needed in the formula can be added without removing the paper from the machine.
LITERATURE
Mikrochimica Acta
Classifying the Carbohydrates
A
SIMPLE CLASSIFICATION SVSteill f o r
carbohydrates has been developed by H. S. Ishell at the National Bureau of Standards. It can be used for classify ing structurally related carbohydrates. By inspection of a code number, or by punched card technique, related deriv atives can be quickly picked out of a heterogeneous collection. Each carbohydrate is assigned a code number which defines its structure and configuration. A number of six or seven digits is used tor simple com pounds; more digits are sometimes needed for more complex structures. A decimal point after the second digit separates figures showing broad generic grouping from those giving definite structure. • The first number denotes the de gree of complexity of the carbohydrate. For instance. 1 means a monosaccha ride; 2, a disaccharide. • The second digit shows substitu tion on the polyol structure. When half or more of the hydroxyls are free, the classification number is 0. When more than half the hydroxyls are sub stituted, the number corresponds to the substituent present in predominating amount. If two classifications are pos sible, the one with the lower number is used. • The first digit to the right of the decimal point defines the skeleton of the fundamental carbon chain. • The second digit after the decimal shows configuration of the main struc tural unit. No distinction is made be tween η and L modifications because enantiomorphic substances give like infrared absorption spectra. • The third digit after the decimal indicates the characteristic structure of the substance. Products containing anomeric forms in equilibrium such as amorphous sugars and materials not falling in a specific class are represented by 0; pyranose and furanose structures by 1 to β; glycitols bv 7; open-chain aldehyde and ketone derivatives by 8: and aldonic acids by 9 whether or not they arc1 present as the acid. salt, ester, amide, or lactone. • The fourth and fifth positions to the right of the decimal tell the char acter of the main functional group. 9 0
C&EN
JUNE
2 4,
1957
usually the gl\ cosidic group. Because there are more than 10 common substituents, two spaces arc allowed tor this. For example, α-D-glucopyranose is given the code number 10.2110. The first " 1 " means it is a monosaccharide; "()," that the hydroxyl groups are pre dominantly unsuhstitutecl; "2," that it has a primary 6-carbon structure; " 1 , " that it has the glucose configuration; " 1 , " that it has a CI pyranose ring with an axial glycosidic group; and "0," that the glycosidic hydroxyl is not substi tuted. The codes for all a-o-glucopyranose structures have the .211 sequence. In other words, each structural grouping has a characteristic sequence of num bers. The system of coding was worked out in a program sponsored at the Bureau of Standards by the Office of Naval Research on structure, configura tion, and ring; conformation of the sugars and their derivatives by infra red absorption measurements.
Mikrochimica Acta, now published by Springer-Yerlag in Vienna, Austria, is successor to Mikrochemie and to Mikrochcmie vereinight mit Mikro chimica Acta, but is not a continuation of the MikrocJiimica Acta published 1937-38. The journal will not use volume numbers but identifies volumes by years. The publisher has agreed to publish in six installments (about two months apart), one volume (about 800 pages) per year. Subscription for 1957 is $26. In acknowledgment of the past contributions of microchemical societies to the spreading and improve ment of micromethods, the publisher is offering a special arrangement to scientific societies recognizing Mikro cJiimica Acta as their official journal: 2 5 ' "< discount on all subscriptions handled by the society, of which I5f"c> is to be passed on to the subscriber ( 1 0 ' ; for handling). The journal is international, witli contributions in English, French, Ger man, Italian, and Spanish, by those well known in the field.
• The New
York
Herald
Tribune
is
issuing Engineers Sews Supplement as a section of its Sunday edition once a month.
Benzene Rings on the Typewriter It is now possible to type structural formulas on an ordinal)· typewriter bv means of an innovation suggested to Hemington-Rancl Co. by T. E. R. Singer, New York consultant. When the cornpan)· introduced a typewriter with five extra keys that have removable type faces. Singer proposed that they make some special type laces with characters that could be used in building structural
CHOH.CH,
• T h e late Sir Alexander Fleming, dis coverer of penicillin, will have as his biographer Andre Maurois, French author.
NEW BOOKS The Structure of Nucleic Acids and Their Role in Protein Synthesis. Ε. Μ. Crook, editor. 74 pages. Cambridge Universitv Press, 32 East 57th St., New York 22', Ν. Υ. 1957. $3.75. Six papers from a symposium in London. February 1950. Paperbound
HO
Recherches sur le Mécanisme d'Oxydation de Cristaux Uniqaes de Fer a Haute Température et sous Basse Pression d'Oxygène.
formulas. The accompanying illustra tion shows what can be done in this typewriter (reduced to three quarters of actual size). The advantage of this sort of ma chine is that it can be used for ordinary typing as well. Thus, any letters
JEAN BAHDOLLE.
58 pages. Service de Documentation et d'Information Technique, 4, avenue de la Porte-d'Issv, Paris-NX'*", France. 1957. 1.000 fr. Rendiconti lstituto Superiore di Sanita. Vol. XVII. English edition. 249 pages. Fondazione Emanuele Paterno, Viale Regina Elena, 299, Rome, Italv. 1954. Pre/./o Lit. 5.000.
