Free and glycosidically bound volatiles obtained from the fruit pulp of Sicana odorifera by liquid-liquid extraction and by chromatography, followed by enzymatic hydrolysis with Rohapect D5L, respectively, were analyzed by capillary gas chromatography (HRGC), HRGC-mass spectrometry (HRGC-MS), and HRGC-Olfatometry (HRGC-O) analyses. A total of 37 free volatiles was detected, with the major components being 3-methyl-2-butanol, 3-hydroxy-2-butanone, ethyl 3-hydroxybutanoate, and (Z)-3-hexenol. Among the 22 detected glycosidically bound compounds, 4-hydroxybenzyl methyl ether, 4-hydroxybenzyl alcohol, and 2-phenylethanol were found to be the major constituents. Additionally, two glucoconjugates were isolated in pure form by multilayer coil countercurrent chromatography (MLCCC) of the glycosidic extrac and further purification. Their structures were elucidated by MS and NMR analyses to be the novel [4-(beta-D-glucopyranosyloxy)benzyl] 2,3-dihydroxy-3-methylbutanoate 2, and the known 4-(beta-D-glucopyranosyloxy)benzyl alcohol 1. Compounds 1 and 2 are precursors of 4-hydroxybenzyl alcohol, one of the major volatiles generated by enzymatic hydrolysis of the glycosidic fraction.

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Volatile compounds from sour guava (Psidium guineense Swartz) fruit were isolated by headspace solid-phase microextraction (HS-SPME) and simultaneous distillation-solvent extraction (SDE), and identified by GC-FID and GC/MS. A total of 181 compounds were reported for the first time in this fruit, 119 and 163 compounds were identified as headspace volatiles and fruit volatiles, respectively. Ethyl butyrate, ethyl hexanoate, b-caryophyllene and selin-11 -en-4a-ol were the major compounds. Esters (69.5%) and terpenes (60.8%) were the major classes of compounds found in the headspace volatiles and fruit volatiles. Key Word IndexPsidium guineense, Myrtaceae, headspace volatiles, fruit volatiles, ethyl butyrate, ethyl hexanoate, b-caryophyllene, selin-11-en-4a-ol.

3,4-Dimethoxyphenyl P-D-glucopyranoside l a was identified for the first time in a glycosidic extract obtained from piiiuela (Bromefia p l m e n ' Kartens) fruit by adsorption on Amberlite XAD-2 resin and elution with EtOAc and MeOH. After prefractionation of the MeOH eluate using countercurrent chromatography techniques (RLCC and MLCCC) the glycoside was peracetylated and purified by flash chromatography and subsequent HPLC to be characterized as its tetraacetate l b by NMR and ESI-MS techniques.