X-ray structural investigation of gossypol and its derivatives XXIX. Molecular and crystal structure of a complex of gossypolic acid lactone with acetic acid

The lactone of gossypolic acid, obtained by the demethylation of the tetramethyl ether of gossypolic acid, forms with acetic acid a stable complex having the 14 composition. The crystallographic parameters of single crystals are as follows:a=20.251(2) Å, b=12.028(3) Å, c=15.934(4) Å, V=3881.2(2.3) ų,Z=4, D _calc=1.32 g/cm³, sp. gr. Pbcn. The molecule is characterized by considerable strain because of the formation of the five-membered lactone ring the atoms of which are coplanar with the atoms of the naphthyl fragment. Unlike the clathrates of racemic gossypol and dianilinegossypol, the gossypolic acid lactone — acetic acid comples does not belong to the type of clathrate inclusion compounds.A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, Ul. Akad. Kh. Abdullaeva, 83. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 458–463, July–August, 1999.     

X-ray structural investigation of gossypol and its derivatives XX. Structure of the solvate of gossypol with pyridine

The structure of the solvate of gossypol with pyridine has been determined by x-ray structural analysis. The crystalline solvate is a H-clathrate with the channel type of structure in which there are three pyridine molecules to each host molecule. On the desolvation of gossypol tripyridine, a new polymorph is formed.Communications (XI–XIX) are represented by the publications given in the Literature Cited under Nos. 1–9.Institute of Bioorganic Chemistry, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 186–191, March–April, 1992.     

X-ray structural investigation of gossypol and its derivatives. X. Unusual inclusion compounds based on gossypol

More than 100 crystalline molecular complexes of gossypol with various organic molecules have been obtained and identified, and for 67 of them single crystals have been grown and their crystallographic parameters have been determined. On the basis of an interpretation of the structures of 30 complexes by the method of x-ray structural analysis, it has been shown that gossypol exhibits unusual including properties. Thus, in addition to all possible types of inclusion compounds this substance forms five polymorphic modifications, solvates, and a coordinoclathrate. The inclusion compounds of gossypol clearly distinguish polar guest molecules from nonpolar ones.A. S. Sadykov Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 675–679, September–October, 1988.     

X-ray investigation of gossypol and its derivatives

The first four homologues of the carboxylic acid series and first two homologues of the monohydric alcohol series with gossypol give equimolar H-clathrates with the channel-type structure that are isostructural with gossypolacetic acid. Formic and acetic acids are capable of forming with gossypol a continuous series of solid substitution solutions. The desolvation of the unstable H-clathrates of carboxylic acids and monohydric alcohols form one and the same polymorph of gossypol. By x-ray structural analysis, the structures have been determined of two complexes of gossypol: an H-clathrate with methanol and a solid solution on the replacement of formic acid by acetic acid in a gossypol matrix.Institute of Bioorganic Chemistry, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 191–197, March–April, 1992.     

X-ray structural investigation of gossypol and its derivatives XXV. Structure of the clathrate of gossypol with isopropyl alcohol

With isopropyl alcohol, gossypol forms a clathrate isostructural with the complexes of gossypol formed by ketones (acetone), aldehydes (butyraldehyde),or alcohols (propyl alcohol). The hydroxy group of isopropyl alcohol acts as the proton acceptor in a hydrogen bond of the host-guest type.A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 62 70 71. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 220–225, March-April, 1995. Original article submitted September 6, 1994.     

X-ray structural investigation of gossypol and its derivatives XXII. Structure of the H-clathrate of gossypol with dimethyl sulfoxide

In crystals obtained from solutions in DMSO, gossypol molecules are again present in the aldehyde tautomeric form. These crystals are H-clathrates with the channel type of structure which has much in common with the structure of the complexes of gossypol with methanol and with formic acid.Institute of Bioorganic Chemistry, Uzbekistan Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, Nos. 3,4, pp. 330–334, May–August, 1992.     

X-ray structural investigation of gossypol and its derivatives. VII. Molecular and crystal structure of dianilinegossypol

A complete x-ray structural investigation of the complex of dianilinegossypol with ethyl acetate has been made and it has been shown that in these crystals the dianilinegossypol gossypol has predominantly the quinoid tautomeric form.A. S. Sadykov Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 661–666, September–October, 1988.     

X-ray structural investigation of gossypol and its derivatives XXIV. Structure of a clathrate of dianilinegossypol with 1,2-dichloroethane

The crystal structure of the 1:2 clathrate of dianilinegossypol with 1,2-dichloroethane, which is unstable under ordinary conditions, has been determined. In the clathrate there are two systems of mutually perpendicular channels in which two crystallographically different molecules of the guest are arranged. No intermolecular H bonds of the host-guest type are observed in the structure of the clathrate.A. S. Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax 627071. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 58–66, January–February, 1994.     

X-ray structural investigation of gossypol and its derivatives XXIII autoclathrates based on a mixed gossypol — 1,4-Dioxane matrix

Gossypol forms various complexes with the isomeric dioxanes. The clathrate with 1,4-dioxane is the only complex of gossypol in which the intrinsic symmetry of the gossypol molecule — the symmetry of a twofold axis — is retained. In this complex, two out of the three 1,4-dioxane molecules belonging to each gossypol molecule participate in the construction of a mixed H-bound gossypol -dioxane matrix, while the third molecule plays the part of guest, the guest molecules having no H-bonds with the host matrix and undergoing desolvation at 108–110°C.     

X-ray structural investigation of gossypol and its derivatives. VIII. A new class of inclusion compounds based on dianilinegossypol

Summary The existence of a new class of ICs based on DAGP has been established. Single crystals have been obtained and the crystallographic characteristics of 15 ICs of this GP derivative have been determined.A. S. Sadykov Institute of Bioorganic Chemistry, Uzbek SSR Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 666–669, September–October, 1988.     

X-ray structural investigation of gossypol and its derivatives. XXVIII. Separation of the dilactol tautomeric form of gossypol hexamethyl ether into individual stereoisomers and evaluation of their clathrate-forming capacity

All three possible stereoisomers of gossypol hexamethyl ether in the dilactol tautomeric form have been separated with the aid of fractional crystallization and have been identified crystallographically. These stereoisomers have been subjected to x-ray stuctural investigation, and their configurations and clathrateforming properties have been determined.Sadykov Institute of Bioorganic Chemistry, Academy of Sciences of the Republic of Uzbekistan, Tashkent, fax (3712) 62 70 71. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 682–686, September–October, 1995. Original article submitted February 6, 1995.     

Novel cellulose derivatives. V. Synthesis and thermal properties of esters with trifluoroethoxy acetic acid

Esters of cellulose with trifluoroethoxy acetic acid (TFAA) were prepared in homogeneous phase using a mixed anhydride with p‐toluenesulfonic acid. Esters with low degree of substitution (DS), and with DS rising from 0 to 3, had hydrophobic character that prevented the usual association with moisture, which is otherwise typical of cellulose esters with low DS. Cellulose trifluoroethoxy acetate (CT) had T_g's declining by about 40 °C per DS‐unit (from 160 to 41 °C) as DS rose from 1 to 3. Mixed esters, cellulose derivatives with acetate and trifluoroethoxy acetate substituents (CAT), exhibited glass‐to‐rubber and melting transitions by DSC. A linear relationship between both T_g and T_m with respect to DS was recorded with the T_g and T_m separated by 30° to 40 °C. This is consistent with cellulose esters described elsewhere. Surprisingly, the T_g's of CT and CAT were found to be identical when the DS was equivalent to the DS of the fluoro substituents (DS_F). © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 486–494, 2000