RESUMEN
Aromatic compounds are important for fruit quality and can vary among fruit cultivars. Volatile compounds formed during the ripening of two banana cultivars, Brazilian and Fenjiao, were determined using headspace solid-phase micro-extraction (SPME) and gas chromatography coupled with mass spectrometry (GC-MS). These two cultivars exhibited different physiological characteristics during storage. Fenjiao fruit exhibited faster yellowing and softening, a higher respiration rate and greater ethylene production. Also, the soluble sugar content in Fenjiao fruit was much higher than in Brazilian fruit. In total, 62 and 59 volatile compounds were detected in Fenjiao and Brazilian fruits, respectively. The predominant volatile components isoamyl acetate, butanoic acid, 3-methyl-3-methylbutyl ester, hexanal, trans-2-hexenal and 1-hexanol varied during ripening stages. Moreover, esters were more abundant in Fenjiao, and propanoic acid 2-methylbutyl ester, and octanoic acid were only detected in Fenjiao. These compounds contribute to the unique flavors and aromas of the two cultivars.
Asunto(s)
Frutas/química , Musa/química , Compuestos Orgánicos Volátiles/química , Aldehídos/química , Brasil , Cromatografía de Gases , Ésteres/química , Frutas/crecimiento & desarrollo , Hexanoles/química , Musa/crecimiento & desarrollo , Pentanoles/química , Microextracción en Fase SólidaRESUMEN
A kinetic study of the gas-phase reactions of OH radicals with three unsaturated biogenic alcohols, (E)-3-hexen-1-ol, (Z)-3-hepten-1-ol, and (Z)-3-octen-1-ol, has been performed. The rate coefficients obtained are (in units of 10(-10) cm(3) molecule(-1) s(-1)) k1 (OH + (E)-CH2(OH)CH2CHâCHCH2CH3) = (1.14 ± 0.14), k2 (OH + (Z)-CH2(OH)CH2CHâCHCH2CH2CH3) = (1.28 ± 0.23), and k3 (OH + (Z)-CH2(OH)CH2CHâCHCH2CH2CH2CH3) = (1.49 ± 0.35). In addition, a product study on the reactions of OH with (E)-3-hexen-1-ol and (Z)-3-hepten-1-ol is reported. All the experiments were performed at (298 ± 2) K and 1 atm of NOx-free air in a 1080 L photoreactor with in situ FTIR detection of organics. This work constitutes the first kinetic study of the reactions of OH radicals with (Z)-3-hepten-1-ol and (Z)-3-octen-1-ol as well as the first determination of the fate of the hydroxy alkoxy radicals formed in the title reactions. An analysis of the available rates of addition of OH and Cl to the double bond of different unsaturated alcohols at 298 K has shown that they can be related by the expression log kOH = (0.29 ± 0.04) log kCl - 10.8. The atmospheric lifetimes of the alcohols studies were estimated to be around 1 h for reaction with OH radicals. The products formed in the title reactions are mainly carbonylic compounds that can contribute to the formation of ozone and PANs-type compounds in the troposphere.
Asunto(s)
Atmósfera/química , Heptanol/análogos & derivados , Hexanoles/química , Radical Hidroxilo/química , Octanoles/química , Alcoholes/química , Heptanol/química , Cinética , Relación Estructura-Actividad , TermodinámicaRESUMEN
ETHNOPHARMACOLOGICAL RELEVANCE: Leaf and seed decoctions of Casimiroa spp. are used in Mexican traditional medicine to treat high blood pressure. Previous researches showed as Casimiroa extracts are able to induce relaxation of rat aortic and caudal arteries. To study the influence of the aging, we determined the vascular effect induced by extracts of Casimiroa edulis and Casimiroa pubescens in arterial tissues from young and old rats. MATERIALS AND METHODS: The activity of Casimiroa edulis extracts: hexanic-leaf (Ce5), methanolic-leaf (Ce6), hexanic-seed (Ce7) and methanolic-seed (Ce8), and Casimiroa pubescens: hexanic-leaf (Cp9), methanolic-leaf (Cp10), hexanic-seed (Cp11) and methanolic-seed (Cp12) were investigated in precontracted caudal arteries of young (4 months) and old (20 months) rats. RESULTS: The Casimiroa extracts tested at 20 µg/ml induced vasorelaxation in phenylephrine-precontracted arterial tissues both in young and old arterial tissues. Methanolic seed extracts of Casimiroa edulis (Ce8) and Casimiroa pubescens (Cp12) caused a higher relaxation in young than in old arterial tissues. Nifedipine (0.01 µM) did not change the vasorelaxation induced by Casimiroa edulis extract either in young and old rat arterial tissues. CONCLUSIONS: The vasorelaxation induced by Casimiroa edulis and Casimiroa pubescens extracts is decreased from aging since the effects were higher in young than in old rat arterial tissues. However, the methanolic-seed extracts of both plant species induced a relevant vasorelaxation also in old arterial tissues. Thus the results support the traditional use of Casimiroa decoctions as antihypertensive, also in elderly.
Asunto(s)
Envejecimiento , Antihipertensivos/farmacología , Arterias/efectos de los fármacos , Casimiroa , Extractos Vegetales/farmacología , Vasodilatación/efectos de los fármacos , Vasodilatadores/farmacología , Factores de Edad , Animales , Antihipertensivos/química , Antihipertensivos/aislamiento & purificación , Casimiroa/química , Hexanoles/química , Masculino , Medicina Tradicional , Metanol/química , México , Nifedipino/farmacología , Extractos Vegetales/química , Extractos Vegetales/aislamiento & purificación , Hojas de la Planta , Plantas Medicinales , Ratas , Ratas Wistar , Semillas , Solventes/química , Vasodilatadores/química , Vasodilatadores/aislamiento & purificaciónRESUMEN
The molecule of the title compound, C19H20O2S, corresponds to a chiral sulfinyldienol with two stereogenic centres, viz. the C atom susbtituted by the hydroxy group and the sulfinyl S atom. The molecule displays a V-shape in the solid state. The dihedral angle defined by the least-squares planes of the aromatic rings is 72.9 (1) degrees. The packing pattern exhibits the following intermolecular hydrogen bonds: one O-H...O [H...O = 1.98 A, O...O = 2.785 (4) A and O-H...O = 166 degrees] and two C-H...O [H...O = 2.58 and 2.60 A, C...O = 3.527 (5) and 3.347 (5) A, and C-H...O = 164 and 134 degrees]. These define a chain along b.
Asunto(s)
Hexanoles/química , Compuestos Orgánicos/química , Sulfóxidos/química , Cristalografía por Rayos X , Enlace de Hidrógeno , Modelos Moleculares , Estructura MolecularRESUMEN
Modified oligonucleotides that contain the hydrophobic 1-hexanol-1,N(6)-etheno-2'-deoxyadenosine adduct have been synthesized using a mild solid phase phosphoramidite chemistry. The presence and the integrity of the modified nucleoside in the synthetic oligomers were confirmed by electrospray ionization and MALDI mass spectrometry measurements together with analysis of the complete enzymatic hydrolysate by high performance liquid chromatography coupled to UV and fluorescent detection techniques.