Metabolites from the Actinobacterium Saccharomonospora piscinae Isolated from a Fishpond Sediment

Chemistry of Natural Compounds -     

Secondary Metabolites from the Actinobacterium Amycolatopsis taiwanensis

Chemistry of Natural Compounds -     

从红树林内源真菌2526#分离到Sterigmatocystin

从海洋资源中寻找药物已越来越受到重视 ,已有的研究表明海洋资源有可能成为治疗人类疑难病症和延年益寿药物的丰富源泉[1] 。本研究组在从海洋微生物筛选新药的过程中 ,已发现多种结构奇特而具有强生理活性的化合物[2～ 4 ] 。Ｓｔｅｒｉｇｍａｔｏｃｙｓｔｉｎ最早分离自陆生真菌Ａｓｐｅｒｇｉｌｌｕｓｖｅｒｓｉｃｏｌｏｒ的代谢产物[5] ,随后人们对其结构、生源合成及药理活性进行了广泛的研究。结果表明 ,ｓｔｅｒｉｇｍａｔｏｃｙｓｔｉｎ是细胞毒性更强的化合物ＡｆｌａｔｏｘｉｎＢ1的生源合成前体。本文报道从采自香港红树Ａｖｉ…     

南海红树林内生真菌ZSUH 36次级代谢物的分离鉴定

红树林;内生真菌;次级代谢产物;抗肿瘤活性     

南海红树林内生真菌cephalosporium sp.代谢产物

红树林内生真菌;代谢产物;cephalosporium sp.     

Chromatographic Purification and Identification of Polar Metabolites of Benazolin-Ethyl from Soybean

Abstract

The metabolism of benazolin-ethyl (4-chloro-2-oxobenzothiazolin-3-ylacetic acid ethyl ester), a post emergence herbicide, has been studied in soybean using (¹⁴C)-phenyl labelled compound. Preliminary studies were performed on excised soybean leaves. Following hydrolysis of the ethyl ester to benazolin acid (4-chloro-2-oxobenzothiazolin-3-ylacetic acid), extensive metabolism to polar conjugates was observed. The polar fraction from a Bligh-Dyer extraction was purified by solvent partitioning, preparative TLC and reverse phase HPLC with ion suppression. The two major metabolites were characterised by fast atom bombardment mass spectrometry with accurate mass determination as an aspartate conjugate and a malonyl-β-glucose ester of benazolin acid. Subsequent experiments were performed by spraying intact plants at growth stage V4. The major polar metabolite isolated one month after treatment was identified as the aspartate conjugate by mass spectrometry and high resolution nuclear magnetic resonance spectroscopy.     

A New Isomer and Other Metabolites Isolated from Alternaria alternata

Chemistry of Natural Compounds - The marine derived fungus Alternaria alternata (Fr.) Keissl. was isolated from branch samples of Beibu Gulf, Qinzhou, Guangxi, China and identified by 16s rDNA....     

Oleanane‐Type Triterpenoids from the Endophytic Fungus Pestalotiopsis clavispora Isolated from the Chinese Mangrove Plant Bruguiera sexangula

Three new triterpenoid derivatives, named (15α)‐15‐hydroxysoyasapogenol B ( 1 ), (7β,15α)‐7,15‐dihydroxysoyasapogenol B ( 2 ), and (7β)‐7,29‐dihydroxysoyasapogenol B ( 3 ), were isolated from cultures of the plant endophytic fungus Pestalotiopsis clavispora. Their structures and relative configurations were elucidated by extensive spectroscopic analysis and X‐ray crystallography.     

Phytotoxic Metabolites Isolated from Aspergillus sp., an Endophytic Fungus of Crassula arborescens

Aspergillus sp., an endophytic fungus isolated from Crassula arborescens, displayed potent inhibitory activity against the seed germination of Arabidopsis thaliana. The bioactivity-guided fractionation of the culture extract of Aspergillus sp. MJ01 led to the isolation of nine compounds, including one previously undescribed furanone, namely aspertamarinoic acid (1), and eight known compounds, (−)-dihydrocanadensolide (2), kojic acid (3), citreoisocoumarin (4), astellolide A (5), astellolide B (6), astellolide G (7), cyclo-N-methylphenylalanyltryptophenyl (8) and (−)-ditryptophenaline (9). In the evaluation of the phytotoxic activities of compounds 1–9, the results suggested that 1 and 5 showed significant inhibitory activity on the seed germination of A. thaliana. This is the first report to disclose the phytotoxic activity of these compounds.     

