7. MONOSACCHARIDES AND OLIGOSACCHARIDES
319
like, D-galactopyranosides and some D-glucopyranosides, having complex aglycones, and which are termed cerebrosides and gangliosides
(74b). In the familial syndrome of Gaucher's disease, excessive amounts
of these complex lipids are laid down in many tissues including the
spleen. It is thought that such abnormally occurring cerebrosides
contain unusual amounts of the D-glucopyranosyl derivatives (75). O-DGlucopyranosides of mannitol, where the latter is substituted at position 1 or positions 1 and 6, have been isolated from Laminaria cloustoni
(75a), from Fucus spiralis and Desmarestia aculeata (75b), and from
the green algae Enteromorpha compressa and Chlorella sp. (75c).
The polysaccharide cellulose, so characteristic of the higher plants,
has long been known to form the outer integument of the marine invertebrates known as tunicates. The chemistry of tunicate cellulose
(76) and its physical nature are identical with those of the celluloses of
angiosperms and gymnosperms and also with the extracellular cellulose
produced by some bacteria (77). Recent observations, mainly based on
X-ray crystallographic measurements have shown that human connective tissue appears to contain a small amount of material seemingly
cellulosic in nature (78).
B. L-GLUCOSE
Two early reports (79) of the occurrence of this sugar have never
been followed up nor confirmed.
C. D-FRUCTOSE
1. Free
Free D-fructose is widespread in plants; until comparatively recently
it was considered to occur solely in the vegetable kingdom with the
one exception that phosphoric esters,* which might yield "escape"
amounts of fructose, were known to be of virtually universal occurrence.
In 1907 Noel Paton et al. (80) reported that the embryonic fluids of
certain ruminants gave color tests for hexuloses. This observation attracted little notice until 1948, when D-fructose was isolated from and
identified in the blood of fetal sheep (81). It is now known that relatively large amounts of D-fructose are present in the blood of fetal ungulates [including the whale (82)] but that, in other species, e.g., man,
only traces of this sugar occurs in the fetal circulation (83). D-Fructose
has been identified in appreciable amounts also in the seminal plasma
of numerous mammals where it is produced by organs accessory to the
seminal tract (84). Birds (85) (domestic cocks) do not possess such
* See Vol. I, Chapter 4, and Vol. II, Chapter 1.
319
like, D-galactopyranosides and some D-glucopyranosides, having complex aglycones, and which are termed cerebrosides and gangliosides
(74b). In the familial syndrome of Gaucher's disease, excessive amounts
of these complex lipids are laid down in many tissues including the
spleen. It is thought that such abnormally occurring cerebrosides
contain unusual amounts of the D-glucopyranosyl derivatives (75). O-DGlucopyranosides of mannitol, where the latter is substituted at position 1 or positions 1 and 6, have been isolated from Laminaria cloustoni
(75a), from Fucus spiralis and Desmarestia aculeata (75b), and from
the green algae Enteromorpha compressa and Chlorella sp. (75c).
The polysaccharide cellulose, so characteristic of the higher plants,
has long been known to form the outer integument of the marine invertebrates known as tunicates. The chemistry of tunicate cellulose
(76) and its physical nature are identical with those of the celluloses of
angiosperms and gymnosperms and also with the extracellular cellulose
produced by some bacteria (77). Recent observations, mainly based on
X-ray crystallographic measurements have shown that human connective tissue appears to contain a small amount of material seemingly
cellulosic in nature (78).
B. L-GLUCOSE
Two early reports (79) of the occurrence of this sugar have never
been followed up nor confirmed.
C. D-FRUCTOSE
1. Free
Free D-fructose is widespread in plants; until comparatively recently
it was considered to occur solely in the vegetable kingdom with the
one exception that phosphoric esters,* which might yield "escape"
amounts of fructose, were known to be of virtually universal occurrence.
In 1907 Noel Paton et al. (80) reported that the embryonic fluids of
certain ruminants gave color tests for hexuloses. This observation attracted little notice until 1948, when D-fructose was isolated from and
identified in the blood of fetal sheep (81). It is now known that relatively large amounts of D-fructose are present in the blood of fetal ungulates [including the whale (82)] but that, in other species, e.g., man,
only traces of this sugar occurs in the fetal circulation (83). D-Fructose
has been identified in appreciable amounts also in the seminal plasma
of numerous mammals where it is produced by organs accessory to the
seminal tract (84). Birds (85) (domestic cocks) do not possess such
* See Vol. I, Chapter 4, and Vol. II, Chapter 1.