NOVEL ESTERS ON LONG-CHAIN METHYL-BRANCHED ALCOHOLS IN PUPAE OF THE TOBACCO HORNWORM, MANDUCA-SEXTA - PROPIONATE, BUTYRATE, ISOBUTYRATE, PENTANOATE AND ISOVALERATE

Isobutyrate (2-methylpropionate) (13-mu-g/pupa), n-butyrate (3.8-mu-g/pupa), isovalerate (3-methylbutyrate) (2.4-mu-g/pupa), propionate (1.9-mu-g/pupa), and n-pentanoate (0.5-mu-g/pupa) esters of long-chain methyl-branched alcohols (LMA; C25-C32) were identified as minor components of the wax ester fraction of internal lipids of developing male pupae of the tobacco hornworm, Manduca sexta. Propionate esters (2.6-mu-g/pupa) of very long-chain methyl-branched alcohols (VLMA; C36 to > C44) were also present. The major ester of both the LMA and the VLMA were the acetate esters (750-mu-g/pupa) (Nelson et al., 1990a). The short-chain acid esters of the LMA were essentially absent at the beginning and end of the pupal stadium. Maximum levels of these esters were reached at approximately midpoint, between days 8 and 10, of the pupal stage. The amount of butyrate plus isobutyrate esters reached a maximum of 17-mu-g/pupa, the propionate esters rose to about 4.5-mu-g/pupa and the pentanoate plus 3-methylbutyrate esters reached a level of about 3-mu-g/pupa.