Hydrocolloids containing cellulose microfibrils having a diameter smaller than 3nm are found to be present in the berries of mistletoe, Viscum album L., and the outer epidermis layer of basil seeds. The cellulose microfibrils in V. album are tightly coiled in a rope-like fashion with their axes perpendicular to the long axis of the cells in the viscin tissue. In the case of basil, the cellulose microfibrils are also tightly coiled in a doughnut-like fashion in the cylindrical cells present at the outer epidermis of their seeds. When the viscin tissues and cylindrical cells adsorbed water, the cellulose microfibrils became unwound to be perfectly aligned along the stretching direction. The hydrocolloids are present as a kind of cellulose-hemicellulosic polysaccharide composite. In both hydrocolloids, the presence of highly branched arabinogalactan in addition to (1, 4)-linked xylan and glucomannan is noted by methylation analysis. The remainder of the glucose and mannose after partial acid hydrolysis of the hydrocolloids indicates that glucomannan type hemicellulose is closely attached to cellulose while acidic polysaccharides may act to keep cellulose-hemicellulose composite soluble in water.
Galactosylsulfatide (SM4s), a sulfated glycosphingolipid (GSL), is present most abundantly in the brain as the major component of the myelin sheath. Next to the nervous tissue, the kidneys of mammals are rich in sulfated GSLs. Not only SM4s but also various sulfated GSLs, including lactosylsulfatide (SM3), bis-sulfated GSLs and a sulfated ganglioside, have been isolated and characterized from the kidney, suggesting their function as ion barriers to environmental osmolality. On the other hand, seminolipid (SM4g), a sulfated glyceroglycolipid (GGL), is the principal glycolipid in spermatozoa of mammals, suggesting that SM4g plays an essential role in spermatogenesis and the fertilization process. In this review, we summarize the results of the knockout mice generated by gene-targeted disruption of enzymes which catalyze synthesis of SM4s and SM4g, and discuss the potential function of sulfoglycolipids in the kidney and testis. As the basis of functional analyses, the progress of analytical methods of sulfoglycolipids is also described.
Sulfated polysaccharides including glycosaminoglycans show various chemical and biological functions. These functions strongly depend on the presence and spatial positioning of their sulfo groups. Therefore, chemical modifications such as partial, per-O-sulfonation or desulfonation are expected to alter the function of sulfated polysaccharides. There are many reports on the chemical modification of polysaccharides. This paper focuses on the investigation of both the chemical modification of polysaccharides and its effect biological function. A structure-activity relationship, SAR, is established on both intact and chemically modified polysaccharides.