n-Hexanal and Some Volatile Alcohols

Both α-tocopherol and a 1: 1.7 mixture of α-tocopherol and tocotrienols at a 0.2% dietary level significantly depressed the age-related increase in the systolic blood pressure of spontaneously hypertensive rats (SHRs) after 3 weeks of feeding. The aortic production of prostacyclin was increased 1.5 times both by α-tocopherol and a tocotrienol mixture, suggesting a possible relevance to their hypotensive effect. These vitamins did not influence the Δ6- and Δ5-desaturase activities of liver microsomes, but fatty acid profiles of the liver phospholipids predicted a reduction of linoleic acid desaturation. These effects were in general more clear with tocotrienols than with α-tocopherol. Platelet aggregation by 5 μM ADP remained uninfluenced. Thus, tocotrienols may have effects on various lipid parameters somewhat different from those of α-tocopherol.     

Volatile polysulphides of asafoetida

By means of steam distillation, adsorption chromatography and GC/MS analysis, seven sulphur components (di-, tri- and tetra-sulphides) have been characterised in addition to those previously reported from Ferula asafoetida of Afghan origin. The identity of some of the components has been confirmed by synthesis and comparison of GC retentions. The quantitative composition of the constituents in the volatile oil has also been determined.     

Volatile constituents of peony flowers

Fragrance components of fresh peony flower include oxygenated mono-and sesqui-terpenes and a number of aliphatic and aromatic aldehydes, esters and alcohols. 3-Oxo-1,8-cineole is a new natural product.     

Volatile constituents of Capillipedium parviflorum

The essential oil of aerial parts of Capillipedium parviflorum (family Poaceae) was obtained by hydrodistillation in 0.4% yield on dry weight basis. The oil was analysed by capillary GC and GC-MS techniques. Two new compounds from plant source 4-nonanol 51.7% and 4-undecanone 23.5% predominated in the essential oil and were separated by column chromatography, identified and confirmed by 1H and 13C NMR. Thirty one compounds were identified from the essential oil accounting for 96% of total identifications.     

Volatile oil constituents of sagebrush

The volatile oil of Artemisia arbuscula arbuscula contained a new irregular monoterpene, 2,5-dimethyl-4-vinyl-1,5-hexadiene-3-ol (isolyratol), which was isolated and identified by spectral means. The optically pure furanoid (2S,5S)-trans-5-methyl-5-vinyltetrahydrofur-2-yl methyl ketone (arbusculone), was also characterized by transformation to known (2S,5S)-trans-linalyl oxide. The former component has never been isolated from natural sources prior to this study. The neutral pentane extract also contained several previously characterized non-head-to-tail monoterpenes including artemiseole, artemisia ketone, artemisyl acetate, methyl santolinate, and santolina triene, as well as the regular monoterpenes 1,8-cineole, camphor, p-cymene, camphene and the C₆ fragment, terelactone.     

Volatile constituents of Aristolochia argentina

The essential oils from leaves, aerial stems and underground organs of Aristolochia argentina Gris., a medicinal plant popularly known as "charrúa", were obtained by hydrodistillation and analyzed by GC and GC/MS. Forty-three components were identified in the oils. All parts of the plant afforded volatile oils characterized by high levels of argentilactone (57-89%) and the presence of undecatriene isomers (0.3-4.0%), these latter compounds providing the essential oils and extracts with an intense particular odor. Terpenes account for the remaining portion of the essential oils (5-29%). Bicyclogermacrene predominates in the aerial parts of the plant, whereas ishwarane is the main terpene of the subterranean organs. Argentilactone, a suspected carcinogenic compound, was also identified in a medicinal commercial tincture of A. argentina.     

Volatile Components of Roasted Shrimp

The components of the strong and favorable aroma obtained from roasted shrimp were investigated. The aroma concentrate of roasted shrimp was isolated by combining the dichloromethane extract and carbon dioxide distillation methods. The concentrate was fractionated into acidic, basic and neutral fractions. Each fraction was analyzed by combined gas chromatography-mass spectrometry. Seventy-seven compounds were identified, among which isovaleric acid, alkyl pyrazines, isovaleramide, ketones and some sulfur-containing compounds were the main and characteristic constituents of the roasted shrimp aroma.

These constituents were compared with those of the volatiles of boiled shrimp, which was prepared by using simultaneous distillation and extraction methods in a modified Likens and Nickerson’s apparatus.     

Volatile flavour components of guava

An essence of fresh guava fruit obtained by well-established procedures possessed the characteristic aroma of the fruit. It was analysed by GC/MS using     

Volatile Flavor of Black Tea

The volatile components extracted from fresh tea leaf, fermented leaf and black tea were analysed by gas chromatography.

Quantitative difference in the composition of essential oils was observed between fresh leaf and manufactured black tea; the former was rich in alcohols, whereas the latter in aldehydes and acids.

During fermentation process the following components mainly brought about changes: n-capronaldehyde (4.1 times after fermentation for 3hrs.), trans-2-hexen-l-al (13.2 times) and cis-3-hexenoic acid (1.2 times) increased, but n-hexylalcohol (0.7 time), cis-3-hexen-l-ol (0.7 time) and methylsalicylate (0.8 time) decreased.

