Long-chain alkanediols from Myricaria germanica leaf cuticular waxes

In the leaf cuticular waxes of Myricaria germanica L. four different series of alkanediols were identified: (1) hentriacontanediol isomers with one functional group in the 12-position arid a second group in positions ranging from 2 to 18, (2) C-30-C-34 alkanediols carrying one hydroxyl function on a primary and one on a secondary carbon atom, (3) homologous series of C-25-C-43 beta -diols predominantly with 8,10- and 10,12-functionalities, and (4) homologous series of C-39-C-43 gamma -diols with a predominance of 8,11- and 10,13-isomers. Primary/secondary diols and gamma -diols constituted only trace portions of the total wax mixture. The hentriacontanediols and the beta -diols amounted to 3.5 and 0.6 mug per cm(2) of leaf surface area, corresponding to 9 and 2% of the wax mixture, respectively. Based on the different homolog and isomer patterns of respective diol fractions, two independent biosynthetic routes leading to the hentriacontanediols and the beta -diols are proposed. (C) 2000 Elsevier Science Ltd. All rights reserved.