4. SPECIES DIFFERENCES IN BILE SALTS
207
of the formula await final elucidation. It will be especially interesting if
it can be conclusively shown that the chief biliary alcohol, pentahydroxybufostane, does, as Kazuno claims, contain 28 carbon atoms in
its molecule, for this will imply that the molecules of a sterol occurring
in major amounts in toad liver must have at least as many. Other alcohols called tetrahydroxynorbufostane, tetrahydroxycholane, and isotrihydroxycholene (C24H4ÜO3) have been reported from toad bile (7,
8). Tetrahydroxyisohomocholane, (?) C 25 H 4 40 4 , was obtained by
Okasaki (9) from the bile of the newt Diemyctylus pyrrhogaster. The
frog Rana temporaria has, as its chief bile salt, ranol sulfate; the parent
alcohol, ranol, can be easily obtained as a crystalline tetraacetate, probably C 2G H 42 CHOH-(OCOCH 3 )4 (5). Ranol does not contain the simple
cholic acid nucleus and probably has the same nuclear structure as
cyprinol, a very similar alcohol from Cyprinidae (10, 11). The frog
Rana catesbiana, in addition to ranol, is said (12, 13) to have a biliary
trihydroxyhomocholane, C25H44O3. Biliary alcohols of unknown constitution occur in a coelacanth (14).
The very primitive chordate, hagfish (Class Marsipobranchii), has
been shown to contain the disulfate of an alcohol (myxinol) which does
not have the cholic acid nucleus. This alcohol sulfate, which was the
chief or only bile salt in the specimens examined, has been isolated from
the Atlantic species Myxine glutinosa as well as the Pacific form, Eptatretus stoutii (15).
2. C 27 (or C 2S ) Acids
The isomeric acids, trihydroxybufosterocholenic and trihydroxyisosterocholenic, from toad bile, were described by T. Shimizu and his
colleagues (16); they have both been degraded to bisnorcholic acid
(16,16a), and hence presumably contain the cholic acid nucleus and
side chain as far as C-22 (II). A double bond between C-22 and C-23
follows, and the complete formula is given as C 2 8H 46 0 5 , based on a
"sterocholanic acid," C 28 H 4S 0 2 . Claims to have prepared naturally occurring 24-methyl coprostanic acids from cholanic acids (17, 18) have
been made. If C 28 acids do in fact constitute an important part of toad
bile salts, then their occurrence raises the same interesting questions as
appear if pentahydroxybufostane is a C 28 alcohol (see above).
Tetrahydroxysterocholanic and tetrahydroxyisosterocholanic acids
have been isolated from turtle and tortoise bile (19-21) and formulated
as C 2 7_2SH4 6 _4 S O G . Each forms a lactone, and the former contains the
cholic acid nucleus (22). Acids originally named a- and ß-trihydroxybisnorsterocholanic, C 26 H 4 40 5 , and found in the frog Rana catesbiana (23,
24) were later shown to have the formula C 27 H4 6 0 5 and to be C-25
epimers of 3a,7a,12«-trihydroxycoprostanic acid (III) (-25). One of
207
of the formula await final elucidation. It will be especially interesting if
it can be conclusively shown that the chief biliary alcohol, pentahydroxybufostane, does, as Kazuno claims, contain 28 carbon atoms in
its molecule, for this will imply that the molecules of a sterol occurring
in major amounts in toad liver must have at least as many. Other alcohols called tetrahydroxynorbufostane, tetrahydroxycholane, and isotrihydroxycholene (C24H4ÜO3) have been reported from toad bile (7,
8). Tetrahydroxyisohomocholane, (?) C 25 H 4 40 4 , was obtained by
Okasaki (9) from the bile of the newt Diemyctylus pyrrhogaster. The
frog Rana temporaria has, as its chief bile salt, ranol sulfate; the parent
alcohol, ranol, can be easily obtained as a crystalline tetraacetate, probably C 2G H 42 CHOH-(OCOCH 3 )4 (5). Ranol does not contain the simple
cholic acid nucleus and probably has the same nuclear structure as
cyprinol, a very similar alcohol from Cyprinidae (10, 11). The frog
Rana catesbiana, in addition to ranol, is said (12, 13) to have a biliary
trihydroxyhomocholane, C25H44O3. Biliary alcohols of unknown constitution occur in a coelacanth (14).
The very primitive chordate, hagfish (Class Marsipobranchii), has
been shown to contain the disulfate of an alcohol (myxinol) which does
not have the cholic acid nucleus. This alcohol sulfate, which was the
chief or only bile salt in the specimens examined, has been isolated from
the Atlantic species Myxine glutinosa as well as the Pacific form, Eptatretus stoutii (15).
2. C 27 (or C 2S ) Acids
The isomeric acids, trihydroxybufosterocholenic and trihydroxyisosterocholenic, from toad bile, were described by T. Shimizu and his
colleagues (16); they have both been degraded to bisnorcholic acid
(16,16a), and hence presumably contain the cholic acid nucleus and
side chain as far as C-22 (II). A double bond between C-22 and C-23
follows, and the complete formula is given as C 2 8H 46 0 5 , based on a
"sterocholanic acid," C 28 H 4S 0 2 . Claims to have prepared naturally occurring 24-methyl coprostanic acids from cholanic acids (17, 18) have
been made. If C 28 acids do in fact constitute an important part of toad
bile salts, then their occurrence raises the same interesting questions as
appear if pentahydroxybufostane is a C 28 alcohol (see above).
Tetrahydroxysterocholanic and tetrahydroxyisosterocholanic acids
have been isolated from turtle and tortoise bile (19-21) and formulated
as C 2 7_2SH4 6 _4 S O G . Each forms a lactone, and the former contains the
cholic acid nucleus (22). Acids originally named a- and ß-trihydroxybisnorsterocholanic, C 26 H 4 40 5 , and found in the frog Rana catesbiana (23,
24) were later shown to have the formula C 27 H4 6 0 5 and to be C-25
epimers of 3a,7a,12«-trihydroxycoprostanic acid (III) (-25). One of