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 15 毫秒
1.
E Mappus  C Y Cuilleron 《Steroids》1979,33(6):693-718
The 3-(O-carboxymethyl)oximino derivative of 17β-hydroxy-5α-androstan-3-one (5α-dihydrotestosterone) was prepared. Thin-layer chromatography of the corresponding methyl ester showed the presence of two syn (60%) and anti (40%) geometrical isomers of the oxime chain to the C-4 position, which were characterized by 13C nmr. The 3β-hemisuccinami-do-5α-androstan-17β-ol was obtained after selective saponification with potassium carbonate of the 17β-hemisuccinate group of the 3,17-dihemi-succinoylated derivative of the previously described 3β-amino-5α-androstan-17β-ol. This 3β-hemisuccinamide was purified as the corresponding methyl ester-17β-acetate and was regenerated after saponification. The 3,3'-ethylenedioxy-7-oxo-5α-androstan-17β-yl acetate was obtained in quantitative yield by catalytic hydrogenation over 10% palladium-oncharcoal of the Δ5-7-oxo precursor in a dioxane-ethanol mixture containing traces of pyridine. The exclusive 5α-configuration of this hydrogenated product was established from nmr data and was confirmed by the synthesis of methyl 3,3'-ethylenedioxy-7-oxo-5β-cholan-24-oate as 5β-H-reference compound. The preceding 5α-H-7-ketone was converted into the 7-(O-carboxymethyl)oximino derivative (syn isomer to the C-6 position, exclusively) which was esterified into the corresponding methyl ester. The selective hydrolysis of the 3-ethyleneketal group was achieved by a short treatment with a formic acid-ether 1:1 (v/v) mixture at 20°C. Saponification of the latter reaction product with ethanolic potassium hydroxide gave the 7-(O-carboxymethyl)oximino-17β-hydroxy-5α-androstan-3-one derivative, which was characterized as the corresponding methyl ester. The reduction of the oxime of the 5α-H-7-ketone with sodium in ethanol or with lithium-aluminium hydride gave respectively the 7β-amine or the 7α-amine as the major product. The 7β- and 7α-configurations were established from nmr spectra of the corresponding 7-acetamido derivatives. The 7β- and 7α-hemisuccinamido derivatives were prepared from the mixture of 7β- and 7α-amines, as described above for 3-derivatives and were isolated after thin-layer chromatography of the methyl esters, followed by saponification of the corresponding 17β-acetates.  相似文献   

2.
(22R,23R)-22,23-dihydroxystigmast-4-en-3-one, (22R,23R)-22,23-dihydroxystigmast-4-en-3,6-dione, (22R,23R)-3β,5α,6β,22,23-pentahydroxystigmastane, (22R,23R)-5α,6α-oxido-3β,22,23-trihydroxystigmastane, (22R,23R)-5β,6β-oxido-3β,22,23-trihydroxystigmastane, and (22R,23R)-3β,6β,22,23-tetrahydroxystigmast-4-ene were synthesized. Their cytotoxicities were comparatively studied using the MCF-7 line of carcinoma cells of human mammary gland and cells of human hepatoma of the Hep G2 line.  相似文献   

3.
Three new steroid glycosides (evasteriosides C, D, and E) along with six known compounds were isolated from two Pacific starfish of the genus Evasterias. Evasterioside C from E. retiferacollected from the Sea of Japan was identified as (20R, 22E)-3-O-(β-D-xylopyranosyl)-24-nor-5α-cholest-22-ene-3β,6β,15α,26-pentaol 26-sulfate sodium salt. The structures of evasteriosides D and E from E. echinosoma (collected from the Gulf of Shelichov, the Sea of Okhotsk) were established as (20R, 24S)-24-O-(β-D-glucopyranosyl)-5α-cholestane-3β,6α,8,15β,24-pentaol and (20R,24S)-3,24-di-O-(β-D-xylopyranosyl)-cholest-4-ene-3β,6β,8,15α,24-pentaol, respectively. In addition, the known compounds pycnopodiosides A and C, luridoside A, 5α-cholestane-3β,6α,8,15β,16β,26-hexaol. 5α-Cholestane-3β,6α,8,15β,24-pentaol 24-sulfate sodium saltand marthasterone sulfate sodium salt were identified in E. echinosoma. The structures of the isolated compounds were established on the basis of spectroscopic analyses, using 1D and 2D NMR techniques, mass spectrometry, and some chemical transformations.  相似文献   

