Formamidobisabolene-based derivatives from a sponge Axinyssa sp.

Marine Isonitriles and Their Related Compounds

“…In 2014, Cheng et al reported the isolation of ten oxygenated formamidobisabolanes ( Bi26 – Bi35 ) from a Chinese sponge ( Axinyssa sp.) [ 92 ]. Axinyssine C ( Bi26) has two hydroxy groups at C-10 and C-11 and a double bond in 8-position.…”

“…Examination of an Axinyssa sp. collected in the Andaman Sea (inner coral reef, Thailand) in 2014 by Cheng et al revealed the bisabolene-based formamides axinyssine A ( Mis29 ), axinyssine B ( Mis30 ) and 1-acetyl-4-formamido-4-methylcyclohexane ( Mis31 , Figure 34 ) [ 92 ]. The corresponding isonitrile of Mis32 1-acetyl-4-isocyano-4-methylcyclohexane had already been discovered in the nudibranch Phyllidia sp.…”

Syntheses and biological studies of marine terpenoids derived from inorganic cyanide

“…These efforts include the isolation of epoxides, 14 and 15 , as well as a large number oxidatively modified structures in a single isolation study from Axinyssa sponges, termed the axinyssines A-L, 16 to 27 . xiii,xiv Relative and absolute assignments were obtained through mix of derivatization, NMR, MS, and CD experiments. In several instances the stereochemical assignment at C7, the position adjacent to the cyclohexane ring, remains to be defined.…”

New Highly Oxidized Formamidobisabolene‐Derived Sesquiterpenes from a Hainan Sponge Axinyssa variabilis

“…). The known compounds were readily identified as axinyssine G ( 3 ) , axinyssine J ( 4 ) , axinyssine K ( 5 ) , axinyssine E ( 6 ) , theonellin formamide ( 7 ) , theonellin isothiocyanate ( 8 ) , and 7 α ,8 α ‐epoxy theonellin isothiocyanate ( 9 ) , respectively, by comparison of their spectroscopic data with those reported. The observed doubling of many of the NMR signals in the 1 H‐ and 13 C‐NMR spectra of 6 is due to the occurrence of inseparable exo and endo isomers of the formamide group, which could be readily recognized by the coupling constant of the aldehydic H‐atom with a doublet for exo ( J ≈ 12 Hz) form and a broad singlet for endo form.…”

“…The relative configuration at C(3) and C(6) of 1 was proposed to be the same as those of 4 , because the 13 C‐NMR chemical shifts of the sp 3 C‐atoms in the two compounds are almost the same ( δ (C) 52.6/53.4, 47.0/47.3 for 1 vs. δ (C) 52.6/53.9, 47.1/47.4 for 4 ), and their 1 H‐NMR signals of H–C(6) are the same ( δ (H) 1.37 – 1.41 ( m )). The configuration at C(7) and C(10) was not determined due to the scarcity of the product.…”