The pentadecanolide was biosynthesized in cyclohexane from 15-hydroxypentadecanoic acid, which as prepared from 15-tetracosenoic acid in Malania Olcifera Chum oil using lipase as catalyst. The effect of lipase activity on the lactonization was investigated. Lipases from fiften strains (13 strains of Candida and 2 strains of Penicillium) showed different catalytic effects to the synthesis reactions. The lipases from strains of Penicillium sp. and 4 strains of Candida sp. have catalytic lactonization activity, and the conversion ratio of substrate reached 88% by using lipase Candida sp.GXU01.
Synthesis of mcrocyclic lactones has been applied to medical and flavor field. Triglycerides(2) of ω-hydroxycarboxylic acids synthesized from malania oleifera chum oil(1) via ozonization and reduction, and compound 2 were catalytically transformed to macrocyctic lactones(3). This is a new method involving fewer steps and a 61% yield of cyclopentadecanolide was obtained. The reactive properties of macrolactonization of ω-hydroxycarboxylic acids were also studied. The result obtained shows that the priority order of macrolactonization as follows: 11-undecalactone>cyclotridecanolide>cyclopentadecanolide, i.e. the short chain ω-hydroxycarboxylic acids were preferentially cyclized.
Ozonization processes of 15 tetracosenoic acid methyl ester(TAE) and 9 octadecenoic acid methyl ester(OAE) obtained from Malania Oleifera Chum oil have been monitored by combined gas chromato graphy mass spectrometry(GC MS) or gas chromatography(GC). The effect of reaction temperature and solvent( heptane , toluene, n butyl acetate, ethanol, and heptane ethanol) on the ozonization selectivity of TAE and OAE were investigated. The results show that TAE has good selectivity in heptane because of its small dielectric constant. The k TAE / k OAE of the ozonization reaction decreased with the increase of ethanol in heptane ethanol , whereas the ozonization selectivities of TAE and OAE reduced with the increase of the reaction temperature .