4.
A new iridoid, 5β,6β-dihydroxyantirrhide (1) was isolated from the dried leaves of Pseuderanthemum carruthersii (Seem.) Guill. var. atropurpureum (Bull.) Fosb. (Acanthaceae), together with 13 known compounds, including two iridoids, linarioside and antirrhinoside; five phenylethanoids, echipuroside A, verbascoside, isoverbascoside, isomartynoside and osmanthuside B; and six flavonoids, luteolin 7-O-β-d-glucopyranoside, luteolin 7-O-rutinoside, apigenin 7-O-rutinoside, apigenin 6-C-α-l-arabinopyranosyl–8-C-β-l-arabinopyranoside, apigenin 6,8-di-C-α-l-arabinopyranoside and apigenin 6-C-β-d-xylopyranosyl–8-C-α-l-arabinopyranoside. Their chemical structures were elucidated by 1D and 2D NMR as well as HR-ESI-MS spectroscopic analysis. Some purified compounds were evaluated the acetylcholinesterase inhibition and cytotoxic activities against the HeLa cervical cancer cell line and the MCF-7 breast cancer cell line at the concentration of 100 μg/mL. Luteolin 7-O-β-d-glucopyranoside exhibited cytotoxic activities against both the HeLa cervical cancer cell line and the MCF-7 breast cancer cell line. Verbascoside and isoverbascoside showed strong cytotoxic activity against the MCF-7 breast cancer cell line. The tested compounds showed the AChE inhibitory activity fairly weak.  相似文献   

5.
Two new steroid glycosides: distolasteroside D6, (24S)-24-O-(β-D-xylopyranosyl)-5α-cholestane-3β,6α,8,15β,16β,24-hexaol, and distolasteroside D7, (22E,24R)-24-O-(β-D-xylopyranosyl)-5α-cholest-22-ene-3β,6α,8,15β,24-pentaol were isolated along with the previously known distolasterosides D1, D2, and D3, echinasteroside C, and (25S)-5α-cholestane-3β4β,6α,7α,8,15α,16β,26-octaol from the Far Eastern starfish Distolasterias nipon. The structures of new compounds were elucidated by NMR spectroscopy and MALDI TOF mass spectrometry. Like neurotrophins, distolasterosides D1, D2, and D3 were shown to induce neuroblast differentiation in a mouse neuroblastoma C1300 cell culture.  相似文献   

6.
Three new steroidal saponins, spirosta-5,25(27)-diene-1β,3β-diol-1-O-α-l-rhamnopyranosyl-(1→2)-β-d-fucopyranoside (fruticoside H) 1, 5α-spirost-25(27)-ene-1β,3β-diol-1-O-α-l-rhamnopyranosyl-(1→2)-(4-O-sulfo)-β-d-fucopyranoside (fruticoside I) 2, and (22S)-cholest-5-ene-1β,3β,16β,22-tetrol 1-O-β-galactopyranosyl-16-O-α-l-rhamnopyranoside (fruticoside J) 3, together with the known quercetin 3-O-β-d-glucopyranoside, quercetin 3-O-[6-trans-p-coumaroyl]-β-d-glucopyranoside, quercetin 3-rutinoside, apigenin 8-C-β-d-glucopyranoside and farrerol, were isolated from the leaves of Cordyline fruticosa. Their structures were elucidated by spectroscopic techniques (1H NMR, 13C NMR, HSQC, 1H–1H COSY, HMBC, TOCSY, NOESY), mass spectrometry (HRESIMS, Tandem MS–MS), chemical methods and by comparison with published data. Compounds 1 and 2 showed moderate cytotoxic activity against MDA-MB 231 human breast adenocarcinoma cell line, HCT 116 human colon carcinoma cell line, and A375 human malignant melanoma cell line, while compound 3 was not active. Compound 2 also showed a moderate antibacterial activity against the Gram-positive Enterococcus faecalis.  相似文献   

