11 つのろう虫(Ceroplastes ceriferus)の分泌物

抄録

Examination of the secreted wax of a scale insect, Ceroplastes ceriferus has shown the presence of various compounds of considerable biogenetic interest. (a) The sesquiterpenes were enantiomeric with respect to those from C. rubens, which infests the same host tree. Each insect may possess a specific set of C-C cyclases for the formation of sesquiterpenes. (b) Among the identified twelve diterpenes, two of labdane skeletons were the first naturally occurring compounds. (c) The sesterterpenes (1-6)(7-10) having 14-membered monocyclic skeletons were the first naturally occurring compounds being independent of the host tree. Remarkable is the finding of sesterterpenes resulting from different biogenetic cyclization mode from the same species, collected in different districts, or from the different species of the same genus. (d) The "cyclic" wax were the esters consisting of fatty acids (C_<10>-C_<32>) and unusual cyclic alcohols (diterpenes and sesterterpenes). Structures and stereochemistry of nine new sesterterpenes will be discussed on the basis of spectroscopic and chemical methods: Cericerol-I (1), cericerol-II (2), 13-methoxy cericerene (3), 13-ethoxy cericerene (4), α-cericerol-I (5), cericeroic acid (6), 18-dihydro-19-ol cericeroic acid (7), cericera-2(E),6(Z),10(E),15(22), 18-pentene-25-acid (8), cericera-2(E),6(Z),10(E),15(22), 18-pentene-24-acid (9), and cericerene-15,24-diol (10). Possibility of the configurational isomers for the structures (8)and (9) at the position C-24 and C-25 are still remained to be elucidated. Bridged hydrocarbon (16) which was obtained by acid treatment of tosylate of cericerol-I (1) indicated the crown shape (A) for (1).