title: Nodulisporisteriods A and B, the first 3,4-seco-4-methyl-progesteroids from Nodulisporium sp.
abstract: Two new 4-methyl-progesteroids, nodulisporisteriod A (1) and nodulisporisteriod B (2), were isolated from the extract of an endolichenic fungal strain Nodulisporium sp. (No. 65-17-2-1), along with two related metabolites, demethoxyviridin (3) and inoterpene B (4). Their structures were determined by detailed spectroscopic analyses, X-ray crystallographic analysis and comparison of the NMR data with those of the closely related compounds previously reported. Nodulisporisteriod A (1) and nodulisporisteriod B (2) possess new carbon skeletons, which are the first cases of fission at C-3,4 in 4-methyl-progesteroids. A hypothetical biosynthetic pathway for 1 and 2 was proposed. Moreover, the Aβ42 aggregation inhibitory activities of 1-4 were evaluated using standard thioflavin T (ThT) fluorescence assay with epigallocatechin gallate (EGCG) as positive control. Demethoxyviridin (3) displayed anti-Aβ42 aggregation activity with IC50 value of 13.4μM.
authors.affiliation: Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, Guangzhou 510632, People's Republic of China.
authors.forename: Qi-Chang
authors.initials: QC
authors.lastname: Zheng
authors.forename: Guo-Dong
authors.initials: GD
authors.lastname: Chen
authors.forename: Ming-Zhu
authors.initials: MZ
authors.lastname: Kong
authors.forename: Guo-Qiang
authors.initials: GQ
authors.lastname: Li
authors.forename: Jia-Yu
authors.initials: JY
authors.lastname: Cui
authors.forename: Xiao-Xia
authors.initials: XX
authors.lastname: Li
authors.forename: Zu-Yan
authors.initials: ZY
authors.lastname: Wu
authors.forename: Liang-Dong
authors.initials: LD
authors.lastname: Guo
authors.forename: Ying-Zhou
authors.initials: YZ
authors.lastname: Cen
authors.forename: Yi-Zhi
authors.initials: YZ
authors.lastname: Zheng
authors.forename: Hao
authors.initials: H
authors.lastname: Gao
mesh_terms: D000544:Alzheimer Disease / Q000188:drug therapy; D016229:Amyloid beta-Peptides / Q000737:chemistry; D000736:Androstenes / Q000737:chemistry / Q000302:isolation & purification; D002392:Catechin / Q000031:analogs & derivatives / Q000737:chemistry; D018360:Crystallography, X-Ray; D004353:Drug Evaluation, Preclinical; D006801:Humans; D007783:Lactones / Q000737:chemistry* / Q000302:isolation & purification; D008958:Models, Molecular; D008968:Molecular Conformation; D010446:Peptide Fragments / Q000737:chemistry; D011422:Propionates / Q000737:chemistry* / Q000302:isolation & purification; D055503:Protein Multimerization; D012632:Secosteroids / Q000737:chemistry* / Q000302:isolation & purification; D013098:Xylariales / Q000737:chemistry*
chemical_list: D016229:Amyloid beta-Peptides; D000736:Androstenes; D007783:Lactones; D010446:Peptide Fragments; D011422:Propionates; D012632:Secosteroids; C075222:amyloid beta-protein (1-42); C070594:demethoxyviridin; D002392:Catechin; C045651:epigallocatechin gallate
keywords: 3,4-Seco-4-methyl-progesteroid; 4-Methyl-progesteroid; Anti-Aβ42 aggregation activity; Endolichenic fungus; Nodulisporium sp.; Xylariaceae