256
JOHN C. DITTMER
cabbage leaves with and without prior steaming to destroy enzymes,
indicates that the naturally occurring lipids are probably of the classic
types. Smith (148) showed that a similar production of phosphatidic
acid occurs in rubber latex, and analysis of lipids isolated with boiling
ethanol show that probably 79% of the natural phospholipid is lecithin.
Subsequent work (149) showed that reducing sugar, inositol, and
ethanolamine are also present in latex phospholipids.
Maruo and Benson (150) have identified α,α-diglycerol phosphate
in mild alkaline hydrolyzates of the lipids of the alga Scenedesmus and
have also now demonstrated by Chromatographie techniques that it is
a component of lipids from tobacco, sweet clover, and barley leaves
(151). Their Chromatographie demonstration of the presence of glycerylphosphoryl-choline, -ethanolamine, -serine, and -inositol in mild alkaline hydrolyzates of the phospholipids from these four sources suggests
that the corresponding glycerophosphatides may be present. It should
be noted that the composition of plant phospholipids they report have
been based on the percentage of total radio activity from incorporated
P
32 . Since the specific activity of the phosphate in the different phospholipids was not shown to be the same, nor under the circumstances
would they be expected to be the same, the data presented are only of
qualitative value. A study by Kates (152) using techniques similar to
those used by Benson and Maruo (151) suggests that the same range
of phospholipids is also present in runner bean leaves. Finally, it has
often been suggested that betaine can be substituted for choline in
plant lipids. However, this has recently been investigated by Simenauer
(153), who found no evidence for betaine in the phospholipids of the
flower, root, and fruit of sugar beet Beta vulgaris, nor in the phospholipids of Cicer arietmum. Choline was identified in the phospholipids of
all these sources.
C. FUNGI
In early studies on the phospholipids of yeast, choline and ethanolamine were found in the phospholipids of Saccharomyces cerevisiae
and ToruL· utilis in the molar ratios of 4:1 and 3:1, respectively (154,
155). In the latter, the presence of other phospholipids was suggested
by the fact that 23% of the nitrogen could not be accounted for as
either choline or ethanolamine (155). In contrast to this, the phospholipids of Rhodotorula gracilis have been reported to contain no ethanolamine, but serine was tentatively identified as a component. Both
sphingosine and inositol were absent (156).
More recently, Hanahan and Jayko (157) reported the isolation of
dipalmitoylglycerylphosphorylcholine from S. cerevisiae. Further work
JOHN C. DITTMER
cabbage leaves with and without prior steaming to destroy enzymes,
indicates that the naturally occurring lipids are probably of the classic
types. Smith (148) showed that a similar production of phosphatidic
acid occurs in rubber latex, and analysis of lipids isolated with boiling
ethanol show that probably 79% of the natural phospholipid is lecithin.
Subsequent work (149) showed that reducing sugar, inositol, and
ethanolamine are also present in latex phospholipids.
Maruo and Benson (150) have identified α,α-diglycerol phosphate
in mild alkaline hydrolyzates of the lipids of the alga Scenedesmus and
have also now demonstrated by Chromatographie techniques that it is
a component of lipids from tobacco, sweet clover, and barley leaves
(151). Their Chromatographie demonstration of the presence of glycerylphosphoryl-choline, -ethanolamine, -serine, and -inositol in mild alkaline hydrolyzates of the phospholipids from these four sources suggests
that the corresponding glycerophosphatides may be present. It should
be noted that the composition of plant phospholipids they report have
been based on the percentage of total radio activity from incorporated
P
32 . Since the specific activity of the phosphate in the different phospholipids was not shown to be the same, nor under the circumstances
would they be expected to be the same, the data presented are only of
qualitative value. A study by Kates (152) using techniques similar to
those used by Benson and Maruo (151) suggests that the same range
of phospholipids is also present in runner bean leaves. Finally, it has
often been suggested that betaine can be substituted for choline in
plant lipids. However, this has recently been investigated by Simenauer
(153), who found no evidence for betaine in the phospholipids of the
flower, root, and fruit of sugar beet Beta vulgaris, nor in the phospholipids of Cicer arietmum. Choline was identified in the phospholipids of
all these sources.
C. FUNGI
In early studies on the phospholipids of yeast, choline and ethanolamine were found in the phospholipids of Saccharomyces cerevisiae
and ToruL· utilis in the molar ratios of 4:1 and 3:1, respectively (154,
155). In the latter, the presence of other phospholipids was suggested
by the fact that 23% of the nitrogen could not be accounted for as
either choline or ethanolamine (155). In contrast to this, the phospholipids of Rhodotorula gracilis have been reported to contain no ethanolamine, but serine was tentatively identified as a component. Both
sphingosine and inositol were absent (156).
More recently, Hanahan and Jayko (157) reported the isolation of
dipalmitoylglycerylphosphorylcholine from S. cerevisiae. Further work