| abstract |
The present invention is directed to a pyridine derivative of the formula (I): (see formula I) wherein A is group of the following formulae: (see formula II) (R1 and R2 are each H, or protected or unprotected OH, R31, R41 and R42 are protected or unprotected hydroxymethyl, R32 is H, lower alkyl, or protected or unprotected hydroxymethyl, R33 is substituted or unsubstituted lower alkyl, and the dotted line means the presence or absence of a double bond), R5 and R6 are H, or protected or unprotected amino, or both combine together with the adjacent nitrogen to form substituted or unsubstituted heterocycle, or a pharmaceutically acceptable salt thereof. These compounds showing excellent bronchoconstriction inhibitory activity and/or airway anti-inflammatory activity, and are useful in the prophylaxis or treatment of asthma. |