alone hydrochloride, '77 mg., and noradrenaline, 53 mg., a 2S% yield. The activity was 8.5 X lo4 c.p.m. per mg. Identity and purity of the noradrenaline were established by microanalysis, pharmacological activity and isotope dilution assay. Full experimental details for this synthesis are available on m i ~ r o f i l m . ~ (3) For full experimental details of this synthesis order Document 3817 from American Documentation Institute, c/o Library of Congress, Washington 25, D. C., remitting $1.25 for microfilm (images 1 inch on standard 35-mm. motion picture film) or $1.25 fur photostats readable without optical aid.
RHEUMATIC FEVERRESEARCH INSTITUTE SCHOOL NORTHWESTERN UNIVERSITY MEDICAL CHICAGO, ILLINOIS
Temperature Coefficients of Rotation of Some oand p-Nitrophenyl Glycosides and their Polyacetates' BY JACK A. SNYDER AND KARLPAULLISK RECEIVED NOVEMBER 1 5 , 1932
Pigman2 has suggested that the anomalous positive rotations of the ortho-substituted phenyl pD-glycoside tetraacetates are due to. "interactions I
I
I
I
I
I
1
60
between the acetyl and aglycon groups. Such interaction might take the form of weak bonds between these groups or it might operate through steric hindrance to free rotation of the aglycon group about the glycosidic linkage." This wzjs postulated on the basis of the large temperature coefficients of rotation of these glycosides in contrast to those of their m- and p-isomers. We have determined the rotations of several 0- and p-nitrophenyl glycosides and their polyacetates over the range l.i-43", and find that the ortho compounds have large temperature coefficients while the para compounds have normal coefficients. This indicates that the acetate groups are not directly concerned with the production of large temperature coefficients and favors their explanation on the basis of steric hindrance. Experimental Change of Specific Rotation with Temperature.-The method of preparation of the compounds studied has been reported p r e v i ~ u s l y . ~Rotations were determined with a Schmidt and Haensch polarimeter No. 52-b with monochromator. A 2-dm. jacketed tube was used, with water, maintained a t t 5 0.2" by means of a thermostatically controlled water-bath, as the circulating fluid. No correction was made for liquid density change with temperature.
TABLE I SOLVEYTS ASD CONCENTRATIONS I N DETERMINATIOS OF CEIASCEOF SPECIFIC ROTATION W r r H TEMPERATURE Concn , Compound
o-Sitrophenyl P-D-glucoside tetraacetate (I) p-Xitrophenyl P-D-glucoside tetraacetate (11) o-Sitrophenyl 0-D-galactoside tetraacetate (111) p-Sitrophenyl P-D-galactoside tetraacetate (IV) o-Sitrophenyl P-D-glucoside ( V ) p-Sitrophenyl B-o-glucoside ( V I ) o-Sitrophenyl p-D-galactoside (VII) p-Sitrophenyl p-D-galactoside (VIII) o-Xitrophenyl or-L-arabinoside ( I X ) p-Sitrophenyl or-L-arabinoside (X)
40
2o0
- 20 1. b. -40
Solvent
76
Chloroform
1.966
Ch!oroform
1.884
Chloroform
1.865
Chlorofortn W'ater n'ater \\rater \\rater M'ater \Vater
1.983 0.828 0.987 1,065 0.980 .290 ,265
(3) J. A Snyder and K P Link, THISJOURNAL, 1 4 , 1883 (1952).
DEPARTMENT OF BIOCHEMISTRY OF WISCONSIN UNIVERSITY MADISOX6, WISCONSIN -80
(b
vm V
n
"
rn
V
"
n
n
-o
-100
The Sedimentation Constant of Insulin in Acid Solution : A Re-examination' BY FRANK TIETZE AND HANSNEURATH 1, 1952 RECEIVEDSOVEMBER
-120 I
15
20
I
I
I
25 30 35 TEMPERATURE, "C.
I
40
45
Fig. 1.-Influence of temperature on specific rotation of some 0- and p-nitrophenyl glycosides and their polyacetates. ( 1 ) Published with t h e approval of t h e Director of the W'isconsin Agricultural Experiment Station. Supported in part by the Research Committee of t h e Graduate School from funds supplied by t h e Wisconsin Alumni Research Foundation. ( 2 ) W. W. Pigman, J . Research Natl. Bur. Standauds. 33, 129 (1944).
On the basis of their observations on the sedimentation and diffusion constants of bovine insulin in acid solution, Fredericq and Neurath2 concluded that the minimum molecular weight of this protein was about GOOO. Although this conclusion has received support from the more recent work of Harfenist and Craig3 on counter-current distribui I ) This work has been ,upported by t h e Lilly Research Laboratories Eli I.rlly and Cornpan>, Indianapolis, Indiana, to a h o m we are a l i o indebted for the supply of crystalline inwlin (2) I5 Fredericq and H. Neurath, THIS J O U R N A L , 1 2 , 2684 (1950) ( 3 ) E . J. I-larfenist and L. Craig, i b i d . , '74, 3087 (1952).
