A GC-MS study of the volatile organic composition of straw and oyster mushrooms during maturity and its relation to antioxidant activity

Mushrooms are very popular in the market for their nutritional and medicinal use. Mushroom volatiles are not only an important factor in the flavor, but also contain many antioxidant compounds. Antioxidant activity is a very important property for disease prevention. The volatile compositional characteristics of straw mushrooms (Volvariella volvacea [Bull. ex Fr.] Sing.) and oyster mushrooms (Pleurotus ostreatus [Jacq. ex Fr.] Kummer) during maturity and the mushroom antioxidant activity related to the non-volatiles and volatiles are studied by a chromatographic method in combination with a spectrophotometric method. The volatile compounds of straw and oyster mushrooms are sampled and identified by a combination sampling method, including headspace solid phase microextraction and steam distillation, followed by gas chromatography-mass spectrometry detection. Among all the volatile compounds identified, 1-octen-3-ol and 3-octanone are the two main compounds with the highest amounts in the volatile compositions of straw and oyster mushrooms. During maturity time of the straw mushrooms, the unsaturated 1-octen-3-ol peak area is reduced, whereas the saturated 3-octanone peak area is increased. However, during normal maturity time of oyster mushrooms, the peak areas of 1-octen-3-ol and 3-octanone remain at the same level. 1-Octen-3-ol has a different antioxidant activity from 3-octanone. Combining the results of antioxidant experiments of water extract and main volatile components by the use of a phosphomolybdenum spectrophotometric method, the conclusion is drawn that oyster mushrooms might possess stronger antioxidant activities than straw mushrooms.     

The chemical composition of the oleoresin of the genus Picea diterpenoids of the oleoresin of Picea obovota

Chemistry of Natural Compounds -     

Structure and composition studies of chemical vapour-deposited BCN fibre coatings

The composition and structure of boron carbonitride (BCN) films were studied. The films were continuously deposited on fibres by atmospheric pressure CVD. The precursors were ammonia, trimethyl borate and toluene. The composition was determined by photoelectron spectra of boron 1s, nitrogen 1s, carbon 1s and oxygen 1s. By fixing the C 1s peak at 285 eV, the position of the B 1s peak and the N 1s peak in the BCN films was equal to BN films. The C content of the films increases from about 6 at% to 60 at%, leaving the stoichiometric boron/nitrogen ratio as well as the oxygen content below 10 at% unchanged. Generally, the carbon content in the films is lower than predicted by the precursor ratios. Obviously, the insertion of carbon into the film is decreased in the presence of ammonia, which is known to etch carbon. With a decreasing ammonia/toluene ratio, the undesired effect in the reaction is suppressed and the carbon deposition becomes considerable. Transmission electron microscopic studies were performed on cross-sections of the coated fibres. High-resolution images generally show a hexagonal turbostratic structure with different orientation preferences of the atomic lamellae similar to hexagonal turbostratic boron nitride and pyrolytic carbon. When a noticeable carbon concentration (20 at%) is reached, the atomic sheets become uniformly distributed in all directions in space.     

火龙果茎化学成分的GC-MS/ICP-MS分析

采用GC-MS/ICP-MS分析火龙果茎的化学成分,确定了其中的有机成分,并对所含的12种无机元素进行定量分析.结果表明,火龙果鲜茎含有多种人体必需的微量元素,以及大量的植醇、维生素E及各种植物甾醇,有很高的利用价值和广阔的开发前景.     

Polysaccharide composition ofPolygonum aviculare

A polysaccharide isolated from the epigeal parts ofPolygonum aviculare has been fractionated. It has been shown that the initial polysaccharide consists of at least four fractions differing in their monosaccharide compositions and physico-mechanical properties.I. P. Pavlov Ryazan' Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 619–622, September–October, 1985.     

气质联用技术在药食同源植物分析中的研究进展

药食同源植物是指既可食用又能作为药材防病治病的植物,此类植物不良反应小、药用作用强且价格低廉,因此在临床上应用广泛.对于该类药物含有的活性成分进行深入研究能够更好地明确与发挥其药用价值和营养价值. 20世纪以来,气相色谱质谱联用技术的飞速发展推动了药食同源植物的活性成分的发现与研究,在药食同源植物的质量分析与成分开发中得到广泛应用并成为其主流分析技术之一.本文从近年来气质联用技术发展以及其在药食同源植物中的应用两个方面,对该技术在药食同源类植物的活性成分分析中的应用进行了综述.     

Combination of two chromatographic methods in the study of the chemical composition of officinal herbs

Two complementary chromatographic methods, ion exclusion chromatography and gas-liquid chromatography, are suggested for the analysis of the chemical composition and the standardization of raw herbs. The potentialities and limitations of these methods are illustrated by the example of common valerian (Valeriana officinalis) and yarrow (Achillea millefolium). The chromatographic conditions required for the determination of ascorbic acid by the ion exclusion chromatography are determined.