7.
In order to understand the effect of polar head group modification on the thermotropic and barotropic phase behavior of phospholipid bilayer membranes, the phase transitions of dipalmitoylphosphatidylethanolamine (DPPE), dipalmitoylphosphatidyl-N-methylethanolamine (DPMePE), dipalmitoylphosphatidyl-N,N-dimethylethanolamine (DPMe2PE) and dipalmitoylphosphatidylcholine (DPPC) bilayer membranes were observed by differential scanning calorimetry and high-pressure optical methods. The temperatures of the so-called main transition from the gel (Lβ) or ripple gel (Pβ′) phase to the liquid crystalline (Lα) phase were almost linearly elevated by applying pressure. The slope of the temperature-pressure boundary, dT/dp, was in the range of 0.220-0.264 K MPa−1 depending on the number of methyl groups in the head group of lipids. The main-transition temperatures of N-methylated DPPEs decreased with increasing size of head group by stepwise N-methylation. On the other hand, there was no significant difference in thermodynamic quantities of the main transition between the phospholipids. With respect to the transition from the subgel (Lc) phase to the lamellar gel (Lβ or Lβ′) phase, the transition temperatures were also elevated by applying pressure. In the case of DPPE bilayer the Lc/Lβ transition appeared at a pressure higher than 21.8 MPa. At a pressure below 21.8 MPa the Lc/Lα transition was observed at a temperature higher than the main-transition temperature. The main (Lβ/Lα) transition can be recognized as the transformation between metastable phases in the range from ambient pressure to 21.8 MPa. Polymorphism in the gel phase is characteristic of DPPC bilayer membrane unlike other lipid bilayers used in this study: the Lβ′, Pβ′ and pressure-induced interdigitated gel (LβI) phases were observed only in the DPPC bilayer. Regarding the bilayers of DPPE, DPMePE and DPMe2PE, the interdigitation of acyl chain did not appear even at pressures as high as 200 MPa.  相似文献   

8.
Five cycloartane-type triterpene glycosides were isolated from the methanol extract of the roots of Astragalus amblolepis Fischer along with one known saponin, 3-O-β-D-xylopyranosyl-16-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxy-cycloartane. Structures of the compounds were established as 3-O-β-D-xylopyranosyl-25-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxy-cycloartane, 3-O-[β-D-glucuronopyranosyl-(1 → 2)-β-D-xylopyranosyl]-25-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxy-cycloartane, 3-O-β-D-xylopyranosyl-24,25-di-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxy-cycloartane, 6-O-α-L-rhamnopyranosyl-16,24-di-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxy-cycloartane, 6-O-α-L-rhamnopyranosyl-16,25-di-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxy-cycloartane by using 1D and 2D-NMR techniques and mass spectrometry. To the best of our knowledge, the glucuronic acid moiety in cycloartanes is reported for the first time.  相似文献   

9.
10.
Three new triterpene glycosides ursan-3β,19α,22β-triol-3-O-β-d-glucopyranosyl (2′→1″)-β-d-glucopyranoside (1), ursan-3α,11β-diol-3-O-α-d-glucopyranosyl-(6′→1″)-α-d-glucopyranosyl-(6″→1‴)-α-d-glucopyranosyl-(6‴→1‴′)-α-d-glucopyranoside (2) and lanost-5,24-dien-3β-ol-3-O-β-d-glucopyranosyl-(6′→1″)-β-d-glucopyranosyl-(6″→1‴)-β-d-glucopyranoside (3), together with one known compound were isolated and identified from the marc of red ginseng. Their structures were elucidated by spectroscopic data analysis. Compounds (13) were investigated for anti-inflammatory effects using the RAW 264.7 macrophage cell line. In the cell proliferation assay, lipopolysaccharide stimulation decreased cell proliferation of RAW 264.7 macrophage cells, but the suppression of cell proliferation was significantly protected by treatment with compounds 2 and 3. Compounds 2 and 3 had a suppressive effect on the production of nitric oxide (NO), and they inhibited mRNA expression of proinflammatory mediators such as inducible nitric oxide synthase, and cyclooxygenase-2, and proinflammatory cytokines such as two interleukins and tumor necrosis factor-α. These findings suggest that compounds 2 and 3 have potential anti-inflammatory activities.  相似文献   

