Thin-layer chromatography of malto-oligosaccharides.
Abstract Procedures for the separation, location and elution of malto-oligosaccharides are described. Best separations were obtained on glass plates (20 × 46 × 0.5 cm) coated with Kieselguhr G, serially developed in solvents of varying proportions of x-butanol, pyridine and water. Major zones were temporarily visualized by exposing the plates to iodine vapors. The located zones were eluted from the thin-layer plates into fiberglass filter pieces with water. Radioactivity of the zone can be determined directly by placing the filter in a toluene-based scintillation fluid and counting in a scintillation counter. After radioactivity determination, the carbohydrates can be eluted from the filter with water and quantitatively measured.
A Novel Method for the Action Patterns and the Differentiation of α-1,4-Glucan Hydrolases
Abstract An "oligosaccharide map" procedure is described for the identification of the products of action of hydrolases on malto-oligosaccharides and for the differentiation of α-1,4-glucan hydrolases. The method involves chromatography of malto-oligosaccharides-1-14C in one direction on paper, incubation of the oligosaccharides with the hydrolase after spraying the enzyme directly on the chromatogram, separation of the hydrolytic products by chromatography in a second direction, and location of the radioactive hydrolytic products by autoradiography. Characteristic oligosaccharide maps are recorded for the hydrolases from Bacillus subtilis, Aspergillus niger, Rhizopus delemar, saliva, and sweet potato. A new enzyme, α-1,4-glucan:α-1,4-glucan 4-maltosyltransferase, has been detected by the use of the technique with enzyme preparations from B. subtilis and R. delemar.
First diamino Daphniphyllum alkaloid, daphnipaxinin, with an unprecedented heterohexacyclic skeleton from Daphniphyllum paxianum.
[structure: see text] The first diamino Daphniphyllum alkaloid, daphnipaxinin (1), with an unprecedented hexacyclic fused skeleton, along with a known alkaloid, daphnicyclidin A (2), was isolated from the stem of Daphniphyllum paxianum Rosenth. The structure and absolute stereochemistry of 1 were established by spectral methods, especially two-dimensional NMR techniques and CD analysis.