共查询到20条相似文献,搜索用时 31 毫秒
1.
《Phytochemistry》1986,25(11):2672-2674
A new triterpenoid glycoside, glochidioside, has been isolated from Glochidion heyneanum. Its structure has been established as 3β[(O-β-D-glucopyranosyl-(1 → 3)-O-α-L-arabinopyranosyl)oxy]-16β-benzoyloxy-olean-12-ene-21β,23,28-trio 相似文献
2.
《Phytochemistry》1992,31(1):349-351
Arjunolic acid diglycoside, which we have named arjunolitin, has earlier been reported fromTerminalia arjuna. Its structure has now been established as 3-O-β-d-glycopyranosyl 2α,3β-23-tri-hydroxyolean-12-en-28-oic acid 28-O-β-d-glucopyranoside by chemical and spectral data. 相似文献
3.
From the seed of fenugreek, a new glycoside has been isolated and shown to have the structure, (25S)-22-O- methyl-5α-furostan-3β,22,26-triol 3-O-α-rhamnopyranosyl(1→2)[-β-d-glucopyranosyl (1→3)]-β-d- glucopyranoside-26-O-β-d-glucopyranoside. 相似文献
4.
From the roots and rhizomes of Helleborus macranthus a new glycoside, macranthoside I, has been isolated and shown to have the structure 25(27)-dehydro-5β-furostan-3β,22,26-triol-3-O-β-d-glucopyranosyl(1 → 6)-β-d-glucopyranoside, 26-O-β-d-glucopyranoside. 相似文献
5.
Two new diterpenes have been isolated from Sideritis sicula: sideripol, ent-18-acetoxy-7α-hydroxykaur-15-ene and epoxysideritriol, ent-15β,16β-epoxykauran-7α,17,18-triol. The previously known diterpene eubol, ent-7α-acetoxykaur-16-en-15β,18 diol has also been obtained from the same source. 相似文献
6.
A new steroidal saponin has been isolated from the ethanolic extract of the roots of Agave cantata and shown to be 3-O-[β-d-glucopyranosyl]-6O-[β-d-glucopyranosyl]-(25R)-5α-22α-O- spirostan-3β, 6α-diol. 相似文献
7.
Structures of verbascoside and orobanchoside,caffeic acid sugar esters from Orobanche rapum-genistae
The complete structural elucidation of the two caffeic acid sugar esters verbascoside and orobanchoside, has been realized by 1H and 13C NMR studies. It has been demonstrated that verbascoside is β-(3′,4′-dihydroxyphenyl)ethyl-O-α-L-rhamnopyranosyl(1→3)-β-D-(4-O-caffeoyl)-glucopyranoside, and orobanchoside is β-hydroxy-β-(3′,4′-dihydroxyphenyl)-ethyl-O-α-L-rhamnopyranosyl(1→2)-β-D-(4-O-caffeoyl)-glucopyranoside. 相似文献
8.
A new glycoside, 3,4-dihydroxychalcone 4-O-β-l-arabinopyranosyl-O-β-d-galactopyranoside has been identified from the seeds of Bauhinia purpurea. 相似文献
9.
Borbála Vermes Lorand Farkas Mihály Nógrádi Hildebert Wagner Richard Dirscherl 《Phytochemistry》1976,15(8):1320-1321
The structure of afzelin (kaempferol 3-O-α-l-rhamnopyranoside) and paeonoside (kaempferol 3,7-bis-O-β-d-glucopyranoside) has been confirmed by total synthesis. Synthetic kaempferol 3-O-β-rutinoside had a mp of 190–192° suggesting that those natural kaempferol 3-O-rhamnoglucosides which melt in the same range are also 3-O-β-rutinosides. 相似文献
10.
Yohei Hashimoto Yukiko Ohta Hiroyuki Ishizone Masayuki Kuriyama Masaru Ogura 《Phytochemistry》1982,21(9):2335-2337
Periandrin III, a new sweet triterpene glycoside of the roots of Pepiandra dulcis, has been shown to possess the structure 3-β-O-[β-d-g 相似文献
11.
A new steroidal saponin, torvonin-A, has been isolated from S. torvum leaves and its structure has been established as neochlorogenin-3-O-β-L-rhamnopyranosyl (1→2)β-L-rhamnopyranoside. 相似文献
12.
The trisaccharide, O-(2,3,4-tri-O-benzoyl-β-L-rhamnopyranosyl)-(1→4)-O-(2,3,6-tri-O-benzoyl-β-D-glucopyranosyl)-(1→6)-1,2,3,4-tetra-O-acetyl-β-D-glucopyranose has been prepared by two different routes. Condensation of this trisaccharide with oleanolic acid afforded the corresponding 1,2-trans glycosyl ester. Some other glycosyl esters of oleanolic acid were also prepared by the same method. 相似文献
13.