11.
Three undescribed flavonol triglycosides, rhamnetin-3-O-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→6)]-β-d-glucopyranoside (champaluangoside A), rhamnetin-3-O-α-l-rhamnopyranosyl-(1→2)-[α-l-rhamnopyranosyl-(1→6)]-β-d-galactopyranoside (champaluangoside B) and rhamnocitrin-3-O-α-l-rhamnopyranosyl-(1→2)-[α-l-rhamnopyranosyl-(1→6)]-β-d-glucopyranoside (champaluangoside C), were isolated from Magnolia utilis in addition to eleven known compounds; quercetrin-3-O-α-l-rhamnopyranosyl-(1→2)-[α-l-rhamnopyranosyl-(1→6)]-β-d-glucopyranoside, oxytroflavoside G, magnoloside A, magnoloside M, magnoloside D, manglieside A, manglieside B, 1,2-di-O-β-d-glucopyranosyl-4-allylbebzene, syringrin, benzyl β-d-allopyranoside and (+)-syringaresinol-O-β-d-glucopyranoside. The structure elucidation of these compounds was based on analyses of physical and spectroscopic data.  相似文献   

12.
Monte Carlo simulations of the temperature-induced unfolding of small gas-phase polyalanines in a static, homogeneous electric field are reported, based on the AMBER ff96 force field. The peptides exhibit a structural transition from the native α-helix state to entropically favored β-sheet conformations, before eventually turning to extended coil at higher temperatures. Upon switching the electric field, the molecules undergo preferential alignment of their dipole moment vector toward the field axis and a shift of the α-β transition to higher temperatures. At higher field strengths (>108 V/m) the molecules stretch and the α-β and β-coil transitions merge. A simple three-state model is shown to account for the observed behavior. Under even higher fields, density functional theory calculations and a polarizable force field both show that electronic rearrangements tend to further increase the dipole moment, polarization effects being approximately half in magnitude with respect to stretching effect. Finally a tentative (temperature, field-strength) phase diagram is sketched.  相似文献   

13.
Two new saponins, yuccoside C and protoyuccoside C, have been isolated from the methanolic extract of Yucca filamentosa root and their structures elucidated. Yuccoside C is 3-O-[α-d-galactopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranosyl]-(25S)-5β-spirostan-3β-ol, whereas protoyuccoside C is 3-O-[α-d-galactopyranosyl-(1 → 2)-β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranosyl]-26-O-[β-d-glucopyranosy]-(25S)-5β-furostan-3β,22α,26-triol.  相似文献   

14.
Three saponins, named ceposide A, ceposide B, and ceposide C were isolated from the bulbs of white onion, Allium cepa L. Elucidation of their structure was carried out by comprehensive spectroscopic analyses, including 2D NMR spectroscopy and mass spectrometry, and chemical evidences. The structures of the compounds were identified as (25R)-furost-5(6)-en-1β,3β,22α,26-tetraol 1-O-β-d-xylopyranosyl 26-O-α-d-rhamnoyranosyl-(1  2)-O-β-d-galactopyranoside (ceposide A), (25R)-furost-5(6)-en-1β,3β,22α,26-tetraol 1-O-β-d-xylopyranosyl 26-O-α-d-rhamnoyranosyl-(1  2)-O-β-d-glucopyranoside (ceposide B), and (25R)-furost-5(6)-en-1β,3β,22α,26-tetraol 1-O-β-d-galactopyranosyl 26-O-α-d-rhamnoyranosyl-(1  2)-O-β-d-galactopyranoside (ceposide C). The isolated compounds, alone and in combinations, were evaluated for their antimicrobial activity on ten fungal species. Antifungal activity of all three saponins increased with their concentration and varied with the following rank: ceposide B > ceposide A–ceposide C. We found a significant synergism in the antifungal activity of the three ceposides against Botrytis cinerea and Trichoderma atroviride, because growth of these fungi was strongly inhibited when the three saponins were applied in combination. In contrast, Fusarium oxysporum f. sp. lycopersici, Sclerotium cepivorum and Rhizoctonia solani were very little affected by saponins.  相似文献   

