Ophiobolin M and analogues, noncompetitive inhibitors of ivermectin binding with nematocidal activity

Cytotoxic sesterterpenes, 6-epi-ophiobolin G and 6-epi-ophiobolin N, from marine derived fungus Emericella variecolor GF10

“…0.2-0.3 ppm in comparison with the A/B-cis isomer having H-6b. 12 These phenomena were also observed in this study (Tables 1 and 2); thus, the C-1 carbon and the H-2 proton of compound 1 and ophiobolin G (2) were observed at d C 46.1 and d C 35.7; d H 2.65 (m) and d H 3.11 (brs), respectively. The orientation of H-6 in ophiobolin G (2) has been previously reported to be a.…”

Nematicidal Substances from Fungi

“…Ophiobolin K and ophiobolin M had similar nematicinal activities with LD 50 values of 26 M and 13 M respectively. The epimers 6-epiophiobolin C and M were less potent with LD 50 values around 130 M. These compounds are non-competitive inhibitors of ivermectin binding to membranes prepared from C. elegans [69].…”

“…These two were obtained from Aspergillus ustus [68]. In addition to these two compounds, ophiobolin M (82), 6-epiophiobolin M (83), ophiobolin C (84) and 6-epiophiobolin C (85) have also been isolated from the ascomycete Cochliobolus heterostrophus [69]. Ophiobolin C was first obtained from Helminthosporium species [70] and it was the most active compound among these six with an LD 50 value of 5 M against C. elegans.…”

Isolation, structure, and HIV-1-integrase inhibitory activity of structurally diverse fungal metabolites

“…To evaluate the SAR (structure activity relationship), several previously reported [45,62] ophiobolins were evaluated by these assays. These included ophiobolins A (16), B (17), C (18), H (19), and K (20), which exhibited IC 50 values of 48, 21.5, 6.7, 30, and 23 lM, respectively, against the coupled assay and >125, 125, 33, >120, and >120 lM, respectively, against the strand-transfer assay.…”