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D. J. BELL
of eggs of Echinus esculentus (106c) it has been obtained from algal
polysaccharides found in Gelidium spp. (agar) (107), Chondrus ocellatus (107a), Chondrus crispus, and Gigartina stellata (109) (Irish
moss, carrageenin) (108), in Porphyra crispata (109), P. tenera (109),
P. capensis (110), and Gliopeltis furcata (110a). Flaxseed mucilage
(111, 112) also yields some L-galactose.
It may be recalled that the well-known mucic acid "test for galactose" does not distinguish between the D- and L-isomers (113).
F. D-MANNOSE
1. Free
The free sugar has been detected in small amounts in sphagnum
mosses and in peat (113a).
2. Combined (114)
D-Mannose is found in the hemicelluloses of woods, especially from
the gymnosperms and in the endosperms of certain seeds, especially
nuts. It forms a major constituent of the cell wall of bakers' yeasts
(115), along with the yeast glucan; and D-mannose-derived polysaccharides are found in a marine alga (116) Porphyra umbilicalis and in
culture media of Penicillium charlesii (117). Small amounts of units
derived from D-mannose have recently been found in samples of laminarin (117a). Along with other sugars, combined D-mannose is found
in a few plant gums (97) and in Mycobacterium tuberculosis (118).
Mannans are formed by B. polymyxa (118a) and diphtheria bacteria
(118b).
D-Mannose forms a prominent part of the carbohydrate fragments of
many glycoproteins including those in mammalian blood plasma (102)
and hens' eggs (103).
Few if any terrestrial plant glycosides contain D-mannose, but a
D-mannoside of D-glyceric acid occurs in algae of Polysiphonia spp.
(119). A dimannoside of phosphatidylinositol has been found in a
Mycobacterium
(120).
G. D-XYLOSE
1. Free
D-Xylose is a sugar apparently missing from the animal kingdom*
although it is not metabolically inert in mammals (121, 122); in its
* D-Xylose has recently been obtained from an invertebrate animal product (see
reference 26a).
D. J. BELL
of eggs of Echinus esculentus (106c) it has been obtained from algal
polysaccharides found in Gelidium spp. (agar) (107), Chondrus ocellatus (107a), Chondrus crispus, and Gigartina stellata (109) (Irish
moss, carrageenin) (108), in Porphyra crispata (109), P. tenera (109),
P. capensis (110), and Gliopeltis furcata (110a). Flaxseed mucilage
(111, 112) also yields some L-galactose.
It may be recalled that the well-known mucic acid "test for galactose" does not distinguish between the D- and L-isomers (113).
F. D-MANNOSE
1. Free
The free sugar has been detected in small amounts in sphagnum
mosses and in peat (113a).
2. Combined (114)
D-Mannose is found in the hemicelluloses of woods, especially from
the gymnosperms and in the endosperms of certain seeds, especially
nuts. It forms a major constituent of the cell wall of bakers' yeasts
(115), along with the yeast glucan; and D-mannose-derived polysaccharides are found in a marine alga (116) Porphyra umbilicalis and in
culture media of Penicillium charlesii (117). Small amounts of units
derived from D-mannose have recently been found in samples of laminarin (117a). Along with other sugars, combined D-mannose is found
in a few plant gums (97) and in Mycobacterium tuberculosis (118).
Mannans are formed by B. polymyxa (118a) and diphtheria bacteria
(118b).
D-Mannose forms a prominent part of the carbohydrate fragments of
many glycoproteins including those in mammalian blood plasma (102)
and hens' eggs (103).
Few if any terrestrial plant glycosides contain D-mannose, but a
D-mannoside of D-glyceric acid occurs in algae of Polysiphonia spp.
(119). A dimannoside of phosphatidylinositol has been found in a
Mycobacterium
(120).
G. D-XYLOSE
1. Free
D-Xylose is a sugar apparently missing from the animal kingdom*
although it is not metabolically inert in mammals (121, 122); in its
* D-Xylose has recently been obtained from an invertebrate animal product (see
reference 26a).