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Seventeen native fir populations from the presumed zones of natural hybridization in the Balkan Peninsula were analyzed using headspace needle volatiles and GC-MS/FID analyses. The multivariate statistical analyses revealed clear differentiation between populations of Abies alba and A. cephalonica, suggesting that Silver and Greek Fir are characterized by distinct volatile profiles. Three populations from northern and central Greece identified as A. x borisii-regis shared the volatile profiles with both of the supposed parent species, whereby profile frequencies changed clinally along the latitudinal gradient connecting the ranges of parent species. Therefore, observed geographical distribution of volatile entities support the hypothesis that studied A. x borisii-regis populations are of secondary origin, formed by hybridization between A. alba and A. cephalonica. All three populations should be included in conservation projects, as the genetic constitution of these polymorphic fir populations may contain useful genetic variation necessary for survival regarding the future environmental challenges in this area.

A new guaianolide, 3-deacetyl-9-O-acetylsalograviolide A, along with four known closely related lactones, salograviolide A, 9-O-acetylsalograviolide A, kandavanolide and salograviolide B were detected in the aerial parts of the flowering plant Centaurea nicolai. Antifungal tests performed on salograviolide A and its 9-O-acetyl and 3-O-deacetyl-9-O-acetyl derivatives revealed inhibitory activity against Aspergillus niger, A. ochraceus, Penticillium ochrochloron,Cladosporium cladosporodies, Fusharium tricinctum and Phomopsis helianthi. Neither of them was active against Trichoderma viride. (C) 1999 Elsevier Science Ltd. All rights reserved. null

Fatty acid composition of nutlet lipids in 62 species from the Saturejoideae, seven species from the Ajugoideae and four species from the Scutellarioideae have been analysed. Linolenate was the predominant acid in all species from the Saturejoideae but in the Ajugoideae, linoleate and linolenate were the major fatty acids. In the Scutellarioideae, linoleate was the dominant fatty acid. Results showed that the fatty acid composition of nutlet lipids and their linolenate/linoleate ratios may be useful as taxonomic markers for the differentiation of genera belonging to different subfamilies of the Lamiaceae.

Nine species from the genus Stachys L. representing subgenera Stachys and Betonica were surveyed for flavonoid glycosides by means of HPLC coupled to diode-array detection and LC-APCI-MS. Those species belonging to subgenus Betonica were characterised by the presence of glycosides of tricetin methyl ethers, including a new derivative, which was isolated from S. scardica Griseb. and identified as tricetin 3',4',5' -trimethyl ether 7-O-beta-glucopyranoside by spectroscopic methods. This type of flavonoid was absent from species belonging to subgenus Stachys and can be considered as a chemosystematic marker for subgenus Betonica.

A survey of leaf surface constituents in the family Lamiaceae using HPLC with diode array detection revealed the presence of two characteristic phenolic compounds in many species. The distribution of these phenolics in the Lamiaceae was found to be of taxonomic significance, as they were present in the great majority of species investigated for the subfamily Nepetoideae, including representatives of the well-known genera of culinary herbs, mint, rosemary, sage, thyme and basil. In contrast, they were absent from species of the other subfamilies of Lamiaceae studied and from the related families Verbenaceae, Scrophulariaceae, Acanthaceae and Buddlejaceae. The compounds were isolated from Plectranthus crassus and identified by NMR spectroscopy as the known caffeic acid esters (Z,E)-[2-(3,5-dihydroxyphenyl)ethenyl] 3-(3,4-dihydroxyphenyl)-2-propenoate and (Z,E)-[2-(3,4-dihydroxyphenyl)ethenyl] 3-(3,4-dihydroxyphenyl)-2-propenoate, for which the trivial names nepetoidins A and B are proposed. The presence of this pair of caffeic acid esters adds another character to the chemical, palynological and embryological features distinguishing the Nepetoideae from the other subfamilies of Lamiaceae and related families, and supports the view that the Nepetoideae are a specialised and monophyletic group within the family. Nepetoidin B was shown to have a greater antioxidant activity than gallic, rosmarinic and caffeic acids, and showed activity as an insect phagostimulant. Both compounds were antifungal.

Fatty acids were analysed in the seeds of 40 species from 12 genera of the Papaveraceae and 14 species from four genera of the Fumariaceae. Linoleate was predominant in both families; however, its content was 11% greater on average in the Papaveraceae. With Papaver orientale and Corydalis cava intraspecific variability of fatty acid patterns of seed lipids was studied; no large differences between samples were encountered. Triacylglycerols were the dominant lipid class. Members of Papaveraceae show a higher triacylglycerol but lower free fatty acid content than members of Fumariaceae.

Analyses of fatty acids of seed lipids in five species of Mentha from different localities in Serbia are reported.