Some products of the coupling of gossypol with diazotized amines

Summary A series of products of the coupling of gossypol with diazotized amines has been obtained. It has been established that they are monoadducts. The possibility of using them as dyes for cotton fabric has been shown.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 607–609, September–October, 1976.     

Inclusion complexes of the natural product gossypol. Crystal structure of the 2:1 complex of gossypol withm-Xylene

The crystal structure of a 2: 1 inclusion complex of gossypol withm-xylene has been determined by X-ray structure analysis. The crystals of C₃₀H₃₀O₈·0.5C₈ H₁₀ are triclinic, space groupPl^–,a = 8.478(1),b = 14.087(2),c = 14.411(2) Å, = 115,39(1), = 75.11(1), = 86.80(1)°,V = 1475.2(4) ų,Z = 2,D _x = 1.29 g cm^–3,T = 295 K, (CuK ) = 7.01 cm^–1. The structure has been solved by direct methods and refined to the finalR value of 0.079 for 3910 observed reflections. The gossypol molecules are linked by intermolecular hydrogen bonds and form bimolecular layers parallel to the ab plane. Disorderedm-xylene molecules occupy cavities between these layers. All polar groups of the gossypol molecule are packed in the interior of the bilayer while non-polar groups are directed outwards. An analysis of the crystal packing of other inclusion complexes of gossypol shows that such bilayers are formed in four complexes and three of those structures are generically related to each other.Deceased.     

Inclusion complexes of the natural product gossypol. Crystal structure of the 1 : 1 complex of gossypol with isovaleric acid

The crystal structure of the 1 : 1 lattice inclusion complex of gossypol with isovaleric acid has been determined by X-ray structure analysis. The crystals of C₃₀H₃₀O₈C₅H₁₀O₂ are monoclinic, space groupC2/c,a=28.835(7),b=9.063(2),c=26.880(4)Å, =109.66(1)°,V=6615(2) ų,Z=8,D _x = 1.25 g cm^–3, (CuK) = 7.14 cm^–1,T = 295 K. The structure was solved by direct methods and refined with isotropic thermal parameters to the finalR value of 0.132 for 1114 observed reflections. Hydrogen bonded gossypol molecules form columns along the [1 0 1] direction. These columns pack into layers parallel to the (101) plane. The layers of gossypol molecules are separated by the layers of isovaleric acid. The acid molecules are connectedvia a pair of O-H...O hydrogen bonds forming centrosymmetric dimers. There is no hydrogen bond interaction between the carboxylic acid dimers and gossypol molecules.     

Inclusion complexes of the natural product gossypol. Crystal structure of the 2:1 complex of gossypol with amyl acrylate

The crystal structure of the 2: 1 inclusion complex of gossypol with amyl acrylate has been determined by X-ray structure analysis. The crystals of (C₃₀H₃₀O₈)₂C₈H₁₄O₂ are triclinic, space group P ,a = 14.425(2),b = 15.519(1),c = 16.409(2) Å, =97.89(1), = 117.80(1), =67.01(1)° (reduced cell:a = 14.425(2),b = 15.519(2),c = 16.017(2)Å, = 92.19(1), = 115.01(l), =67.01(1)°],V = 2986.7(5) ų,Z = 2,D _x = 1.31 g cm^–3, (CuK ) = 7.40 cm^–1,T = 292 K. The structure has been solved by direct methods and refined to the final R value of 0.059 for 5155 observed reflections. The gossypol molecules bonded via several hydrogen bonds form centrosymmetric tetramers. The two independent gossypol molecules, A and B, are related within the tetramer by a local noncrystallographic 2-fold axis. The host molecules in the crystal form cavities in which two guest molecules are placed. The ester molecule interacts via a pair of C-...H-O hydrogen bonds with two gossypol molecules of the same chirality and belonging to the same tetramer unit. The amyloxy group of the ester molecule shows a very large thermal motion. It adopts a non-extended conformation in which it can be fitted into the cavity formed by the host molecules.     

