Soldier defense secretions of the genus Hospitalitermes (Isoptera, Termitidae, Nasutitermitinae) were chemically analyzed by GC-MS and were found to contain volatile monoterpenes and polyoxygenated diterpenes. Interspecific and intraspecific chemical variations for H. umbrinus, H. hospitalis, H. flaviventris, and H. bicolor are described. Interspecific variations in monoterpene and diterpene structures and compositions were evident. A remarkable example of large intraspecific variation from a single species was observed inH. umbrinus, indicating that colonies of this species can be separable into two chemically distinct groups. The diterpenes found in one of these groups have unusually high molecular weights.
The defense secretions of five species of MalaysianNasutitermes,N. longinasus, N. matangensis, N, havilandi, N. johoricus, andNasutitermes species 01, are compared.N. longinasus andN. species 01 provide trinervitene alcohols,N. havilandi mainly tricyclic trinervitene and tetracyclic kempane alcohols and acetates, whereasN. matangensis furnish acetyl/propionyl derivatives of trinervita-11(12),15(17)-dien-3α,9β,13α-triol (XXI and XXII). A new diterpene, assigned as trinervita-11(12),15(17)-dien-3α,13α-diol-3,13-O-diacetate (XVII), is isolated fromN. havilandi. The mono- and diterpenoid compositions, being species-specific, are useful for chemotaxonomic and phylogenetic studies.
The defense secretions of the soldiers of the Malaysian rhinotermitid,Parrhinotermes aequalis (Havilandi) andP. pygmaeus (John),Termitogeton planus (Havilandi) andSchedorhinotermes malaccensis (Holmgren) consist mainly of vinyl ketones, whereas that ofProrhinotermes flavus (Bugnion & Popoff) gives (E)-1-nitropentadecene. The chemistry of the defense secretions ofParrhinotermes andTermitogeton is documented and based on their chemical relationships;Termitogeton shows a closer affinity to the Rhinotermitinae than Heterotermitinae.
Soldiers of free-ranging termites of the genusLacessititermes (Isoptera, Nasutitermitinae) secrete from their frontal glands a mixture of monoterpenes, sesquiterpenes, and diterpenes.Lacessititermes ransoneti, L. laborator, andL. species A produce species-specific secretions, the composition being most complex forL. laborator. Apart from known mono- and dihydroxytrinervitadienes, the following new diterpenes were isolated and tentatively assigned as trinervita-1(15),8(19)-dien-2β,3α,9α,14α-tetraol 2,3,14-O-triacetate, trinervita-1(15),8(19)-dien-2β,3α,9β,14α-tetraol 2,3,14-O-triacetate, 2β,3α,9α, 14α-tetraacetoxy-1 (15), 8(19)-trinervitadiene, and 2β,3α,11α,13α-tetraacetoxy-1(15),8(19)-trinervitadiene. Data on intragenus chemical variations were subjected to canonical discriminant analysis and genetic distances among the species were calculated to depict intragenus identities and affinities.
The chemical defense secretions of major and minor soldiers of over 18 colonies of the primitive glue-squirting nasute termiteLongipeditermes longipes (Isoptera, Termitidae, Nasutitermitinae) were analyzed chormatographically. The colonies, collected from four rainforest sites in peninsular Malaysia, showed monoterpene patterns rich in pinenes and limonene but with few quantitative differences between colonies. In marked contrast, the diterpene chemistry is high variable, and includes tricyclic (trinervitane), tetracyclic (rippertane), bicyclic (secotrinervitane), and a new spirotetracyclic (longipane) skeleton. Three new natural products are included in this remarkable and unprecedented example of structural diversity among different colonies of a single species.
Trinervita-1(15),8(19)-dien-2β,3α-diol and the new trinervita-1(15),8(19)-dien-2β, 3α-diol 2-O-acetate constitute the major diterpene constituents of the soldier defense secretions of the NasutitermiteHospitalitermes umbrinus of Malaysian region. Studies on the intraspecific variations on sympatric and allopatric populations indicate two distinct patterns of chemical composition.