Vyssotski M, Ryan J, Lagutin K, Wong H, Morgan X, Stott M
Industrial Research Limited, PO Box 31-310, Lower Hutt 5040, New Zealand.
Lipids. 2012 Jun;47(6):601-11. doi: 10.1007/s11745-012-3668-z. Epub 2012 Apr 5.
The major fatty acids of a novel species of Thermogemmatispora sp. (strain T81) from the phylum Chloroflexi were identified as i18:0 (42.8 % of total fatty acids), i19:0 (9.7 %), and i17:0 (5.9 %). Also observed was a number of unidentified fatty acids, including a major acid (16.3 %) with ECL of 19.04 (BP1), and 18.76 (TG-WAXMS A). GCMS revealed that this compound is a saturated 20-carbon atom fatty acid. (1)H- and (13)C-NMR, with (1)H-(1)H-COSY and (1)H-(13)C-HSQC experiments suggested the structure of dimethyl octadecanoic acid with iso-branching, and an extra middle-chain methyl group. A pyrrolidide derivative demonstrated the characteristic gaps in GCMS indicating methyl branching at C12 and C17, which was eventually confirmed by a (1)H-(13)C-HSQC-TOCSY experiment. This 12,17-dimethyloctadecanoic acid has not been previously detected or described in these organisms. However, a recent description of a phylogenetically related species of Thermogemmatispora (Yabe et al., Int J Syst Evol Microbiol 61:903-910, 2010), noted an unidentified 20:0 fatty acid with matching GC behavior and GCMS data to that of strain T81. These data suggest that Thermogemmatispora share an ability to synthesize the same fatty acid. A number of other dimethyl-branched fatty acids, namely 8,14-diMe 15:0; 12,15-diMe 16:0; 10,15-diMe 16:0; 12,16-diMe 17:0; 10,16-diMe 17:0; 12,17-diMe 18:0; 12,18-diMe 19:0; 14,19-diMe 20:0, were also identified in strain T81.
来自绿弯菌门的一个新型嗜热芽胞菌属物种（菌株T81）的主要脂肪酸被鉴定为异18:0（占总脂肪酸的42.8%）、异19:0（9.7%）和异17:0（5.9%）。还观察到一些未鉴定的脂肪酸，包括一种主要酸（16.3%），其等效链长（ECL）为19.04（BP1），以及18.76（TG-WAXMS A）。气相色谱-质谱联用（GCMS）显示该化合物是一种饱和的20碳原子脂肪酸。氢核磁共振（¹H-NMR）和碳核磁共振（¹³C-NMR），以及¹H-¹H-COSY和¹H-¹³C-HSQC实验表明其结构为具有异分支和一个额外中链甲基的二甲基十八烷酸。一种吡咯烷衍生物在GCMS中显示出特征性间隙，表明在C12和C17处有甲基分支，这最终通过¹H-¹³C-HSQC-TOCSY实验得到证实。这种12,17-二甲基十八烷酸此前在这些生物体中未被检测到或描述过。然而，最近对嗜热芽胞菌属的一个系统发育相关物种的描述（矢部等人，《国际系统与进化微生物学杂志》61:903 - 910，2010年）指出，有一种未鉴定的20:0脂肪酸，其气相色谱行为和GCMS数据与菌株T81的相匹配。这些数据表明嗜热芽胞菌属具有合成相同脂肪酸的能力。在菌株T81中还鉴定出了其他一些二甲基支链脂肪酸，即8,14-二甲基15:0；12,15-二甲基16:0；10,15-二甲基16:0；12,16-二甲基17:0；10,16-二甲基17:0；12,17-二甲基18:0；12,18-二甲基19:0；14,19-二甲基20:0。
