Isolation of triterpene saponins from Gypsophila capillaris.

Four novel triterpenoid saponins have been isolated from Gypsophila capillaris. Three were monodesmosidic: 3 beta-hydroxyolean-12-en-23,28-dioic acid 28-O-[beta-D-glucopyranosyl-(1-->3)-beta-D-glucopyranosyl-(1-->2)] [beta-D-galactopyranosyl(1-->6)]beta-D-glucopyranoside, 3 beta-hydroxyolean-12-en-23-oxo-28-oic acid 28-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->3)] [beta-D-glucopyranosyl(1-->6)]beta-D-galactopyranoside, 3 beta-hydroxyolean-12-en-23,28-dioic acid 28-O-[beta-D-glucopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->3)] [beta-D-glucopyranosyl(1-->6)]beta-D-galactopyranoside. The fourth was bisdesmosidic: 3 beta-hydroxyolean-12-en-23,28-dioic acid 23-O-beta-D-glucopyranosyl-28-O-[beta-D-glucopyranosyl-(1-->2)-beta-D- galactopyranosyl-(1-->3)][beta-D-glucopyranosyl-(1-->6)]beta-D- galactopyranoside. The structures of the compounds were elucidated by 1D and 2D NMR techniques and from other spectroscopic evidence.

Diphenylamine, an antihyperglycemic agent from onion and tea.

Diphenylamine has been isolated as one of the active antihyperglycemic agents of onion. It was identified by ir, uv, cmr, pmr, and mass spectra. It attained the highest percentage in mature onion bulbs; other onion organs contained diphenylamine in lower percentages. Green and black teas were found to contain relatively high percentages of diphenylamine, being higher in the former. Cooking was found to decrease the diphenylamine content.

Colorimetric assay of quinine and quinidine in raw materials, formulations, and biological fluids.

The two characteristic erythroquinine and thalleioquin tests for quinine and quinidine were studied to optimize the experimental conditions for quantitative analysis. Both methods were quantitatively sensitive for either quinine or quinidine in a concentration range of 0.1--10 microgram/ml with the erythroquinine method and of 3--50 microgram/ml with the thalleioquin method. A TLC--colorimetric method also is described for the assay of quinine and quinidine in the presence of cinchonine, cinchonidine, and other cinchona alkaloids. The results were compared with those obtained with a spectrophotometric method.

Selective estimation of aconitine in presence of aconine and benzoylaconine.

A selective and simple colorimetric method is presented for the estimation of aconitine in drugs in the presence of aconine and benzoylaconine. The method is based on the formation of an iron hydroxamate complex through the acetate ester group to which the biological activity is due. The color is measured at 530 nm (5--250 microgram/ml). Under the experimental conditions, neither the benzoyl group of benzoylaconine nor aconine is involved in the process of hydroxylaminolysis.

Colorimetric assay of reserpine in formulations and biological fluids.

Two colorimetric methods are presented for determining reserpine. In the first method, an iron hydroxamate complex is formed through the ester group in position 16 in the reserpine molecule. The color is measured at 535 nm (0.5-6 mg/25 ml). This method is useful for routine and control analyses of reserpine formulations. In the second method the tertiary amino group of reserpine reacts with 2% citric acid in acetic anhydride to form a red-violet complex which is measured at 505 nm (5-400 mug/10 ml). This method could be useful in measuring trace amounts of reserpine present in biological fluids.

Colorimetric determination of aconitine in galenicals and in biological samples.

A sensitive method is presented for determining aconitine. Aconitine is complexed with Co2+, the aconitine-cobalt complex is extracted with chloroform, and the absorbance is measured at 320 nm. The sensitivity of the method ranged between 0.06 and 3 mg/25 ml, and the color was stable for 6 hr. The method was successfully applied for the quantitative determination of aconitine in animal tissues.

Spectrophotometric assay of salsolidine hydrochloride.

The proposed method is based on the reaction of salsolidine HCl with carbon disulfide and ammoniacal copper sulfate. The resulting salsolidine-copper-dithiocarbamate complex is extracted with benzene and measured spectrophotometrically at 448 nm. The method is applicable for the detection of 40-500 mug salsolidine/5 ml.

Colorimetric and volumetric assays of colchicine in galenicals and in pharmaceutical preparations.

In the method described the amide group in the colchicine molecule is reduced with lithium aluminum hydride to the corresponding secondary amine. The latter is extracted with chloroform and then determined either colorimetrically by the copper dithiocarbamate reaction or volumetrically by dissolving in acid and titrating with sodium hydroxide or perchloric acid. The results were comparable with those obtained by the Egyptian Pharmacopoeia spectrophotometric method.

Colorimetric and gas-liquid chromatographic determination of atropine-hyoscyamine and hyoscine (scopolamine) in solanaceous plants.

Two colorimetric micromethods are described for the determination of atropine-hyoscyamine and hyoscine (scopolamine), using p-dimethylaminobenzaldehyde and citric acid-acetic anhydride as the color reagents. These methods are sensitive to 60-1200 and 10-360 mug alkaloid/10 ml. The colorimetric methods were also successfully applied after a preliminary thin layer chromatographic separation of the alkaloids. A gas-liquid chromatographic procedure was also developed, which yielded comparable results with the colorimetric methods.

Estimation of glycoalkaloids as solasodine in Solanum laciniatum.

Solasodine is isolated from Solanum laciniatum leaves by a rapid, one-step procedure which involves extraction and hydrolysis of the glycoalkaloids. The resulting steroidal aglycone is directly estimated by the formation of a colored complex with bromocresol green. The method is applicable to concentrations of 25-125 mug solasodine/7ml.

Colorimetric assay of strychnine and brucine in nux vomica.

Two colorimetric methods are described for the estimation of strychnine and brucine in nux vomica. The first is a modification of the Karawya and Ghourab method for the determination of strychnine, in which the sensitivity of the color is increased by changing certain conditions of the method. The second was developed for the determination of brucine and is based on measuring the intensity of the violet color produced by treating brucine with nitric acid and methanolic stannous chloride. In the presence of large amounts of strychnine, brucine is isolated prior to colorimetric analysis by a quantitative thin layer chromatographic technique.