Actinidine and glucose from the defensive secretion of the stick insect Megacrania nigrosulfurea

Abstract

1. Subject and sourceMegacrania nigrosulfurea Redtenbacher is a stick insect from the mountainous interior of the island of New Britain (PapuaNew Guinea). The insect was first described by Redtenbacher in 1908 but has not been reported in the wild since(Redtenbacher,1908). In common with some other stick insect species M. nigrosulfurea is able to spray a defensive secretionfrom its prothoraxic glands and approximately 1 ml of the secretion was obtained from 40 insects collected within a 2 kmradius of the village of Paka in the Nakanai Mountains of New Britain, Papua New Guinea (S 0537.5482, E 15106.3832). Themilky colloid-like secretion was collected by holding two screw cap plastic vials against each prothoraxic gland and thenagitating the insect by touching its abdomen. Identification of insect specimens was carried out by Dr Oliver Zompro at theMax-Planck-Institut fuer Limnologie, Germany where voucher specimens are lodged (PHA 10099–PHA 10107).2. Previous workThere are no previous chemical investigations on M. nigrosulfurea.3. Present studyActinidine(1)wasisolatedbyactivity-guidedfractionationofthedefensivesecretionfollowingtheantibacterialactivityoffractions against Staphylococcus epidermidis NCTC 13360 using the well diffusion method. 50