共查询到19条相似文献,搜索用时 93 毫秒
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生物碱是中药中具有生理活性的重要组分,科学高效地从天然产物中提取、纯化其中的生物碱活性成分是生物碱制备的关键环节。文章对生物碱制备常用的提取工艺与新技术的应用进展进行了综述,分析了它们的原理及优缺点并探讨了发展前景。 相似文献
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Armer CA 《Journal of chemical ecology》2004,30(4):883-888
The Colorado potato beetle feeds only on glycoalkaloid-laden solanaceous plants, appears to be toxic to predators, and has aposematic coloration, suggesting the beetle may sequester alkaloids from its host plants. This study tested 4th instars and adults, as well as isolated hemolymph and excrement, to determine if the beetles sequester, metabolize, or excrete alkaloids ingested from their host plants. HPLC analysis showed: that neither the larvae nor the adults sequestered either solanine or chaconine from potato foliage; that any alkaloids in the beetles were at concentrations well below 1 ppm; and that alkaloids were found in the excrement of larvae at approximately the same concentrations as in foliage. Analysis of alkaloids in the remains of fed-upon leaflet halves plus excreta during 24 hr feeding by 4th instars, as compared to alkaloids in the uneaten halves of the leaflets, showed that equal amounts of alkaloids were excreted as were ingested. The aposematic coloration probably warns of a previously-identified toxic dipeptide instead of a plant-derived alkaloid, as the Colorado potato beetle appears to excrete, rather than sequester or metabolize, the alkaloids from its host plants. 相似文献
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Lupinus leucophyllus is one of many lupine species known to contain toxic and/or teratogenic alkaloids that can cause congenital birth defects.
The concentrations of total alkaloids and the individual major alkaloids were measured in three different years from different
plant parts over the phenological development of the plant. All of the alkaloids were found in the different plant tissues
throughout the growing season, although their levels varied in different tissues. Concentrations of total alkaloids and the
individual alkaloids varied on an annual basis and in their distribution in the different tissues. Anagyrine levels were highest
in the floral tissue, lupanine and unknown F accumulated to the greatest level in the vegetative tissue, and 5,6-dehydrolupanine
accumulated to the highest level in the stem. These alkaloids appear to be in a metabolically active state with the teratogenic
alkaloid anagyrine accumulating to its highest level in the developing seed. The latter is, thus, the phenological stage posing
the greatest danger to grazing livestock. 相似文献
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利用生物碱在不同pH值下存在形式不同的性质,采用pH梯度萃取法将长春花总生物碱分为单吲哚生物碱部分(含有文多灵和长春质碱)和双吲哚生物碱部分(含有长春碱),然后采用碱性氧化铝柱层析对单吲哚生物碱部分进行分离。pH梯度萃取后得到的单吲哚生物碱部分中文多灵和长春质碱的含量分别为18.12%和11.44%,收率分别为80.86% 和88.91%;经碱性氧化铝柱层析分离后,得到文多灵和长春质碱含量分别为85.56%和76.73%,收率分别为85.23%和86.34%;重结晶后文多灵和长春质碱纯度分别达到95.22%和98.46%,收率分别为92.15%和98.24%。此方法适合文多灵和长春质碱的工业化大规模生产。 相似文献
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Saporito RA Norton RA Andriamaharavo NR Garraffo HM Spande TF 《Journal of chemical ecology》2011,37(2):213-218
Poison frogs are chemically defended from predators by diverse alkaloids, almost all of which are sequestered unchanged from
alkaloid-containing arthropods in the frog diet. Oribatid mites recently have been proposed as a major dietary source of poison
frog alkaloids. Here, we report on alkaloids common to an oribatid mite and poison frogs. Gas chromatographic-mass spectrometric
analysis of methanol extracts of adult Scheloribates laevigatus (Oribatida: Scheloribatidae) revealed nine alkaloids. Five of these have been detected previously in the skin glands of poison
frogs: two isomers of the pumiliotoxin 291G, two isomers of the 5,6,8-trisubstituted indolizidine 209C, and the 5,6,8-trisubstituted indolizidine 195G. The other four alkaloids, a pumiliotoxin, a tricyclic (coccinelline-like), and two isomers of an izidine, were not previously
known, but are similar in structure to alkaloids found in poison frogs. Alkaloids were not detected in immature S. laevigatus, suggesting that they are adult-specific and possibly the result of mite biosynthesis. Although most of the alkaloids detected
in S. laevigatus are common to poison frogs, the geographic distributions of these organisms are not sympatric. The findings of this study
indicate that oribatid mites, and in particular, members of the genus Scheloribates, represent a relatively unexplored arthropod repository for alkaloids and a significant dietary source of alkaloids in poison
frogs. 相似文献
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Wesley T. Beaulieu Daniel G. Panaccione Corey S. Hazekamp Michelle C. Mckee Katy L. Ryan Keith Clay 《Journal of chemical ecology》2013,39(7):919-930
Ergot alkaloids are mycotoxins that can increase host plant resistance to above- and below-ground herbivores. Some morning glories (Convolvulaceae) are infected by clavicipitaceous fungi (Periglandula spp.) that produce high concentrations of ergot alkaloids in seeds—up to 1000-fold greater than endophyte-infected grasses. Here, we evaluated the diversity and distribution of alkaloids in seeds and seedlings and variation in alkaloid distribution among species. We treated half the plants with fungicide to differentiate seed-borne alkaloids from alkaloids produced de novo post-germination and sampled seedling tissues at the cotyledon and first-leaf stages. Seed-borne alkaloids in Ipomoea amnicola, I. argillicola, and I. hildebrandtii remained primarily in the cotyledons, whereas I. tricolor allocated lysergic acid amides to the roots while retaining clavines in the cotyledons. In I. hildebrandtii, almost all festuclavine was found in the cotyledons. These observations suggest differential allocation of individual alkaloids. Intraspecific patterns of alkaloid distribution did not vary between fungicide-treated and control seedlings. Each species contained four to six unique ergot alkaloids and two species had the ergopeptine ergobalansine. De novo production of alkaloids did not begin immediately, as total alkaloids in fungicide-treated and control seedlings did not differ through the first-leaf stage, except in I. argillicola. In an extended time-course experiment with I. tricolor, de novo production was detected after the first-leaf stage. Our results demonstrate that allocation of seed-borne ergot alkaloids varies among species and tissues but is not altered by fungicide treatment. This variation may reflect a response to selection for defense against natural enemies. 相似文献