Microbial transformation of cycloastragenol and astragenol by endophytic fungi isolated from astragalus species
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Tarih
2019
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
American Chemical Society
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Biotransformation of Astragalus sapogenins (cycloastragenol (1) and astragenol (2)) by Astragalus species originated endophytic fungi resulted in the production of five new metabolites (3, 7, 10, 12, 14) together with 10 known compounds. The structures of the new compounds were established by NMR spectroscopic and HRMS analysis. Oxygenation, oxidation, epoxidation, dehydrogenation, and ring cleavage reactions were observed on the cycloartane (9,19-cyclolanostane) nucleus. The ability of the compounds to increase telomerase activity in neonatal cells was also evaluated. After prescreening studies to define potent telomerase activators, four compounds were selected for subsequent bioassays. These were performed using very low doses ranging from 0.1 to 30 nM compared to the control cells treated with DMSO. The positive control cycloastragenol and 8 were found to be the most active compounds, with 5.2- (2 nM) and 5.1- (0.5 nM) fold activations versus DMSO, respectively. At the lowest dose of 0.1 nM, compounds 4 and 13 provided 3.5- and 3.8-fold activations, respectively, while cycloastragenol showed a limited activation (1.5-fold). © 2019 American Chemical Society and American Society of Pharmacognosy.
Açıklama
Anahtar Kelimeler
Kaynak
Journal of Natural Products
WoS Q Değeri
Scopus Q Değeri
Q1
Cilt
82
Sayı
11
