Fluorogenic derivatives of maltotriose, maltotetraose, maltopentaose, and maltohexaose were prepared using dextrin as a starting material. The derivatives are not hydrolyzed by α-glucosidase or glucoamylase owing to 2-pyridylamino group at the C₆ position of the non-reducing end glucose residue. Fluorogenic maltopentaose (O-6-deoxy-6-[(2-pyridyl) amino]-α-D-glucopyranosyl-(1→4)-O-α-D-glucopyranosyl-(1→4)-O-α-D-glucopyranosyl-(1→4)-O-α-D-glucopyranosyl-(1→4)-D-glucopyranose) was used as a substrate for the α-amylase assay which included separation and detection of the product and the substrate by HPLC. This method for α-amylase assay was also modified in order to differentiate the activities of human pancreatic and salivary α-amylases, by taking advantage of transglycosylation using O-α-D-glucopyranosyl-(1→4)-O-α-Dglucopyranosyl-(1→4)-1-deoxy-1-[(2-pyridyl) amino]-D-glucitol as an acceptor.

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Direct debranching enzymes can attack amylopectin and glycogen. They are principally divided into isoamylase and pullulanase. In this paper, distribution, production, properties and application of the enzymes are described. Distribution of isoamylase is quite limited in bacteria, but pullulanase seems to occur widely in different kinds of bacteria. Isoamylase can split all the branching points of glycogen, but not those of pullulan whereas pullulanase can split pullulan completely, but has limited hydrolytic activity on glycogen. There are several differencesin the modes of decomposition of starch by isoamylase and pullulanase. Isoamylase is produced in high yield by a mutant strain of Pseudomonas amyloderamosa SB15 and shows very high specific activity towards starch. Pseudomonas isoamylase is preferable to Klebsiella pullulanase for the production of glucose or maltose from starch in the combination with glucoamylase or β-amylase . Bacillus pullulanase seems also to be useful for the purpose.

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The difference between glucoamylase [EC 3.2.1.3 exo-1, 4-α-D-glucosidase] and α-glucosidase [EC 3.2.1.20 α-glucosidase] was discussed on the basis of the kinetic parameters, Km, ko(-V/eo; eo, enzyme concentration), and ko/Km, for maltooligosaccharides . In glucoamylase, there is a large difference between the ko values of maltose and those of other maltooligosaccharides. In α-glucosidases, however, the ko values are little dependent on the degree of polymerization of glucosyl residues in a series of maltooligosaccharides. The active site of α-glucosidase, like glucoamylase, have been also considered to be made up by the subsite structure. The subsite affinities of three kinds of glucoamylases were compared with those of five kinds of α-glucosidases from various origins. The difference in the substrate specificities between glucoamylase and aglucosidase was reasonably interpreted by their subsite affinities. In the "Enzyme Nomenclature, " the distinction between glucoamylase and a group of α-glucosidases capable of attacking α-glucan is not always clear, that is, lysosomal a-glucosidase and acid maltase, which usually mean mammalian acid α-glucosidase, are classified into the category of EC 3.2.1.3. However, it has been reported that the acid a-glucosidases from pig liver and rabbit muscle also produce α-glucose. Glucoamylase can be definitely distinguished from α-glucosidase in their anomeric forms of the product glucose: the former releases J3-anomer, and the latter releases a-anomer. Therefore, it appears to be not proper that certain kinds of α-glucosidase are included in the group of EC 3.2.1.3, and also that the trivial name recommended for glucoamylase is exo-1, 4-α-D-glucosidase. The term glucoamylase itself may be more proper for the trivial name. The reaction mechanisms of glucoamylase and α-glucosidase were proposed, by which the mechanisms of hydrolysis, transglucosylation and reverse reaction were discussed . Moreover, the reason why the configuration of the carbonyl carbon of the product glucose is retained or inverted was explained.

