龙胆酸及其3-和4-甲基取代的同系物作为间甲酚、3,5-二甲酚和2,5-二甲酚细菌降解的中间体。

Intact cells of a non-fluorescent Pseudomonas grown with m-cresol, 2,5-xylenol, 3,5-xylenol, 3-ethyl-5-methylphenol or 2,3,5-trimethylphenol rapidly oxidized all these phenols to completion. 3-Hydroxybenzoate and 2,5-dihydroxybenzoate (gentisate) were also readily oxidized. 2. 3-Hydroxybenzoic acid and 2,5-dihydroxybenzoic acid were isolated as products of m-cresol oxidation by cells inhibited by alphaalpha'-bipyridyl. Alkyl-substituted 3-hydroxybenzoic acids and alkyl-substituted gentisic acids were formed similarly from 2,5-xylenol, 3,5-xylenol, 3-ethyl-5-methylphenol and 2,3,5-trimethylphenol. 3. When supplemented with NADH, not NADPH, extracts of cells grown with 2,5-xylenol catalysed the oxidation of all five phenols and accumulated the corresponding gentisic acids in the presence of alphaalpha'-bipyridyl. 4. Cells of a fluorescent Pseudomonas grown with m-cresol oxidized m-cresol, 3,5-xylenol and 3-ethyl-5-methylphenol to completion and oxidized 2,5-xylenol and 2,3,5-trimethylphenol partially. The oxidation product of 2,5-xylenol was identified as 3-hydroxy-4-methylbenzoic acid. In the presence of alphaalpha'-bipyridyl, 3-hydroxy-5-methylbenzoic acid and 3-methylgentisic acid were formed from 3,5-xylenol.

用间甲酚、2,5 - 二甲酚、3,5 - 二甲酚、3 - 乙基 - 5 - 甲基苯酚或2,3,5 - 三甲基苯酚培养的非荧光假单胞菌完整细胞能迅速将所有这些酚类完全氧化。3 - 羟基苯甲酸和2,5 - 二羟基苯甲酸（龙胆酸）也很容易被氧化。
3 - 羟基苯甲酸和2,5 - 二羟基苯甲酸是由受αα'- 联吡啶抑制的细胞氧化间甲酚的产物而分离得到的。烷基取代的3 - 羟基苯甲酸和烷基取代的龙胆酸也以类似方式由2,5 - 二甲酚、3,5 - 二甲酚、3 - 乙基 - 5 - 甲基苯酚和2,3,5 - 三甲基苯酚形成。
当用2,5 - 二甲酚培养的细胞提取物补充NADH而非NADPH时，在αα'- 联吡啶存在下，能催化所有五种酚类的氧化并积累相应的龙胆酸。
用间甲酚培养的荧光假单胞菌细胞能将间甲酚、3,5 - 二甲酚和3 - 乙基 - 5 - 甲基苯酚完全氧化，将2,5 - 二甲酚和2,3,5 - 三甲基苯酚部分氧化。2,5 - 二甲酚的氧化产物被鉴定为3 - 羟基 - 4 - 甲基苯甲酸。在αα'- 联吡啶存在下，由3,5 - 二甲酚形成3 - 羟基 - 5 - 甲基苯甲酸和3 - 甲基龙胆酸。

Gentisic acid and its 3- and 4-methyl-substituted homologoues as intermediates in the bacterial degradation of m-cresol, 3,5-xylenol and 2,5-xylenol.