Biodiversity of Secondary Metabolites Compounds Isolated from Phylum Actinobacteria and Its Therapeutic Applications

The current review aims to summarise the biodiversity and biosynthesis of novel secondary metabolites compounds, of the phylum Actinobacteria and the diverse range of secondary metabolites produced that vary depending on its ecological environments they inhabit. Actinobacteria creates a wide range of bioactive substances that can be of great value to public health and the pharmaceutical industry. The literature analysis process for this review was conducted using the VOSviewer software tool to visualise the bibliometric networks of the most relevant databases from the Scopus database in the period between 2010 and 22 March 2021. Screening and exploring the available literature relating to the extreme environments and ecosystems that Actinobacteria inhabit aims to identify new strains of this major microorganism class, producing unique novel bioactive compounds. The knowledge gained from these studies is intended to encourage scientists in the natural product discovery field to identify and characterise novel strains containing various bioactive gene clusters with potential clinical applications. It is evident that Actinobacteria adapted to survive in extreme environments represent an important source of a wide range of bioactive compounds. Actinobacteria have a large number of secondary metabolite biosynthetic gene clusters. They can synthesise thousands of subordinate metabolites with different biological actions such as anti-bacterial, anti-parasitic, anti-fungal, anti-virus, anti-cancer and growth-promoting compounds. These are highly significant economically due to their potential applications in the food, nutrition and health industries and thus support our communities’ well-being.     

Chemical Diversity and Biological Activity of Secondary Metabolites Isolated from Indonesian Marine Invertebrates

Marine invertebrates have been reported to be an excellent resource of many novel bioactive compounds. Studies reported that Indonesia has remarkable yet underexplored marine natural products, with a high chemical diversity and a broad spectrum of biological activities. This review discusses recent updates on the exploration of marine natural products from Indonesian marine invertebrates (i.e., sponges, tunicates, and soft corals) throughout 2007–2020. This paper summarizes the structural diversity and biological function of the bioactive compounds isolated from Indonesian marine invertebrates as antimicrobial, antifungal, anticancer, and antiviral, while also presenting the opportunity for further investigation of novel compounds derived from Indonesian marine invertebrates.     

红树林植物尖瓣海莲内生真菌Penicillium sp.B21次级代谢产物的分离鉴定

研究了红树林植物尖瓣海莲叶内生真菌Penicillium sp.B21次级代谢产物。 用硅胶柱层析、制备薄层层析和重结晶等方法,从该菌发酵液的乙酸乙酯萃取相中首次分离获得5个单体化合物,运用现代波谱技术、单晶X射线衍射以及文献数据对照,鉴定其结构分别为8-羟基-6甲基-1-甲氧羰基酮(1)、大黄素(2)、ω-羟基大黄素(3)、(3R,4S)-6,8-二羟基-3,4,5-三甲基-3,4-二氢异香豆素(4)和3,6,8-三羟基-3,5,7-三甲基-3,4-二氢异香豆素(5)。 首次获得了sclerotinin B单晶结构。     

Reduction of Weed Growth under the Influence of Extracts and Metabolites Isolated from Miconia spp.

Weeds pose a problem, infesting areas and imposing competition and harvesting difficulties in agricultural systems. Studies that provide the use of alternative methods for weed control, in order to minimize negative impacts on the environment, have intensified. Native flora represents a source of unexplored metabolites with multiple applications, such as bioherbicides. Therefore, we aimed to carry out a preliminary phytochemical analysis of crude extracts and fractions of Miconia auricoma and M. ligustroides and to evaluate these and the isolated metabolites phytotoxicity on the growth of the target species. The growth bioassays were conducted with Petri dishes with lettuce, morning glory, and sourgrass seeds incubated in germination chambers. Phytochemical analysis revealed the presence of flavonoids, isolated myricetin, and a mixture of quercetin and myricetin. The results showed that seedling growth was affected in a dose-dependent manner, with the root most affected and the seedlings of the lettuce, morning glory, and sourgrass as the most sensitive species, respectively. Chloroform fractions and myricetin were the most inhibitory bioassays evaluated. The seedlings showed structural changes, such as yellowing, nonexpanded cotyledons, and less branched roots. These results indicate the phytotoxic potential of Miconia allelochemicals, since there was the appearance of abnormal seedlings and growth reduction.     

两种南海海洋真菌2508代谢产物的DNA活性研究

研究了从南海海洋真菌2508号分离得到的一种新的海洋代谢产物Xylopyridine A (1)和一个已知代谢产物xylopyrazine A (2).他们的结构由光谱数据确定。同时通过荧光淬灭实验和光谱滴定实验研究了两种化合物与DNA的结合。结果表面1显示出很强的DNA结合作用并且是通过扦插结合的,可开发用于强DNA结合剂方面的用途。     

南海红树林内源真菌#2240的3个蒽醌类次级代谢产物的鉴别和药理活性

红树林内源真菌;蒽醌;次级代谢产物;DNA拓扑异构酶;抑制活性