摘要:

The water soluble methanol extract from Shiraz leaves, was passed through a XAD 2 column, and elution with methanol yielded a crude glycoconjugate composite. Further separation of this polar fraction using IIPLC semi preparative Cm18column followed by acetylation and flash chromatography yielded Alangioside J and a new norisoprenoid β-glucopyranoside. Using1II- and13C-NMR techniques, the latter was shown to be the C-9 conjugate of the same (3S, 5R, 6S,9R)-megastigmane-3,9-diol as the C-3 conjugated former one.

ISSN:1041-2905    

DOI:10.1080/10412905.2000.9712183

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The configuration of the chiral secondary alcohols of a megastigmane-3,9-diol was determined using ROESY experiments performed on its peracetylated β-glucopyranosides, previously isolated fromVitis ViniferaShiraz leaves. On the basis of the data available for structurally related disaccharides, the rules reported previously to determine the conformation of disaccharide linkage were applied to predict the applicability of this method to other chiral secondary alcohols with no or only one bulky substituent on the β-carbons. That would lend additional support to the applicability of the method based on the β-effects of glycosylation in13C-NMR.

ISSN:1041-2905    

DOI:10.1080/10412905.2000.9712184

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The volatile constituents from aerial and underground parts ofCroton flavensL, a medicinal plant from Curacao, were investigated by GC and GC/MS (El) analysis. The various plant parts yielded 0.27-0.50% (v/w) essential oil on a dry weight basis. There were only small differences in the qualitative composition of the oils analyzed. A total of 70 components were identified. The main compounds in the oil were α-pinene (15-24%), isocaryophyllene (0.7-9%), spathulenol (3-5%), and an unknown oxygenated sesquiterpene (RI=1556), amounting to 7%.

ISSN:1041-2905    

DOI:10.1080/10412905.2000.9712185

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The essential oil composition of leaves, branches and female cones ofPinus laricioPoiret collected in Sicily, Italy, has been studied by GC and CKVMS. The three oils show both qualitative and quantitative differences, especially for α-pinene. The leaf oil was found to contain α-pinene (53.4%), β-caryophyllene (10.5%) and germacrene D (20.1%). Oils from the branches contained α-pinene (89.2%), and female cones contained α-pinene (68.6%) and β-caryophyllene (9.1%).

ISSN:1041-2905    

DOI:10.1080/10412905.2000.9712186

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Commercially produced cold-pressed oil of bitter orange (Citrus aurantiumL.) produced in Cuba was analyzed by GC/MS. Thirty components were characterized representing 98.9% of the total components detected. Limonene (86.2%) was the major constituent.

ISSN:1041-2905    

DOI:10.1080/10412905.2000.9712187

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

A concentrate of the hydrodistilled volatiles from the fruitsof Malpighia glabraL. was analyzed by GC and GC/MS. More than 95% of the volatile compounds were identified with 2-furfuraldehyde (56.8%) and heptanoic acid (21%) being the major constituents.

ISSN:1041-2905    

DOI:10.1080/10412905.2000.9712188

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Three methyl substituted bicyclo[2.2.1]heptane-2-carboxaldehydes, thus, 1,3,3-trimethylhicyclo[2.2.1]heptane-2-carboxaldehyde, 1,7,7-trimethylbicydo[2.2.1]-hep-tane-2-carboxaldehyde, and 7,7-dimethylbicyclo[2.2.1]heptane-2-carboxaldehyde, were synthesized from the corresponding methylene compounds by epoxidation, followed by a rearrangement using boron trifluoride diethyl etherate. Theendo/exostereochemistry of these aldehydes was determined by NMR. The stability of these aldehydes was predicted by an MM2 model calculation and the calculatedendo/exoisomer ratios are in fair agreement with the observed values.

ISSN:1041-2905    

DOI:10.1080/10412905.2000.9712189

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

GC/MS analysis of the essential oil from the wood ofDrimys winteri Forst.allowed the identification of 56 components and showed a high content of α-pinene (14.9%) and α-cubebene (10.9%).

ISSN:1041-2905    

DOI:10.1080/10412905.2000.9712190

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The oil ofLallemantia peltata(L.) Fisch. et Mey. (Labiatae) obtained by Simultaneous Distillation-Kxtraction (SDE) using Likens-Nickerson apparatus, was analyzed by GC/MS. Thirteen compounds were identified representing all of the components detected. Germacrene D (27.4%), (E)-β-ocimene (20.1%) and geijerene (12.0%) were the major constituents of the oil.

ISSN:1041-2905    

DOI:10.1080/10412905.2000.9712191

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Volatile constituents of the aerial parts ofCerastium candidissimumCorr. were investigated by GC/MS. Nineteen components were identified in the oil representing 97.5%. The major compounds were nonanal (10.5%), geranyl acetone (13.5%), 3-methyltetradecane (17.3%), (E)-β-ionone (11.1%) and hexahydrofarnesyl acetone (21.7%).

ISSN:1041-2905    

DOI:10.1080/10412905.2000.9712192

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor