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1.
Structure of monardaein was determined to be 3-0-(6-0-trans-p-coumaryl-β-D-glucopyranosyl)-5-O- (4,6-di-O-malonyl-β-D-glucopyranosyl) pelargonidin (1).  相似文献   

2.
4-O-(2,6-diamino-2,3,4,6-tetradeoxy-3-C-methyl-β-L-arabino and lyxo-hexopyranosyl) and 4-O-(2-amino2,3,4,6-tetradeoxy-5-c-methyl-L-threo-hexopyranosyl-6-O-(3-amino-3-decxy-α-D-glucopyranosyl)-2-deoxystreptamine (6, 7 and 12) were synthesized from a kanamycin B derivative (1) by regiospecific methylation and stereospecific hydrogenation followed by removal of masking groups, converting a D-sugar moiety (4-O-glycoside portion) into L-sugar. The usual conformation of 6 and 7 were determined as boat and skew by 250 MHz PMR spectra respectively.  相似文献   

3.
Three new flavonol C-glycosides: 3′-(3″,7″-dimethyl-2″,6″-octadiene)-8-C-β-D-glucosyl-kaempferol 3-O-β-D-glucoside (1), 3′-(3″,7″-dimethyl-2″,6″-octadiene)-8-C-β-D-glucosyl-kaempferol 3-O-β-D-glucosyl [1→4]-α-D-glucoside (2) and 6-(3″-methyl-2″-butene)-3′-methoxyl-8-C-β-D-glucosyl-kaempferol 3-O-β-D-glucosyl [1→4]-β-D-glucoside (3) have been isolated from 80% ethanolic extract of the aerial parts of Sida cordifolia Linn followed by partitioning with ethyl acetate. Structures were established by chemical and spectroscopic methods.  相似文献   

4.
A new non-bitter quassinoid, named shinjulactone C (1), was isolated from the root bark of Ailanthus altissima SWINGLE and shown to be 1α, 12α:5α, 13α-dicyclo-1β, 12β, 20-trihydroxy-9βH-picras-3-ene-2, 11, 16-trione by X-ray diffraction method.  相似文献   

5.
Aloeresin A, a major constituent of Cape Aloe, is shown to be 2′-O-(E)-p-coumaroyl aloesin (3) instead of 6′-O-(E)-p-coumaroyl aloesin (2) as accepted so far.  相似文献   

6.
The stereoselective synthesis of 3-O-methyl-7α-p-toluenesulphonyl-8α, 9α, 14β-estradiol (25) and its 11-oxo derivative (26) via thermolysis of 1β-tert-butoxy-2α-[2-(4-methoxybenzocyclobutenyl)ethyl]-2β-methy1-3α-[2-(p-toluenesulphonyl)ethenyl] cyclopentane (22) and its oxo derivative (24), which were derived from condensation product (9) of optically active aldehyde (8) and 1-cyano-4-methoxybenzocyclobutene through 10 and 11 to selenides 16 and 21, is described.  相似文献   

7.
The structure of sarothamnoside (genistein 7,4′-di-O-[4-O-β-D-glucopyranosyl-β-D-apiofuranoside]), a new isoflavone glycoside from Sarothamnus scoparius and S, patens, has been established by spectral analysis, mainly 13C NMR.  相似文献   

8.
- 14α-Methyl-5α-cholest-9(11)-en-3β-ol (2) and 4α,14α-dimethyl-5α-cholest-9(11)-en-3β-ol (3) have been isolated from the sea cucumber Psolusfabricii and characterised by 1H NMR, 13C NMR and mass spectrometry. Lanost-9(11)-en-3β-ol (4) has also been tentatively identified. The relevance of this series of Δ9(11)-sterols to holothurin biosynthesis is briefly discussed.  相似文献   

9.
建立中药普乐安片的质量标准.采用TLC法对普乐安片中主要有效成分山奈酚-3-O-β-D-(2-O-β-D-葡萄糖基)吡喃葡萄糖苷(KMP)进行定性鉴别.采用HPLC法对普乐安片中主要有效成分山奈酚-3,4′-双-O-β-D-葡萄糖苷(KMG)和山奈酚-3-O-β-D-(2-O-β-D-葡萄糖基)吡喃葡萄糖苷进行含量测定...  相似文献   

