased the concentration-dependent expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (INOS). Molecular docking was used to predict the binding of the inflammation-associated proteins COX-2 and INOS to compound 14.

Structurally Diverse Coumarins from Peucedanum praeruptorum and their Anti-Inflammatory Activities via NF-κB Signaling Pathway.

The phytochemical study of Peucedanum praeruptorum led to the isolation of twenty-five coumarins (1-25). Of which, (±) praeruptol A (±1), one pair of previous undescribed seco-coumarin enantiomers were obtained. Their structures were established according to HR-ESI-MS, NMR, X-ray single crystal diffraction analysis, as well as ECD calculation. All compounds were tested for anti-inflammatory activity in the RAW264.7 macrophage model, and eight compounds (7-10, and 13-16) exhibited significant inhibitory effects with IC50 values ranging from 9.48 to 34.66 µM. Among them, compound 7 showed the strongest inhibitory effect, which significantly suppressed the production of IL-6, IL-1ß, and TNF-α, as well as iNOS and COX-2 in a concentration-dependent manner. Further investigated results showed that compound 7 exerted an anti-inflammatory effect via the NF-κB signaling pathway.

Metabolomic and transcriptomic analyses reveal the biosynthetic mechanisms of pigments and main taste compounds in an albino tea cultivar.

Significant variations in leaf colours, pigment contents, and main taste compounds in young shoots from albino tea plants (Camellia sinensis) influence tea flavour. However, the seasonal metabolic pattern and molecular regulatory mechanism of these metabolites remain largely elusive. Herein, we conducted morphological, biochemical, metabolomic and transcriptomic analyses between an albino tea cultivar 'Zhonghuang 3' ('ZH3') and a green strain 'Tai cha 15' ('TC15') at four-time points (April 12, May 31, July 14, and August 17) to elucidate dynamic changes in these compounds and predict the relationships among transcription factors (TFs), target genes (TGs), and metabolite abundance. Generally, leaf colours and pigment contents were significantly lighter and lower, respectively, in 'ZH3' than in 'TC15' from spring to summer, but were subsequently similar. Compared to 'TC15', 'ZH3' had a lower and broader phenol/ammonia ratio as well as stable caffeine content and showed more significantly different metabolites and differentially expressed genes. The relationship between pigments, main taste compounds, and their biosynthetic genes, as well as TFs and their TGs, had genetic specificity. These results suggested that the biosynthesis of these compounds was probably both season- and variety-dependent. In total, 12 models of the TF-TG-metabolite regulatory network were proposed to uncover the biosynthetic and regulatory mechanisms of these metabolites in tea plants. A high correlation was observed between some structural genes and TFs with the accumulation of these metabolites. These findings provide novel insights into the regulatory mechanisms underlying accumulation of pigments and main taste compounds in tea plants.

[Population status and protection evaluation of Syzygium album, a species with extremely small population.] / 极小种群植物白果蒲桃种群现状与保护评价.

Syzygium album is a plant species with extremely small population and endemic to Yun-xiao County, Fujian Province. We examined its population status and conservation evaluation. The results showed that there were 25 individuals of S. album, with only one mother tree. Except for the mother tree and one small tree, the others were all young seedlings, which was rare in abundance and lack of age stage of middle and strong trees. The spatial distribution of young seedlings was not uniform, with most of individuals within the range of 10-25 m from the mother tree. The age class structure of the population was not continuous and the population development was unsustainable. The competition mainly came from other species. Cryptocarya chinensis accounted for 66.6% of the total competition index, which was much higher than other species. We established a comprehensive evaluation index system for the protection of rare and endangered plants with extremely small populations and evaluated the protection of S. album from three aspects, i.e., endangered degree, protection value, and protection priority. The endangered degree of S. album was level Ⅰ (the endangered degree index was 4.510), belonging to extremely endangered species, the protection value was level Ⅰ (the protection value index was 4.052), which was of great value, and the protection priority was level Ⅰ (the protection priority index was 4.016), which should be listed as the highest priority protection level.

Genome-wide identification and expression analysis of SABATH methyltransferases in tea plant (Camellia sinensis): insights into their roles in plant defense responses.

SABATH methyltransferases convent plant small-molecule metabolites into volatile methyl esters, which play important roles in many biological processes and defense reactions in plants. In this study, a total of 32 SABATH genes were identified in the Camellia sinensis var. sinensis (CSS) genome, which were renamed CsSABATH1 to CsSABATH32. Genome location annotation suggested that tandem duplication was responsible for the expansion of SABATH genes in tea plant. Multiple sequence alignment and phylogenetic analysis showed that the CsSABATHs could be classified into three groups (I, II and III), which were also supported by gene structures and conserved motifs analysis. Group II contained only two CsSABATH proteins, which were closely related to PtIAMT, AtIAMT and OsIAMT. The group III SABATH genes of tea plant exhibited expansion on the CSS genome compared with Camellia sinensis var. assamica (CSA) genome. Based on RNA-seq data, the CsSABATHs exhibited tissue-specific expression patterns, and the members with high expression in buds and young leaves were also obviously upregulated after MeJA treatment. The expression of many transcription factors was significantly correlated with that of different members of the CsSABATH gene family, suggesting a potential regulatory relationship between them. Quantitative real-time PCR (qPCR) expression analysis showed that CsSABATHs could respond to exogenous JA, SA and MeSA treatments in tea plants. RNA-seq data analysis and qPCR validation suggested that CsSABATH8, 11, 16, 25, 29 and 32 might play a special role in plant defense against insect herbivory. These results provide references for evolutionary studies of the plant SABATH family and the exploration of the potential roles of CsSABATHs in tea plant defense responses.