부산대학교 도서관

Mycolic acids are major components of the cell wall of Mycobacterium tuberculosis and other mycobacteria. They are usually long chain high molecular mass branched β-hydroxy fatty acids, containing 70- 90 carbons, a-alkyl (C₂₂-C₂₄) and containing different functionalities in the main chain. Their presence is thought to explain the characteristic resistance of these mycobacteria to most antibiotics and other chemotherapeutic agents. Synthetic mycolic acids have applications in the detection and treatment of tuberculosis and in the treatment of asthma. This project consists of three parts. The first part was to synthesise (R,R)-epoxy-trans-alkene-mycolic acid (I) and (S,S)-epoxy-trans-alkene-mycolic acid (II). The target for this part of the project was an epoxy-mycolate present in the cell wall of Mycobacterium fortuitum. Two synthetic stereoisomers (I) and (11) were compared by ¹H and ¹³C NMR spectra with natural epoxy-trans-alkene mycolic acid and the stereochemistry of natural mycolic acid was also proved to be as in compound (II). The second part was to synthesise (S,R)-cis-cyclopropane (R,R)-epoxy-mycolic acid (III) and (S,R)-cis-cyclopropane (S,S)-epoxymycolic acid (IV) from Mycobacterium smegmatis. Two synthetic stereoisomers (III) and (IV) were compared by proton NMR spectroscopy with natural cis-cyclopropane epoxy mycolic acid isolated from M smegmatis. The third part was to synthesise (E/Z)-(R,R)-epoxy-alkene mycolic acid methyl ester (V) and (E/Z)-(S,S)-epoxy-alkene mycolic acid methyl ester (VI) from M smegmatis. An attempt was made to separate the (E/Z)-alkene-epoxy mycolic acid methyl esters by silver ion TLC but was not successful.