15.
Six cycloartane-type triterpene glycosides were isolated from Astragalus icmadophilus along with two known cycloartane-type glycosides, five known oleanane-type triterpene glycosides and one known flavonol glycoside. The structures of the six compounds were established as 3-O-[α-L-arabinopyranosyl-(1  2)-O-3-acetoxy-α-L-arabinopyranosyl]-6-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxycycloartane, 3-O-[α-L-rhamnopyranosyl-(1  2)-O-α-L-arabinopyranosyl-(1  2)-O-β-D-xylopyranosyl]-6-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxy cycloartane, 3-O-[α-L-arabinopyranosyl-(1  2)-O-3,4-diacetoxy-α-L-arabinopyranosyl]-6-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxycycloartane, 3-O-[α-L-arabinopyranosyl-(1  2)-O-3-acetoxy-α-L-arabinopyranosyl]-6-O-β-D-glucopyranosyl-3β,6α,16β,25-tetrahydroxy-20(R),24(S)-epoxycycloartane, 3-O-[α-L-arabinopyranosyl-(1  2)-O-β-D-xylopyranosyl]-6-O-β-D-glucopyranosyl-3β,6α,16β,24α-tetrahydroxy-20(R),25-epoxycycloartane, 3-O-[α-L-rhamnopyranosyl-(1  2)-O-α-L-arabinopyranosyl-(1  2)-O-β-D-xylopyranosyl]-6-O-β-D-glucopyranosyl-3β,6α,16β,24α-tetrahydroxy-20(R),25-epoxycycloartane by the extensive use of 1D- and 2D-NMR experiments along with ESIMS and HRMS analysis.The first four compounds are cyclocanthogenin and cycloastragenol glycosides, whereas the last two are based on cyclocephalogenin as aglycone, more unusual in the plant kingdom, so far reported only from Astragalus spp.  相似文献   

16.
Two new dammarane saponins, 2α,3β,12β-trihydroxydammar-20(22),24-diene-3-O-[β-d-glucopyranoxyl(1→2)-β-d-6″-O-acetylglucopyranoside (1, namely damulin C) and 2α,3β,12β-trihydroxydammar-20(21),24-diene-3-O-[β-d-glucopyranoxyl(1→2)-β-d-6″-O-acetylglucopyranoside (2, namely damulin D), were isolated from the ethanol extract of Gynostemma pentaphyllum, which had been heat processed by steaming at 125 °C. The NMR spectroscopic data of the novel saponins were completely assigned by using a combination of 2D NMR experiments including 1H–1H COSY, HSQC, and HMBC. Their cytotoxic activities of human liver adenocarcinoma HepG2 cells were evaluated in vitro. They showed cytotoxicities against HepG2 cell line with IC50 of 40 ± 0.7 and 38 ± 0.5 μg/ml, respectively.  相似文献   

