Nitroalkenes and Sesquiterpene Hydrocarbons from the Frontal Gland of Three Prorhinotermes Termite Species

Abstract

Frontal gland contents of soldiers of three Prorhinotermes species, Prorhinotermes canalifrons, Prorhinotermes inopinatus, and Prorhinotermes simplex, consisted of two groups of compounds: nitroalkenes and sesquiterpene hydrocarbons. Analysis by gas chromatography-mass spectrometry revealed (E)-1-nitropentadec-1-ene as the major component of the glands with mean values of 152, 207, and 293 microg/individual for P. canalifrons, P. inopinatus, and P. simplex, respectively. Four other 1-nitroalkenes (C13, C14, C16, and C17), and two nitrodienes (C15 and C17) were also detected in the three species. The C17:1 nitroalkene was identified as (E)-1-nitroheptadec-1-ene. The sesquiterpene composition of the gland was species-specific: P. simplex contained (3Z,6E)-alpha-farnesene (mean of 39 microg/individual), while P. canalifrons and P. inopinatus contained the same compound (means of 0.5 and 1.5 microg/individual, respectively) as well as the (3E,6E) isomer (means of 1.8 and 0.7 microg/individual, respectively). Two other sesquiterpenes, trans-beta-bergamotene and (Z)-gamma-bisabolene, were also found in low quantities in the frontal gland of P. canalifrons.

Modulation of Nitro-fatty Acid Signaling

“…However, biosynthesis of other nitroalkene-containing molecules has also been described in Gram-negative bacteria, fungi, plants, and insects (27)(28)(29)(30). Several enzymes capable of nitroalkene reduction have been described in these organisms, including pentaerythritol tetranitrate (PETN) reductase from Enterobacter cloacae PB2 and members of the old yellow enzyme family such as Escherichia coli N-ethylmaleimide reductase, Pseudomonas putida M10 morphinone reductase, and OYE1 from Saccharomyces carlsbergensis (31)(32)(33).…”

Chemical Identification and Ethological Function of Soldier-Specific Secretion in Japanese Subterranean TermiteReticulitermes speratus(Rhinotermitidae)

“…5,6) The chemical composition of the secretion from this gland has been studied in various termite species: it is a multi-component mixture which may contain different chemical compounds that include alkanes, alkenes, nitroalkanes, vinyl ketones, ketoaldehydes, monoterpenes, sesquiterpenes, diterpenes, sesterterpenes, and organic acid compounds. [6][7][8][9][10][11][12][13][14][15][16] Past research has shown that some individual elements of these compound groups act as irritants or effective toxicants to predators or competitors, i.e., the monoterpenes -pinene, -pinene, limonene, 3-carene, [17][18][19] (E)-1-nitropentadec-1-ene and geranyl linalool. [20][21][22] In addition to its defensive role, the frontal gland secretion has also been reported for alarm communication in Nasutitermes (Termitidae), Prorhinotermes and Reticulitermes (Rhinotermitidae) termites.…”

Ability of the Oriental Fruit Moth Grapholita molesta (Lepidoptera: Tortricidae) to Detoxify Juglone, the Main Secondary Metabolite of the Non-host Plant Walnut

“…Identification of juglone and 1,4,5-trihydroxynaphthalene was based on chromatographic and mass spectrometric characteristics and confirmed with synthetic standards; 1,4,5-trihydroxynaphthalene was synthesized previously in our laboratory (Piskorski and Dorn, 2011). Linear retention indices (RI) were calculated using nalkanes as standards and argon as an unretained compound (Piskorski et al, 2007). If juglone or related compounds were not detected in a given extract, the extract was concentrated and re-analyzed.…”