排序方式： 共有19条查询结果，搜索用时 46 毫秒
1.
Ernst L. Back 《Journal of Wood Science》2002,48(3):167-170
There is a general pattern of resin chemistry for parenchyma cells and secretory tissue. In sapwood the parenchyma resin is composed of fats, steryl esters, and occasionally waxes. Secretory tissue (most often resin canals) contains terpenes, terpenoids, and polyisoprenes. Other types of canal resin occur in a few hardwood families. The pattern is valid for softwoods and hardwoods. It has been defined from a comparison of available information on wood chemistry, wood anatomy, and the chemistry of oleoresin exudates from trees. This is a short overview with the most important references of two detailed reports. 相似文献
2.
The heart wood of Gliricidia sepium stem yielded stigmastanol glucoside (1) and 3',4'-dihydroxy-trans-cinnamic acid octacosylester 2, along with three other known constituents. 相似文献
3.
Whole grain wheat and rye are important sources of many bioactive compounds and contribute significantly to the total intake of cereals in many countries. Alkylresorcinols, benzoxazinoids, lignans, phenolic acids, phytosterols and tocols are common bioactive compounds present in these cereals. In this review, we report recent findings (mainly from 2010 onwards) regarding their content, composition, effects of food processing and their uptake, elimination and bioactivities with implications for health. 相似文献
4.
The aim of this investigation is to compare the physicochemical properties and chemical composition of Phoenix canariensis seed oil at different stages of seed date ripening. It was demonstrated that the saponification number of the oil increases during the maturation from 179.24 to 191.28 (mg KOH/g of oil), whereas the seed oil yield, the iodine number, the p-anisidine value, the peroxide value, the acidity and the unsaponifiable matter decrease from 14.73% to 10.36%, from 89.37 to 76.66 (g/100 g of oil), from 5.51 to 3.67, from 17.66 to 3.62 (mequiv. O2/kg of oil), from 1.49% to 0.59% and from 2.72% to 1.77%, respectively. The tocol content increases as the maturity advanced. The percentages of sterols show continuous changes during ripening. The saturated fatty acid content increases throughout the ripening process. The oleic fatty acid content decreases during the seeds maturation, but increases at the end, whereas linoleic acid content initially shows an increase, and then a decrease. The total phosphorus content decreases during the period of ripening. The three samples of the seed oil show a high kinetic stability during the heating and cooling, as characterised by the differential scanning calorimetry (DSC). The DSC curves reveal an increase in the melting point from −7.73 °C to 3.71 °C but the melting enthalpy remains the same, 62.06 J/g, during the ripening of the dates. 相似文献
5.
6.
Phytochemical and antimicrobial studies on Drynaria quercifolia 总被引：1，自引：0，他引：1
N. Ramesh M. B. Viswanathan A. Saraswathy K. Balakrishna P. Brindha P. Lakshmanaperumalsamy 《Fitoterapia》2001,72(8):283-936
Friedelin, epifriedelinol, beta-amyrin, beta-sitosterol, beta-sitosterol 3-beta-D-glucopyranoside, and naringin were isolated from the dried rhizome of Drynaria quercifolia. The methanol extract showed broad and concentration-dependent antibacterial activity. 相似文献
7.
Marcone MF Kakuda Y Yada RY 《Plant foods for human nutrition (Dordrecht, Netherlands)》2003,58(3):207-211
The analysis of 4 commonly available amaranth varieties (Amaranthus K343, RRC1011, K433, K432) revealed the presence of all three major phytosterols (beta-sitosterol, campesterol, stigmas-terol) with a total sterol content being several fold higher than those found in other studied plants. Substantial differences in total phytosterol content and beta-sitosterol content were found between the amaranth varieties. The most commonly cultivated amaranth variety in the United States, i.e., Amaranthus K343 was found to possess the highest levels of phytosterols of the varieties tested. The possibility of screening for superior amaranth varieties with various health properties is outlined. 相似文献
8.
大麻籽油不皂化物的分离与分析 总被引：5，自引：0，他引：5
采用薄板层析、气相色谱对大麻籽油中甾醇、4－甲基甾醇及三萜醇等不皂化物的成分进行了分离和分析。并用气相色谱－质谱联用确定了甾醇中的6种化合物。 相似文献
9.
Zhizhou He Anjiang Zhang Lisheng Ding Xinxiang Lei Jianzhang Sun Lixue Zhang 《Fitoterapia》2010,81(8):1125-1128
A new sterol, 24-R-stigmasta-4,25-diene-3β,6β-diol (1), along with three known compounds (2–3), was isolated from the green alga Codium divaricatum Holmes, a traditional Chinese medicine, which is efficacious against cancer. All structures were determined by spectroscopic methods and comparison with related known compounds. Single-crystal X-ray crystallography allowed us to confirm the structure of 1. To our knowledge, the compound 1 is reported as the first from natural source, and compounds 2, 4 have not been isolated from green algae before. 相似文献
10.
Jorge Triana Mariana Lpez Francisco Javier Prez Javier Gonzlez Platas Francisco Estvez Juan Francisco Len Juan Carlos Hernndez Ignacio Brouard Jaime Bermejo 《Fitoterapia》2009,80(7):437-441
Phytochemical research of two Tolpis species, T. webbii and T. sp., led to the isolation of three new compounds: 2,4′-dihydroxy-4-methoxybenzophenone (1) and the triterpenes 21α, 22α-epoxy-20α-hydroxy-20(30)-dihydrotaraxasterol (2) and 3β-hydroxytaraxaster-20-en-30-oic acid (3) together with 16 known compounds. The structures of the new compounds were elucidated by means of extensive IR, NMR, MS and X-ray analysis and by comparison of data reported in the literature. 相似文献