A COMPARISON OIt SOME UI TEE ERGOT ALKALOIDS. being a Thesis Presented for the Degree of Doctor of Medicine Edinburgh University by Adam Cairns White, ßß.B., Ch.B., Ph.D., Wellcome Physiological Research Laboratories, Langley Court, Beckenham, Kent. INS, September, 1939. Com-parison alLome FrEot Alkaloids. A- Section I. Contents. Introduction pp 1-8 General Toxic Symptoms in:- Monkey pp. 8 - 27 Fowl pp. 27 - 34 Canary pp. 34 - 36 Ct pp. 36a - 43 Rabbit pp. 43 - 44 Guinea Pig pp. 44 - 45 Mice pp. 45 - 55 Frog p) 55 Discussion of Toxic Symptoms pp. 55 - 60 Actions on Temperature Regulation in:- Mice pp. 60 - 76 Rabbit pp. 77 - 96 -1- The ergot alkaloids, other than those that are molecular compounds, fail into two groups, a laevorotatory physiologically active group, and a dextrorotatory group which is considerably less active. Smith and Timmis drew attention to this fact in their paper on isoergine and isolysergic acids (1). In Table l I have assembled the ergot alkaloids in descending order of the number of constituent carbon atoms, and given, where possible, their rotations in chloroform. The figures are obtained from the papers of Smith and Timmis (1) (2). The decomposition products, ergine and isoergine have also been included. -2- 200 Table 1. (« } 5461 Ergotoxine C35114105N5 -226e Ergotinine 035H4106N5 +446° 191 Ergotinine C35H4106N5 +513° Ergotamine C33H3505N5 -1810 Ergotaminine C33113505N5 +4500 Ergosine C30113705N5 -1930 Ergosinine C30H3705N5 +5220 Ergotnetrine C19x2302N3 - Ergometrinine C19i-12302N3 . +5200 isoErgine C16H170 N3 Ergine C10170 N3 +598° -3- Since the publications of Smith and Timis (1) (2), Stoll and Burckhardt (3) have reported the isolation of yet another large moleculed pair of alkaloids, ergocristine and ergocristinine C35H3905N5 (this is the same gross formula as they give for ergotoxine) for which they have rotations (el )p in chloroform of -186° and +365e respectively. Ergometrine and isoergine are too insoluble in chloroform to give a rotation figure but Smith and Timmis (1) give a series of figures for p aridine. (Table 2.) -4- Table 2 200 (a ) 5461 Ergorrletrine c19H2302N3 -16° Ergometrinine 02N3 +596o isoErgine C19H170 N3 +25° Ergine C10170 N3 +6350 Lysergic Acid C16H1602N2 +490 isoLysergic Acid C16H1602N2 +3650 -5- The rotations for ergometrine and ergometrinine in pyridine show analogous differences to those found for the alkaloids with the higher molecular weights in chloroform solution. Ergosine and ergosinine are two new alkaloids (2) (4), but they also (as will be shown in this communication) fall into line. The ergine and lysergic acid series, while showing considerable differences in rotation do not show quite such marked differences in physiological action as is the case with the alkaloids of higher molecular weights. It should be noted that ergine belongs to the ergotinine ergometrinine series whereas lysergic acid belongs to the ergotoxine ergometrine series. That this differentiation in the nomenclature has arisen is unfortunate but it was a consequence of the historical sequence of isolation of these substances by Smith and Timis (5) and Jacobs and Craig (6) respectively. These lists include all the alkaloids definitely characterised as pure substances, as well as the breakdown products of -6- the erg;ine, and lysergic acid series. Sensibarnin (7) and ergoclavin (8) have been excluded. These two have been .characterised by Stoll (9) as mixtures, sensibarain as an e::¡juimolecular mixture of ergotamine and ergotarninine and ergoclavin as a mixture whose components are still under investigation. In a later paper he further states that Kftssner's (8) ergoclavin is composed of a dextro- and laevo- rotatory fraction. Smith and Tiinmis (2) reported leucine to be one of the products of acid hydrolysis of ergosinine and also report analytical figures strongly suggesting ergoclavin is a mixture of ergosine and ergosinine. Jacobs and Craig (11) report the presence of leucine as a product of the acid hydrolysis of ergoclavin. Kftssner himself (12) has also recognised that his ergoclavin is a mixture of two alkaloids. Further evidence of the non -unity of ergoclavin has been brought forward by Kofler and Kofler (13) who conclude that ergoclavin may possibly consist of two compounds, one of ergosine and -7- ergosinine, the other of ergotamine and ergosinine. Stoll and Burckhardt's (3) first isolation of ergocristine was from a double compound found in the mother liquors of ergotoxine from Spanish and Portuguese ergots the other component of which was ergosinine. These authors remarked on the analogies of this compound with erg=,oclavin. A. Kofler (14) has now described and characterised at least fourteen such molecular addition compounds between ergot alkaloids of opposing rotations. Provided suitable conditions are