Echium rauwolfii, Echium horridum, Boraginaceae, Pyrrolizidine Alkaloids, Capillary GLC Echimidine was isolated from Echium rauwolfii and Echium horridum and identified by MS, *H-and 13C NMR as a major alkaloid. In addition, structures of 12 minor alkaloids were inferred from GLC and GLC-M S analyses: 7-angeloylretronecine, 7-tigloylretronecine, lycopsamine, 7-acetyllycopsamine, uplandicine, 7-angeloyllycopsamine, 7-tigloyllycopsamine, tigloyl isomer of echimidine, 7-angeloyl-9-(2-methylbutyryl)retronecine, 7-tigloyl-9-(2-methylbutyryl)retronecine, 7-angeloyl-9-(2,3-dihydroxybutyryl)retronecine, and 7-tigloyl-9-(2,3-dihydroxybutyryl)retronecine. Both species had similar alkaloid profiles. Alkaloid extracts exhibited antibacterial effects with a MIC of 1.7 mg/ml in E. coli. Microscopic examination of E. coli treated with different subtoxic alkaloid concentrations (1 3 -5 2 ng/ml) revealed extensive filamentation.

The occurrence of thiophenic compounds in diverse plant organs and in in vitro root-, callus-and cell suspension cultures of Tagetes patula cv. Carmen was investigated using capillary GLC and GLC-MS. The separation of thiophenes by capillary GLC and the group specific MS fragmentation with the typical sulfur isotope peaks allowed the unequivocal assignment of individual thiophenes in complex mixtures, even when occurring in traces and in the presence of different geometrical isomers. The extracts of Tagetes patula cv. Carmen contained the following 8 thiophene compounds: 5-(3-buten-1-ynyl)-2,2Ј-bithienyl (BBT), 5Ј-methyl-5-(3-buten-1-ynyl)-2,2Ј-bithienyl (MeBBT), 5-(1-pentynyl)-2,2Ј-bithienyl (PBT), 5-(4-hydroxy-1-butynyl)-2,2Ј-bithienyl (BBTOH), 2,2Ј,5,2Љ-terthienyl (α-T), 5-(4-acetoxy-1-butynyl)-2,2Ј-bithienyl (BBTOAc), 5-methylaceto-5Ј-(3-buten-1-ynyl)-2,2Ј-bithienyl (AcOCH 2 BBT), and 5-(3,4-diacetoxy-1-butynyl)-2,2Ј-bithienyl (BBT(OAc) 2 ). The most complex thiophene profile, including the less common PBT was detected in aerial parts of freshly harvested plant material. Under in vitro conditions only the root cultures, but not callus or cell suspension cultures produced substantial amounts of irregular thiophenes confirming that roots are the main site of thiophene biosynthesis.

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Gas chromatography coupled with mass spectrometry has been used to analyse the alkaloids present in the aerial parts of Genista tenera. Anagyrine, cytisine, N-formylcytisine, N-methylcytisine and lupanine were the major compounds, the last two alkaloids being known for their hypoglycaemic activity. Dehydrocytisine, 5,6-dehydrolupanine, rhombifoline, aphylline and thermopsine were the minor alkaloids. The characterisation of the constituents was based on comparison of their Kovats retention indexes and electron impact-mass spectrometric data recorded on-line with those of reference compounds and literature data.

The bark of Commiphora tenuis Vollensen exudes a translucent, free-flowing odoriferous liquid upon wounding which was analysed by capillary GLC and GLC-MS. 42 mono- and sesquiterpenes were detected and 37 identified. The main components of the monoterpenoid fraction were alpha-pinene (60.8%), beta-pinene (8.8%), sabinene (6.3%), alpha-thujene (8.9%), limonene (5.5%), 3-carene (3.7%), beta-myrcene (1.8%), and beta-elemene (1.1%) constituting 97% of the oil. Identified sesquiterpenoid components constituted approximately 1.6% of the oil. Oleanolic acid acetate was isolated and identified as the main triterpene from the resin by 1H- and 13C-NMR. Three other triterpenes of the olean-12-ene group were also detected using GC-MS. The essential oil exhibited antibacterial activities against Staphylococcus aureus. Proteus mirabilis and E. coli with MIC between 0.5 and 1%.