These changes during fermentation were scarcely carried out in nitrogen atmosphere.     

Volatile Flavor of Black Tea

The first effluent of essential oil of black tea in the gas chromatographic analysis is important for characterizing black tea flavor. The isolation and identification of main unknown components were conducted by means of gas chromatography, and also by infrared spectra and ultraviolet spectra. Ethylacetate, ethylalcohol and β-myrcene were identified as the increasing compounds during fermentation. cis-β-Ocimene and trans-β-ocimene were also identified only in completely manufactured black tea. These three terpenoid hydrocarbons are newly found constituents of essential oil of black tea and are supposed to contribute considerably to the black tea flavor.     

Volatile constituents of wood-rotting basidiomycetes

Phytochemical investigation of the hydrodistillation products of the basidiomycetes Fomitopsis pinicola, Piptoporus betulinus, Gloeophyllum odoratum and Trametes suaveolens led to the identification of numerous mono- and sesquiterpenes as well as many aliphatic alcohols, aldehydes and ketones and some aromatic compounds. In addition, some diterpenes were identified as constituents of Fomitopsis pinicola. The absolute configuration of some terpenes was determined     

山胡椒挥发油的提取及其抑菌活性研究

目的:研究山胡椒中挥发油最佳提取方法和其抑菌作用。方法:采用水蒸汽蒸馏法、微波萃取法和超临界CO2萃取法三种方法提取干山胡椒果实中的挥发油,研究山胡椒挥发油对7种细菌、4种霉菌、2种酵母的抑菌活性及其最低抑菌浓度(MIC)。结果:水蒸汽蒸馏法提取的山胡椒挥发油为淡黄色液体,提取率为10.0%;微波萃取法提取的山胡椒挥发油为黄褐色液体,提取率为11.6%;超临界CO2萃取的山胡椒挥发油为亮黄色液体,提取率为14.7%。山胡椒挥发油经固相和气相扩散,对细菌、酵母有较强的抑菌能力,对霉菌具有很强的抑制能力。对所有供试菌的最低抑菌浓度(MIC)为0.2%。结论:提取干山胡椒果实中的挥发油的最好方法是超临界CO2萃取法。山胡椒挥发油有较强的抑菌能力,最低抑菌浓度(MIC)为0.2%。     

Volatile Components of Roasted Chufa-tubers

The desmutagenic activities of some vegetable and fruit juices to the mutagenicity of 2-tert-butyl-p-quinone (t-BQ) were assayed by the Ames test using Salmonella typhimurium TA 100. t-BQ is a strong mutagen and is produced from butylated hydroxyanisole when treated with nitrite under acidic conditions. The juices of sweet pepper, lemon, tomato, orange, strawberry, melon, and kiwi fruit reduced the mutagenicity of t-BQ, the desmutagenic activities being proportionally related to the content of the sulfhydryl group contained in these juices. The authentic sulfhydryl compounds, glutathione, pantetheine and dithiothreitol, were then tested for their desmutagenicity against t-BQ by the induced-mutation frequency method, and they were proved responsible for the desmutagenicity. Glutathione reduced half of the t-BQ to 2-tert-butyl-hydroquinone during the desmutagenic reaction, the other half being suggested to have been a conjugated compound between glutathione and t-BQ.     

Volatile constituents of Trichothecium roseum

In the course of investigation of Trichothecium roseum (Fungi Imperfecti) for its attractancy against Tyrophagus putrescentiae (cheese mite), the twenty following volatile compounds produced at a very low concentration by the microfungus were identified by gc, gc/ms, gc/c.i.ms and tlc: 3-methyl-1-butanol, 3-octanone, 1-octen-3-one, 3-octanol, octa-1,5-dien-3 one, 1-octen-3-ol, 6-methyl-5-hepten-2-ol, octa-1,5-dien-3 ol, furfural, linalool, linalyl acetate, terpineol (alpha and beta) citronellyl acetate, nerol, citronellol, phenylacetaldehyde, benzyl alcohol geranyl acetate, 1-phenyl ethanol and nerolidol. Octa-1,5-dien-3-ol and octa-1,5-dien-3-one have not been previously isolated from fungi; octa-1,5-dien-3-ol is the most potent attractant amount the volatile compounds detected by gc.     

Comparison of Volatile Compounds from Chungkuk-Jang and Itohiki-Natto

Volatile compounds from two South-East Asian fermented soybean foods, Chungkuk-jang (CKJ) and Itohiki-natto (natto), were analysed by gas chromatography-mass spectrometry (GC-MS), gas chromatography (GC), and GC-sniffing. A total of 112 compounds were identified. A large amount of ethanol was detected from CKJ, while acetone and methyl isobutyrate were major components of natto. The characteristic odor compounds of CKJ were some ethyl esters of short chain fatty acids, diallyl disulfide, and several natto-like odor compounds were identified as ammonia, 2,5-dimethylpyrazine, and 2-methylbutanoic acid.