Dec. 5, 1952 tube was established by dissolving an aliquot of the upper phase in alkaline methanol and reading the optical density a t 255 mp. Figure 1 shows the distribution pattern for a typical extract after 100 transfers. Two major constituents and a t least one minor constituent are present with partition ratios of 0.9, 1.9 and 3.2. In addition, the tubes a t each extremity of the distribution train contain mixtures of unidentified substances. A sample of pure humulone (0-phenylenediamine complex, m.p. 117')) after conversion to isohurndone either by the method of Windisch, et al.,I or by boiling in aqueous phosphate buffer of p H 5.2, yields a product conforming to the properties of isohumulone and also having a partition ratio of 1.9 when distributed using this solvent system. A search for the origin of the substance showing maximum concentration in tube 47 and a partition ratio of 0.92 revealed that this substance did not arise from lupulone, soft resins, hard resins or humulinone but was produced, together with isohumulone, by boiling the lead salt salt fraction of a hop extract.
NOTES 0.5
6119
1
"/ /6
20
24 TUBE
d9 32 NUMBER
36
40
44
Fig. 2.-Distribution pattern for the lead salt fraction of a hop extract: 7t = 6 5 ; solvent system, 2,2,4-trimethylpentane and phosphate buffer PH 8.5; optical density units, mP.
Cook and Harris2 have reported the presence of humulinone in the lead salt fraction of Kent Golding and Worcester Fuggle hops. I n the present investigation humulinone has been isolated from ISOHUMULONE several varieties of Canadian and American hops. S I K=OO ?/9 Purified humulinone from these sources distributes with a partition ratio of approximately 1 in a system of 2,2,4-trimethylpentane and 0.5 M monosodium phosphate adjusted to PH 3.2 with phosphoric acid. No humulinone, however, can be detected in these hops by distribution of either the lead salt fractions or the complete extracts. This evidence is supported by infrared and ultraviolet absorption spectra of humulinone, humulone Oj0 and the lead salt fraction and permits us to conclude ' 0 only that humulinone is not a natural constituent .Y ,-o' of hops but is an artifact in the method of isolation. * 30 3 46 54 62 70 78 86 The second maximum in the distribution pattern, 0" ruBE NUMBER. Fig. 2 , is due predominantly to humulone but a Fig. 1.-Distribution pattern for a beer extract: n = 100; theoretical curve for one substance cannot be fitted solvent system, 2,2,4-trimethylpentane and phosphateto this portion of the pattern. It is apparent, citrate buffer PH 4.9. therefore, that a third component is present in the It was necessary therefore as a result of these lead-salt fraction and it may be possible to acobservations to make a critical study of the lead complish its isolation by the use of a larger number salt fraction. Figure 2 shows the distribution of transfers or another solvent system. pattern for the lead salt fraction of 1951 B. C. (2) A. H . Cook and G. Harris, J . Ckem. SOL.,1873 (1950). Bullion hops after 65 transfers using the system CANADIAN BREWERIES LIMITED 2,2,4-trirneth ylpentane-p hosphate buffer p H 8.5. RESEARCH DIVISION The substance showing maximum concentration TORONTO, ONTARIO, CANADA in tube 22 and a partition ratio of 0.53 is believed to be a new constituent of hops and has been assigned the name cohumulone. This substance Derivatives of 0-, m-,and @-Aminobenzotrifluoride. 11. Azomethines Containing the was purified by repeated distributions using two Trifluoromethyl Group' solvent systems and high transfer numbers. The final product was a light-yellow oil a t room temB Y PAULM. MAGINNITY AND JOHN L. EISENMANN perature which formed a waxy solid on slight coolRECEIVED JUNE 30, 1952 ing. Anal. Calcd. for CzoHa;06: C, 69.23; H, A previous paper in this series2 describes the 8.79; mol. wt., 364. Found: C, 69.1, 69.4, 69.4; H, 8.6, 8.8, 8.8; mol. wt. (by titration), 354. Co- preparation of a number of derivatives of the humulone, like humulone, forms both a lead salt isomeric aminobenzotrifluorides, especially heteroand an o-phenylenediamine complex but the solu- cyclic compounds. In conjunction with a study bility of the cohumulone product in each case is of certain azomethines being carried out in this slightly greater than that of the humulone product. L a b ~ r a t o r y i, t~ was found desirable to prepare a t When boiled in phosphate buffer, p H 5.2, cohumu(1) Parts of this paper were taken from a thesis submitted by John lone is transformed to the new bitter substance of L. Eisenmann t o the Graduate School of Boston College in partial fulfillment of the requirements for the degree of Master of Science. beer. (2) P. M . Maginnity and C. A. Gaulin, THISJOURNAL, 78, 3579
- 1
(1) W. Windisch. P. Kolbach and R. Schleicher, Wochschr. Brau., 44, 463, 473, 485, 497 (1927).
(1961). (3) Cf. P . M. Maginnity w d
T. J. Gsir, {bid., 74, 4858 (19521,
A1 20
NOTES TABLE
I
SURSTITIJTE~ SCHIFF'SRASESArCH=KY-, Ar
R
K Picrateh
31 p. (or B p.). "C." 61-62 66-67 05 19-21 114-115 102.5-103 !i5. - 1111 A:
