title: X-ray diffraction and infrared spectroscopy of N,N-dimethylformamide and dimethyl sulfoxide solvatomorphs of betulonic acid.
abstract: X-ray diffraction and infrared spectroscopy measurements for the N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) solvatomorphs of betulonic acid (BA) were investigated. BA [3-oxolup-20(29)-en-28-oic acid, C(30)H(46)O(3)] exhibits a wide spectrum of biological activities and is considered to be a promising natural agent for the treatment of various cancer diseases. BA as a noncrystalline substance was obtained by oxidation of betulin. Crystal structures and the spectral data allowed analysis of hydrogen bonding (H-bonding), molecular conformation, and crystal packing differences in the solvatomorphs. Crystals of BA solvates were grown from the DMF-acetone (1:10, v/v) and DMSO-water (9:1, v/v) solutions. BA-DMF (1:1) solvate crystallizes in the monoclinic P2(1) space group, Z = 2. The unit cell parameters are as follows: cell lengths a = 13.2458(5) Å, b = 6.6501(2) Å, c = 17.9766(7) Å, and β = 110.513(4)°. BA-DMSO (1:1) solvate crystallizes in the orthorhombic P2(1)2(1)2(1) (Z = 4) space group with the following unit cell parameters: a = 6.6484(4) Å, b = 13.3279(8) Å, and c = 32.6821(19) Å. Conformational analysis of the six-membered rings, cyclopentane ring, and isopropenyl group showed differences in comparison with other betulin derivatives examined earlier. For both solvates, the intermolecular packing arrangement was governed mainly by H-bonds. The shortest H-bonds with D···A distances of 2.604 and 2.657 Å, and almost linear DH···A connection occurred between OH of carboxylic group of BA and oxygen atoms from O=C and O=S groups of DMF and DMSO, respectively.
authors.affiliation: Department of Organic Chemistry, Medical University of Silesia, Sosnowiec 41-200, Poland.
authors.forename: Stanisław
authors.initials: S
authors.lastname: Boryczka
authors.forename: Maria
authors.initials: M
authors.lastname: Jastrzebska
authors.forename: Ewa
authors.initials: E
authors.lastname: Bębenek
authors.forename: Joachim
authors.initials: J
authors.lastname: Kusz
authors.forename: Maciej
authors.initials: M
authors.lastname: Zubko
authors.forename: Monika
authors.initials: M
authors.lastname: Kadela
authors.forename: Ewa
authors.initials: E
authors.lastname: Michalik
mesh_terms: D000970:Antineoplastic Agents / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004121:Dimethyl Sulfoxide / Q000737:chemistry*; D004126:Dimethylformamide / Q000737:chemistry*; D008958:Models, Molecular; D009828:Oleanolic Acid / Q000031:analogs & derivatives* / Q000737:chemistry; D013055:Spectrophotometry, Infrared; D000094062:Betulinic Acid
chemical_list: D000970:Antineoplastic Agents; D004121:Dimethyl Sulfoxide; D004126:Dimethylformamide; D009828:Oleanolic Acid; C118308:betulonic acid; D000094062:Betulinic Acid