We describe the characterisation of the O-methyltransferase JerF from the late stages of jerangolid biosynthesis. JerF is the first known example of an enzyme that catalyses the formation of a non-aromatic, cyclic methylenolether. The enzyme was overexpressed in E. coli and the cell-free extracts were used in bioconversion experiments. Chemical synthesis gave access to a series of substrate surrogates
Synthesis and evaluation of the molluscicidal activity of the 5,6-dimethyl-dihydro-pyran-2,4-dione and 6-substituted analogous
作者:Laura Cristiane de Souza、Aldenir Feitosa dos Santos、Antônio Euzébio Goulart Sant'Ana、Dennis de Oliveira Imbroisi
DOI:10.1016/j.bmc.2004.01.001
日期:2004.3
Five dihydro-piran-2,4-diones, including 5,6-dimethyl-dihydro-piran-2,4-dione one of the intermediates of the synthesis of caloverticilic acid, were synthesized and submitted to molluscicidal bioassay. The compound's yields varied from moderate to good (42%- 80%) and were achieved through the preparation of the dianion of ethyl acetoacetate, reaction with and aldehyde followed by hydrolysis of the ester (NaOH, H2O, 2 h, T.A.) and lactonization in acidic medium (HCl, 0degreesC). The 5,6-dimethyl-dihydro-piran-2,4-dione and three analogous dihydro-piran-2,4-diones 6-substituted,-phenyl, (4-methoxy-phenyl), and -propenyl, showed significant activities against the Biomphalaria glabrata egg masses, while the analogous 6-(3,4-dimethoxy-phenyl) was inactive as molluscicide. This activity is reported for the first time, extending the range of biological activities of this group. (C) 2004 Elsevier Ltd. All rights reserved.
717. Studies on compounds related to auxin-a and auxin-b. Part II. Preparation of analogues of auxin-b lactone
作者:H. B. Henbest、E. R. H. Jones
DOI:10.1039/jr9500003628
日期:——
CASTELLINO, S.;SIMS, J. J., TETRAHEDRON LETT., 1984, 25, N 22, 2307-2310