The derivation and use of biosynthetic incorporation and dilution values

Mathematical expressions governing incorporation and dilution values in a simple, three component biosynthetic system are established and used to track the influence of pathway structure and sampling time on the numerical value of these parameters. A more productive manner of using the incorporation concept is suggested.     

Effects of microbial volatile organic compounds on Ganoderma lucidum growth and ganoderic acids production in Co-v-cultures (volatile co-cultures)

Abstract

Co-v-culture (co-cultivations of physically separated microbes that only interact through the air) systems were designed to investigate the effects of microbial volatile organic compounds (mVOCs) from about 20 different microbes, on a medicinal fungus, Ganoderma lucidum. For more accuracy in co-cultivations, a novel synchronized cultivation approach was tested for culturing G. lucidum. The hyphal growth of G. lucidum and the content of its ganoderic acids (GAs) were measured. In almost all of the co-v-cultures, there was an inhibiting effect on hyphal growth and a promoting effect on GAs contents. In inducing GAs production, Bacillus cereus PTCC 1247 and Pseudomonas aeruginosa UTMC 1404 were the most effective ones, as, compared to control cultures, GAs content increased 2.8 fold. Comparing different co-v-cultivations demonstrated that the concentrations of mVOCs, oxygen, and carbon dioxide were the main players in co-v-cultures. No correlation was found between hyphal growth and GAs production. Strains of the same species imposed totally different effects on hyphal growth or GAs production. This study has investigated the effects of mVOCs on G. lucidum for the first time. Moreover, it suggests that co-v-cultivation may be a promising biotechnological approach to improve the production in G. lucidum.     

Microbial Metabolite Signaling Is Required for Systemic Iron Homeostasis

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Human urine: Epicatechin metabolites and antioxidant activity after cocoa beverage intake

Associations between cocoa consumption in humans, excreted metabolites and total antioxidant capacity (TAC) have been scarcely investigated. The aims of the study were to investigate the epicatechin (( ? )-Ec) metabolites excreted in urine samples after an intake of 40 g of cocoa powder along with the TAC of these urine samples and the relation between both the analyses. Each of the 21 volunteers received two interventions, one with a polyphenol-rich food (PRF) and one with a polyphenol-free food (PFF) in a randomized cross-over study. Urine samples were taken before and during 24 h at 0–6, 6–12 and 12–24 h periods after test intake. The excreted ( ? )-Ec metabolites and the TAC were determined in urine samples by LC-MS/MS and TEAC assay, respectively. The maximum excretion of ( ? )-Ec metabolites and the maximum TAC value were observed in urine samples excreted between 6 and 12 h after PRF consumption. Significance of TAC increase was found in urine samples excreted during 0–6 and 6–12 h (66.6 and 72.67%, respectively, with respect to the 0 h).     

The Aging Metabolome—Biomarkers to Hub Metabolites

Aging biology is intimately associated with dysregulated metabolism, which is one of the hallmarks of aging. Aging‐related pathways such as mTOR and AMPK, which are major targets of anti‐aging interventions including rapamcyin, metformin, and exercise, either directly regulate or intersect with metabolic pathways. In this review, numerous candidate bio‐markers of aging that have emerged using metabolomics are outlined. Metabolomics studies also reveal that not all metabolites are created equally. A set of core “hub” metabolites are emerging as central mediators of aging. The hub metabolites reviewed here are nicotinamide adenine dinucleotide, reduced nicotinamide dinucleotide phosphate, α‐ketoglutarate, and β‐hydroxybutyrate. These “hub” metabolites have signaling and epigenetic roles along with their canonical roles as co‐factors or intermediates of carbon metabolism. Together these hub metabolites suggest a central role of the TCA cycle in signaling and metabolic dysregulation associated with aging.     

三株亚肉座菌乙酸乙酯提取物生物活性及GC-MS分析

采用乙酸乙酯提取3株亚肉座菌菌丝体,测试虫生真菌乙酸乙酯提取物（EAE）的抗肿瘤、抗菌和抗氧化活性,并借助GC-MS方法分析各提取物中的化学成分。结果发现2株亚肉座菌的菌丝体EAE对HepG2细胞的抑制活性较强,IC₅₀均小于9μmol/L;抗菌结果表明2株真菌的提取物具有抑制细菌生长的作用;1株供试菌的EAE表现出较强的DPPH自由基清除活性（清除率可达85%）。GC-MS分析表明从亚肉座菌JXJG201717、JXJG201720和ARSEF7697的EAE中分别鉴定出21、35和39种成分,主要成分为酯类、醇类和酸类;盘状亚肉座菌JXJG201720与ARSEF7697有相同化合物13个,与暹罗亚肉座菌JXJG201717存在7个相同化合物。本研究表明虫生亚肉座菌具有产生丰富活性成分的能力,彰显出多种利用价值。     

荷叶离褶伞子实体化学成分

本文对祁连山野生荷叶离褶伞Lyophyllum decastes子实体的化学成分和生物活性进行研究。采用硅胶色谱、高效液相色谱等多种方法进行分离纯化得到8个化合物,通过MS、NMR和电子圆二色谱 （ECD）等方法确定了化学结构,其中有4个为聚炔类化合物。化合物1作为天然产物系首次报道,其相绝对构型是通过比较ECD的方法确定。对所得聚炔类化合物应用细胞模型进行抗氧化活性（CAA）指标检测,化合物1-4均呈现一定抗氧化活性,其中化合物1的抗氧化活性最强,其EC₅₀为(24.73±6.12)μmol/L。聚炔类化合物1-4为荷叶离褶伞首次报道成分,可作为祁连山野生荷叶离褶伞HPLC-DAD化学表征参考化合物。     

Methyltransferase like 3 promotes colorectal cancer proliferation by stabilizing CCNE1 mRNA in an m6A-dependent manner

m6A modification is the most prevalent RNA modification in eukaryotes. As the critical N6-methyladenosine (m6A) methyltransferase, the roles of methyltransferase like 3 (METTL3) in colorectal cancer (CRC) are controversial. Here, we confirmed that METTL3, a critical m6A methyltransferase, could facilitate CRC progression in vitro and in vivo. Further, we found METTL3 promoted CRC cell proliferation by methylating the m6A site in 3′-untranslated region (UTR) of CCNE1 mRNA to stabilize it. Moreover, we found butyrate, a classical intestinal microbial metabolite, could down-regulate the expression of METTL3 and related cyclin E1 to inhibit CRC development. METTL3 promotes CRC proliferation by stabilizing CCNE1 mRNA in an m6A-dependent manner, representing a promising therapeutic strategy for the treatment of CRC.