Low-temperature chromatography as a means for separating terpene hydrocarbons.
Explore the source record for details and available documents.
SEARCH · Search PubMed
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Although less effective than xylene and Kovacs reagent as indole extractants, Hemo-De and Shandon xylene substitute can be used in the Ehrlich indole test if a less toxic solvent is desirable. In doubtful cases, xylene should be used. Because of the blocking action shown in the test, use of indole-nitrite broth cannot be recommended.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Thirty patients with radiolucent stones in a radiologically functioning gall bladder were treated for up to two years with a combination of Rowachol (one capsule twice daily), a mixture of cyclic monoterpenes, and chenodeoxycholic acid (7.0-10.5 mg/kg/day). The patients were not selected for body weight or size of stones. All complete dissolutions diagnosed by oral cholecystography were confirmed or refuted by ultrasound examination. Control of symptoms was excellent, only one patient withdrawing from the study because of persistent biliary pain. No evidence of hepatotoxicity was detected biochemically, and diarrhoea due to chenodeoxycholic acid was minimal at this dose. Stones disappeared completely in 11 patients (37%) within one year and in 15 (50%) within two years. These results compared favourably with those obtained with similar doses of chenodeoxycholic acid alone, in particular those of the National Co-operative Gallstone Study (complete dissolution in 13.5% of patients at two years). Treatment with a combination of medium dose chenodeoxycholic acid with Rowachol for radiolucent gall stones is economical, effective, and likely to minimise persistent symptoms and adverse effects of treatment.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The significant inhibitory action of diclofenac formulated in mixed micelles of lecithin with cholate or deoxycholate was observed on the rat hind paw edema induced by carrageenan. In the primary stage, mixed micelle formulation of deoxycholate was more effective compared with that of cholate. However, in the final term, the inhibitory action was similar in both formulations. In a previous study, the flux of diclofenac was greater in the mixed micelle formulation of deoxycholate compared with that of cholate. It was suggested that the permeation rate of diclofenac through skin was proportional to the pharmacological activity. The hind paw edema was quickly inhibited when cyclic monoterpene such as d-limonene or l-menthol was included in the formulations. All the micelle formulations significantly decreased the value of AUC estimated the hind paw thickness-time profile. This suggests that the micelle formulation of cholate in addition to deoxycholate showed significant anti-inflammatory activity to hind paw edema of rats. Incorporation of d-limonene or l-menthol was more effective on the decrease of AUC. A pharmacological study revealed that micelle formulations were able to reduce the skin irritation of chemicals.
A new monoterpene, platydiol (1), and three new diterpenes, platyclolactonic acid (2), 14,15-bisnor-8(17)-labdene-16,19-dioic acid (3), and 6,7-dehydrosandaracopimaric acid (4), were isolated from the pericarp of Platycladus orientalis. Their structures were elucidated by spectral and chemical methods.
Gas chromatographic separations of the stereoisomers of menthol derivatives, important intermediates in the synthesis of physiologically active natural products, were carried out on several substituted beta-cyclodextrin (CD) columns, including per-O-methyl-beta-cyclodextrin (PME-beta-CD), heptakis(2,3-di-O-acetyl-6-tert-butyldimethylsilyl)-beta-CD (DIAC-6-TBDS-beta-CD), and heptakis(2,3-di-O-methyl-6-tert-butyldimethylsilyl)-beta-CD (DIME-6-TBDS-beta-CD) as chiral stationary phases (CSPs). With the DIME-6-TBDS-beta-CD column, a separation of the Z- and E-isomers of methylidenementhol was accomplished; no separation was achieved with the other columns. The stereoisomers of methylidenementhol and the corresponding tert-butyldimethylsilyl (TBS) ether were separated on both the beta-CD and the heptakis(2,3,6-tri-O-methyl)-beta-cyclodextrin (TME-beta-CD) columns by high-performance liquid chromatography (HPLC) with a mobile phase involving acetonitrile and H(2)O. For the separation of the Z- and E-isomers of methylidenementhol, the TME-beta-CD column was superior. In contrast, the beta-CD column was preferable in the case of the corresponding TBS ether.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The isotope ratios of monoterpene hydrocarbons in Citrus junos Tanaka (yuzu) essential oils from different origins were determined by ordinary high-resolution gas chromatography-mass spectrometry (HRGC-MS). Both intensities of the molecular mass peaks (m/z 136) and of the isotope peaks (m/z 137) of monoterpene hydrocarbons were measured by single-ion monitoring with an MS analysis. The isotope ratios (m/z 137/136) of the ten monoterpene hydrocarbons commonly contained in citrus essential oils, alpha-pinene, beta-pinene, sabinene, myrcene, alpha-phellandrene, alpha-terpinene, limonene, gamma-terpinene, beta-phellandrene and terpinolene, were determined in yuzu samples of the highest commercial quality from 42 different production districts. Statistical treatment of these data by the t-test and sign test revealed significant differences of the isotope effects in each yuzu sample. It is suggested that this technique will be applicable for evaluating the quality, genuineness and origin of citrus fruits and their products. The isotope fingerprints were also demonstrated in several citrus fruits other than the yuzu samples.
Explore the source record for details and available documents.
Rapid Friedel-Crafts chromogenic acylations of alkene groups at ambient temperatures are shown to be successful selective procedures for discriminating among a group of natural products, twelve of which are structurally related low molecular weight hydrocarbons that include nine terpenoids, and nineteen unsaturated and polyunsaturated fatty acid esters. The procedure has all the properties needed of a rapid, routine assay for use as a quality control test reagent for standard reference materials and natural oils, for on-line analyses during their commercial processing, and the potential for applications in the analyses of multicomponent mixtures without the need for prior separation.
Explore the source record for details and available documents.
A detailed chemical analysis of a Philippine marine sponge Smenospongia sp. has been performed. This study yielded four new metabolites, 5-bromo-L-tryptophan (1), 5-bromoabrine (2), 5,6-dibromoabrine (3) and 5-bromoindole-3-acetic acid (4). The pyrroloiminoquinone alkaloid, makaluvamine O (5) as well as 5,6-dibromotryptamine (6), aureol (7) and furospinulosin 1 (8) were also isolated. Although 1 and 4 have been synthesized previously, this is the first report on the isolation of these compounds from a natural source. The furanosesterterpene furospinulosin 1 (8) was obtained for the first time from the genus Smenospongia. The structures of all compounds were established by spectroscopic methods (UV, IR, 1D and 2D NMR, MS, [alpha]D). The cytotoxic potential of 1-8 was evaluated in a panel of isogenic HCT-116 human colon tumor cell lines.