Mass spectra of pseudoguaianolides related to carpesiolin

The main directions of fragmentation and the EI of six pseudoguaianolides related to carpesiolin have been studied. It has been established that acylation of the OH group at C-6 suppresses the selective breakdown of the guaiane skeleton, while the simultaneous presence of AcO groups at C-2 and C-4 favors the formation of a number of characteristic ions. The hydrogenation of the exomethylene group has no appreciable influence on direction of fragmentation.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 530–535, July–August, 1993.     

Mass spectra of 2,3-polymethylene-3,4-dihydroquinazolin-4-ones with substituents at C9

Summary The main fragments in the mass spectra of the 2,3-polymethylene-3,4-dihydroquinazolin-4-one with six- and seven-membered alicyclic rings are formed by the decomposition of ring C through the stage of the cleavage of the C₉-C₁₀ bond, while the compound with a five-membered ring ejects a hydrogen atom.A hydroxy group at C₉ initiates the appearance of fragments due to the initial cleavage of the C₂-C₉ bond. In the spectra of the halogen and acetoxy derivatives the fragmentation of the alicyclic ring is suppressed and the main fragmentation pathway is the splitting out of the substituent. The hypothesis of the protonation of the N₁ nitrogen atom has been adopted to explain the stability of a number of the ions.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 180–187, March–April, 1979.     

Quantitative analysis of the components of the combined metabolites of deoxypeganine and deoxyvasicinone

The quantitative composition of the combined metabolites isolated from the rat organism after the administration of the anticholinesterase preparation deoxypeganine and its analog deoxyvasicinone has been determined by the mass-spectrometric method of integrating the ion current. The results of the determination have been compared with those obtained by UV spectroscopy.Institute of the Chemistry of Plant Substances, Academy of Sciences of the USSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 201–206, March–April, 1981.     

Structure of the products of the metabolism of deoxypeganine and of deoxyvasicinone

The structures of the main components of the total metabolites of the anticholinesterase drug deoxypeganine (DOP) and its analog deoxyvasicinone (DOV) in the rat organism have been studied. The structures of two metabolites of DOP and DOV — 11-hydroxydeoxyvasicinone and 2-(-ethoxycarbonyl)ethyl-4-quinazoline — have been determined by the PMR method. On the basis of their structures and the results of measurements of the elementary compositions of ions, the fragmentation of the compounds has been elucidated. A minor component of the total metabolites has been isolated by chromato-mass spectrometry and for it the structure of 6-methoxydide-hydrovasicinone is proposed. A scheme of the metabolism of DOP and DOV has been put forward.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 758–766, November–December, 1983.     

Oxidation of hexadec-11Z-en-1-ol by Cr(VI) reagents on polymeric supports

A method is proposed for the oxidation of hexadec-11Z-en-1-ol to hexadec-11Z-enal by Cr(VI) reagents on polymeric supports.A. S. Sadykov Institute of Bioorganic Chemistry, Uzbek Academy of Sciences, Tashkent. V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 252–255, March–April, 1990.     

GC-MS analysis of total diterpene alkaloids from roots of Aconitum septentrionale

For the first time, using a MS 25RF chromato-mass spectrometer with a Carlo Erba 5160 chromatograph and a packed column, the possibility of the partial separation of the mixture of diterpene alkaloids of various types from the roots ofAconitum septentrionale has been shown. From their chromatographic parameters and mass-spectral characteristics 18 bases have been detected, including a new one with M⁺ 407 which was probably deoxydelcorine, while 6-O-methyldelcorine and 6-O-methyleldelidine have been found in plants for the first time. Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodynkh Soedinenii, No. 4, pp. 538–543, July–August, 1989.     

Mass spectra of pseudoguaianolides related to carpesiolin

The main directions of fragmentation and the EI of six pseudoguaianolides related to carpesiolin have been studied. It has been established that acylation of the OH group at C-6 suppresses the selective breakdown of the guaiane skeleton, while the simultaneous presence of AcO groups at C-2 and C-4 favors the formation of a number of characteristic ions. The hydrogenation of the exomethylene group has no appreciable influence on direction of fragmentation. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 530–535, July–August, 1993.     

Mass spectra of tetrahydroquinazoline and tetrahydroquinazolin-4-one derivatives

Summary 1. From the combined alkaloids of the epigeal part ofKorolkowia sewertsovii Rgl. collected at Saryagach we have isolated sevkorine, korseveriline, korseveridine, korseverinine, a base with mp 212–214°C, and the new alkaloid severtizidine.2. On the basis of a study of the chemical and physical characteristics of the alkaloids itself and the products of its transformations, the most probable structure and configuration of severtzidine has been established as 3,6,14-trihydroxycevanine.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 367–371, May–June, 1976.