Hotrienol (3,7-dimethyl-1,5,7-octatrien-3-01, 11) is the principal aroma component detected by headspace analysis in leatherwood (Eucryphia lucida) honey. It arises from the dehydration of 2,6-dimethyl-3,7-octadiene-2,6-diol (I), the principal terpene in methylated and unmethylated ether extracts of leatherwood honey. The diol I was detected in leatherwood plant extracts. Methylated ether extracts of the honey also contained methyl 2-hydroxy-2-(4-methoxyphenyl)acetate (1111, which has not been previously reported in honey, in addition to many other aromatic substances.Compound I11 was a major component of the acidic fraction of the plant extract. A methylated extract of unripe leatherwood honey collected after 1 week in the hive was found to contain methyl 2-hydroxy-3-phenylpropionate (N) and an unidentified compound [m / z 91 (loo), 1801 as the principal components. The unidentified compound found in immature honey was not detected in the plant extracts.

Chemical fingerprinting of Australian honey requires information on the composition of natural honey volatiles if it is to be useful as a honey-sourcing method. The naturally occurring volatiles of Australian blue gum (Eucalyptus leucoxylon) and yellow box (Eucalyptus melliodora) honeys were isolated by solvent (ethyl acetate) extraction. Compounds in the extracts were analyzed by gas chromatography (GC) and gas chromatography−mass spectrometry (GC−MS). These procedures have permitted the identification of 55 compounds that include norisoprenoids, monoterpenes, benzene derivatives, aliphatic compounds, and Maillard reaction products. The following 13 compounds were quantitatively identified for the first time in honey:  four isomeric 3,4-dihydro-3-oxoactinidols; 8,9-dehydrotheaspirone; two isomeric 3-oxoretro-α-ionols; megastigm-4-ene-3,9-dione; 1-phenylbutane-2,3-diol; 1-phenylbutane-2,3-dione; 18-hydroxyoleic acid lactone; 3,5-dihydroxy-2-methyl-4H-pyran-4-one; and 2,5-dimethyl-2,4-dihydroxy-3(2H)-furanone. The nature of the volatiles and semivolatiles in these two Australian honeys suggests that Australian honeys are quite distinctive relative to the other honeys that have been chemically studied by GC−MS. Keywords: Australian blue gum (Eucalyptus leucoxylon) honey; yellow box (Eucalyptus melliodora); natural volatiles; norisoprenoids; extractives; monoterpenes; composition

A detailed examination of the metabolites produced in liquid cultures by a strain of Trichoderma harzianum, isolated from wheat roots, has resulted in the identification of a further five metabolites. Two of these, cyclonerodiol [5] and the octaketide keto diol 6, have previously been isolated from a strain of Trichoderma koningii. The structures of the three new octaketide-derived compounds 7, 8, and 10 have been deduced from spectroscopic and chemical studies. All newly isolated compounds show antibiotic activity towards the take-all fungus, Gaeumannomyces graminis var. tritici.

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