obtainable the list of such possible compounds is not yet exhausted. (L. Kofler) (15). So far, no compounds have been described between different ergot alkaloids with similar rotation. Very little is known of the quantitative or qualitative pharmacology of these compounds, and it will require prolonged and accurate comparisons if any results of value are to be obtained. A number of the ergot alkaloid pairs have not so far been examined together, and it is the purpose of this paper to extend these comparisons as far as my material allows. -8- The comparison of the activities of the various alkaloids and their decomposition products will perhaps be simplified if instead of describing the action of each pair as a whole, the actions of all pairs on a given species or physiological system are described together. GENERAL TOXI C SYMP'rO NbS . ( a ) Symptoms in the iVionkey . ERGOSINE. The same type of monkey was used in all our experiments with the ergot alkaloids, namely, silenus rhesus. The highest dose of ergosine given to a monkey was 4 mg. intramuscularly. The earliest symptoms were, pallor of the face and ears, and the animal was obviously ill at ease. The pupil was slightly contracted. The hair was roughened and the animal appeared to maintain its balance with great difficulty. Then the pupils were found to be dilated and did not react to light. Respiration was rapid and now and then a purposeless stretching out of the hands was observed. -9- At other times it sat all huddled up and ground its teeth frequently. When the animal partly lost its balance, it recovered with a convulsive shiver; this might be accompanied by twitching of the wrists. When the eyelids were raised, the pupils were seen to be very dilated. The huddled up position was disturbed every now and then by twitching of the muscles of the forelimbs, giving rise to a beating type of movement (clonus) with the wrists flexed. Four hours later the animal was found slightly more awake, but when the head was kept erect for a short time it finally fell jerkily forward and downward into the huddled up position, accompanied by a few twitches of the forearms. half an hour later, on being given a lump of sugar it was observed that the animal held it more awkwardly than usual and was still very timid. At the end of six hours it had largely recovered. The next day the animal was found to be slightly jumpy and was scratching itself more than normally. An attempt was made to induce chronic ergosine poisoning in a monkey, and between the 16th November, 1936, -10- and the 8th January, 1937, a total of 45.5 mg. was injected intramuscularly, at first in daily doses of 0.5 mg. and then after about three weeks the dose was doubled. A week later the dose was increased to about 2 mg. No symptoms of chronic poisoning were observed during or after the experiment and our supply of the drug did not justify proceeding further to determine the effect of higher doses of ergosine. The animal was apparently able to destroy moderate amounts of the drug without showing any chronic sympi oms. Whether this was due to the gradual developing of a tolerance to the drug or entirely due to insufficient dosage could not be determined. The develop?ient of tolerance to some of the other ergot alkaloids has already been noticed in the literature. RGOSININE . With large doses (il mg.), on intracardiac injection, the animal immediately became unconscious, gave a few dyspnceic gasps, became limp, assuming no characteristic -11- attitude and then died. Smaller doses (2 mg.) showed a much slower effect, the animal became less sure footed, and its movements were slower. At the end of twenty minutes, the animal was sitting in a corner supporting its body with its forelimbs (c.f. Fig. 1. where 5 mgm. had been given); it seemed dazed. It got up onto its perch, and had a great struggle to keep its position. The movements, however, were much slower than usual. The gripping power of the hind limbs was also reduced. The animal seemed, as it were, half awake. It was able to make a sudden rapid movement, but was unable to maintain am attitude or steady level of activity, for instance, when sitting, in the corner, it lay half on the side of its rump using its forelimbs to support the upper part of its body, the head would then slowly fall down and then be jerked back into its original position, (recalling the movements of the head when the human subject nearly drops off to sleep while sitting in a chair) . Fast movements were distinctly clumsy. A very characteristic attitude the animal adopted in this state was -12- a sort of Landseer lion attitude. At times, too, purposeless slow movements of the forelimbs were observed. Figure 1 shows the stage of the effects of 5 mg. ergosinine intracardiac in one of the monkeys. -13- Figure 1. Fig. 1. Monkey No 7.