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The Value of Ecosystem Services from Giant Panda Reserves
No full textEcosystem services (the benefits to humans from ecosystems) are estimated globally at 2.6 and US$6.9 billion/year in 2010. Protecting the panda as an umbrella species and the habitat that supports it yields roughly 10-27 times the cost of maintaining the current reserves, potentially further motivating expansion of the reserves and other investments in natural capital in China
(-)-Gochnatiolide B, synthesized from dehydrocostuslactone, exhibits potent anti-bladder cancer activity in vitro and in vivo
No full textWith limited success achieved in bladder cancer patient management, novel agents are in urgent need for the purpose of therapy and prevention. As a sesquiterpenoid dimmer isolated from Gochnatia pomculat, (-)-gochnatiolide B has been bio-mimetically synthesized in multiple steps with a poor yield, which heavily limited the further research and clinical application. Herein, (-)-gochnatiolide B was synthesized beginning with dehydrocostuslactone in four steps with a total yield of 26%. MTT assays showed that (-)-gochnatiolide B inhibited the growth of vast majority of human cancer cells especially bladder cancer cells. Mechanistically, (-)-gochnatiolide B induced the increased expression of pro-apoptotic proteins and the decreased expression of anti-apoptosis proteins and further resulted in apoptosis of T24 cells. (-)-Gochnatiolide B induced G1 arrest which associated with SKP2 downregulation, leading to p27/Kip1 accumulation and downregulation of cyclin D1 in T24 cells. Furthermore, in vivo studies showed that (-)-gochnatiolide B remarkably inhibited tumor growth by 81% compared with vehicle control. Taken together, (-)-gochnatiolide B exhibits inhibitory activity against bladder cancer cells both in vitro and in vivo by inducing apoptosis, which suggests that (-)-gochnatiolide B could be an important candidate compound for prevention and treatment of bladder cancer
Determination of organic acids for quality evaluation in Coptis herbs by ion chromatography
No full textCoptis herbs are important herbal medicinal materials. The bioactive composition, the quality and medicinal efficacy of these herbs, are determined significantly by their geo-authentic features. Among the effective components of these herbs are seven organic acids (quinic, acetic, formic, tartaric, malic, succinic, and oxalic acids). However, no quantitative data of these seven acids in these herbs are available. Therefore, we developed a method for simultaneous separation and determination of the seven organic acids in Coptis herbs using gradient ion chromatography (mobile phase and gradient were shown in Table 1). The seven acids were separated and determined in no more than 35 min. We found that the organic acid levels in C. teeta was obviously higher than in C. chinensis and C. deltoidea, in particular, the content of quinic acid in C. teeta was about eight times than that in C. chinensis and C. deltoidea. Furthermore, we analyzed the relationships between the contents of organic acids and clinical effects, and found that organic acids (content of total acids or content of quinic acid) could act as an reference ingredient for quality evaluation in Coptis herbs. Our studies would lay the foundation for effective quality evaluation of these herbs
New synonyms, lectotypifications and taxonomical notes on the genus Flemingia (Phaseoleae, Papilionoideae, Leguminosae) from Thai-Indochinese floristic region
No full textWe here proposed Flemingia cavaleriei, F. wangkae, and F. sarmentosa, are new synonyms of F. fluminalis, F. kerrii, and F. paniculata, respectively, based on taxonomic literature, type specimens, protologue and recent observation. Additionally, the lectotype of F. cavaleriei and F. sootepensis are designated, and the taxonomical notes and nomenclature of F. fluminalis are also discussed
Regional to Global Biogenic Isoprene Emission Responses to Changes in Vegetation From 2000 to 2015
No full textIsoprene, a dominant biogenic volatile organic compound that is mainly emitted by trees, has a significant impact on the atmospheric chemistry. Regional to global changes in biogenic isoprene emission associated with vegetation variations between 2000 and 2015 were estimated using the MEGAN model with satellite land cover data for inputs in this study. The satellite data estimates of land cover changes were compared to results from previous investigators that have either conducted regional studies or have used lower resolution land cover data. The analysis indicates that tree coverage increases of >5% occurred in 13% of locations including in central China and Europe. In contrast, a decrease of >5% was observed in about 5% of locations, especially in tropical regions. The trends in global tree coverage from 2000 to 2015 resulted in a global isoprene emission decrease of only 1.5%, but there were significant regional variations. Obvious decreases in tree coverage in some tropical areas (e.g., Amazon Basin, Western Africa, Southeast Asia) resulted in a similar to 10% reduction of regional isoprene emission due to agricultural expansion. Distinct increments of isoprene emission (5-10%) were mainly found in Northeast China and India and were associated with afforestation efforts. Deforestation and afforestation associated with managed plantations does not only affect the total forest coverage but also impacts average isoprene emission capacity, which can result in accelerated isoprene emission variations. Consequently, isoprene variation assessments are needed that not only account for changes in vegetation fractions but also consider the changes in plant species compositions of forests and other landscapes
Phylogenetic surveys on the newt genus Tylototriton sensu lato (Salamandridae, Caudata) reveal cryptic diversity and novel diversification promoted by historical climatic shifts
