88
F. B. SHORLAND
fats of the porpoise and dolphin but is absent from the liver and other
organs (168). In ruminant depot fats there occur as minor constituents
(-\-)-anteiso acids of the odd series and iso acids of the odd and even
series within the range of Ci 3 to Ci 8 (46-48). The (+)-anteiso acids
also occur in wool grease in the odd series from C 9 to C 3 i. The iso
acids from C 10 to C 28 occur also, but only in the even series (49). The
Ci 3 and Ci7 (-f-)-anteiso and iso acids have also been found in the
liver oil of the shark Galeorhinus australis (17). In the preen glands of
ducks and geese levorotatory branched-chain acids occur in quantity as
octadecyl esters. In the preen glands of ducks 4-methylhexanoic acid
(336, 337) is the main fatty acid constituent, and in geese a dimethyl
branched C 14 acid predominates (338). The occurrence of considerable
amounts of branched-chain acids in the sebum of various mammals has
been reported, but the precise nature of these acids has not been revealed (304, 305). In the lipids of tubercle bacilli the branched-chain
fatty acids are strikingly different from those already discussed. Here
the lipids contain a large proportion of the high molecular weight
(about C 88 ) mycolic acids with long alkyl side chains, lower molecular
weight acids including 10-methylstearic (50, 51),
(-f-)-2,4,6-trimethyltetracos-2-enoic (mycolipenic) (52) acid and (—)-2,4-6-trimethyloctacosanoic (mycoceranic) (53) acid.
The branched acids of the tubercle bacilli as well as those of certain
other acid-fast bacteria are characterized by the fact that the side
chains are located near the center of the chain or near the carboxyl
group. It would appear that in this respect there is a relationship between the elaboration of specific fatty acid types and the position of the
organism in the phylogenetic scale.
4. Cyclic Acids
In the acids possessing a cyclic structure the occurrence of C 16 and
Cis acids with a terminal cyclopentenyl ring is peculiar to the seed fats
of many species belonging to the Flacourtiaceae, thereby affording an
excellent chemical indicator for this family. Apart from these acids, the
only other known lipid fatty acids possessing a cyclic structure are the
cyclopropene acids, sterculic acid
CH 3 (CH 2 ) 7 C=C · (CH 2 ) 7 COOH
found in Sterculia foetida (55) (Sterculiaceae) and a related C i8
acid, malvalic acid, found in Malm verticillata and M. parviflora (254)
(Malvaceae), as well as the cyclopropane acid—lactobacillic acid
F. B. SHORLAND
fats of the porpoise and dolphin but is absent from the liver and other
organs (168). In ruminant depot fats there occur as minor constituents
(-\-)-anteiso acids of the odd series and iso acids of the odd and even
series within the range of Ci 3 to Ci 8 (46-48). The (+)-anteiso acids
also occur in wool grease in the odd series from C 9 to C 3 i. The iso
acids from C 10 to C 28 occur also, but only in the even series (49). The
Ci 3 and Ci7 (-f-)-anteiso and iso acids have also been found in the
liver oil of the shark Galeorhinus australis (17). In the preen glands of
ducks and geese levorotatory branched-chain acids occur in quantity as
octadecyl esters. In the preen glands of ducks 4-methylhexanoic acid
(336, 337) is the main fatty acid constituent, and in geese a dimethyl
branched C 14 acid predominates (338). The occurrence of considerable
amounts of branched-chain acids in the sebum of various mammals has
been reported, but the precise nature of these acids has not been revealed (304, 305). In the lipids of tubercle bacilli the branched-chain
fatty acids are strikingly different from those already discussed. Here
the lipids contain a large proportion of the high molecular weight
(about C 88 ) mycolic acids with long alkyl side chains, lower molecular
weight acids including 10-methylstearic (50, 51),
(-f-)-2,4,6-trimethyltetracos-2-enoic (mycolipenic) (52) acid and (—)-2,4-6-trimethyloctacosanoic (mycoceranic) (53) acid.
The branched acids of the tubercle bacilli as well as those of certain
other acid-fast bacteria are characterized by the fact that the side
chains are located near the center of the chain or near the carboxyl
group. It would appear that in this respect there is a relationship between the elaboration of specific fatty acid types and the position of the
organism in the phylogenetic scale.
4. Cyclic Acids
In the acids possessing a cyclic structure the occurrence of C 16 and
Cis acids with a terminal cyclopentenyl ring is peculiar to the seed fats
of many species belonging to the Flacourtiaceae, thereby affording an
excellent chemical indicator for this family. Apart from these acids, the
only other known lipid fatty acids possessing a cyclic structure are the
cyclopropene acids, sterculic acid
CH 3 (CH 2 ) 7 C=C · (CH 2 ) 7 COOH
found in Sterculia foetida (55) (Sterculiaceae) and a related C i8
acid, malvalic acid, found in Malm verticillata and M. parviflora (254)
(Malvaceae), as well as the cyclopropane acid—lactobacillic acid