Studies on the Secondary Metabolites from the Indian Gorgonian Subergorgia suberosa:  Isolation and Characterization of Four Analogues of the Cardiotoxin Subergorgic Acid

Calamenenes – aromatic bicyclic sesquiterpenes – from the Indian gorgonianSubergorgia reticulata(Ellis and Solander, 1786)

“…Previously, we have reported triquinane sesquiterpene subergorgic acid and analogues from a related species, Subergorgia suberosa (Parameswaran et al, 1998). Another species, S. hicksoni, is reported to be a rich source for dioxygenated calamenene derivatives (Kashman, 1979).…”

Natural sesquiterpenoids

“…170 A chemical study of a methanolic extract of the Indian ocean gorgonian coral Subergorgia suberosa led to the isolation of the four novel sesquiterpenes 115-118. 171 12 Humulane, pentalenane, tremulane, hirsutane, cucumane, ceratopicane, lactarane, isolactarane, precapnellane, capnellane, protoilludane, illudane, africanane and asteriscane 1(10)-Epoxyhumula-4,7-diene, 1(10),4-diepoxyhumul-7-ene and other known sesquiterpenes have been isolated from the wood bark of Guarea guidonia. 172 The stereochemical structures of natural sesquiterpenes of the humulene type have been reviewed.…”

Synthesis of a Highly Functionalized Triquinane: Studies Towards a Total Synthesis of Subergorgic Acid and Its Analogues

“…Subergorgic acid is an angular sesquiterpene triquinane with a silphiperfolane skeleton (1) [5,6]. It has been shown that subergorgic acid (2) exhibits cardiotoxic activity [5], anticholinesterase activity [7], and activity against "Soman" toxicity in mice [8].…”

“…Therefore, triquinane (9), along with its precursors, allows for the functionalization of any carbon atom on an angular triquinane skeleton. Thus (9) represents an important intermediate in synthesis of naturally occurring triquinanes such as subergorgic acid (2) and its analogues (3)(4)(5)(6) [5,6]. …”