title: Isolation and structural elucidation of proline-containing cyclopentapeptides from an endolichenic Xylaria sp.
abstract: Two new cyclic pentapeptides (1 and 2) and the known blazein (3), ganodesterone (4), ergosterin (5), cerevisterol (6), 24-methylcholesta-4,6,8(14),22-tetraen-3-one (7), 5,8-epidioxyergosta-6,22-dien-3-ol (8), 16-α-d-mannopyranosyloxyisopimar-7-en-19-oic acid (9), and 16-hydroxy isopimar-7-en-19-oic acid (10) have been isolated from the crude extract of an endolichenic Xylaria sp. The structures of 1 and 2 were elucidated primarily by NMR and MS methods. The absolute configurations of 1 and 2 were assigned using Marfey's method on their acid hydrolysate. Compounds 1-10 were evaluated for activity against fungi and for synergistic antifungal activity. Compound 1 showed synergistic antifungal activity against Candida albicans SC5314 with 0.004 μg/mL ketoconazole.
authors.affiliation: Key Laboratory of Systematic Mycology & Lichenology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
authors.forename: Wen
authors.initials: W
authors.lastname: Wu
authors.forename: Huanqin
authors.initials: H
authors.lastname: Dai
authors.forename: Li
authors.initials: L
authors.lastname: Bao
authors.forename: Biao
authors.initials: B
authors.lastname: Ren
authors.forename: Jingcai
authors.initials: J
authors.lastname: Lu
authors.forename: Yuanming
authors.initials: Y
authors.lastname: Luo
authors.forename: Liangdong
authors.initials: L
authors.lastname: Guo
authors.forename: Lixin
authors.initials: L
authors.lastname: Zhang
authors.forename: Hongwei
authors.initials: H
authors.lastname: Liu
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D002176:Candida albicans / Q000187:drug effects; D002681:China; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010456:Peptides, Cyclic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D011392:Proline / Q000737:chemistry*; D013098:Xylariales / Q000737:chemistry*
chemical_list: D000935:Antifungal Agents; D010456:Peptides, Cyclic; C560110:cyclo(L-Val-D-Ile-L-Leu-L-Pro-D-Leu); C560041:cyclo(N-methyl-L-Phe-L-Val-D-Ile-L-Leu-L-Pro); D011392:Proline