No full textGlobal climatic transitions and Tibetan Plateau uplifts are hypothesized to have profoundly impacted biodiversity in southeastern Asia. To further test the hypotheses related to the impacts of these incidents, we investigated the diversification patterns of the newt genus Tylototriton sensu lato, distributed across the mountain ranges of southeastern Asia. Gene-tree and species-tree analyses of two mitochondrial genes and two nuclear genes revealed five major Glades in the genus, and suggested several cryptic species. Dating estimates suggested that the genus originated in the early-to-middle Miocene. Under different species delimitating scenarios, diversification analyses with birth-death likelihood tests indicated that the genus held a higher diversification rate in the late Miocene-to-Pliocene era than that in the Pleistocene. Ancestral area reconstructions indicated that the genus originated from the northern Indochina Penin-sula. Accordingly, we hypothesized that the Miocene Climatic Transition triggered the diversification of the genus, and the reinforcement of East Asian monsoons associated with the stepwise uplifts of the Tibetan Plateau promoted the radiation of the genus in southeastern Asia during the Miocene-to-Pliocene period. Quaternary glacial cycles likely had limited effects on speciation events in the genus, but mainly had contributions on their intraspecific differentiations
Crystal structure of IspF from Bacillus subtilis and absence of protein complex assembly amongst IspD/IspE/IspF enzymes in the MEP pathway
No full text2-C-Methyl-D-erythritol 2,4-cyclodiphosphate synthase (IspF) is a key enzyme in the 2-C-Methyl-D-erythritol-4-phosphate (MEP) pathway of isoprenoid biosynthesis. This enzyme catalyzes the 4-diphosphocytidyl-2-C-methyl-D-erythritol 2-phosphate (CDPME2P) to 2-C-methyl-D-erythritol 2,4-cyclodiphosphate (MEcDP) with concomitant release of cytidine 5'-diphospate (CMP). Bacillus subtilis is a potential host cell for the production of isoprenoids, but few studies are performed on the key enzymes of MEP pathway in B. subtilis. In this work, the high-resolution crystal structures of IspF in native and complex with CMP from B. subtilis have been determined. Structural comparisons indicate that there is a looser packing of the subunits of IspF in B. subtilis, whereas the solvent accessible surface of its active pockets is smaller than that in Escherichia coli. Meanwhile, the protein-protein associations of 2-C-Methyl-D-erythritol-4-phosphatecytidyltransferase (IspD), CDPME kinase (IspE) and IspF from B. subtilis and E. coli, which catalyze three consecutive steps in the MEP pathway, are analyzed by native gel shift and size exclusion chromatography methods. The data here show that protein complex assembly is not detectable. These results will be useful for isoprenoid biosynthesis by metabolic engineering
A splicing mutation in aryl hydrocarbon receptor associated with retinitis pigmentosa
No full textRetinitis pigmentosa (RP) refers to a group of retinal degenerative diseases, which often lead to vision loss. Although 70 genes have been identified in RP patients, the genetic cause of approximately 30% of RP cases remains unknown. We aimed to identify the cause of the disease in a cohort of RP families by whole exome sequencing. A rare homozygous splicing variant, c.1160+1G> A, which introduced skipping of exon 9 of the aryl hydrocarbon receptor (AHR), was identified in family RD-134. This variant is very rare in several exome databases and leads to skipping of exon 9 in the transcript. AHR is expressed in the human retina and is a ligand-activated transcription factor with multiple functions. Mutant AHR failed to promote 2, 3, 7, 8-tetra-chlorodibenzo-p-dioxin (TCDD)-induced xenobiotic responsive element (XRE) luciferase activity. In parallel, mutation in AHR abolished activation of its downstream target gene, such as CYP1A1 and CYP1A2. To investigate the in vivo roles of Ahr in the retina, we generated a retina-specific conditional knockout mouse model of Ahr. Comparing with wild-type mouse, Ahr knockout mice exhibited reduced electroretinogram responses at 9 months of age. Retinal histology revealed retinal histology showed the degeneration of photoreceptors with a thinner outer nuclear layer. Thus, our data demonstrate that AHR is associated with RP
Improvement of n-caproic acid production with Ruminococcaceae bacterium CPB6: selection of electron acceptors and carbon sources and optimization of the culture medium
No full textBackground: Global energy and resource shortages make it necessary to quest for renewable resources. n-Caproic acid (CA) production based on carboxylate platform by anaerobic fermentation is booming. Recently, a novel Ruminococcaceae bacterium CPB6 is shown to be a potential biotransformation factory for CA production from lactate-containing wastewater. However, little is known about the effects of different electron acceptors (EAs) on the fermentative products of strain CPB6, as well as the optimum medium for CA production. Results: In this study, batch experiments were performed to investigate the fermentative products of strain CPB6 in a lactate medium supplemented with different EAs and sugars. Supplementation of acetate, butyrate and sucrose dramatically increased cell growth and CA production. The addition of propionate or pentanoate resulted in the production of C5 or C7 carboxylic acid, respectively. Further, a Box-Behnken experiment was conducted to optimize the culture medium for CA production. The result indicated that a medium containing 13.30 g/L sucrose, 22.35 g/L lactate and 16.48 g/L butyrate supported high-titer CA production (16.73 g/L) with a maximum productivity of 6.50 g/L/day. Conclusions: This study demonstrated that strain CPB6 could produce C6-C7 carboxylic acids from lactate (as electron donor) with C2-C5 short-chain carboxylic acids (as EAs), but CA (C6 carboxylic acid) was the most major and potential product. Butyrate and sucrose were the most significant EA and carbon source respectively for CA production from lactate by strain CPB6. High titer of CA can be produced from a synthetic substrate containing sucrose, lactate and butyrate. The work provided significant implications for improving CA production in industry-scale
Hymenasplenium pubirhizoma comb. nov (Aspleniaceae) from China
No full textAn earlier known species originally assigned to Asplenium from China, A. pubirhizoma Ching & Z.Y.Liu, is transferred to Hymenasplenium to form H. pubirhizoma (Ching & Z.Y. Liu) K.W. Xu & Li Bing Zhang, comb. nov