Quantum-chemical investigation of deoxypeganine and its salts I. Photochemical oxidation of deoxypeganine

Hypothetical models of the interaction of deoxypeganine molecules with a solvent have been considered by the MO LCAO quantum-chemical method in the AM1 approximation. Excited triplet states of deoxypeganine and its analogues have been calculated by the method of molecular interactions. A free-radical mechanism of photochemical oxidation has been proposed on the basis of the results obtained and of literature information.Institute of Chemistry of Plant Substances, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 546–548, September–October, 1992.     

Structures of deoxypeganine salts

The structures of deoxypeganine (DOP) hydrochloride and oxalate were solved by x-ray structure analysis. An infinite chain along the crystallographic c axis was formed in the crystal structure of DOP oxalate. A molecular framework consisting of Cl anions and DOP cation protonated at N1 was found in the structure of unhydrated DOP hydrochloride. The molecular packing of the “host” (DOP cation) was pseudoisostructural in the studied ion-molecular crystals but differed from other known DOP salts. The “guest” molecules (acid anions) in the studied and known DOP salts formed different intermolecular contacts. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 280–283, May–June, 2006.     

A quantum-chemical investigation of deoxypeganine and its salts II. The photochemical oxidation of deoxypeganine hydrochloride

The stability of deoxypeganine hydrochloride under the action of light has been established. The kinetics of the oxidation of deoxypeganine hydrochloride in aqueous solution in the presence of deoxyvasicinone hydrochloride have been studied. The structures and electronic conformations of hypothetical models of the salt DOP HCl in the ground and excited states have been considered by the MO LCAO method in the AM1 approximation. The difference in the resistance of the molecules of the base deoxypeganine and its hydrochloride to photochemical oxidation is discussed on the basis of the results of experiments and calculations.     

A quantum-chemical investigation of deoxypeganine and its salts II. The photochemical oxidation of deoxypeganine hydrochloride

The stability of deoxypeganine hydrochloride under the action of light has been established. The kinetics of the oxidation of deoxypeganine hydrochloride in aqueous solution in the presence of deoxyvasicinone hydrochloride have been studied. The structures and electronic conformations of hypothetical models of the salt DOP HCl in the ground and excited states have been considered by the MO LCAO method in the AM1 approximation. The difference in the resistance of the molecules of the base deoxypeganine and its hydrochloride to photochemical oxidation is discussed on the basis of the results of experiments and calculations.Abbreviations HPLC high-performance liquid chromatography - MO LCAO molecular orbitals as linear combinations of atomic orbitals - AM1 Austin Model 1 - DOP HCl deoxypeganine hydrochloride - DOV HCl deoxyvasicinone hydrochloride Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 729–733, September–October, 1993.     

Lithiation of deoxypeganine and chiral synthesis of deoxypeganine derivatives

A method was developed for lithiation of deoxypeganine. The reaction of organolithium deoxypeganine derivatives with isobutyraldehyde and benzaldehyde to produce its derivatives was studied. A chiral synthesis of substituted deoxypeganines was performed. The synthesized diastereomers and enantiomers were separated successfully using HPLC and a chiral column.     

Interaction of carboxyl-containing polymers with deoxypeganine

Polymeric complexes of deoxypeganine hydrochloride with a number of carboxyl-containing polymers have been synthesized and investigated. It has been found that in the interaction of polymers with deoxypeganine both hydrogen bonds and electrostatic bonds arise.Translated from Khimiya Prirodnykh Soedinenii, Vol. 33, No. 1, pp. 87–90, January–February, 1997.     

Quantitative determination of deoxypeganine hydrochloride

A procedure has been developed for the quantitative determination of deoxypeganine hydrochloride by nonaqueous titration without the use of mercury acetate. A chromatospectrophotometric method of determining the oxypeganine hydrochloride in technical products has been developed.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 84–86, January–February, 1985.     

Crystal and molecular structure of deoxypeganine hydrochloride dihydrate

The crystal structure of deoxypeganine DOP chloride dihydrate (1) has been established by the x-ray structural method (diffractometer, CuK radiation, 671 reflections, direct method, R = 0.094). A comparative analysis has been made of the crystal structure of (1) with that of another complex of deoxypeganine (DOP) -DOP-ZnCl₂ ·2HCl.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from khimiya Priodnykh Soedinenii, No. 3, pp. 421–425 May–June. Original article submitted June 20, 1994.     

Synthetic analogs of Peganum alkaloids VI. Photochemical oxidation of 2,3-polymethylene-quinazoline derivatives

The rates of the photochemical oxidation of quinazoline alkaloids — deoxypeganine, peganine, pentamethylenequinazoline, and peganol — to the corresponding oxo derivatives have been studied. It has been shown by HPLC that the oxidation of deoxypeganine proceeds through a stage of the formation of a carbinolamine (peganol); in the case of its hydrochloride, the reaction takes place by the same scheme but four times more slowly. Tetra- and pentamethylenequinazolines have been synthesized and information on their melting points in the literature has been corrected. In the series trimethylenequinazoline-pentamethyl-enequinazoline-tetramethylenequinazoline the stability falls from left to right. Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 528–532, July–August, 1991.     

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.     

