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Biomedical subjects

G A Haslewood

Publications and source records attributed to G A Haslewood.

At least 19 recordsLinked to original sources
PubMed1979

Comparison of the bile salts of frogs with those of their tadpoles. Bile-salt changes during the metamorphosis of Rana Catesbeiana Shaw.

1. The bile salts of three frog species of the genus Ptychadena and of Rana catesbeiana have been compared with those of their tadpoles. For R. catesbeiana comparison was made of the bile salts in at least ten of the recognized stages of tadpole metamorphosis. 2. In all cases, adult bile salts were more complex than those of the tadpoles. 3. In R. catesbeiana after stage 18, 26-deoxy-5 alpha-ranol was hydroxylated to form 5 alpha-ranol (27-nor-5 alpha-cholestane-3 alpha, 7 alpha, 12 alpha, 24 xi, 26-pentol) and at least two other bile alcohols appeared in solvolysed bile salts. 4. Tadpole bile salts were not found to be biochemically more primitive than those of fully metamorphosed frogs; in some, but not all, cases tadpole bile alcohols could be regarded as biochemical precursors of those in the adult frogs. 5. Detailed evidence for the structure of the bile salts from mass-spectral fragmentation patterns has been deposited as Supplementary Publication SUP 50097 (2 pages) at the British Library Lending Division, Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1978) 169, 5.

Animals↗
PubMed1978

Bile salts of the green turtle Chelonia mydas (L.)

1. Bile salts of the green turtle Chelonia mydas (L.) were analysed as completely as possible. 2. They consist of taurine conjugates of 3 alpha, 7 alpha, 12 alpha, 22 xi-tetrahydroxy-5 beta-cholestan-26-oic acid (tetrahydroxysterocholanic acid) and 3 alpha 12 alpha, 22 xi-trihydroxy-5 beta-cholestan-26-oic acid, with minor amounts of 3 alpha, 7 alpha, 12 alpha-trihydroxy-5beta-cholan-24-oic acid (cholic acid), 3alpha, 12 alpha-dihydroxy-5beta-cholan-24-oic acid (deoxycholic acid) and possibly other bile acids. 3. Cholic acid and deoxycholic acid represent the first known examples of bile acids common to chelonians and other animal forms: they may indicate independent evolution in chelonians to C24 bile acids. 4. The discovery of a 7-deoxy C27 bile acid is the first evidence that C27 bile acids or their conjugates have an enterohepatic circulation.

Animals↗
PubMed1977

Bile salts of the lungfishes Lepidosiren, Neoceratodus and Protopterus and those of the coelacanth Latimeria chalumnae Smith.

1. Bile salts of the coelacanth Latimeria chalumnae Smith (five specimens) and of the three living genera of lungfish (Dipnoi) were examined as completely as possible and compared. 2. The small 'bile acid' fractions include no more than traces of well-known C27 or C24 acids (free or conjugated) and the functioning bile salts must be regarded as alcohol sulphates. 3. Comparison of the alcohols suggest that (a) Latimeria stands biochemically outside the animal group which includes the Dipnoi, (b) Protopterus and Lepidosiren are more closely related to one another than either is to Neoceratodus, (c) all four primitive osteiychtheans have some amphibian affinities, (d) there are affinities between Latimeria and Dipnoi and ostariophysan families (especially Cyprinidae and Catostomidae) and (e) there are biochemical links between Dipnoi and lampreys.

Amphibians↗
PubMed1976

The specificity of a 7 alpha-hydroxy steroid dehydrogenase from Escherichia coli.

1. Thirty-eight steroids were tested as substrates for a 7 alpha-hydroxy steroid dehydrogenase preparation from a strain of Escherichia coli; an improved method of making the crude enzyme is described. 2. Steroids having a 7 alpha-hydroxyl group in the molecule were substrates except (a) when the 5 beta-cholan-24-oic acid side chain was shortened to less than four carbon atoms and (b) in certain cases when sulphate ester groups were present in the molecule. 3. For testing with the enzyme, a new specimen of 7 alpha-hydroxy-3,12-dioxo-5 beta-cholan-24-oic acid was made, which had properties different from those previously described.

Bile Acids and Salts↗
PubMed1976

Preparation of the 3-monosulphates of cholic acid, chenodeoxycholic acid and deoxycholic acid.

1. The 3-sulphates of cholic, chenodeoxycholic and deoxycholic acids were prepared as crystalline disodium salts. 2. The method described shows that it is possible to prepare specific sulphate esters of polyhydroxy bile acids and to remove protecting acyl groups without removing the sulphate. 3. A study of bile acid sulphate solvolysis showed that none of the usual methods give the original bile acid in major yield in a single step. 4. An understanding of the preparation, properties and methods of solvolysis of bile acid sulphates is basic for investigations of cholestasis and liver disease.

Acetylation↗
PubMed1974

A more detailed study of bile salt evolution, including techniques for small-scale identification and their application to amphibian biles.

1. Methods have been developed for the isolation and identification of small amounts of bile salts and of bile acids and alcohols obtained by solvolysis. These methods involve preparative and analytical t.l.c., purification on columns of protonated Al(2)O(3) and Sephadex LH-20 and also g.l.c.-mass spectroscopy of solvolysis products. 2. Application to 29 species of frogs and toads has confirmed the constancy of bile salt patterns in a single species, including colour phases in two instances, and has revealed great variations between different species in some genera (e.g. Rana, Ptychadena) and little difference between widely distributed species in others (e.g. Bufo). 3. Taxonomic deductions should be made with caution and with regard to the physiological significance of the biochemical character considered. The molecular differences found might be interpreted as indicating variations in the rate of evolution.

Amphibians↗
PubMed1972

Comparative studies of bile salts. A new type of bile salt from Arapaima gigas (Cuvier) (family Osteoglossidae).

