title: Concomitant pseudopolymorphs of 10-deacetyl baccatin III.
abstract: Three new solvates [mono-dimethyl sulfoxide (mono-DMSO), mono-dimethyl acetamide (mono-DMA) and mono-dimethyl formamide (mono-DMF)] of 10-Deacetyl baccatin III, were generated by slow evaporation in DMSO, DMF, and DMSO/DMA (1:1) solvent systems respectively. Two concomitant forms mono-DMSO(a new form) and di-DMSO (a known form) were obtained in the DMSO solvent system. Yet two other concomitant forms mono-DMA (a new form) and di-DMSO (a known form) were obtained in DMSO/DMA (1:1) solvent system. A fourth solvate mono-DMF (a new form) was crystallized in unimolar ratio using DMF as a solvent. These solvates were characterized using powder X-ray diffraction, differential scanning calorimeter, thermogravimetric analysis (TGA), and spectroscopic [(13)C solid-state nuclear magnetic spectroscopy, solution (1)H NMR, and Fourier transform infrared] techniques. The interactions between host and guest molecules were elucitated by single-crystal X-ray diffraction data. In all the cases, guest molecules are connected to the host molecules by O-H∙∙∙O hydrogen bonds. A remarkable difference in the desolvation onset temperatures of di- and mono-DMSO solvates was observed which was also featured by a corresponding weight loss during TGA analysis.
authors.affiliation: Analytical Development, Aptuit Laurus Pvt. Ltd, ICICI Knowledge Park, Turkapally, Shameerpet, Hyderabad 500078, India. kumarltatini@gmail.com
authors.forename: Lakshmi Kumar
authors.initials: LK
authors.lastname: Tatini
authors.forename: N Someswara
authors.initials: NS
authors.lastname: Rao
authors.forename: Muzaffar
authors.initials: M
authors.lastname: Khan
authors.forename: Krishna Sumanth
authors.initials: KS
authors.lastname: Peraka
authors.forename: K V S R Krishna
authors.initials: KV
authors.lastname: Reddy
mesh_terms: D000081:Acetamides / Q000737:chemistry; D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002626:Chemistry, Pharmaceutical; D003460:Crystallization; D018360:Crystallography, X-Ray; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D004126:Dimethylformamide / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D033362:Powder Diffraction; D012997:Solvents / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D043823:Taxoids / Q000737:chemistry*; D013678:Technology, Pharmaceutical / Q000379:methods; D013696:Temperature; D013818:Thermogravimetry
chemical_list: C425406:10-Deacetyl baccatin III dimethyl sulfoxide disolvate; D000081:Acetamides; D000972:Antineoplastic Agents, Phytogenic; D012997:Solvents; D043823:Taxoids; C042213:10-deacetylbaccatine III; D004126:Dimethylformamide; C013959:dimethylacetamide; D004121:Dimethyl Sulfoxide