10.
Four novel polyoxygenated C28-sterols have been identified from the soft coral L. depressum (the Gulf of Eilat, the Red Sea): the 22,28-lactol of 24-methylcholest-5-en-3β,22(R),25-triol-28-al (1), 24-methylcholest-5-en-3β,22(R),25,28-tetraol(2) and the corresponding 5,6β-epoxides (3 and 4).  相似文献   

11.
Two novel nucleosides, mycalisines A and B, have been isolated from a marine sponge and their structures elucidated as 4-amino-5-cyano-7-(3-O-methyl-5-deoxy-β-D-erythro-pent-4-enofuranosyl)-pyrrolo[2,3-d]pyrimidine and 5-cyano-7-(3-O-methyl-5-deoxy-β-D-erythro-pent-4-enofuranosyl)-pyrrolo[2,3-d]pyrimidine-4-one, respectively. Both compounds inhibit cell division of fertilized starfish eggs.  相似文献   

12.
13.
Electron-deficient aromatics, such as 2,5-bis(trifluoromethylmercapto)thiophene (1a) or (trifluoromethylmercapto)benzene (8a), react with F3CSCl in the presence of F3CSO3 as a catalyst to give mainly 3-chloro-2,5-bis(trifluoromethylmercapto)thiophen (3a) and 1-chloro-4- or 2-(trifluoromethylmercapto)benzene (10, respectively. This reaction competes with the one expected to result in 2,3,5-tris(trifluoromethylmercapto)thiophene (2a) and 1,4- and 1,2-bis(trifluoromethylmercapto)benzene (9,9′), respectively. Further reactions of deactivated aromatics with Cl3-nFnCSCl show that the chlorine substitution is in general catalysed by strong acids. Reaction mechanisms are proposed for both Substitutions. The Cl3-nFnCS group in aromatics exerts a -M-effect in the case of an attack of a positive ion, e.g. H, the well-known +M-effect in the case of reactions with positively polarized molecules, e.g. CF3Sβ+Clβ-.  相似文献   

14.
Two steroidal compounds BR-1 (I) and ?2 (II) which had been obtained from the rhizomes of Campylandra aurantiaca Baker, were isolated also from those of Rohdea japonica Roth. They were identified, respectively, by X-ray analysis and chemical correlation as 1β,2β,3β,4β,5β,7α-hydroxy-spirost-25(27)-en-6-one and its corresponding 6β-hydroxy compound.  相似文献   

15.
Lithio reagents derived from 1-triisopropylsilylpropyne (1) and 1,3-bis-[triisopropylsilyl]propane (3) are effective for the synthesis of Z or E terminal enyne units (CHCHCCH) and for carboncarbon bond formation with halides, aldehydes, ketones, epoxides, and α,β-enones.  相似文献   

16.
2β-Fluoro-1α-hydroxyvitamin D3(3) was prepared from 1,2α-epoxy-cholest-5-en-3β-yl tetrahydropyranyl ether(1a via 2β-fluorocholest-5-ene-1α, 3β-diol(2).  相似文献   

17.
A stereoselectivity in an intramolecular cycloaddition of the olefinic o-quinodimethanes 13 and 23 generated insitu from the thermolysis of optically active 4β-[2-(4-methoxybenzocyclobutenyl)ethyl] -5α-methoxymethyl-3-phenyl-thio-methylenefuran-2-ones 12 and 22, respectively, is studied and a stereoselective synthesis of (+)-trans-4,5-( 4-methoxybenzo) -1β,7aβ-(2α-methoxymethyl-5-oxofuro)hydrindane 1 is also described.  相似文献   

18.
A new carotenoid sulphate, Ophioxanthin, has been isolated from the ophiuroid Ophioderma longicaudum; ophioxanthin is the second known naturally occurring carotenoid sulphate and was shown to be 5,6,5′,6′-tetrahydro-β,β-carotene-3,4,3′,4′-tetraol 4,4′-disulphate (1).  相似文献   

19.
Three new triterpenes zeylanol, zeylanonol and zeylandiol isolated from Kokoonazeylanica have been identified as 6β-hydroxyfriedelan-3-one, 6β-hydroxyfriedelan-3,21-dione and 6β,21β-dihydroxyfriedelan-3-one, respectively by spectroscopic methods and chemical interconversions.  相似文献   

20.
Cyclic as well as acyclic ketones, both saturated and α,β-unsaturated, can be converted into their homologous enamines by Horner-Wittig reaction with N-methyl-N-anilinomethyl diphenylphosphine oxide (3).  相似文献   

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