1. Arapaima gigas bile salts were hydrolysed by alkali or cleaved with dioxan-trichloroacetic acid to give cholic acid, arapaimic acid, arapaimol-A and arapaimol-B. 2. I.r., n.m.r. and mass spectroscopy and [alpha](D) measurements indicated that arapaimic acid and arapaimol-A and -B are respectively 2alpha,3alpha,7alpha,12alpha-tetrahydroxy-5beta,25in-cholestan-26-oic acid, 5beta,25R-cholestane-2beta,3alpha,7alpha,12alpha,26-pentol and 5beta-cholestane-2beta,3alpha,7alpha,12alpha,26,27-hexol. 3. Partial synthesis of 2beta,3alpha,7alpha,12alpha-tetrahydroxy-5alpha- and -5beta-cholan-24-oic acid and their spectral examination fully confirmed these conclusions. 4. A. gigas bile salts show primitive features in that they comprise alcohol sulphates and a C(27) acid; they are also specialized in showing 2beta-hydroxylation.

Animals↗
PubMed1971

Bile salts of germ-free domestic fowl and pigs.

1. The bile of germ-free domestic fowl contains taurine conjugates of 3alpha,7alpha-dihydroxy-5beta-cholan-24-oic acid (chenodeoxycholic acid), 3alpha,7alpha,12alpha-trihydroxy-5beta-cholan-24-oic acid (cholic acid) and its 5alpha-epimer (allocholic acid): that of germ-free pigs contains glycine and taurine conjugates of chenodeoxycholic acid, 3alpha,6alpha-dihydroxy-5beta-cholan-24-oic acid (hyodeoxycholic acid), 3alpha,6alpha,7alpha-trihydroxy-5beta-cholan-24-oic acid (hyocholic acid) and (probably) cholic acid. Keto acids were not found. 2. Allocholic acid and hyodeoxycholic acid are thus proved to be primary bile acids in intact animals. 3. The evolutionary and biochemical implications of these findings are briefly considered.

Animals↗
PubMed1970

Comparative studies of bile salts. 5 alpha-Chimaerol, a new bile alcohol from the white sucker Catostomus commersoni Lacépède.

1. G.l.c. examination of bile alcohols prepared from the sucker Catostomus commersoni Lacépède (family Catostomidae) showed that although 5alpha-cyprinol (5alpha-cholestane-3alpha,7alpha,12alpha,26,27-pentol) was a minor constituent, the principal bile alcohol was an undescribed substance, probably present in the bile as the C-26 sulphate ester, whose i.r., n.m.r. and mass spectra agreed with the structure 5alpha-cholestane-3alpha,7alpha,12alpha,24,26-pentol. 2. M(D) studies suggest that this 5alpha-chimaerol is the 24(+), 25S enantiomer and that 5beta-chimaerol (chimaerol) from Chimaera monstrosa bile also has the 24(+), 25S configuration. These findings imply that bile alcohol biosynthesis in suckers and chimaeras includes stereospecific oxidation of cholesterol at C-26. 3. C. commersoni bile acids (present in minor amounts) probably consist largely of 3alpha,7alpha,12alpha-trihydroxy-5alpha-cholan-24-oic acid (allocholic acid). 4. 5alpha-Chimaerol sulphate and 5alpha-cyprinol sulphate are probably biochemically equivalent as bile salts, and can be considered as arising by parallel evolution.

Animals↗
PubMed1969

Comparative studies of bile salts. 16-Deoxymyxinol, a second bile alcohol from hagfish.

1. Material containing the less polar sulphate previously noticed in hagfish bile salts gave, after dioxan-trichloroacetic acid cleavage, 16-deoxymyxinol [3beta,7alpha,-26(27)-trihydroxy-5alpha-cholestane]. 2. Anodic coupling of 3beta-hydroxy-5beta-cholanoic acid and the mixed half esters of dl-methylsuccinic acid, followed by lithium aluminium hydride reduction, yielded 3beta,26(27)-dihydroxy-5beta-cholestane. 3. 16-Deoxymyxinol, the third known bile alcohol having the 3beta-hydroxy-5alpha-hydrogen configuration, poses again the question of how the 3beta-hydroxyl group of cholesterol can be ;retained' in biosynthesis of primitive bile salts.

Alcohols↗
PubMed1969

Comparative studies of bile salts. Bile salts of the lamprey Petromyzon marinus L.

1. Bile salts of Petromyzon marinus L. ammocoetes appeared to consist solely or chiefly of a crystalline substance, whose chromatographic and i.r.-spectral characteristics suggested that it was a monosulphate ester of a bile alcohol having the 3alpha,7alpha,12alpha-trihydroxy pattern of substitution in a 5alpha-steroid nucleus. 2. This substance on cleavage with dioxan-trichloroacetic acid gave petromyzonol, n.m.r. and mass-spectral examination of which suggested the structure 5alpha-cholane-3alpha,7alpha,12alpha,24-tetrol. 3. 3alpha,7alpha,12alpha-Trihydroxy-5alpha-cholanoic acid (allocholic acid) from the lizards Anolis lineatopus lineatopus Gray and Cyclura carinata Harlan (family Iguanidae) was esterified with propan-1-ol and reduced by lithium aluminium hydride to 5alpha-cholane-3alpha,7alpha,12alpha,24-tetrol, identical with petromyzonol. 4. Chromic acid oxidation of petromyzonol sulphate from lamprey bile, followed by acid hydrolysis, gave 24-hydroxy-5alpha-cholane-3,7,12-trione; hence the sulphate ester group is at C-24. 5. Petromyzonol sulphate is both primitive and unique: a study of its biogenesis might improve our understanding of evolution at the molecular level.

Aluminum↗