Oligomeric oxidation products of the flavonoid quercetin

Some of the main oxidation products of quercetin were shown to be compounds formed by oligomerization of the starting flavonoid. Conditions for the preparative synthesis of these compounds were developed. Their structures were established using HPLC-MS and NMR methods. Quercetin oligomers in the natural sample, outer leaves of modified runners of Allium cepa L., were found using chromatographic procedures. The use of quercetin oligomers as indicators of its oxidation was proposed. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 344–347, July–August, 2008.     

Inclusion complexes of the natural product gossypol. Strong influence of the guest on the host structure in channel-type isostructural inclusion complexes of gossypol

The crystal structures of 1 : 1 inclusion complexes of gossypol with tetrahydrofuran (GPTHF), cyclohexanone (GPCHN) and butanal (GPBTA) have been determined by X-ray structure analysis. The crystals of GPTHF are triclinic, space group P,a = 10.788(2),b = 10.979(3),c = 13,880(2) Å, = 80. 11(2), = 103.87(1), = 77.96(2)°,V = 1517.8(6) ų,Z = 2,R = 0.052 for 2701 observed reflections. The crystals of GPCHN are triclinic, space groups P,a = 10.803(4),b = 11.157(5),c = 15.428(6) Å, = 108.75(3), = 106.93(3), = 103.34(3)°,V = 1573(1) ų,Z = 2,R = 0.071 for 1879 observed reflections. The crystals of GPBTA are triclinic, space group P,a = 10.190(2),b = 11.335(1),c = 14.665(2) Å, = 73.04(1), = 103.74(1), = 81.07(1)°,V = 1529.9(5) ų,Z = 2,R = 0.068 for 2964 observed reflections. Crystal data for another 13 isostructural inclusion complexes are given.[/p]In this isostructural group of complexes guest molecules are accommodated in channels and are hydrogen bonded to the host molecules via an 0(1)-H....O(1) hydrogen bond. The molecular association changes significantly with the shape and size of the guest component. In GPTHF centrosymmetric dimers of gossypol formedvia O(5)-H...O(3) hydrogen bonds are associated in columns via a weak O(4)-H...O(8) hydrogen bond. In GPCHN the latter bond disappears as the distance O(4)-O(8) is increased to 3.73 Å. In GPBTA the O(5)-H...O(3) bond is replaced by three centre hydrogen bonds O(5)-H...O(2) and O(3)-H...O(5), and a centrosymmetric dimer of a new type is formed. These dimers are further connected by two weak hydrogen bonds to form columns. The butanal molecule interacts with the host structure via two hydrogen bonds. This indicates that a guest component can activate or deactivate different functional groups of the host in channel inclusion complexes of gossypol for hydrogen bond formation.     

Analysis of the nonvolatile oxidation products of polypropylene I. Thermal oxidation

The nonvolatile products in thermal-oxidized polypropylene sheet have been quantitatively identified by infrared analysis and chemical reaction. The molecular weight changes with oxidation have been studied by gel-permeation chromatography. It was determined that there is a functional group at each end of a chain. A general oxidation mechanism scheme for polypropylene is presented. The discovery of γ-lactone is an indication of the importance of an intramolecular backbiting process. The overall functional group distribution is found to differ from that found in a polyethylene sheet.     

1H and13C NMR spectra of transformation products of gossypol in solutions

The complete cycle of the transformation of gossypol in solutions takes place in the measuring ampul of a NMR spectrometer. It has been established for the first time that, in methanol, gossypol is converted into stereoisomeric dilactol 15,15-dimethyl ethers which change into dianhydrogossypol in chloroform and back into gossypol in aqueous acetone. The¹H and¹³C NMR spectra of the main and intermediate products of the conversion of gossypol in the solvents mentioned have been studied in detail for the first time and a complete assignment of their resonance characteristics has been made. It has been shown that dianhydrogossypol is formed through intermediate stereoisomeric 15,15-dimethyl ethers of the dilactol form of gossypol.Institute of the Chemistry of Plant Substances, Uzbek SSR Academy of Sciences, Tashkent. V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 166–177, March–April, 1990.     

