首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 599 毫秒
1.
Proofs are given of the structures of two new glycosides of the furostan series isolated from the leaves of the plantNolina microscarpa S. Wats. (family Dracaenaceae). Nolinofuroside D is (25S)-furost-5-ene-1,3,22,26-tetraol 1-O--D-galactopyranoside 26-O--D-glucopyranoside (I), and nolinofuroside F is (25S)-furost-5-ene-1,3,22,26-tetraol 1-O--D-fucopyranoside 26-O--D-glucopyranoside 3-O--L-rhamnopyranoside (VII). The latter was characterized as its 22-O-methyl ether (VIII). Nolinofuroside E (IV) has the structure of (25S)-furost-5-ene-1,3,22,26-tetraol 26-O--glucopyranoside 1-O-[O--L-rhamnopyranosyl-(12)--D-fucopyranoside], which followed from the structure of the fermentation product (VI). The products of the fermentation of the above-named compounds were present in the plant in only trace amounts. Only one of them — nolinospiroside D (III) — has not been described previously. This monoside of the spirostan series is (25S)-spirost-5-ene-1,3-diol 1-O--D-galactopyranoside.M. V. Frunze Simferopol' State University. Institute of Chemistry of Plant Substances, Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 678–686, September–October, 1991.  相似文献   

2.
15,16-Methyleneprogesterone was produced from 15,16-methylene-3-hydroxyandrost-5-en-17-one with Wittig olefination of 17-ketone by methoxymethylenetriphenylphosphorane as the key stage.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 203–207, January, 1993.  相似文献   

3.
Summary With strophanthidin as starting material, 3, 5, 10, l4-tetrahydroxy-19-norandrostan-17-one has been obtained by a five-stage synthesis.  相似文献   

4.
A glycoside has been isolated from the plantNolina microcarpa S. Wats. (family Dracaenaceae) which has been called nolinofuroside B and has the structure of 6-methoxy-3,5-cyclo-(25S)-furostan-1,22,26-triol 1-O--D-fucopyranoside 26-O--D-glucopyranoside (I). Enzymatic hydrolysis of the bioside (I) yielded nolinospiroside B (III) and nolinogenin (IV). The latter is 6-methoxy-3,5-cyclo-(25S)-spirostan-6-ol, and glycoside (III) is its 1-O--D-fucopyranoside.M. V. Frunze Simferopol' State University. Institute of Chemistry of Plant Substances, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 218–224, March–April, 1992.  相似文献   

5.
Minor polyhydroxysteroids from the starfishCrossaster papposus have been isolated and characterized: 5-cholestane-3,6,8,15,16,26-hexanol and 24-methyl-5-cholesta-14,22E-diene-3,6,8,26-tetraol 26-O-(3-O-methyl--D-glucopyranoside) (crossasteroside P3). The structures of the compounds were established on the basis of spectral methods.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, USSR Academy of Sciences, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, p. 218–221, March–April, 1990.  相似文献   

6.
From the far-eastern starfishHenricia sp. we have isolated and characterized the new polyhydroxysteroid (24S)-5-cholestane-3,4,6,8,15,24-hexaol and three new glycosides: (24S)-5-cholestane-3,4,6,8,15,24-hexaol 3-O-(2,4-di-O-methyl--D-xylopyranoside) (henricioside H1), 24-methyl-5-cholesta-4,22E-diene-3,6,8,15,16,26-hexaol 3-O-(2,3-di-O-methyl--D-xylopyranoside) (henricioside H2), and the 22,23-dihydro derivative of henricioside H2 (henricioside H3).Pacific Ocean Institute of Bioorganic Chemistry, Far-Eastern Scientific Center, Russian Academy of Sciences, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 249–253, March–April, 1993.  相似文献   

