SEPARATION OF ALKALOIDS BY GAS CHROMATOGRAPHY

ture 6-aminopenicillanic acid (II) has been isolated by absorption on ... CHROMATOGRAPHY. Sir: In the past, the ... min.0-6. Compound min.a'f. 1. Lupi...
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July 20, 1960

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thiazolidineacetic acid, formed by quantitative paper chromatography using ninhydrin as the color reagent. From a suitable batch of reaction mixture 6-aminopenicillanic acid (11) has been isolated by absorption on IR-120 (H+), elution with "4OH a t pH 7.0, concentration in uacuo, and adjusting the fiH to -1.4. The recrystallized product had m.p. 207-208' (dec.) and [ c r ] 4-277 ~ ~ ~ (c 1.0 in 0.1 N hydrochloric acid).5 I t assayed approximately 2730 u.,/mg. based on sodium benzylpenicillin by the hydroxylamine colorimetric procedure6 and by microbiological determination after phenylacetylation' (theor., 2732 u./mg.). Acylation of (11) with the appropriate acid chlorides in aqueous acetone buffered a t pH '7.0 to 7.3 has given good yields of crystalline potassium salts of benzylpenicillin and phenoxymethylpenicillin, which are identical in all respects to the product prepared by fermentation. Both phenoxymethylpenicillin (V) and allylmercaptomethylpenicillin (0) are hydrolyzed by this microbial acylase system. Details on the distribution of this acylase in microorganisms, and its activity on a series of penicillins, including a large number of new semi-synthetic penicillins will be reported elsewhere.

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TABLE I ALKALOID RETENTIOSTIMES Time, Compound min.Q>t 1. Lupin alkaloids Cytisine hlethylcytisine Methylcytisine Soxide Lupanine 13-Hydroxylupanine Slatrine Lupinine Sparteine a-Isosparteine 13-Hydroxysparteine

Compound Pieopine Papaverine Thebaine

5.1 4.3

4.

5.8 5.5 11 .6 8.5

5.20' 1 4 ,3d

5.

2.

Amaryllidaceae

Galanthine Acetylcaranine Lycorenine Galanthamine Crinine Powelline Tazettine Belladine

3.

80.0''

8.P 15 4 35.1 16.8' 25,!Y 40.3

steroidal alkaloids 40 6'~' 74 3r.c 77 .3C'e

Solanidine Solasodine Tomatidine

19.0

10.5 10.6

6.

7.8

L*liscellaneous 3 .0 1.6 0 7' 4.8' 1 6 .2' 50 8 12.7' 33 0 44.7 11.F

Atopine Caffeine Cinchonine Cocaine Corydaline Cryptopine Himbacine Piperine Protopine Quinine

9.5 15.8 15.2 8.7

Pa$avei.aceac

Codeine Gnoscopine Laudanosine LlorDhine

Indole Alkaloids

Brucine Coronaridine Ibogamine Ibogaine Serpentine Strychnine Voacangine

1,:d 5.Qd

Time, min.a,b 9.1 3.5.3 13.2

8.2 90.6 21.0

11.0

Argon ionization detector, 6 ft X 4 nim i d columns b Pressure 15 psi , 2-3/100 SE-30 on Chromosorb tV, 80100 mesh, temperature 204' unless otherwise noted TemTemperature 160". e Pressure 10 psi H. T. HUANG perature 222' A. R. ENGLISH T. A. SETO product was identified as unchanged starting G. M. SHULL material by standard methods. The power of this B. A. SOBIX analytical tool is illustrated in a separation of

( 5 ) j . C . Sheehan and K. R . Henery-Logan, THISJ O U R N A L , 81, 5833 (19591, report [ a ] l l 4-273 ~ ( C 1.2 in 0.1 N hydrochloric acid). (6) G. Boxer and P. hI. Everett, A d . Chem., 21, 670 (1949).

RESEARCH LABORATORIES CHAS.PFIZER& Co., I s c . GROTON, COSSECTICUT, ASD -MAYWOOD, NEW JERSEY RECEIVED MAY28, 1960

Papaaeraceae alkaloids (Fig. 1).

SEPARATION OF ALKALOIDS BY GAS CHROMATOGRAPHY

Sir: I n the past, the separation of alkaloids from crude alkaloid mixtures has depended upon fractional crystallization, precipitation, countercurrent extraction and either adsorption or liquid phase partition chromatography. Several recent communications have reported the use of gas phase chromatographic techniques for the separation and identification of steroidsizz and high molecular weight fatty primary amines3 This communication demonstrates the feasibility of this method for the isolation, separation and identification of alkaloids. Our attention has been focused on alkaloids with molecular weights above 250, since suitable modifications of the conditions should permit separations of lower molecular weight substances without d i f f i ~ u l t y . ~ Alkaloids listed in the table gave single component sharp peaks, consistent with the absence of decomposition. A typical sample was 1-3 pl. of a 0.a-l.070 solution of the alkaloid in methanol, acetone or chloroform. In several cases (Nmethylcytisine, crinine, ibogaine and solanidine) macro samples were chromatographed and the (1) W. J. A. VandenHeuvel, C . C. Sweeley and E. C. Horning, THIS 82, 3481 (1960). (2) R. K Beerthuis and J. H . Recourt, A-aluue, 186, 372 (1960). (3) J. h'elson and A. hfilun, Chemistvy &I~ndusiuy, 663 (1960). ( 4 ) Cf. L. D. Quin, J. Oug. Chem., 24, 911 (1959).

JOURNAL,

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H A LLO~D o r CI~EMISTRY OF H hI FALES LABORATORY XATURAL PRODUCTS P F HIGHET XATIOLAL HEARTISSTITUTE \I' J A t AYDE\HEUVEL BETHESDA 14, MARYLAYD IV C I ~ I L D M A N RECEIVEDJUNE 16, 1960 T H E ENTROPY OF ACTIVATION OF ADDITION O F METHYL RADICALS TO UNSATURATED COMPOUNDS POSSESSING T H E SAME REACTION CENTER'

Sir: Addition of methyl radicals to ethylene,' pro. pylene,3 isobuterie,2 ~ t y r e n e , a-methylstyrene, ~ butadiene4 and isoprene4 was studied in this (1) This work was supported by a grant from the h-ational Science Foundation ( 2 ) R. P . Buckley and 31.Szwarc, PYOC. R o y . Soc., A240,396 (1957). (3) F. Leavitt, M. Levy and SI.Szwarc, THIS J O U R N A L , 77, 5493 (1955). (4) A. Rajbenbach and 11. Szwarc, P i n c . Roy. SOL., A251, 1ZG6 (1959).