Secondary Metabolites And Their Bioactivities Of Three Rhizospheric Fungi From Panax Notoginseng

Rhizospheric fungi of medicinal plants is a resource of bioactive natural products,three fungal isolates were selected from more than 400 strains on the basis of antimicrobial activity and the diversity of metabolites analysis,they were designated as Chaetomium globosum,Penicillium sp.,Phoma sp.according to the morphological and molecular characteristics.Fifteen compounds including one new compound(8)were isolated from the culture of strain Chaetomium globosum YN-1,they were identified as chaetoglobosin A(1),chaetoviridine A(2),epi-chaetoviridine A(3),chaetoviridine E(4),chaetoviridine B(5),chaephilone D(6),chaetoglobosin G(7),(6a S)-5-chloro-6a-methyl-9-((E)-4-methylhex-2-enoyl)-3-(E)-3-methylpent-1-1-en-1-yl-6H-furo[2,3-h]isochromene-6,8(6a H)-dione(8*),prochaetoglobosin I(9),cazaldehyde A(10),cazisochromene(11),prochaetoviridine A(12),4'-epichaetoviridine(13),chaetoglobosin C(14)and chaetomugiln J(15).Fourteen known compounds were obtained from the culture of strain Penicillium sp.W26,they were identified as penialidin C(16),myxotrichin C(17),isochaetochromin B1(18),(-)-2,3-dihydrocitromycin(19),4-methylene-5-oxo-2-pentyltetrahy drofuran-3-carboxylicacidmethylester(20),3-furancarboxylic acid(21),methylenolac tocin(22),striatisporolide A(23),1-5-dimethylcitrate(24),1-2-3-propan etricarboxylicacid(25),penialidin E(26),citromycin(27),brefeldin A(28)and myxotrichin B(29).Eigeht known compounds were obtained from the culture of strain Phoma sp.3121-1,they were identified as deoxyradicinin(30),epoxydon-6-methylsalicylate ester(31),parasitenone(32),3-chloro-2,5-dihydroxy benzylalcohol(33),m-hydroxybenzylalcohol(34),uracil(35),2-methoxyhydroq unone(36)and 3,5-dihydroxybenzoic acid(37).The isolated compounds were evaluated for their biological activities based on their bacteriostasis and cytotoxicity,compound myxotrichin C(17)showed moderate antibacterial activity against S.typhimurium with MIC of 32?g/m L,compound penialidin E(26)showed moderate antibacterial activity against L.monocytogenes,P.aeruginosa and S.typhimurium with MICs of 64?g/m L,and compound parasitenone(32)showed excellent antibacterial activity against S.aureus,B.subtilis,P.aeruginosa and C.albicans with MICs of 32?g/m L.Compounds chaetoglobosin A(1),brefeldin A(28)and 3,5-dihydroxybenzoic acid(37)presented moderate cytotoxic activity against MHCC97H-EGFP with IC₅₀of 2.2?g/m L,3.2?g/m L and 4.4?g/m L,they also presented moderate cytotoxic activity against H1299-EGFP with IC₅₀of 1.5?g/m L,3.1?g/m L,3.1?g/m L.