System for classification of structurally related carbohydrates

A system is presen ted fo r t he classifi cation of stru ctura lly a nd co nfi gurationally related carbohydrates.Each s ubstance is assig ned a code number t hat defines t he s tructure a nd configuration.By inspection of t he code numbers, or by a punched-card tec hn ique, groups of stru ct urally r elated carbohydrate derivatives can be selected read il y fr om a heterogeneo us collect ion .The structures, configurations, and conformat ions of pyranose a nd furanose der ivatives are di sc ussed , and classifications are made on t he bas is of a few fundamental structures.Certain ambiguous and objectionable features in t he classifi cat ion of p y ranose rin g co nformations in t he Cl and I C categori es of R ee ves are pointed out.In this pa per, C I de notes t he chair confor mat ion in both the D and the L aldohexose se1'ies in wh ich t he reference gro up attac hed to carbon 5 of t he rin g is in the eq ua toria l posit ion.Sim ilarly, C2 denotes t he chaiT con formation in bot h seri es in which the r eference group attac hed to carbon 5 of t he ring is in t he axial pos it ion .Xylose and sorbose a re class ifi ed like glu cose; lyxose and t a gatose lik e mannose; arabinose a nd fr uctose like galactose; and ribose an d ps icose like talose.Because the desig nations al'C indcpend ent o f t he D or L seri es, t hey avoid t he erroneo us classifi cation of c nan t iomol'phs in d iff ere nt co nfor mations.3 4 --- ------------------ • •11 a•glueo• a e e e {J•ido• • •53 • •12 {J•glueo• 0 e e e a-ido-• •54 • •21 a-manno-a a e e {J•galo• .•63 • -22 {3-mannoe a c e a-gulo• • -64 • -31 a-galaet o-a e c a {J•altro•