摘要:

The oxidation of tyrosine ethyl ester and O-benzyl protectedo-tyrosine methyl ester with either sodium tungstate/hydrogen peroxide or DMD gave the corresponding tyrosine oximes in high yields. Controlled bromination of the aromatic ring gave either the monobromo oxime, the dibromo oxime, or the spiroisoxazoline depending upon reaction conditions. The bromo tyrosine oximes were further transformed into the naturally occurring nitriles by base hydrolysis of the oximino esters and decarboxylation of the resulting oximino acids with trifluoroacetic acid in CP2Cl2.

ISSN:1057-5634    

DOI:10.1080/10575639508043179

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Three new azaphilones, bulgarialactone A(1), B (2) and C (3), were isolated from both the mycelia and fruit bodies of the AscomyceteBulgaria inquinans. Bulgarialactone A (1) and B (2) possess antimicrobial, cytotoxic and nematicidal activities, and inhibit the binding of3H-SCH 23390 to the dopamine D1 receptor. The isolation, structure determination and biological activities of the bulgarialactones are reported.

ISSN:1057-5634    

DOI:10.1080/10575639508043180

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

In addition to N-acetyl-indoline (2) and N-formylindoline (3), a new N-alkylated derivative of indoline was isolated after incubation with a number of fungal strains. Its structure was elucidated by spectral analysis and comparison with chemically synthetized racemic and optically active 4-hydroxy-2-(N-indolinyl)butane (4).

ISSN:1057-5634    

DOI:10.1080/10575639508043181

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A new phenylpropanoid glycoside, 2-(3,4-dihydroxyphenyl)ethyl3,6-O-bis(β-D-apiofuranosyl)-4-O-caffeoyl-β-D-glucopyranoside was isolated from the aerial parts ofLysionotus pauciflorusand named paucifloside. Its structure was elucidated on the basis of various spectroscopic data and chemical correlation.

ISSN:1057-5634    

DOI:10.1080/10575639508043182

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A new labdane-type diterpene, named zerumin, was isolated from the seeds of the Chinese medicinal plant,Alpinia zerumbet. The structure was elucidated by NMR spectroscopic methods including heteronuclear multiple-bond multiple-quantum coherence (HMBC).

ISSN:1057-5634    

DOI:10.1080/10575639508043183

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Desmosic acid, a novel cytotoxic fatty acid, was isolated fromDesmos cochinchinensisLour. (Annonaceae). Its structure was established by spectroscopic and chemical methods.

ISSN:1057-5634    

DOI:10.1080/10575639508043184

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A mild and efficient preparation of 1,2,4-trioxane through the irradiation of β-ionone and related compounds, in presence of oxygen, is described.

ISSN:1057-5634    

DOI:10.1080/10575639508043185

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A simple and practical glucosidation of oleanolic and ursolic acid has been achieved using α-D-acetobromoglucose under phase-transfer catalysis.

ISSN:1057-5634    

DOI:10.1080/10575639508043186

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A general method for preparing 4′,5′-unsaturated iridoid glycosides is described through Pyridinium Chloro Chromate (PCC) mediated oxidation of iridoids. Oxidation of partially protected derivatives of Loganin (1), 7-Dehydrologanin (2), and Arbortristoside-A (3) with PCC followed by NaBH4reductions furnished the title compounds (11,8a, 8b, and 15). Deprotection of 11 gave 4′-5′unsaturated iridoid glycoside (12b).

ISSN:1057-5634    

DOI:10.1080/10575639508043187

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

From the root ofStellaria dichotomaL. var.lanceolataBge., two new β-carboline alkaloids have been isolated, they were named stellarines A (I) and B (II).

ISSN:1057-5634    

DOI:10.1080/10575639508043188

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor