Accumulation and distribution of the main alkaloidsin the opium poppy in the course of its ontogenesis

Title

Accumulation and distribution of the main alkaloidsin the opium poppy in the course of its ontogenesis

Details

Author: G. K. Nikonov
Pages: 20 to 24
Creation Date: 1958/01/01

Accumulation and distribution of the main alkaloidsin the opium poppy in the course of its ontogenesis

G. K. Nikonov
(All-Union Scientific Research Institute for the Study of Medical and Aromatic Plants)

The laborious nature of the processes whereby opium is obtained, together with the great value of the alkaloids obtained from it, has led research workers to look for other kinds of raw material from which to obtain substances of this group. Research has shown [1-11] that alkaloids occur not only in the opium, but also in the poppy plant. After the discovery of methods of obtaining alkaloids from poppy straw [12-14] , various countries began to extract alkaloids (in most cases morphine only) from the capsules and stems of the oil-bearing poppy, which are waste products of poppy-growing for oil production. The possibility of using the stems (straw) to obtain codeine, narcotine, papaverine, thebaine and narceine, which are extracted exclusively from opium, was still a moot point until recently, for there were only scrappy and often contradictory data on whether the stems contained them. The possibility of using for those purposes varieties of poppies cultivated for the production of opium also remained unexplored, for this would make it impossible to obtain opium as the main product and could be justified only where it was, unquestionably, economically advantageous.

These points could be settled only by thoroughly studying the laws governing the accumulation and distribution of alkaloids in the various parts of the opium poppy, with a view to determining the possible types of raw-material and the proper times for harvesting it.

Accordingly, in 1948-49 we made a study of the dynamics of the accumulation of morphine, codeine, thebaine, narcotine, papaverine and narceine, as well as of total alkaloids in the whole plant and individual organs throughout the growing period. The subject of research was a variety of opium poppy grown near Przhevalsk in Kirghizia, at 1,800 metres above sea-level. The investigation covered the young shoot, rosette, stalk formation, bud formation, flowering and technical (opium) and biological (seed) maturity stages, and dealt with the leaves (upper, middle and lower), stalk, root and reproductive organs, the specimens being analysed after hot-air conservation (105oC for 20 minutes) and air drying. Total alkaloids were isolated by the widely used alcohol-dichlorethane method [10] and individual alkaloids separated and identified by B. A. Klyachkina’s method [15] , from 20 to 400 plants being used in each case.

The study of the dynamics of accumulation of the dry substance showed that it accumulates steadily until biological maturity, and continues to do so at different rates according to the stage of development, maximum accumulation occurring during the period in which the reproductive organs appear and develop (bud formation, flowering and technical maturity). At the end of the growing period the substance is mainly concentrated in the capsules (up to 39% of the total weight of the plant) (see table 1).

The study of the dynamics of the accumulation of total alkaloids revealed that this too proceeds as the plant develops, right up to biological maturity, and is most rapid during the period between flowering and technical maturity. Accumulation at this stage is so vigorous that within a period of fifteen to eighteen days, the plant accumulates over 50% of the total quantity of alkaloids formed during the entire growing period (about 130 days). Up to 48% of this is concentrated in the capsules (see table 2).

The accumulation of alkaloids in the opium poppy is closely connected with the growth of its reproductive organs, which are the main alkaloid repository and are responsible for the intensive formation of alkaloids and their movement from other organs during that period.

Comparing the figures for increase of dry substance per unit of time with those for the alkaloid accumulation rate, we find that the two quantities are correlated: the more dry substance the plant accumulates per unit of time, the greater its capacity for accumulating alkaloids. This phenomenon, which was observed over a period of two years, confirms earlier observations [16] , [17] that the formation of opium alkaloids occurs in young and vigorously developing cells. It follows that the more intensive the accumulation of dry substance in g per unit of time, the more rapidly the alkaloid content of the plant must also be accumulating. Tests have shown that this correlation not only occurs in the whole plant, but can also be traced in the reproductive organs. On testing the alkaloid content of the capsules of various varieties of opium poppy it was found that a high alkaloid content always corresponds with a rapid rate of growth of dry substance during the period from flowering to technical maturity. This correlation could presumably be put to practical use in selecting varieties of poppy with a high alkaloid content.

The accumulation of the various main alkaloids in the plant is somewhat different from that of total alkaloids taken together (see table 3). Accumulation already begins at the time the shoots appear, when all the alkaloids can be identified in the plant, but proceeds very slowly until the stage of stalk formation. During this period, morphine and narcotine predominate, followed by papaverine, codeine, thebaine and narceine. Thereafter the accumulation of morphine and narcotine proceeds almost at the same pace until the stage of technical maturity, after which the amount of morphine decreases while that of narcotine goes on increasing until the plant dies off. The accumulation of codeine, third in point of quantity, proceeds simultaneously with that of morphine, but goes on after technical maturity until biological maturity. The accumulation of thebaine, like that of morphine, ceases at technical maturity.

TABLE 1

Accumulation of dry substance by the plant by stage of growth

(g of absolute dry weight per plant - 1950 experiment)

 

Stage of development

Organ

Young Shoots 15 May

Rosette 2 June

Stalk formation 27 June

Bud formation 6 July

Flowering 11 July

Technical maturity 28 July

Biological maturity 11 August

Re-productive organs
-
-
-
3.05 5.14 33.99 55.45
Leaves
-
1.06 16.95 28.18 32.64 39.54 30.22
Upper
-
-
3.05 10.00 12.14 19.84 16.56
Middle
-
-
9.13 11.27 13.60 12.79 10.60
Lower
-
-
4.77 6.91 6.90 6.91 3.06
Stalk
-
-
4.68 20.32 27.43 41.85 40.60
Root
-
0.08 2.49 6.68 9.51 11.64 13.96
Whole plant
0.017 1.14 24.12 58.23 74.72 127.02 140.23
Increase. in dry substance, in g per day
 
0.06 0.92 3.79 3.30 3.76 0.73

Comparing the accumulation of morphine and codeine, and especially their rate of accumulation in mg per day per unit of dry substance in the plants, we find that the plant cells are better able to accumulate morphine when they are young, and better able to accumulate codeine when they are older. For example, an increase in the morphine accumulation rate occurs when the plant is growing rapidly and forming new tissues (the stalk formation stage) whereas the codeine accumulation rate increases during the periods of slow growth of the already developed tissues (the rosette and flowering stages). Since morphine and codeine are the most closely related of the opium alkaloids in structure, it may be assumed that conversion of morphine into codeine occurs as the plant grows older, owing to the higher methylation capacity of old tissues [18] . Since thebaine accumulation decreases after technical maturity while accumulation of codeine continues up to biological maturity, it may be assumed that the plant's capacity to form alkaloids of the phenanthrene series asthe tissue's age changes, is as follows: morphine - thebaine - codeine.

TABLE 2

Accumulation of total alkaloids in the plant by stage of development

( mg per plant )

 

Stage of development

Organ

Young Shoots

Rosette

Stalk formation

Bud formation

Flowering

Technical maturity

Biological maturity

Reproductive organs
-
-
-
23.00 42.83 487.71 624.97
Leaves
-
3.85 41.45 114.12 132.72 268.84 180.46
Upper
-
-
11.12 55.99 62.89 145.80 93.23
Middle
-
-
25.56 38.30 47.61 82.39
69. O0
Lower
-
-
4.77 19.83 22.22 40.65 18.23
Stalk
-
-
12.15 40.02 86.42 137.69 227.36
Root
-
0.53 11.72 35.08 66.56 102.64 62.54
Whole plant
0.002 4.38 65.32 212.30 328.50 996.90 1,095.30

The course of accumulation of papaverine and narceine resembles that of narcotine and continues up to biological maturity, when it reaches its peak. Examination of the rate of accumulation of narcotine and papaverine shows in a number of cases that narcotine accumulation is more rapid where papaverine accumulation ceases or slows down and vice versa, which indicates that a correlation exists between the formation of these two alkaloids. Since narcotine appears in the plant before papaverine and its accumulation rate increases in periods when new tissues are being formed, which is not the case with papaverine, it may be assumed that as the plant ages its tendency to form and accumulate these alkaloids shifts from narcotine to papaverine. In the case of narceine no pronounced correlation with the processes of the plant’s growth and development is observed. Judging from the course of its accumulation in individual organs and the daily fluctuations of narcotine and papaverine, it may be assumed that narceine represents a proto-alkaloid or intermediate substance in the formation of these two alkaloids.

In the light of the foregoing, it is interesting to follow the amount of the main alkaloids contained by the plants in relation to factors accelerating or retarding their growth, since the likelihood is that accelerating factors promote accumulation of codeine and papaverine and retarding factors that of morphine and narcotine. Checking the alkaloid accumulation rate in the 1949 and 1950 experiments against meteorological data, it was found that for morphine and narcotine accumulation the essential condition is sufficient humidity and a relatively low optimum temperature; for papaverine, higher temperatures and low humidity; and for codeine and papaverine, low temperatures and high humidity. A study of the effect of climatic conditions on the amount of individual alkaloids contained in opium [19] revealed a similar picture.

TABLE 3

Accumulation of the main alkaloids in the opium poppy in the course of its ontogenesis

( mg per plant- 1950 experiment )

 

Stage of development

Alkaloids

Rosette

Stalk formation

Bud formation

Flowering

Technical maturity

Biological maturity

Morphine
0.703 26.93 49.70 58.63 228.17 193.85
Codeine
0.275 4.29 34.63 25.88 62.29 89.57
Thebaine
0.014 2.45 6.59 2.52 23.43 9.50
Narcotine
0.355 24.70 23.02 50.26 144.16 208.43
Papaverine
0.323 1.45 5.09 5.66 16.97 25.77
Narceine
0.080 3.81 5.00 4.71 15.23 43.55
Others
2.920 1.18 79.55 177.75 570.54 545.00

In the course of our investigation, we discovered, for the first time, a big difference between total alkaloids and the total amount of the six main ones. In the period from flowering to biological maturity this difference is equal to the sum of all the main alkaloids. This fact has not so far attracted the attention of research workers, and no practical advantage has been taken of it in connexion with the use of opiumbearing types of poppy for extraction purposes, although the discrepancy may result in a number of difficulties in processing. For example, since substances involved are in the nature of bases, they may complicate the process of separating and purifying alkaloids and decrease the efficiency of absorbents, etc. As we have shown, the most rapid accumulation of the main alkaloids in the poppy plant occurs during the period from flowering to so-called technical maturity, which is also the period chiefly responsible for the accumulation of the above-mentioned bases. Since, in addition, the ratios of the alkaloids to one another fluctuate greatly during this period, the assumption is that the composition of the opium will also fluctuate greatly according to the dates at which the capsules are cut and the opium is obtained. Another thing which is highly specific to the poppy is a sharp reduction in the rate of accumulation of alkaloids (codeine excepted) during the flowering period.

The course of accumulation of the main alkaloids in individual organs is to some extent specific to each organ, obviously depending on the physiological part it plays. In the leaves of the opium poppy, alkaloid accumulation begins at the time of their formation and continues until technical maturity in the case of morphine, thebaine and narcotine and until biological maturity in that of codeine, papaverine and narceine (see table 4). But the relative contribution of the leaves to the plant’s total alkaloid content steadily declines as the plant develops. For example, whereas the leaves contain up to 68% of the total amount of morphine and up to 74% of that of narcotine during the stalk formation stage, the figures are only 30% and 26% during the technical maturity stage and even less, 12% and 9%, at the biological maturity stage. Since the accumulation of alkaloids in the plant as a whole goes on until biological maturity, the decrease in the alkaloid content of the leaves after technical maturity can hardly be ascribed to the destruction of the alkaloids. It is more likely that there is a migration of alkaloids into other organs, particularly into the capsule.

