GLYCOSIDICALLY BOUND VOLATILE COMPONENTS OF NICOTIANA-SYLVESTRIS AND N-SUAVEOLENS FLOWERS

Glycosidically bound volatile components were extracted from flowers of Nicotiana sylvestris and N. suaveolens and isolated using liquid column chromatography with an Amberlite XAD-2 resin. These glycosides, which were putative precursors of fragrance compounds, were hydrolysed enzymatically and a number of the volatiles released were subsequently identified by GC-MS including compounds not previously identified in the floral headspace of these species. Average yields of volatiles released from glycosides were ca 230 and 1050-mu-g g-1 for N. sylvestris and N. suaveolens flowers, respectively. Compounds in the glycosidically bound fraction were all phenylpropanoid-derived volatiles (e.g. benzyl alcohol, benzaldehyde, E-cinnamyl alcohol, benzyl salicylate) with the exception of the monoterpene-alpha-terpineol. No pronounced diurnal changes in the levels of glycosidically bound volatile compounds could be. noted from flowers of either species. However, pronounced differences were obtained in the concentrations of glycosidically bound volatiles at different floral maturity stages.