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α-Glucosidases have been found in a number of strains from different bacterial species. Among these enzymes, however, only five have been purified homogeneously from the following bacteria, Pseudomonas SB 15 (A. Amemura et al ., 1974), Bacillus cereus (Y. Yamasaki and Y. Suzuki, 1974), Bacillus thermoglucosidius (Y. Suzuki et al ., 1979), B, cereus (Y. Suzuki et al., 1982), Bacillus coagulans (Y. Suzuki et al., 1983), Bacillus stearothermophilus (Y . Suzuki and M. Shinji, 1983), and Bifidobacterium adolescentis (I. Igaue et al ., 1983). Also, highly purified enzyme samples have been obtained from Streptococcus mitis (G . J. Walker and A. Pulkownik, 1973), Pseudomonas fluorescens (A. A. Guffanti and W. A. Corpe, 1976), Bacillus subtilis (L.-H. Wang and P. A. Hartman, 1976), Bacillus amyloliquefaciens (H. Urlaub and G . Wober, 1978), thermophilic Bacillus sp. (Y. Suzuki et al., 1978), Bacillus brevis (S. J. McWethy and P. A. Hartman, 1979), and Flavobacterium sp. (H. Bender, 1981). These enzymes can be classifiedinto 4 groups in terms of their substrate specificities: 1) exo-oligo-1, 6-glucosidases from S. mitis, B. cereus, B. coagulans, and B. the rmoglucosidius, 2) exo-α-1, 4-glucosidase from B . stearothermophilus, 3) α-glucosidases active for various oligo- and polysaccharides from Pseudomonas SB 15, B. adolescentis, B, amyloliquefaciens, and Flavobacterium sp ., and 4) a-glucosidases highly specific for maltose from B. cereus, B. subtilis, B, brevis, thermophilic Bacillus sp., and lavobacterium fuorescens. B. stearothermophilus exo-α-1, 4-glucosidase is a hitherto unrecognized type of α-glucosidase, since the enzyme activity is exclusively narrowed to successive splitting of α-1, 4-bonds with the release of α-glucose residues from the non-reducing termini of lowmolecular weight maltosaccharides, α-limit dextrins, dextrin, amylose, amylopectin, soluble starch, and glycogen among a number of naturally distributed sugars tested, and since the α-1, 6-bonds in these saccharides are not hydrolyzed by the enzyme at all.

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1. "Amylase" should be defined as 'starch-hydrolyzing enzyme.' They necessarily hydrolyzeα-1, 4 and/or α-1, 6 glucoside linkage(s). Oligosaccharides can be substrates of amylases, while the rate of hydrolysis may depend on the chain length and the mode of branching of oligosaccharides. Debranching enzymes, isoamylase and pullulanase are, therefore, to be classified to amylases. 2. “α-Glucosidases” may well be differentiated from amylases, although some of the enzymescan hydrolyze not only short chain oligosaccharides but also starch as well, like glucoamylase. Conventionally, discrimination between α-glucosidase and glucoamylase seems to be made on the basis of the degree of polymerization (DP) of ‘good’ substrates. However, this is marginal and confusing in some cases. The anomer form of the released product must be the most definite and reliable criterion for the discrimination between α-glucosidase and glucoamylase. 3. Condensation is merely the reverse process of hydrolysis. It should clearly be differentiated from glucosyl transfer, although products of DP higher than starting substrates can beformed via either mechanism. The notion that hydrolases may be included in transferases in the sense that hydrolysis is a transfer to water is not incorrect, but is practically inconvenient. Amylases may have more or less transferring activity. Cyclomaltodextrin glucanotransferase [EC2.4.1.19, one of the other names, Bacillus macerans amylase] is classified into transferase, butit may better be classified into amylase since it does actually hydrolyze starch. 4. The present numbering of glycohydrolases are not unified with respect to the order of arrangement: 3.2.1. grouping is natural but the fourth numbers are confused; for example, amylases are distributed in several parts. Rearrangement and renumbering should urgently beconsidered. 5. Useful and important criteria for classification of amylases will be, (a) hydrolyzing ability of α-1, 4 and/or α-1, 6 glucosidic linkage(s), (b) exo- or endo-type in splitting mode, and (c) the anomeric form of the product.

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Streptococcus mutans is strongly implicated in the development of dental caries in experimental animals as well as in humans. This organism produces glucosyltransferases, which catalyze the synthesis of water-soluble and -insoluble glucan from sucrose. Glucan synthesis promotes the adherence of S. mutans to smooth surfaces, including those of teeth. Furthermore, S. mutans produces acids from a wide variety of sugars leading to localized decalcification (erosion) of the enamel surface. Among many sugars, sucrose has been shown to induce the highest level of dental caries in animal model systems. Therefore, a logical approach to prevent dental caries is to restrict sucrose consumption by substituting non- or anti-cariogenic sweetening sugars in foods. Panose, 4-α-D-isomaltopyranosyl-D-glucose, and palatinose, α-D-glucopyranosyl-1, 6-D-fructofuranose, have been shown to inhibit water-insoluble glucan synthesis from sucrose by S, mutans glucosyltransferases. Both sugars are practically non-fermentable by many oral bacterial species including S, mutans. This review describes caries control measures based on dietary approaches.

