IDENTIFICATION OF CATECHOLAMINE BETA-GLUCOSIDES IN THE HEMOLYMPH OF THE TOBACCO HORNWORM, MANDUCA-SEXTA (L), DURING DEVELOPMENT

Catecholamine conjugates were isolated from the hemolymph of larval, p upal and adult stages of the tobacco hornworm, Manduca sexta, and thei r identities were determined by synthesis from C-14-labeled precursors , HPLC analysis, H-1-NMR and FAB-mass spectrometry, and GLC analysis o f the sugar moieties, beta-Glucosides of N-acetyldopamine (NADA) and N -beta-alanyldopamine (NBAD) were the primary conjugates identified and their relative abundance depended on the stage of development. NADA g lucosides were the predominant conjugates in hemolymph of pharate or n ewly ecdysed fifth stadium larvae with 86% as the 3-O-glucoside and 14 % as the 4-O-glucoside. Low concentrations of dopamine (DA) 3-O-glucos ide and NBAD 3-O-glucoside also were found. In pharate or newly ecdyse d pupal hemolymph, NBAD 3-O-glucoside was the major conjugate (98%) al ong with small amounts of NBAD 4-O-glucoside, DA 3-O-glucoside and NAD A 3-O-glucoside. In hemolymph of pharate or newly ecdysed adults, NADA CO-glucoside (67%) was more abundant than NADA 3-O-glucoside. Only tr aces of NBAD 3-O-glucoside were found. Therefore, a preponderance of c atecholamine 3-O-glucosides occurred in larval and pupal hemolymph as storage precursors for cuticle sclerotization agents, whereas the 4-O- glucoside of NADA predominated in adult hemolymph. The role of catecho lamine glucosides in hemolymph in relation to cuticle sclerotization i s discussed.