Quasi-enantiomeric single-nucleoside and quasi-racemic two-nucleoside hydrochloride salts and ruthenium complexes of cytidine and 2′,3′-dideoxycytidine analogs unveiling the negligible structure-driving role of the 2′,3′-moieties

Abstract

The role of differences at the 2′,3′-positions in the crystal structure of cytidine nucleosides.

Ru(II)-based complexes with N-(acyl)-N′,N′-(disubstituted)thiourea ligands: Synthesis, characterization, BSA- and DNA-binding studies of new cytotoxic agents against lung and prostate tumour cells

“…The complexes present one acylthiourea derivative, one 2,2'-bipyridine, and two triphenylphosphine ligands, forming slightly distorted octahedral geometries, highlighted by the bond angles around the metal centres ( Table 3) (Table 3). Ru-N bipy and Ru-P PPh3 bond lengths found in complexes 1-4 are in agreement with values present in complexes obtained from the same Ru (II) precursor [11,49]. .…”

Vibrational and thermal analyses of multicomponent crystal forms of the anti-HIV drugs lamivudine and zalcitabine

“…The carbonyl stretching is observed at a frequency lower than that expected (1700-1730 cm −1 ) in both hydrochloride salts of lamivudine and in that of zalcitabine due to the engagement of this moiety as a hydrogen bonding acceptor from 5 -OH group. The O5 H•••O2 C2 hydrogen bonding is responsible for contacting neighboring lamivudine molecules in the three salts [8,14]. Similar bathochromic shift in the C O stretching frequency is also observed in the IR spectrum of 4 (Fig.…”

“…In case of 4, maleic acid was directly dissolved into the solution of lamivudine in isopropyl alcohol instead. Full details of synthesis and crystal structure determination of the five salts can be found in four related papers [5,8,13,14]. Before thermal and vibrational studies, authenticity and purity of each crystal form were first checked by X-ray powder diffraction (XRPD) technique using CuK␣ radiation ( = 0.15418 nm) generated at 40 kV and 30 mA on a Shimadzu XRD-6000 Bragg-Brentano geometry diffractometer (Kratos Analytical Inc., NY).…”

Isostructurality and the conformational role of the 2′,3′-moieties in the diversity of lamivudine crystal forms probed in halide salts

“…Crystal engineering of the anti-HIV drug lamivudine has currently provided improvement in its pharmaceutical performance besides getting insights into several branches of nucleoside structural chemistry. [1][2][3][4][5][6][7][8][9][10][11][12][13] Targeting pharmaceutical improvements, the design of crystal structures has produced some salts of active pharmaceutical ingredients showing important improvement in its solubility and purity. 11,14 Furthermore, the ability of nucleosides to assemble base-stacked and base-paired double-stranded helices even without phosphodiester linkages in crystals was demonstrated in three structures of the drug similar to DNA duplexes.…”