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As an introduction, luminal, contact, and membrane digestion of starch and maltooligosaccharides were briefly summarized. Hardly digestive starch granules, for example those of potato, banana, and high-amylose maize having amylose-extender gene were digested in vivo better than in vitro. Approximately 50% of potato starch granules ingested by rats fed on a PSG diet containing the starch granules as the main carbohydrate disappeared in rat bodies with making corrections for starches in feces and in contents of the gastrointestinal tracts. α-Amylase activity in pancreas and small-intestinal tract of rats fed on the PSG diet was either lower than or similar to that of rats fed on a PPS diet which consists of pregelatinized potato starch instead of potato starch granules in the PSG diet. Activities of maltase and isomaltase of small-intestinal mucosa of rats fed on the PSG diet were similar to those of rats fed on the PPS diet. However, activities of sucrase, lactase, and "glucoamylase" of the mucosa of rats fed on the PSG diet were higher than those of rats fed on the PPS diet. Disaccharidases of the mucosa were fractionated by Sephacryl gel filtration. Sucraseisomaltase complex and maltase fraction having "glucoamylase" activity degraded considerably pancreatic a-amylase limit dextrin. This strongly suggests that the increased sucrase and "glucoamylase" activities by feeding the PSG diet play a role in degradation of products by luminal a-amylolysis.

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Citrus fruits contain various kinds of flavanone compounds, such as hesperidin and naringin. Hesperidin is slightly soluble in water and causes turbidity in canned mandarin orange products. This study was carried out to find efficient solubilizing agents for hesperidin. It was found that the turbidity of canned mandarin orange syrup was reduced by the addition of β-cyclodextrin through the formation of an inclusion complex between β-cyclodextrin and hesperidin. Naringin, one of the bitter taste constituents of citrus fruit products, is chemically analogous to hesperidin. The bitterness of naringin was reduced by addition of β-cyclodextrin. The bitterness of limonin, a constituent of citrus fruits, was reduced by addition of β-cyclodextrin. Since β-cyclodextrin has been commercially available in pure food-grade form for several years, these findings are of practical interest to the citrus industry.

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As studied on the metabolism of arachidonic acid cascade, the physiological significance of prostaglandins (PGs) and other metabolites has been dissolved. In the present paper, the basic studies on the dosage form containing PGs and thei stabilization are summarized. There are two difficult problems when we design the PG formulation, namely the stabilization for unstable PGs and content uniformity for the formulation containing small quantity of PGs. These problems are dissolved by using of cyclodextrin (CD) to make complex with PGs. And these PG-CD complexes show improvement of solubility, chemical stability and bioavailability. At present, CD polymer, methylated CD, substance consisting of 10-20 glucose units and other CD analogues have been studied. In the near future, CD analogues having both properties stabilization and long lasting release will be developed.

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Pesticides included in cyclodextrin (CD) possess the following excellent properties: 1. stabilization of labile compounds and improvement of residual activity, 2. applicability in powdery formulations, 3. selectivity between target pests and beneficial species by introducing the stomach poisonrelated biological properties additionally, 4. reduction of phytotoxicity, 5. reduction of dermal toxicity.As shown in the cases of Pyrethrins CD 5 % WP and Pyrethrins CDN Dust containing 0.1% pyrethrins plus 2% carbaryl, they were proved to be useful in practical applications. At present, the cyclodextrins are on the market mainly for use in fine chemical products such as pharmaceuticals and foods. The application of the inclusion techniques to the bulky agricultural fields requires the development of CD manufacturing processes for large-scale production leading to considerable cost reductions. It is hoped therefore that studies in this area will be encouraged.

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Nine strains of Agrobacterium, 10 strains of Rhizobium and Alcaligenes faecalis var. myxogenes 10C3 were found to produce extracellular cyclic (1→2)-β-D-glucan. The cyclic (1→2)-β-D-glucan was a mixture of materials with different molecular weights. Eight components were isolated by paper chromatography and liquid chromatography. The degrees of polymerization of the components were determined by liquid chromatography of their partial hydrolysates to be 17, 18, 19, 20, 21, 22, 23, and 24. 13C-NMR of these cyclosophoraoses was studied. Cyclic (1→2)-β-Dglucans from 19 strains of Agrobacterium and Rhizobium were divided into four classes on the basis of differences in the distribution patterns of the eight cyclosophoraoses.

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