New Glycosides of the Fungus Acremonium striatisporum Isolated from a Sea Cucumber

Abstract

Four new diterpene glycosides, virescenosides R (1), S (2), T (3), and U (4), have been isolated from a marine strain of Acremonium striatisporum KMM 4401 associated with the holothurian Eupentacta fraudatrix. Their structures have been elucidated on the basis of HRFABMS, 1D and 2D NMR (1H, 13C, DEPT, COSY-45, COSY-RCT, HSQC, HMBC, and NOESY spectra), and the results of acidic hydrolysis as 19-O-[beta-D-glucopyranosyl(1-->6)-beta-d-altropyranosyl]-isopimara-7,15-diene-2alpha,3beta-diol (1), 19-O-beta-D-altropyranosyl-3-oxo-isopimara-8(14),15-diene-7alpha-ol (2), 19-O-beta-D-altropyranosyl-3,7-dioxo-isopimara-8,15-diene (3), and 19-O-beta-D-altropyranosyl-3,7-dioxo-isopimara-8(14),15-diene (4). The cytotoxic activity of the virescenosides was examined.

Recent researches of bioactive metabolites in marine organisms-associated microorganisms

“…Virescenosides A, B, C, M and N showed cytotoxic effects on developing eggs of sea urchin Strongylocentrotus intermedius with MICs0 range from 2.7 to 20 t, mol L -1 , and their activities decreased in the order of C, M, B, A and N. It was shown that these glycosides exhibited cytotoxic action against tumor cells of Ehrlich carcinoma (ICs0 range from 10 to 100t,molL -1 ) in vitro. Further investigations for metabolites of this fungal strain Acremonium striatisporum KMM 4401 led to the isolation of three new cytotoxic glycosides, virescenosides O, P and Q (43-45 in Fig.3) (Afiyatullov et al, 2002). It was shown that virescenosides O, P and Q exhibited cytotoxic action against tumor cells of Ehrlich carcinoma with ICs0 range from 20 to 100/,mol L -1 in vitro.…”

Culturable Microorganisms Associated with Sea Cucumbers and Microbial Natural Products

“…Terpene glycosides are a group of natural products with a triterpene or sterol core, and marine diterpene glycosides (MDGs) are a subset of terpene glycosides [66]. Thirty-one new diterpene glycosides, including virescenosides M-R (76-81), R 1 -R 3 (82-84), S-X (85-90), Z (91), and Z 4 -Z 18 (92-106), and three known diterpenic glycosides, virescenosides A (107), B (108), and C (109), together with three known analogues, virescenoside F (110), G (111), a lactone of virescenoside G (112), and the aglycon of virescenoside A (113), were isolated from the fungus Acremonium striatisporum KMM 4401, associated with the sea cucumber Eupentacta fraudatrix, which was collected from Kitovoe Rebro Bay in the Sea of Japan [21,46,[67][68][69][70][71]. Compounds 76, 77, 79, and 107-109 showed cytotoxic effects on developing eggs of the sea urchin Strongylocentrotus intermedius (MIC 50 = 2.7-20 µM) [21,67].…”

“…Compounds 76, 77, 79, and 107-109 showed cytotoxic effects on developing eggs of the sea urchin Strongylocentrotus intermedius (MIC 50 = 2.7-20 µM) [21,67]. Compounds 76-81, 85-87, and 107-109 exhibited cytotoxic activities against Ehrlich carcinoma tumor cells (IC 50 = 10-100 µM) in vitro [21,67,68]. Compounds 81 and 85-87 showed weak cytotoxic effects on developing eggs of the sea urchin S. intermedius (IC 50 = 100-150 µM) [68].…”

Glycosylated Natural Products From Marine Microbes

“…Bioassay testing showed that virescenosides M-U (174-182) displayed cytotoxic action against tumor cells Ehrlich carcinoma (IC 50 = 10-100 µM) in vitro. In addition, virescenosides M-N (174-175) and P (177) displayed cytotoxic effects on developing eggs of the sea urchin, Strongylocentrotus intermedius (IC 50 = 2.7-20 µM) (Afiyatullov et al, 2000(Afiyatullov et al, , 2002(Afiyatullov et al, , 2004(Afiyatullov et al, , 2006(Afiyatullov et al, , 2011(Afiyatullov et al, , 2016. Two phenylspirodrimane-type glucosidic meroterpenoids, stachybosides A- B (195-196, Figure 13), were seperated from the sponge-derived fungus, Stachybotrys chartarum MXH-X73 (Ma et al, 2013).…”