TABLE 4

Accumulation of alkaloids in the leaves of the poppy in the course of its ontogenesis

( mg per plant - 1950 experiment )

 

Stage of Development

Alkaloids

Rosette

Stalk formation

Bud formation

Flowering

Technical maturity

Biological maturity

Morphine
0.58 18.20 28.16 27.95 69.15 23.50
Codeine
0.24 1.93 11.22 10.00 9.57 11.86
Thebaine
0.11 0.77 1.96 1.21 5.19 3.22
Narcotine
0.10 18.40 14.90 27.63 37.88 19.57
Papaverine
0.03 0.75 3.21 3.64 1.92 2.78
Narceine
0.07 2.85 2.71 1.65 2.42 9.11

In general, the accumulation of alkaloids in the stalk and root resembles that in the leaves (see tables 5 and 6), except in the cases of narcotine and papaverine. These two organs, however, make only a very small contribution to the plant’s alkaloid content. The root, which is small during the technical maturity period, accounts for less than 7% of the total amount of alkaloids in the plant and is of no possible practical value. The stalk contains 11% to 17% of the alkaloids during this period, but since it is large in bulk (32% to 34% of the whole plant), its alkaloid content is so low percentagewise (morphine 0.06%, papaverine 0.006% etc.) that no method of obtaining alkaloids from it is likely to be devised in the near future.

TABLE 5

Accumulation of the main alkaloids in the stalk and root of the poppy in the course of its ontogenesis

( mg per plant- 1950 experiment )

 

Stage of Development

Alkaloids

Rosette

Stalk formation

Bud formation

Flowering

Technical maturity

Biological maturity

In the stalk
           
Morphine
-
3.95 10.38 11.79 25.95 22.33
Codeine
-
1.96 15.64 7.41 11.30 19.49
Thebaine
-
0.93 2.84 0.27 4.18 0.40
Narcotine
-
1.78 3.25 7.27 24.78 16.16
Papaverine
-
0.20 1.17 1.01 2.51 1.14
Narceine
-
0.68 1.69 1.81 3.31 21.92
TOTAL
-
12.15 40.02 86.42 137.69 227.36
In the root
           
Morphine
0.12 4.38 4.81 8.87 13.38 8.00
Codeine
0.03 0.40 4.25 1.26 2.73 4.47
Thebaine
0.003 0.75 0.87
traces
0.81 0.15
Narcotine
0.26 4.53 2.57 4.79 5.21 6.84
Papaverine
0.005 0.49 0.29 1.33 1.16 0.50
Narceine
0.01 0.28 0.33 0.45 0.51 1.98
TOTAL
0.53 11.71 35.08 66.56 102.64 62.54

TABLE 6

Accumulation of the main alkaloids in the poppy’s reproductive organs

(Percentage of absolutely dry substance (numerator) and mg per plant (denominator) - 1950 experiment)

 

Development stage

Alkaloid

Bud formation

Flowering

Technical maturity

Biological maturity

Morphine
0.208 0.311 0.452 0.505
 
6.35 16.00 119.69 140.02
Codeine
0.115 0.14 0.146 0.194
 
3.51 7.20 38.68 53.79
Thebaine
0.03 0.02 0.05 0.019
 
0.92 1.03 13.25 5.27
Narcotine
0.075 0.205 0.288 0.598
 
2.29 10.57 76.30 165.86
Papaverine
0.014 0.017 0.041 0.077
 
0.43 0.87 10.86 21.35
Narceine
0.009 0.015 0.034 0.038
 
0.27 0.78 9.11 10.54
TOTAL, in mg
23.10 42.83 487.71 624.96

The most rapid accumulation of alkaloids occurs in the reproductive organs (see table 6), where accumulation continues, in the case of all the alkaloids except thebaine, up to biological maturity.