Preparation of deoxypeganine hydrochloride

Details are given of the technology of the synthesis and stagewise analysis of the alkaloids deoxyvasicinone and deoxypeganine hydrochlorides.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 506–507, July–August, 1990.     

Modication of the properties of allapinin and deoxypeganine by their mechanical treatment

The change in the physicochemical properties of plant drugs — allapinin and deoxypeganine — on their grinding in an AGO-2U activator with a regulable energy loading have been studied.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 272–276, March–April, 1995. Original article submitted November 1, 1994.     

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.     

Complex salts of deoxypeganine

Institute of the Chemistry of Plant Substances, Uzbek Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 862–864, November–December, 1991.     

Direction of bromination and nitration of deoxypeganine and its hydrochloride using HPTLC. Synthesis of 6-bromo(nitro)-, 6,8-dinitrodeoxyvasicinones, 6-nitro(bromo)-, 6,8-dinitrodeoxypeganines,and 6H(bromo)peganols

The reaction of deoxypeganine (DOP) (1) and its hydrochloride (DOP·HCl) (2) with N-bromosuccinimide and a nitrating mixture was studied. It was found that bromination of DOP occurred at C-4 and the aromatic ring. Nitration of DOP·HCl produced either 6-nitro- or 6,8-dinitro-deoxypeganines and 6-nitrodeoxyvasicinone or their mixture in various ratios depending on the substrate:nitrating mixture ratio. 6Hand 6-Br-deoxypeganines were transformed into the 4-hydroxy derivatives, 6H(Br) peganols or deoxyvasicinones. A method for qualitative and quantitative analysis of the pure compounds and the mixture of reaction products using HPTLC was developed. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 505–509, September-October, 2008. Original article submitted March 26, 2008.     

Isolation of peganine and deoxypeganine from the total alkaloids ofPeganum harmala through their complex salts

Abtsract The possibility has been shown of combining the processes of the reduction of deoxyvasicinone and vasicinone to deoxypeganine and peganine and the isolation of the latter in the form of complex salts from the natural total mixture of alkaloids.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 89 14 75. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 70–73, January–February, 1996. Original article submitted April 5, 1994.     

Synthetic analogs ofPeganum alkaloids VIII. A quantum-mechanical investigation of the reduction of deoxypeganine and its derivatives

The alkaloid deoxypeganine and some of its derivatives have been subjected to reduction with sodium tetrahydroborate and with the complex NaBH₄·BF₃·Et₂O. It has been shown that the structures of the reduction products depend on the presence and positions of substituents in the benzene ring. The quantumchemical calculations performed have confirmed the probable formation of reduced structures of the type ofo-aminobenzylpyrrolidine and the type of a macrocyclic diamine.Deceased.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (371) 120 64 75. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 220–225, March–April, 1999.     

Synthetic analogs of Peganum alkaloids VI. Photochemical oxidation of 2,3-polymethylene-quinazoline derivatives

The rates of the photochemical oxidation of quinazoline alkaloids — deoxypeganine, peganine, pentamethylenequinazoline, and peganol — to the corresponding oxo derivatives have been studied. It has been shown by HPLC that the oxidation of deoxypeganine proceeds through a stage of the formation of a carbinolamine (peganol); in the case of its hydrochloride, the reaction takes place by the same scheme but four times more slowly. Tetra- and pentamethylenequinazolines have been synthesized and information on their melting points in the literature has been corrected. In the series trimethylenequinazoline-pentamethyl-enequinazoline-tetramethylenequinazoline the stability falls from left to right.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 528–532, July–August, 1991.     

XRF Analysis of Microsamples of Semiconductor Type Multielement Materials by the Thin Layer Method. Determination of Cr, Co, Ni, Cu, Zn, Ga, Se, Sb, Yb

 A simple and quick method of durable samples preparation by the thin layer method through direct digesting of the analysed material on the substrate has been presented. Four- and three-component mono- and polycrystals have been analysed. Standards have been used in calibration containing: Cr, Co, Ni, Cu, Zn, Ga, Se, Sb, Yb. To improve the correlation between the concentration and the fluorescent radiation models of mathematical corrections have additionally been used: multiple linear regression, Lucas-Tooth-Pyne model (L. T. P.) and de Jongh model (d. J.). Statistical parameters: detection limits for 0.5 mg samples: Cr–0.041%, Co–0.034%, Ni–0.042%, Cu–0.053%, Zn–0.054%, Ga–0.057%, Se–0.057%, Sb–0.113%, Yb–0.077%. Correlation coefficients: simple regression 0.9946–0.9997, multiple regression 0.9974–1.0000, L. T. P. 0.9993–1.0000, d. J. 0.9995–1.0000. Received August, 1, 1998. Revision March 25, 1999.     

An improved version of Junmeng–Fang–Weiming–Fusheng approximation for the temperature integral

An improved version of Junmeng–Fang–Weiming–Fusheng approximation for the temperature integral has been developed. The accuracy of the improved approximation for the temperature integral has been tested by some numerical analyses. The systematic analysis of the relative errors involved in the kinetic parameters obtained from Junmeng–Fang–Weiming–Fusheng integral method and its improved version has been also carried out. The results have shown that the improved approximation is more accurate than Junmeng–Fang–Weiming–Fusheng approximation as the solution of the temperature integral, and that more accurate kinetic parameters can be determined from the integral method based on the improved temperature integral approximation.