4-Pyridinecarboxylic acid, [(3-hydroxyphenyl)methylene]hydrazide 840-80-2 Acroteben Isonicotinic acid, (m-hydroxybenzylidene)hydrazide Isonicotinoyl-m-hydroxybenzalhydrazone NSC33761 m-Hydroxybenzaldehyde isonicotinoylhydrazone m-Oxyberon