The individual alkaloids accumulate in the capsules at markedly different rates: narcotine outstrips morphine and becomes the main alkaloid in the capsules by the time the seeds are fully ripe.

The capsule of the opium poppy is the main organ and the richest one in alkaloids, and at the end of the growing period contains up to 70% of all the morphine in the plant, up to 80% of the narcotine and papaverine and up to 60% of the codeine and thebaine, and this makes it a suitable raw material source for obtaining those alkaloids. The best time to pick the opium poppy for extraction purposes is the stage of biological maturity if the capsules are used, and the stage of technical maturity if the plant is harvested whole. As the use of the whole plant presents a number of difficulties (drying the fresh stem, large number of ballast substances, loss of seeds and low alkaloid content), the best raw material is the capsule.

Conclusions

  1. The rate of accumulation of alkaloids in the opium poppy depends upon the rate of accumulation of dry substance in the plant. Where this is high (in terms of g of dry substance per day) the plant has a higher alkaloid content.

  2. The accumulation of alkaloids in the plant occurs from the time of the appearance of the shoots up to biological maturity and is most rapid in the period from flowering to technical maturity.

  3. Accumulation of the main alkaloids depends on the age of the plant. Morphine and narcotine accumulate most rapidly when it is young; codeine and papaverine as it ages.

  4. Apart from the main alkaloids, considerable quantities of basic substances, the nature of which still remains to be ascertained, occur in the opium poppy.

  5. The amount of alkaloids in individual organs depends on the stage reached in the plant's development. The organwith the highest alkaloid content is the capsule at the stage of technical and particularly of biological maturity, when it contains an average of about 70% of all the main alkaloids in the plant.

  6. Opium poppy capsules harvested at the stage of biological maturity, and the whole plant harvested at the stage of technical maturity, may be used as raw materials for extraction.

Bibliography

001

MALIN, A., Ber. Pharm. Ges., 40, 59, 1907.

002

KEPBOSCH, M., Arch. Pharm., 248, 536, 1910.

003

MOSSLER, G., Pharm. Post, 89, 647, 1919.

004

PROCHASKA, M., Zeitschr. f. Pfl., 12, I. 1926.

005

KOPP, E., Heil- und Gewürzpflanzen, 12, 1929.

006

FUCHS, L., Pharmazeutische Monats., 10, 223, 1932.

007

KRIGER., G.K., Soviet Pharmacy, No. 10, 1933.

008

ROTERMEL, A. L, Soviet Pharmacy, No. 10, 1933.

009

KUSSNER, W., Chem. Abstr., 35, 22, 8203, 1941.

010

BANKOVSKY, A.I. & MURAVIEVA, V.I., Collected Transactions of VILAR, 7, 1942, Moscow.

011

KUSHKE, E. E. & TUSHNYAKOVA, M. Pharmacy, Nos. 1-2, 1942.

012

HEEGER, E.F. & POETHKE, Die Pharmacie, 4, 131, 1948.

013

KOBAJ., Bet. ungar. Pharm. Ges., Budapest, 260, 1930.

014

HEEGER., E.F. & BAUER, K.H., J. Landwirtschaft, Jahrbücher 90, 1940.

015

KLYACHKINA, B.A., The Chemical and Pharmaceutical Industry, USSR, No. 4, 1933.

016

CLAUTRIAU, G., Memoires Soc. belge de Microscop. Bot. Centr, 40, 148, 67-85, 188.

017

ERRER, L., Cours pratique de Microscopie vegetale, Brussels, 1906.

018

BLAGOVESCHENSKY, A.V., The Biochemical background of evolutionary processes in plants, Moscow and Leningrad, 1950.

019

ILINSKAJA, T.N. & JOSIFOVA, M. G., Bull. on Narcotics, 8, 3, 38-42, 1956.