Alarm pheromones from the Mediterranean opisthobranch Haminoea navicula

Structure and absolute stereochemistry of two new 3-alkylpyridines, haminol-A (3) and haminol-B (4), isolated from the cephalaspidean mollusc Haminoea navicula, have been determined by means of spectral and chemical methods. Haminols are secreted by H. navicula when it is molested, and these induce an alarm response in trail-following conspecifics.