ABSTRACT
Two rearranged triterpenoids, representing new subtypes of pentacyclic triterpenoids, with unique 6/6/6/7/5 and 6/6/5/6/6/6 ring systems were isolated from Alstonia scholaris. Their structures were established by spectroscopic analysis, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Both compounds exhibited potent antihyperuricemic bioactivity in vitro and in vivo.
Subject(s)
Alstonia/chemistry , Gout Suppressants/pharmacology , Triterpenes/pharmacology , Crystallography, X-Ray , Gout Suppressants/analysis , Gout Suppressants/chemistry , Plant Leaves/chemistry , Triterpenes/chemistry , Triterpenes/isolation & purificationABSTRACT
Endophytic fungi play important roles for host's stress tolerance including invasion by pathogenic microbes. Small molecules are common weapons in the microbe-microbe interactions. Panax notoginseng is a widely used traditional Chinese medicinal plant and harbors many endophytes, some exert functions against pathogens. Here, we report six new compounds named myrothins A-F (1-6) produced by Myrothecium sp. BS-31, an endophyte isolated from P. notoginseng, and their antifungal activities against pathogenic fungi causing host root-rot disease. Their structures were elucidated with analysis of spectroscopic data including 1D and 2D NMR, HR-ESI-MS. Myrothins B (2) and E (5) showed the weak activity against Fusarium oxysporum and Phoma herbarum, and myrothins F (6) showed weak activity against F. oxysporum.
Subject(s)
Antifungal Agents/pharmacology , Endophytes/chemistry , Hypocreales/chemistry , Panax notoginseng/microbiology , Antifungal Agents/chemistry , Antifungal Agents/isolation & purification , Dose-Response Relationship, Drug , Fusarium/drug effects , Microbial Sensitivity Tests , Molecular Structure , Phoma/drug effects , Stereoisomerism , Structure-Activity RelationshipABSTRACT
A novel Gram-positive bacterium, designated strain YIM PH21725T, was isolated from a sample of rhizospheric soil of Panaxnotoginseng cultivated in Anning, Yunnan. The strain contained meso-diaminopimelic acid in the cell-wall peptidoglycan. The main fatty acids identified were C17â:â0, iso-C15â:â0, iso-C16â:â0 and C16â:â0. The main menaquinone was MK-9 (H4). The polar lipids included phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylinositol, phospholipids and phospholipids of an unidentified structure containing glucosamine. The G+C content of genomic DNA was 69.43 mol%. On the basis of its 16S rRNA gene sequence, strain YIM PH21725T should belong to the genus Amycolatopsis, and was closely related to Amycolatopsis sulphurea DSM 46092T (98.57â%), Amycolatopsis jejuensis JCM13280T (97.27â%), Amycolatopsis jiangsuensis KCTC 19885T (96.88â%) and Amycolatopsis ultiminotia JCM 16989T (96.8â%). The phenotypic, chemotaxonomic, phylogenetic and digital DNA-DNA hybridization results clearly indicated that strain YIM PH21725T represents a novel species of the genus Amycolatopsis, for which the name Amycolatopsispanacis sp. nov. is proposed. The type strain is YIM PH21725T (=CCTCC AA 2017044T=KCTC 49031T=DSM 105902T).
