Kuroki S, Schteingart C D, Hagey L R, Cohen B I, Mosbach E H, Rossi S S, Hofmann A F, Matoba N, Une M, Hoshita T
Department of Surgery, Beth Israel Medical Center, New York, NY 10003.
J Lipid Res. 1988 Apr;29(4):509-22.
The bile salts present in gallbladder bile of the West Indian manatee, Trichechus manatus latirostris, an herbivorous marine mammal of the tropical and subtropical margins of the Atlantic Ocean, were found to consist of a mixture of bile alcohol sulfates. Bile acids, previously believed to be present in all mammals, were not detected. Using chromatography, mass spectrometry, and 1H- and 13C-nuclear magnetic resonance spectroscopy, the major bile alcohol was identified as 5 beta-cholestane-3 alpha,6 beta,7 alpha-25,26-pentol; that is, it had the nuclear structure of alpha-muricholic acid and the side chain structure of bufol. This compound has not been described previously and the trivial name "alpha-trichechol" is proposed. The second most abundant compound was 5 beta-cholestane-3 alpha,7 alpha,25,26-tetrol. Other bile alcohols were tentatively identified as 5 beta-cholestane-3 alpha,6 beta,7 beta,25,26-pentol (named beta-trichechol), 3 alpha,6 alpha,7 beta, 25-26-pentol (named omega-trichechol) and 5 beta-cholestane-3 alpha,6 beta,7 alpha,26-tetrol. The 1H and 13C NMR spectra of the four 6,7 epimers of 3,6,7 trihydroxy bile acids are described and discussed. All bile alcohols were present as ester sulfates, the sulfate group being tentatively assigned to the 26-hydroxy group. 12-Hydroxy compounds were not detected. The manatee is the first mammal found to lack bile acids, presumably because it lacks the enzymes required for oxidation of the 26-hydroxy group to a carboxylic acid. Trichechols, like other bile salts, are water-soluble end products of cholesterol metabolism; whether they also function as biological surfactants in promoting biliary cholesterol secretion or lipid digestion is unknown.
西印度海牛（Trichechus manatus latirostris）是一种生活在大西洋热带和亚热带边缘的草食性海洋哺乳动物，其胆囊胆汁中的胆汁盐被发现是胆汁醇硫酸盐的混合物。此前认为所有哺乳动物都存在的胆汁酸未被检测到。通过色谱法、质谱法以及1H和13C核磁共振光谱法，确定主要的胆汁醇为5β-胆甾烷-3α,6β,7α-25,26-戊醇；也就是说，它具有α-鼠胆酸的核结构和蟾蜍胆的侧链结构。该化合物此前未被描述过，因此提议使用俗名“α-海牛胆醇”。第二丰富的化合物是5β-胆甾烷-3α,7α,25,26-四醇。其他胆汁醇初步鉴定为5β-胆甾烷-3α,6β,7β,25,26-戊醇（命名为β-海牛胆醇）、3α,6α,7β,25-26-戊醇（命名为ω-海牛胆醇）和5β-胆甾烷-3α,6β,7α,26-四醇。描述并讨论了3,6,7-三羟基胆汁酸的四种6,7-差向异构体的1H和13C NMR光谱。所有胆汁醇均以酯硫酸盐形式存在，硫酸基团初步确定连接在26-羟基上。未检测到12-羟基化合物。海牛是首个被发现缺乏胆汁酸的哺乳动物，推测是因为它缺乏将26-羟基氧化为羧酸所需的酶。海牛胆醇与其他胆汁盐一样，是胆固醇代谢的水溶性终产物；它们是否也作为生物表面活性剂促进胆汁胆固醇分泌或脂质消化尚不清楚。
