Collection of Czechoslovak Chemical Communications - digital archive 

Abstract

The defense secretion of Nasutitermes ephratae soldiers was analyzed and its constituents were identified. The volatile fraction contains monoterpenic hydrocarbons α-pinene, camphene, sabinene, β-pinene, myrcene, 4-carene, 3-carene, α-terpinene, limonene, γ-terpinene, β-phellandrene, and terpinolene. From the non-volatile fraction four alcohols derived from trinervitane skeleton were isolated: 1(15),8(19)-trinervitadien-3α-ol (I), 1(15),8(19)-trinervitadien-2β,3α-diol (II) and its 2α,3α- (III) and 2α,3β- (IV) isomers. 3α-Hydroxy-1(15),8(19)-trinervitadien-2-one (V), which was also isolated, is probably an artefact formed during the work-up of the extract. The structure of 3β-hydroxy-1(15),8(19)-trinervitadien-2-one (VI) was determined on the basis of mass, IR and ¹H NMR spectra, comparison with model compounds and analogy with the literature. The absolute configuration of the trinervitane skeleton was studied by CD spectra of tris(2,2,6,6-tetramethyl-3,5-heptanedionato)praseodymium complexes of the 2,3-diols II-IV and by the ¹H NMR spectra of esters of the alcohol I with (R)- and (S)-α-methoxy-α-(trifluoromethyl)phenylacetic acid. The results obtained by both methods are identical and confirm the earlier suggested absolute configuration of the trinervitane skeleton.