Beissner R S, Guilford W J, Coates R M, Hager L P
Biochemistry. 1981 Jun 23;20(13):3724-31. doi: 10.1021/bi00516a009.
The presence of naturally occurring volatile halohydrocarbons in marine organisms, seawater, and the upper atmosphere has prompted a serach for their biosynthetic origin. An earlier report documented the preparation of an enzyme extract from a marine algae which catalyzed the formation of dibromomethane, tribromomethane, and 1-bromopentane from 3-oxooctanoic acid. This report did not establish a pathway nor did it examine potential intermediates involved in the synthesis of the halometabolites (Theiler, R., Cook, J., Hager, L., & Siuda, J. (1978) Science (Washington, D.C.) 202, 1094-1096). This paper shows that an extract of the green marine algae, Penicillus capitatus, which contains a potent bromoperoxidase activity, is capable of catalyzing the incorporation of bromide ion into organic combination in the presence of 3-oxooctanoic acid. By use of gas chromatography and mass spectroscopy, it has been possible to identify tribromomethane, 1-bromo-2-heptanone, 1,1-dibromo-2-heptanone, and 1,1,1-tribromo-2-heptanone as products of this reaction. The properties of the enzymatically synthesized products have been compared to authentic compounds and found to be identical. The mono- and dibromoheptanones can be utilized as precursors for the enzymatic formation of tribromoheptanone, but the final hydrolysis of the tribromoheptanone to bromoform appears to be a nonenzymatic reaction with the P. capitatus extracts.
海洋生物、海水和高层大气中天然存在的挥发性卤代烃的存在促使人们探寻它们的生物合成起源。一份较早的报告记录了从一种海藻中制备酶提取物的过程，该提取物能催化3-氧代辛酸生成二溴甲烷、三溴甲烷和1-溴戊烷。该报告既未确立一条途径，也未研究卤代代谢产物合成过程中涉及的潜在中间体（泰勒，R.，库克，J.，哈格，L.，& 休达，J.（1978年）《科学》（华盛顿特区）202，1094 - 1096）。本文表明，绿色海洋藻类头状笔螅的提取物具有强大的溴过氧化物酶活性，在3-氧代辛酸存在的情况下，能够催化溴离子与有机化合物结合。通过气相色谱和质谱分析，已鉴定出三溴甲烷、1-溴-2-庚酮、1,1-二溴-2-庚酮和1,1,1-三溴-2-庚酮是该反应的产物。已将酶促合成产物的性质与纯品化合物进行比较，发现二者相同。一溴庚酮和二溴庚酮可作为酶促生成三溴庚酮的前体，但三溴庚酮最终水解为溴仿似乎是与头状笔螅提取物发生的非酶促反应。
