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Separation and analysis of molecular species of mycolic acids in Nocardia and related taxa by gas chromatography mass spectrometry
Author(s) -
Yano Ikuya,
Kageyama Katsuhiro,
Ohno Yoshimi,
Masui Masamiki,
Kusunose Emi,
Kusunose Masamichi,
Akimori Norimi
Publication year - 1978
Publication title -
biomedical mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0306-042X
DOI - 10.1002/bms.1200050104
Subject(s) - chemistry , mycolic acid , mass spectrometry , nocardia , gas chromatography , chromatography , mass spectrum , molecular mass , trimethylsilyl , double bond , bond cleavage , stereochemistry , bacteria , mycobacterium , organic chemistry , biology , enzyme , genetics , catalysis
The gas chromatographic separation and mass spectrometric identification of mycolic acids ranging from C 28 to C 68 in Nocardia and related acid‐fast groups of bacteria was established. Using this method, the molecular species of mycolic acids were clearly separated as the trimethylsilyl (TMS) derivatives of the methyl esters, according to their total carbon numbers. From the[ M ] − ˙, [M−15] + and[ M − 90 ] − ˙ions produced by gas chromatography mass spectrometry, the total carbon and double bond numbers were determined, while the straight and branched chain structures were identified by the mass fragment ions due to C 2 ∼ C 3 cleavage [RCHOSi(CH 3 ) 3 ] + , and C 3 ∼ C 4 cleavage [(CH 3 ) 3 SiOCHCH(R′)COOCH 3 ] + , respectively. Based on the molecular species composition, the average carbon numbers of the mycolic acids from 16 strains of Nocardia and related taxa ( Mycobacterium rhodochrous complex and Gordona bronchialis ) were determined. Each species of bacteria was demonstrated to possess a characteristic profile of mycolic acid composition, and they were shown to be classified approximately into at least four groups: (1) C 28 to C 48 (average carbon numbers C 33 ∼ 38 ) mostly saturated for Nocardia erythropolis and several ‘ Mycobacterium rhodochrous complex ’; (2) C 34 to C 50 (average C 43 ∼ 34 ) monoenoic and dienoic for N. rubra, N. corallina and N. lutea ; (3) C 44 to C 58 (average C 51 ∼ 52 ) monoenoic to tetraenoic for N. asteroides and ‘true’ nocardiae; (4) C 56 to C 68 (average C 62 ∼ 64 ) monoenoic to pentaenoic for N. polychromogenes and Gordona bronchialis. The results indicate that the structural determination of mycolic acids by gas chromatography mass spectrometry can be one of the most useful criteria for the chemotaxonomy of Nocardia and related bacteria.