7.
Summary The effect of the substitution in position 1 on the low-energy conformations of the oxytocin/vasopressin 20-membered ring was investigated by means of molecular mechanics. Three representative substitutions were considered: -mercapto-,-dimethyl)propionic acid (Dmp), (-mercapto-,-cyclopentamethylene)propionic acid (Cpp), both forming strong antagonists, and (,-dimethyl--mercapto)propionic acid (-Dmp), forming analogs of strongly reduced biological activity, with the -mercaptopropionic (Mpa) residue taken as reference. Both ECEPP/2 (rigid valence geometry) and AMBER (flexible valence geometry) force fields were employed in the calculations. Three basic types of backbone conformations were taken into account which are distinguished by the type of -turn at residues 3 and 4: 1/III, II, and I/III, all types containing one or two intra-annular hydrogen bonds. The allowed (ring-closed) disulfide-bridge conformations were searched by an algorithm formulated in terms of scanning the disulfide-bridge torsional angle C-S-S-C. The ECEPP/2 and AMBER energies of the obtained conformations were found to be in reasonable agreement. Two of the low-energy conformers of the [Mpa1]-compound agreed very well with the cyclic part of the two conformers found in the crystal structure of [Mpa1]-oxytocin. An analysis of the effect of -substitution on relative energies showed that the conformations with the N-C-CH2-CH2 (1) and C-CH2-CH2-S (1) angles of the first residue around (–100°, 60°) and (100°, –60°) are not affected; this in most cases implies a left-handed disulfide bridge. In the case of -substitution the allowed values of 1 are close to ± 60°. This requirement, being in contradiction to the one concerning -substitution, could explain the very low biological activity of the -substituted analogs. The conformational preferences of substituted compounds can largely be explained by the analysis of local interactions within the first residue. Based on the selection of the conformations which are low in energy for both the reference and -substituted compounds, two distinct types of possible binding conformations were proposed, the first one being similar to the crystal conformer with a left-handed disulfide bridge, the second one having a right-handed bridge, but a geometry different from that of the crystal conformer with the right-handed bridge. The first type of disulfide-bridge arrangement is equally favorable for both I/III and II types of backbone structure, while the second one is allowed only for the II type of backbone. No conformation of the I/III type has a low enough energy to be considered as a possible binding conformation for all of the active compounds studied in this work.  相似文献   

8.
The known compound trojanoside A (1) and a new cycloartane glycoside cyclostipuloside E (2) were isolated from the aerial parts of Tragacantha stipulosa Boriss. The structure of cyclostipuloside E was proposed as 24R-cycloartan-3,6,16,24,25-pentaol 6,16,25-tri-O--D-glucopyranoside 3-O--D-xylopyranoside based.  相似文献   

9.
Conclusions The condensation of chloral with hypophosphorous acid has given,,-triebloro--hydroxyethyl phosphonous and bis-(, ,-trichloro--hydroxyethyl)-phosphinic acids.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, p. 1095, June, 1966.  相似文献   

10.
Summary Ring opening of -trifluoromethyl- -methyl- -propiolactone is unidirectional and leads to derivatives of -trifluoromethyl- -hydroxybutyric acid.  相似文献   

11.
Three new glycosides, D1, D2, and D3, have been isolated from the Far Eastern starfishDistolasterias nipon. They have been identified by chemical and physicochemical methods as 5-cholestane÷3,6,8,15,24-pentaol 3,24-di-O--D-xylopyranoside, t-cholest-22-ene-3,6,8,15,24-pentaol 3,24-di-O--D-xylopyranoside (II), and 5-cholestane-3,6,8,15,24-pentaol 24-O--D-glucopyranoside 3-O--D-xylopyranoside (III).Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 250–255, March–April, 1987.  相似文献   

12.
Summary Four substances have been isolated from the seeds ofCoronilla hyrcana: hyrcanoside, deglucohyrcanoside, hyrcanogenin, and substance E.It has been established that hyrcanoside (I) has the structure 3-(O--D-xylopyranosyl- <4 1 > -O--D-glycopyranosyl)-14-hydroxy-19-oxocard-4, 20 (22)-dienolide; deglucohyrcanoside (VII) is 3-(O--D-xylopyranosyl)-14-hydroxy-19-oxocard-4, 20 (22)-dienolide; and hyrcanogenin (V) is 3, 14-dihydroxy-19-oxocard-4, 20 (22)-dienolide. Both the aglycone hycanogenin (V) and its glycosides (I) and (VII) are new compounds.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 4, pp. 251–257, 1966  相似文献   

13.
Summary From a methanolic extract of the skins of the bulbs ofAllium giganteum Rgl, a new steroid glycoside has been isolated — aginoside, which is (25R)-5-spirostan-2, 3, 6-triol 3-0-{[0--D-xylopyranosyl-(13)-]-[0--D-glucopyranosyl-(12)]-0--D-glucopyranosyl-(14)-0--D-galactopyranoside}.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 480–486, July–August, 1976.  相似文献   

14.
Another two methylsteroids of the cycloartane series have been isolated from the epigeal part ofAstragalus alopecurus. The structures of the compounds isolated, cycloalpigenin and cycloalpioside, have been established as (20R,24R)-16,24:20, 24-diepoxycycloartane-3,7,25-triol and (20R,24R)-16, 24:20,24-diepoxycycloartane-3,7, 25-triol 3-O--D-xylopyranoside, respectively, on the basis of chemical transformations and spectral characteristics. The structure of cycloalpigenin has been confirmed by chemical correlation with that of cycloalpigenin D.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 700–708, September–October, 1995. Original article submitted February 1, 1995.  相似文献   