《Biotechnology advances》2017,35(1):1-19
The present review provides up-to-date information on the occurrence and methodologies used for producing and purifying endo-β-mannanases and a comprehensive comparison of their biochemical properties. The amalgamation of biochemical, molecular and structural biology approaches which have been used for understanding endo-β-mannanase families, catalytic mechanism, substrate binding, non-catalytic modules, trans-glycosylation, and multi-functional enzyme complexes has been given critical attention. A separate section entailing the state-of-the-art about thermostable endo-β-mannanases, which has emerged as an exciting field of both basic and applied research, is also deliberated. The remarkable progress made by endo-β-mannanases in various industrial sectors like food, feed, detergents, biofuel and oil drilling is also emphasized. 相似文献
14.
《Phytochemistry》1987,26(6):1789-1790
A new steroidal saponin has been isolated from the aerial part of Agave cantala and characterized as gitogenin-3-O-β-D-glucopyranosyl (1 → 3)-β-D-glucopyranoside. 相似文献
15.
Manuela Grimaldi Mario Scrima Cinzia Esposito Anna Ramunno Gerardino D'Errico Anna Maria D'Ursi 《生物化学与生物物理学报:生物膜》2010,1798(3):660-1426
Aβ (16-35) is the hydrophobic central core of β-amyloid peptide, the main component of plaques found in the brain tissue of Alzheimer's disease patients. Depending on the conditions present, β-amyloid peptides undergo a conformational transition from random coil or α-helical monomers, to highly toxic β-sheet oligomers and aggregate fibrils. The behavior of β-amyloid peptide at plasma membrane level has been extensively investigated, and membrane charge has been proved to be a key factor modulating its conformational properties. In the present work we probed the conformational behavior of Aβ (16-35) in response to negative charge modifications of the micelle surface. CD and NMR conformational analyses were performed in negatively charged pure SDS micelles and in zwitterionic DPC micelles “doped” with small amounts of SDS. To analyze the tendency of Aβ (16-35) to interact with these micellar systems, we performed EPR experiments on three spin-labeled analogues of Aβ (16-35), bearing the methyl 3-(2,2,5,5-tetramethyl-1-oxypyrrolinyl) methanethiolsulfonate spin label at the N-terminus, in the middle of the sequence and at the C-terminus, respectively. Our conformational data show that, by varying the negative charge of the membrane, Aβ (16-35) undergoes a conformational transition from a soluble helical-kink-helical structure, to a U-turn shaped conformation that resembles protofibril models. 相似文献
16.
A new polyhydroxy pregnane ester named tenasogenin was isolated from the seeds of Marsdenia tenacissima. On the basis of chemical and spectroscopic evidence and identification of its hydrolysis products, its structure has been established as 11α-O-β,β-dimethylacryloyl-3β,12β,14β,20R-tetrahydroxypregn-5-ene. 相似文献
17.
Isolation and identification of nystose from seeds of the horse chestnut (aesculus hippocastanum L.)
From the seeds of the horse chestnut (Aesculus hippocastanum L.), a tetrasaccharide containing 1 mol. of glucose and 3 mol. of fructose has been isolated and shown to be nystose [β-D-Fruf-(2→1)-β-D-Fruf-(2→1)-β-D-Fruf-(2→1)-α-D-Glcp · H2O]. 相似文献
18.
A new ellagitannin, punicafolin has been isolated from the leaves of Punica granatum and characterized by physicochemical data and spectral evidence as 1,2,4-tri-O-galloyl-3,6-(R)-hexahydroxydiphenoyl-β-D-glucose. The occurrence in the leaves of the known tannins, granatins A and B, corilagin, strictinin, 1,2,4,6-tetra-O-galloyl-β-D-glucose and 1,2,3,4,6-penta-O-galloyl-β-D-glucose has also been demonstrated. 相似文献
19.
Filippo Imperato 《Phytochemistry》1985,24(9):2136-2137
From aerial parts of the fern Asplenium bulbiferum, besides kaempferol 3,7-diglucoside and kaempferol 3-O-rhamnoside- 7-O-glucoside, the new glycoside kaempferol 3-O-β-glucoside-7-O-β-galactoside has been characterized. 相似文献
20.
J. Alberto Marco Oscar Barberá Juan F. Sanz Juan Sanchez-Parareda 《Phytochemistry》1985,24(10):2471-2472
A new flavonol glycoside, rhamnocitrin 3-O-β-D-galactopyranoside, has been isolated from aerial parts of Anthyllis onobrychioides, together with the known 3-O-β-D-galactopyranosides of quercetin, isorhamnetin and kaempferol. 相似文献