Conformational Behaviour of 11-O-Methylazithromycin in the Solid and Solution State

Conformational behaviour of azithromycin 11-OMe derivative 2 (Scheme 1) has been studied in the solid and solution state. In the CDCl3 and DMSO solution, 2 mainly adopts the »folded-in« conformation. 11-OMe group is oriented toward the centre of aglycone ring. The crystal structure of DMSO solvate of 2 has been solved by the molecular replacement method using the solution state conformation as the search model. Conformation of 2 in the solid and solution state is very similar. Molecules of 2 are held together in the crystal by van der Waals interactions, forming a solvent channel along the b axis. The DMSO molecule is found to be disordered and bound to cladinose moiety of 2 by H-bond O4"-H...01s

Synthesis and Anti-inflammatory Activity of Novel Furochromenes

A series of variously substituted furochromenes, hemiacetals 2, acetals 3, and rearranged compounds 4, were synthesized from variously substituted 4-hydroxycoumarins and evaluated in several in vitro assays, inhibition of mast cell degranulation induced by the activation of Fcε receptor type I or calci-um ionophore and leukotriene B4 (LTB4) inhibition. The most active derivatives, 3p and 4p (8-iso-propyl substitution in coumarin ring) and 3r (5-methyl-8-chloro substitution), showed significant inhibition of mast cell degranulation (Fctriggered) and LTB4, and exhibited significant local anti-inflammatory activity in PMA induced ear edema in CD1 mice, with potency equal (compounds 3p and 4p) or better (compound 3r) in comparison with zileuton, a reference drug used. It might be a promising direction for developing novel drugs as potential agents for the treatment of allergies and other inflammatory diseases.(doi: 10.5562/cca2240