Volatiles Emission by after Insect Attack.

Plants are known to increase the emission of volatile organic compounds upon the damage of phytophagous insects. However, very little is known about the composition and temporal dynamics of volatiles released by wild plants of the genus (Fabaceae) attacked with the specialist lepidopteran caterpillar (Linnaeus) (Erebidae). In this work, the herbivore-induced plant volatiles (HIPV) emitted by Kunth plants were isolated with solid phase micro-extraction and the conventional purge and trap technique, and their identification was carried out by GC/MS.

LC/MS study of the diversity and distribution of pyrrolizidine alkaloids in Crotalaria species growing in Colombia.

Hepatotoxic and genotoxic pyrrolizidine alkaloids have been involved in the acute poisoning of animals and humans. Crotalaria (Fabaceae) species contain these alkaloids. In this work, the diversity and distribution of pyrrolizidine alkaloids in roots, leaves, flowers, and seeds of Crotalaria pallida, Crotalaria maypurensis, Crotalaria retusa, Crotalaria spectabilis, Crotalaria incana, and Crotalaria nitens were studied.

GC-MS study of compounds isolated from Coffea arabica flowers by different extraction techniques.

Headspace (HS), extractive, and distillative methods were employed to isolate volatile and semivolatile compounds from fresh Coffea arabica flowers. Static HS solid-phase microextraction (HS-SPME), microwave-assisted HS-SPME (MW-HS-SPME) with simultaneous hydrodistillation, and extraction with hexane or supercritical CO2 -isolated mixtures in which around 150 different chemical substances were identified or tentatively identified by GC-MS analysis. n-Pentadecane (20-37% relative peak area, RPA) was the most abundant compound in the HS fractions from fresh flowers, followed by 8-heptadecene (8-20% RPA) and geraniol (6-14% RPA).

Composition of three essential oils, and their mammalian cell toxicity and antimycobacterial activity against drug resistant-tuberculosis and nontuberculous mycobacteria strains.

Tuberculosis (TB) is the most ancient epidemic disease in the world and a serious opportunistic disease in HIV/AIDS patients. The increase in multidrug resistant Mycobacterium tuberculosis (MDR-TB, XDR-TB) demands the search for novel antimycobacterial drugs. Essential oils (EOs) have been widely used in medicine and some EOs and their major components have been shown to be active against M.

Anethole isomerization and dimerization induced by acid sites or UV irradiation.

The formation of cis-anethole and various dimers as a result of the exposure of trans-anethole to microporous solid acids (dealuminated HY zeolites), or UV-Vis irradiation was established by means of high resolution gas chromatography coupled to mass spectrometry. 3,4-bis-(4-Methoxyphenyl)-(E)-hex-2-ene was the most abundant compound among eight different methoxyphenyl-disubstituted hexenes produced by electrophilic addition and elimination reactions induced by HY zeolites. (1a,2a,3b,4b)-1,2-bis(4-Methoxyphenyl)-3,4-dimethylcyclobutane was the principal component in the mixture of 5 methoxyphenyl-disubstituted cyclobutanes found, together with cis-anethole, after UV-Vis irradiation of a trans-anethole solution in toluene.

Chemical composition and antiprotozoal activities of Colombian Lippia spp essential oils and their major components.

The chemical composition and biological activities of 19 essential oils and seven of their major components were tested against free and intracellular forms of Leishmania chagasi and Trypanosoma cruzi parasites as well as Vero and THP-1 mammalian cell lines. The essential oils were obtained from different species of Lippia, a widely distributed genus of Colombian plants. They were extracted by microwave radiation-assisted hydro-distillation and characterised by GC-FID and GC-MS.

Determination of the volatile and semi-volatile secondary metabolites, and aristolochic acids in Aristolochia ringens Vahl.

Volatile and semi-volatile secondary metabolites, as well as aristolochic acids (AA), present in leaves, stems, and flowers of Aristolochia ringens were determined by gas chromatography (GC)-mass spectrometry (MS) and high-performance liquid chromatography (HPLC) methods, respectively. Metabolite isolation was performed using different extraction techniques: microwave-assisted hydrodistillation (MWHD), supercritical fluid extraction, and headspace solid-phase microextraction (HS-SPME). The chemical composition of the extracts and oils was established by GC-MS.

Sampling flower scent for chromatographic analysis.

The analysis of flower volatiles requires special methods for their isolation with enrichment. Living flowers show a continuous change in their volatile profile that depends on intrinsic (genetic) and external (light, temperature, hydric stress) factors. Excised flowers suffer rapid deterioration and loss of volatiles.

Synthesis and antiparasitic properties of new 4-N-benzylamino-4-hetarylbut-1-enes.

New derivatives of 4-N-benzylamino-4-hetarylbut-1-ene containing a pyridyl nucleus were synthesized from benzylamines and pyridine aldehydes. N-oxide derivatives were obtained from these homoallylamines. Study of the antiparasitic properties of obtained pyridine derivatives as well as of four related benzazepines previously described, was carried out using cytotoxicity assays against Trichomonas vaginalis and epimastigote form of Trypanosoma cruzi protozoa.

Analysis of volatile secondary metabolites from Colombian Xylopia aromatica (Lamarck) by different extraction and headspace methods and gas chromatography.

Hydrodistillation (HD), simultaneous distillation-solvent extraction (SDE), microwave-assisted hydrodistillation (MWHD), and supercritical fluid (CO2) extraction (SFE), were employed to isolate volatile secondary metabolites from Colombian Xylopia aromatica (Lamarck) fruits. Static headspace (S-HS), simultaneous purge and trap (P&T) in solvent (CH2Cl2), and headspace (HS) solid-phase microextraction (SPME) were utilised to obtain volatile fractions from fruits of X. aromatica trees, which grow wild in Central and South America, and are abundant in Colombia.

Comparison of different extraction methods for the analysis of volatile secondary metabolites of Lippia alba (Mill.) N.E. Brown, grown in Colombia, and evaluation of its in vitro antioxidant activity.

Hydrodistillation (HD), simultaneous distillation solvent extraction (SDE), microwave-assisted hydrodistillation (MWHD), and supercritical fluid (CO2) extraction (SFE) were employed to isolate volatile secondary metabolites from fresh leaves and stems of Colombian Lippia alba (Mill.) N.E.