Crystal structure of Schiff base derivative of gossypol with 3,6,9-trioxa-decylamine

Crystals of the Schiff base derivative of gossypol with 3,6,9-trioxa-decylamine were examined using X-ray diffraction, FT-IR and CPMAS spectroscopy. The Schiff base crystallizes as a racemate in the space group C2/c with a=24.390(5), b=12.026(2), c=14.810(3) Å, β=102.78(3)°, and Z=4. The results of the FT-IR, and CPMAS study of the crystals are in agreement with the X-ray data. The FT-IR spectrum of the crystals shows that the OH groups at position 1,1′ and 6,6′ as well as the N₁₆-H proton are involved in weak intermolecular and intramolecular hydrogen bonds, respectively. The FTIR and CP-MAS spectral behaviour is in agreement with the crystallographic results demonstrating the existence of the enamine-enamine tautomeric form of the Schiff base studied.     

1,4-Dioxanes as products of the oxidation of N-vinyllactams

2, 5-Disubstituted 1,4-dioxanes have been obtained by the oxidation of N-vinyllactams, represented by N-vinylpyrrolidone, N-vinylpiperidone, and N-vinylcaprolactam, and their structure has been shown by independent synthesis: the reaction of trans-2, 5-dichloro-1,4-dioxanes with alkali-metal salts of the lactams also gave 2,5-di(N-2-oxopolymethyleneimino)-1,4-dioxanes.     

1,4-Dioxanes as products of the oxidation of N-vinyllactams

2, 5-Disubstituted 1,4-dioxanes have been obtained by the oxidation of N-vinyllactams, represented by N-vinylpyrrolidone, N-vinylpiperidone, and N-vinylcaprolactam, and their structure has been shown by independent synthesis: the reaction of trans-2, 5-dichloro-1,4-dioxanes with alkali-metal salts of the lactams also gave 2,5-di(N-2-oxopolymethyleneimino)-1,4-dioxanes.     

Investigation of the electrochemical oxidation products of zotepine and their fragmentation using on-line electrochemistry/electrospray ionization mass spectrometry

When zotepine, an antipsychotic drug, was electrochemically oxidized using electrospray ionization mass spectrometry (ESI-MS) coupled with a microflow electrolytic cell, [M + 16 + H]+ (m/z 348), [M-H]+ (m/z 330) and [M-14 + H]+ (m/z 318) were observed as electrochemical oxidation product ions (M represents the zotepine molecule). Although a major fragment ion that was derived from the dimethyl aminoethyl moiety was observed only at m/z 72 in the collision-induced dissociation (CID) spectrum of zotepine, new fragments such as m/z 315 and 286 ions could be generated in the CID spectrum by combining electrochemical oxidation and CID. Since these fragments were relatively specific with high ion strength, it was thought that they would be useful for developing a sensitive LC-MS/MS assay. The S-oxide and N-demethylated products were detected by electrolysis assuring that a portion of P450 metabolites of zotepine could be mimicked by the electrochemistry/electrospray ionization mass spectrometry (EC/ESI-MS) system.     

Structures of enzymatic oxidation products of epigallocatechin

To understand the structures of uncharacterized black tea polyphenols, the oxidation products of (−)-epigallocatechin were investigated. Enzymatic oxidation and subsequent heating of the reaction mixture afforded four new oxidation products (6, and 9–11) along with theasinensins C (4) and E (5), dehydrotheasinensin E (12), epitheaflagallin, hydroxytheaflavin, and desgalloyl oolongtheanin. The structures of the new compounds were determined chemically and spectroscopically. Isotheasinensin E (6) is a C-2 epimer of 5, and compounds 9 and 10 are oxidation products of 12. Another new compound, 11, is a yellow pigment and presumed to be a degradation product of proepitheaflagallin. The results disclosed new oxidation mechanisms that occur during black tea production.