15.
The effects of -cyclodextrin (-CyD), heptakis(2,6-di-O-methyl)--cyclodextrin (DMCyD) and heptakis(2,3,6-tri-O-methyl)--cyclodextrin (TMCyD) ontrans-cis photoisomerization of 1-ethyl-4-(4-hydroxystyryl)pyridinium (POH) have been studied in aqueous solutions. The ratio of [cis]/[trans] for POH in the photostationary state at pH 8.54 was remarkably reduced by the presence of CyD or DMCyD. The reduction of the [cis]/[trans] ratio in the photostationary state was explained in terms of the shift of the equilibrium of POH + trans PO trans + H toward PO trans formation. The binding constants of CyD and DMCyD for PO trans were 2.00- and 1.36-fold larger than those for POH + trans , respectively. The binding constants of TMCyD for both species are much smaller than those of CyD and DMCyD. This result indicates that PO trans , which has a betain structure, forms stable complexes with CyD and DMCyD with its hydrophobic parts inside and the charged parts outside the CyD cavities.  相似文献   

16.
Literature information is given on the current state of the study of the chemical transformation of cycloartane triterpenoids. A method has been developed for the transformation of the genin part of glycosides of 20,24-epoxycycloartan-25-ols with retention of the carbohydrate constituents. Three 25-norglycosides have been synthesized from natural cyclosieversigenin glycosides, namely 16-acetoxy-3,6-dihydroxy-20R,25-norcycloartan-20,24-olide 3-O-[O--L-arabinopyranosyl-(12)--D-xylopyranoside] 6-O--D-xylopyranoside (VIII), sodium 3,6,16,20-tetrahydroxy-20R,25-norcycloartan-24-oate 6-O--D-glucopyranoside 3-O--D-xylopyranoside (XII), and 20R,25-norcycloartane-3,6,16,20,24-pentaol 6-O--D-glucopyranoside 3-O--D-xylopyranoside (XIII).Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 710–718, September–October, 1993.  相似文献   

17.
Two new steroid glycosides have been isolated from an ethanolic extract of the starfishCrossaster papposus — crossasterosides P1 and P2. On the basis of chemical transformations and spectral characteristics, the structure of crossasteroside P1 has been established as (24R)-24-ethyl-5-cholestane-3,6,8,15,16,29-hexaol 29-O-[2-O-methyl--D-xylopyranosyl-(1 2)--D-galactofuranoside]. Crossasteroside P2 is its 4-hydroxy analogue.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 669–673, September–October, 1989.  相似文献   

18.
Four new polyhydroxysteroids, 5-cholesta-3,5,6,15,16,25,26-heptaol, 24-ethyl-5-cholesta-3,5,6,15,28,29-heptaol-29-sulfate, (22E)-24-methyl-5-cholest-22-ene-3,5,6,15,25,26-hexaol-26-sulfate, 24-propyl-5-cholesta-3,5,6,8,15,28,29-heptaol, and the known 5-cholesta-3,5,6,15,16,26-hexaol, have been isolated from the starfishCtenodiscus crispatus.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1821–1825, October, 1994.  相似文献   

19.
In addition to the know steroid sapogenin (25S)-ruscogenin (I), three new glycosides have been isolated from the leaves ofNolina microcarpa S. Wats. (family Dracaenacea), and the following structures are suggested for them: (25S)-spirost-5-ene-1,3-diol 1-O--D-fucopyranoside (nolinospiroside C, II), (25S)-furost-5-ene-1,3,22,26-tetraol 1-O--D-fucopyranoside (nolinofuroside A, III), and (25S)-furost-5-ene-1, 3, 22, 26-tetraol 1-O--D-fucopyranoside 26-O--D-glucopyranoside (nolinofuroside C, V).M. V. Frunze Simferopol' State University. Institute of Chemistry of Plant Substances, Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 672–678, September–October, 1991.  相似文献   

20.
The reaction of dibenzylphosphine oxide with O-methyloximes of some ,-unsaturated ketones results in the phosphorylation at the -carbon atom to form methoxyiminophosphine oxides, whereas the reaction of dibenzylphosphine oxide with O-methyloximes of ,-unsaturated aldehydes affords aminodihydrophosphole oxides.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号