The oligosaccharides formed during the sucrose-invertase reaction

490

LETTERS

TO THE EDITORS

This will cause a corresponding increase in pressure of the gas by y - e, but not y. Similarly, if the fluid in the closed arm and the open arm be raised f and y’, respectively, the pressure of the gas will be increased by y’ - f instead of y’. By the gas law, we have V,P, = (V, - de)

(PO + y i

e) = (V, - +f)

(PO

f

y’ - f)

Thus: V, = de

(PO

+ 2( - e)l(y - e) =

ii+f(Po

f d - f)l(y’

- f).

Since PO is large compared with y - e and y’ - f, we have,approximately e/h - 4 = f/(y’ - f). This can be reduced to the following form, y/e = y’/f, which occurs as an intermediate equation in Vogler’s derivation. From here on, the derivation is the same aa Vogler’s. REFERENCES 1. VOQLER, K. G., J. Gen. Physiol. 26, 106 (1942). 2. UMBREIT, W. W., BURRIS, R. H., AND STAUFFER, J. F., Manometric Techniques and Related Methods for the Study of Tissue Metabolism, Rev. Ed. Burgess Publishing Co., Minneapolis, 1949. 21 .&I Oxford St. Berkeley, California Received February

PING-YAO CHENG11, 1952

The Oligosaccharides

Formed During the Sucrose-Invertase

Reaction

The incomplete hydrolysis of sucrose by crude, commercial, and purified invertasc has been shown to yield at least three oligosaccharides that occupy the region between sucrose and raffinose on paper chromatograms (14). On complete hydrolysis by invertase these saccharides yield only fructose and glucose. On the basis of qualitative evidence, two of them have been tentatively identified as trisaccharides composed of two fructose and one glucose units. We have now found a fourth component that lies between raffinose and the origin on paper chromatograms and also a fifth that lies in the leading edge of the sucrose zone. Judging from its reaction to sprays and position, the fifth component appears to be a reducing disaccharide. It occurred only in minute traces. We have quantitatively determined the ratio of fructose to glucose units in the four most abundant of the saccharides and noted the reaction of each of them with three sprays and with Fehling’s solution after elution from the paper. The saccharides were formed by allowing 1 ml. of “Difco invertase solution (for analytical use)” to act for 25 min. at 17°C. on 5 g. of pure sucrose in a total volume of 10 ml., after which the enzyme was destroyed by boiling. Chromatographic techniques employed were those of Williams and Bevenue (5) using 1-butanol-ethanol-water (10 : 1: 2) as the irrigant. Table I shows the chromatographic properties of the components. For quantitative work, the, saccharide components were separated chromatographically. After elution, suitable quantities of each were hydrolyzed on paper with invertase (6), and the fructose and glucose formed were separated chromatographically, eluted, and their ratio determined. See Table I.

LETTERS

TO THE

TABLE Properties

and Composition

EDITORS

I of Certain

Oliyosaccharides

=

ZXX

Reaction

to sprays~ Silver nitrate

mm.

sucrose (:omponent C’omponent Component Component

I II III IV

Reaction Fehling’s salntionn

to 0 .-

-

147 104 60 45 18

+ -

-

QPlus (+) or minus (-) indicates the presence or ahsrnrc, of a spot or precipitate under the conditions of the test.. * After elution from the paper. c Nomenclature follows that used by Bacon and Ed&n:m (I). I~Authentic sucrose, maltose, melibiose, and raenose moved 147, 96, 58, and :12 mm.. respectively, on the dame chromatogram. Component I is of particular interest because it is a new reducing disaccharide. As measured by alkaline ferricyanide, unhydrolyzed component I has approximately 60;0% of the reducing power of the acid-hydrolyzed sample. Component I is definitel) different in Rf and in reaction with invertase than turanose, t,he only previousl) reported reducing disaccharide containing fructose. None of the five components referred to above was found by rhromatographic rsxmination of the sucrose or invertase used. REFERENCES 1. BACON, J. S. II., AND EDELNAN, J., Arch. Biochem. 28, 467 (1950). 2. BLANCHARD, P. H., AND ALBON, N., Arch. B&hem. 28, 220 (1950). 4. DF, WHALLEY, H. C. S., -~LBON, S., AND GROSS, D., Analyst 76, 287 (1951). 1. FISCHER, E. H., KOHTES, L., AND FILLIG, J., Helu. Chim. Actu 34, 1132 (1951). 5. WILLIAMS, K. T., AND BEVENUE, A., Cereal Chem. 28, 416 (1951). 6. WILLIAMS, Ii. T., AND BEVENUE, A., Science 113, 582 (1951). Il’estern

Regional Research Laboratory, of Agricultural and Industrial [J. S. Department of Agriculture,

&rear6

Albany 6, Calgfornia Received

Feb. 4, 19&f

Chemistry,

I,AWRENCE GERALDINE

M. WHITE E. &X-OR