17.
Two oligofurostanosides and two spirostanosides, isolated from a methanol extract of Asparagus adscendens (leaves), were characterized as 3-O-[{α-l-rhamnopyranosyl (1 → 4)} {α-l-rhamnopyranosyl (1 → 6)}-β-d-glucopyranosyl]-26-O-[β-d-glucopyranosyl]-22α-methoxy-(25S)-furost-5-en-3β,26-diol (Adscendoside A), 3-O-[{α-l-rhamnopyranosyl (1 → 4)} {α-l-rhamnopyranosyl (1 → 6)}-β-d-glucopyranosyl]-26-O-[β-d-glucopyranosyl]-(25S)-furost-5-en-3β,22α,26-triol-(Adscendoside B), 3-O-[{α-l-rhamnopyranosyl (1 → 6)}-β-d-glucopyranosyl]-(25S)-spirostan-5-en-3β-ol (Adscendin A) and 3-O-[{α-l-rhamnopyranosyl (1 → 4)} {α-l-rhamnopyranosyl (1 → 6)}-β-d-glucopyr anosyl]-(25S)-spirostan-5-en-3β-ol (Adscendin B), respectively. Adscendin B and Adscendoside A are the artefacts of Adscendoside B formed through hydrolysis and methanol extraction respectively.bl]  相似文献   

18.
Paul Gaskin 《Phytochemistry》1975,14(7):1575-1578
C-α and C-β, previously isolated from seed of Phaseolus coccineus, are shown respectively to be the bis-O-isopropylidene and the 16,17-mono-O-isopropylidene derivatives of ent-6α,7α,16β,17-tetrahydroxykauranoic acid. By GC-MS characterization of the products of acidic, basic and enzymatic hydrolysis, water soluble conjugates of the following compounds have been shown to occur in P. coccineus seed: GA8, GA17, GA20, GA28, ent-6α,7α,13-trihydroxykaurenoic acid, ent-6α,7α,17-trihydroxy-16β-kauranoic acid, ent-6α,7α,16β,17-tetrahydroxykauranoic acid, 7β,13-dihydroxykaurenolide and abscisic acid.  相似文献   

19.
The alkaloid mixture of Datura suaveolens shows distinct differences compared with that of other tree daturas. Aerial parts contain in addition to hyoscine, apohyoscine, norhyoscine, atropine and noratropine, a relatively high proportion of tigloyl esters—3α,6β-ditigloyloxytropan-7β-ol, 6β-tigloyloxytropan-3α,7β-diol,3α-tigloyloxytropan-6β,7β-diol (meteloidine) and (—)- and (±)-3α-tigloyloxytropan-6β-ol. The roots contain hyoscine, meteloidine, atropine, littorine, 3α-acetoxytropane, 6β-(α-methylbutyryloxy)-3α-tigloyloxytropane, 3α,6β-ditigloyloxytropan-7β-ol, 3α-tigloyloxytropan-6β-ol, tropine and cuscohygrine. Other, as yet uncharacterized, bases are present in the plant. Norhyoscine is a principal alkaloid of the corollas.  相似文献   

20.
Eight neutral oligosaccharide fractions were obtained from the pooled urine of two patients with mannosidosis by Bio-Gel P2 and Bio-Gel P4 column chromatography. The structures of seventeen oligosaccharides were determined by monosaccharide composition analysis, methylation studies, acetolysis, Smith degradation, and 13C NMR analysis. Three of the proposed structures, Manα1-3Manβ1-4GlcNAc, Manα1-2Manα1-3Manβ1-4GlcNAc, and Manα1-2Manα1-2Manα1-3Manβ1-4GlcNAc are identical to those first published by Norden et al. (N. E. Norden, A. Lundblad, S. Svennson, P. A. Ockerman, and S. Autio, 1973. J. Biol. Chem.248, 6210–6215; N. E. Norden, A. Lundblad, S. Svennson, and S. Autio, 1974. Biochemistry13, 871–874). Thirteen of them, Manα1-3Manα1-6(Manα1-3)-Manβ1-4GlcNAc, Manα1-3Manα1-6(Manα1-2Manα1-3)Manβ1-4GlcNAc, and 11 isomers of (Manα1-2)0–4[Manα1-6(Manα1-3)Manα1-6(Manα1-3)Manβ1-4GlcNAc], are the same as those first published by Yamashita et al. (K. Yamashita, Y. Tachibana, K. Mihara, S. Okada, H. Yabuuchi, and A. Kobata, 1980, J. Biol. Chem.255, 5126–5133); a tetrasac-charide, Manα1-6(Manα1-3)Manβ1-4GlcNAc, is newly reported and several other structural possibilities are proposed.  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