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Alkaloids of Vinca species V: structure elucidation of herbadine, an alkaloid isolated from Vinca libanotica.

Herbadine, a novel dihydroindole alkaloid, was isolated from the arterial parts of Vinca libanotica Zucc. (Apocynaceae). The physical and spectral data (UV, IR, NMR, and mass spectroscopy) indicated the alkaloid to be a derivative of aimaline. Comparative high-resolution NMR studies with quebrachidine and high-resolution mass spectral studies established the structure of the alkaloid to be 2-epi-3-hydroxyquebrachidine. Herbadine was previously isolated from another species by Russian workers and a structure was postulated. The current paper gives evidence for a corrected structure of herbadine.

Ajmaline↗

Structure determination of the anorexic agent mazindol.

The anorexic agent mazindol was shown to exist as the carbinolamine tautomer 5-p-chlorophenyl-2,3-dihydro-5H-imidazol[2,1-a]isoindol-5-ol in solution and in the solid state. The latter was established by diffuse UV reflectance spectroscopy.

Carbon Isotopes↗

High-pressure liquid chromatographic analysis of penicillin G potassium and its degradation products.

An anion-exchange high-pressure liquid chromatographic system capable of separating penicillin G potassium from five of its degradation products was developed. The retention times were: penicillin G potassium, 17.5 min; DL-penicillamine, 4.5 min; benzylpenilloic acid, 7.0 and 8.0 min; benzylpenamaldic acid, 13.0 min; benzylpenicilloic acid, 19.5 min; and benzylpenillic acid, 22.0 min. In addition, the system permits quantification using linear calibration curves.

Benzyl Compounds↗

High-performance liquid chromatographic determination of diethylpropion hydrochloride in tablets: isolation and identification of two decomposition products.

A rapid assay was developed for diethylpropion hydrochloride tablets using high-performance liquid chromatography (HPLC) with UV detection. This technique provided separation of the drug from other UV-absorbing components present as the result of decomposition. A major decomposition product detected by HPLC in extracts of tablets and of the cotton filler from a tablet bottle was collected from the column effluents. This product was subsequently identified as 1-phenyl-1,2-propanedione, a highly volatile compound. A second decomposition product, isolated from decomposed drug by distillation from alkaline solution, was identified as diethylamine, apparently present as the hydrochloride salt, GLC, UV, IR, NMR, and mass spectrometry were used to confirm the identity of the decomposition products. HPLC assay results compared favorably with results of the NF assay; the latter procedure separated the drug from 1-phenyl-1,2-propanedione via liquid-liquid extraction.

Chromatography, Gas↗

New compounds: organoboron derivatives of tetracyclines I: synthesis of carboxamido derivative of tetracycline with perhydro-2-phenyl-1,3,6,2-dioxazaborocine.

An organoboron carboxamido derivative of tetracycline, designed for use in the 105B-thermal neutron-capture treatment of cancer, was synthesized under the conditions of the Mannich reaction using perhydro-2-phenyl-1,3,6,2-dioxazaborocine as the amine component. Spectral data (UV, IR, and NMR) for the compound and its hydrolytic stability are discussed.

Boron Compounds↗