摘要:

Three new triterpenoid saponins (1–3), together with one known saponin scaberoside B6methyl ester (4) were isolated from an ethanol extract of roots ofAster auriculatus. The structures of1–3have been determined on the basis of spectral and chemical evidence as 3-O-β-D-glucuronyl-16α-hydroxy-olean-12-en-28-oic acid 28-O-[α-L-arabinopyranosyl(1 → 4)-α-L-rhamnopyranosyl(1 → 2)]-[β-D-xylopyranosyl(1 → 3)-β-D-xylopyranosyl(1 → 3)]-α-L-arabinopyranoside (1), the methyl ester of 3-O-β-D-glucuronyl-16α-hydroxy-olean-12-en-28-oic acid 28-O-[β-D-xylopyranosyl(1 → 3)-α-L-arabinopyranosyl(1 → 4)]-[β-D-apiofuranosyl(1 → 3)]-α-L-rhamnopyranosyl(1 → 2)-β-D-xylopyranoside (2), and 3-O-β-D-glucuronyl-olean-12-en-28-oic acid 28-O-β-D-xylopyranosyl(1 → 3)-β-D-xylopyranosyl(1 → 4)-α-L-rhamnopyranosyl(1 → 2)-α-L-arabinopyranoside (3).

ISSN:1028-6020    

DOI:10.1080/10286029808039839

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

A new flavonoid glycoside (1) was isolated from the roots ofMimosa rubicaulis, its structure was elucidated as 5,7,4′-trihydroxy-6,3′,5′-trimethoxy-flavone-7-O-α-L-arabinopyranosyl-(1 → 6)-O-β-D-glucopyranoside by chemical degradation and spectral analysis.

ISSN:1028-6020    

DOI:10.1080/10286029808039840

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Four tetracyclic triterpene glycosides picfeltarraenins VI(4), VII(5), VIII(6) and IX(7) along with three known compounds picfeltarraenins IA, IBand II were isolated from the water soluble part ofPicria fel-tarrae. Their structures were elucidated on the basis of chemical and spectroscopic methods.

ISSN:1028-6020    

DOI:10.1080/10286029808039841

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Ras proteins must be isoprenylated at a conserved cysteine residue near the carboxyl terminus (Cys-186 in mammalian Ras P21proteins) in order to extend their biological activity. Previous studies indicated that an intermediate in mevalonate pathway, most likely farnesyl pyrophosphate, is the donor of this isoprenyl group, that using inhibitors of the mevalonate pathway could block the transforming properties of ras oncogene. Unfortunately, mevalonate is the precursor of various end products essential to mammalian cells, such as dolichols, ubiquinones, heme A, and cholesterol. In this study, we partially purified farnesyl protein transferase (FPTase) capable of catalyzing the farnesylation of unprocessed Ras P21proteinsin vitrofrom porcine kidney epithelial-like LLC-PK1 cells, human lung adenocarcinoma A549 cells and human pancreatic cancer MIA PaCa-2 cells. We observed the effects of the monoterpene compound, d-limonene (1); turmeric derivatives, TD-I (2) and TD-II (3); polyphenol compound, gallotannin; salviol derivative, SMD; and retinoid acid derivative, RAD on FPTase activity. We found that turmeric derivatives and gallotannin had a strong inhibition on FPTase besides d-limonene, while gallotannin was the strongest among synthetic and natural compounds tested. Saliviol and retinoid acid derivatives had no influence on FPTase activity. Our results suggest that compounds containing polyphenol hydroxyl may be a new source of FPTase inhibitors. The experiment also showed that availability of anin vitroFPTase assay could be useful in screening for potential inhibitors of ras oncogene function that will not interfere with other aspects of the mevalonate pathway.

ISSN:1028-6020    

DOI:10.1080/10286029808039842

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The effects of (-)clausenamide (claus) on brain development were studied. Sixty kunming strain weaning mice were divided into 4 groups. One group was served as control administered with normal saline, the other 3 groups were treated with (-)claus 5, 10 and 20mg kg−1respectively by gavage once a day for 4 weeks. Results showed that (-)claus at dosage of 5 and 10 mg kg−1facilitated learning and memory acquisition in step down and step through tests and increased thickness of cerebral cortex and synapse density significantly in the dentate cells over pyramidel cells in hippocampal region using quantitative technique of synapses analysis. These data provided the morphological basis of the nootropic effect of (-)claus.

ISSN:1028-6020    

DOI:10.1080/10286029808039843

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

A new isomer of Julibroside J2(Chen, S.P., Zhang, R.Y., Ma, L.B. and Tu, G.Z.Acta Pharm. Sinica, 1997,32, 110–115) was obtained from the cytotoxic fraction of 95% ethanol extracts of stem barks ofAlbizia julibrissinDurazz, together with Julibroside J2. Its structure was elucidated as 3-O-[β-D-xylopyranosyl-(1 → 2)-α-L-arabinopyranosyl-(1 → 6)-β-D-glucopyranosyl]-21-O-{(6S)-2-trans-2-hydroxymethyl-6-methyl-6-O-[3-O-((6S)-2-trans-2-hydroxymethyl-6-methyl-6-hydroxy-2,7 -octadienoyl)-β-D-quinovopyranosyl]-2,7-octadienoyl} acacic acid 28-O-β-D-glucopyranosyl-(1 → 3)-[α-L-arabinofuranosyl-(1 → 4)]-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl ester(1), named as Julibroside J7, based on chemical and spectral methods. Julibroside J2showed good inhibitory action against KB cell linein vitro.

ISSN:1028-6020    

DOI:10.1080/10286029808039844

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

A novel phenylpropanoid ester of sucrose, shegansu C (1), was isolated from the rhizome ofBelamcanda chinensis(L.) DC. (Iridaceae) along with 18 known compounds. The structure of1was characterized as β-D-[3-O-(4-O-(3,4-,dimethoxycinnamoyl)-5-O-feruloyl)-caffeoyl]-fructofuranosyl(2-1′)-α-D-(3′-O-acetyl)-glucopyranoside on the basis of chemical and spectral evidence including 2DNMR studies.

ISSN:1028-6020    

DOI:10.1080/10286029808039845

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

ISSN:1028-6020    

DOI:10.1080/10286029808039838

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor