Abstract: A high quality ink jet recording medium with a printed image non-vulnerable and excellent in scratch resistance is obtained with an ink jet recording using a water pigment ink. An ink jet recording medium having a substrate and an ink receiving layer including an inorganic particle and a binder on the substrate is provided. A surface of the ink receiving layer has (a) a projected valley portion depth (Rvk) of not less than 20 nm and not more than 100, (b) an arithmetic average roughness (Ra) of not less than 5 nm and not more than 100 nm, and (c) an average spacing (S) of local peaks of not more than 1.0 ?m.

Abstract: 9-Dihydro-9-O-alkyldesmycosin derivatives and their salts are disclosed. The 9-dihydro-9-O-alkyldesmycosin derivatives are represented by the following formula (I), ##STR1## --wherein X represents an --O-- mycinose or a di-lower alkylamino group, R.sup.1 represents a hydrogen atom or a lower alkanoyl group, R.sup.2 represents a lower alkyl group, a cycloalkyl-lower group, or phenyl-lower alkyl group which may have a substituent, and R.sup.3 represents a hydrogen atom or a hydroxyl group. The compounds and the salts are useful as an antimicrobial agent. Unlike known desmycosin derivatives, the compounds give a high blood concentration by oral administration.