Alkaloids of Peganum harmala

N. D. 2000. Alkaloids of Peganum harmala. Chemistry of Natural Compounds, 36(6) 602-605. 

The condensation of a heterocyclic enamine with o-aminobenz-aldehyde, leading to the alkaloids of Peganum harmala, desoxy-vasicine371 and vasicine,372 also include aldol-type reactions. The... 

The numbering of the carboline ring system (I) adopted here is that of the Ring Index. It differs from some of the systems in use, but, since there has been considerable diversity and some confusion, it is hoped that the present system will be generally adopted. This chapter is a summary and extension of that dealing with the alkaloids of Peganum harmala, Volume II, p. 393. 

Nmr spectroscopy has been very helpful in the structure elucidation of these alkaloids (Table 1). The methylene protons at C-9 of vasicine and deoxyvasicine appear as a singlet around 6 4.5 (9,95). In isopeganidine and deoxypeganidine, the methine proton at C-9 appears between 5 5.02—5.14 as a triplet (230). Further details can be found in the original papers. The alkaloids of Peganum harmala have been comprehensively reviewed by Telezhenetskaya and Yunusov (208). 

The paths of the interconversions which occur among the alkaloids of Peganum harmala have also not been elucidated so far. Such studies have been hindered by the rapid metabolism of these compounds. After feeding pH]-vasicine, the label was detected in vasicinone and deoxyvasicinone. As only 65% of the administered radioactivity was recovered, it is possible that vasicine may have been degraded in the plant. Pegamine (6) is a potential intermediate for deoxyvasicinone (42). 

Koretskaya, N. I. Alkaloids of Peganum harmala. I. Isolation of Two New Alkaloids. Zhur. Obshchei Khim. 27, 3361 (1957) (Russ). 

Liljegren, D. J. Biosynthesis of Quinazoline Alkaloids of Peganum harmala. Phytochemistry 10, 2661 (1971). 

Plekhanova, N. V., and S. T. Aktanova Alkaloids of Peganum harmala. Issled. Flory Kirgizii na Alkaloidonosnost, Akad. Nauk Kirg. SSR, Inst. Organ. Khim. 1965, 57 (Russ) [Chem. Abstr. 64, 11550f (1966)]. 

All these factors are important for the development of plant cell cultures. For example, cultures of Lupinus polyphyllus only synthesize alkaloids when kept in the light and alkaloid content is correlated with chlorophyll content. This may be explained by a better supply of lysine (formed in the chloroplasts), the fact that the enzymes of alkaloid biosynthesis have a pH optimum of about pH 8, which is created in the chloroplast stroma only in the light, and that the enzymes are subject to activation by reduced thioredoxin which is generated only in the light (Wink, 1987). The alkaloids of Peganum harmala, which are formed in the roots of the plant, act in an opposing manner. Cultures maintained in the light fail to produce the alkaloids, whereas those kept in the dark synthesize harman alkaloids (Barz and Hiisemann,... 

Nenaah G (2010) Antibacterial and antifungal activities of (beta)-carboline alkaloids of Peganum harmala (L) seeds and their combination effects. Eitoterapia 81 779-782... 

Liljegren DR (1968) The biosynthesis of quinazoline alkaloids of Peganum harmala L. Phytochemistry 7 1299-1306... 

Liljegren DR (1971) Biosynthesis of quinazoline alkaloids of Peganum harmala. Phytochemistry 10 2661-2669... 

Ross, S. A., Megalla, S. E., Bishay, D. W. and Awad, A. H. 1980. Studies for determining antibiotic substances in some Egyptian plants. Part II. Antimicrobial alkaloids from seeds of Peganum harmala. L. Fitoterapia, 6 309-312. 

Zayed, R. and Wink, M. 2005. Beta-carboline and quinoline alkaloids in root cultures and intact plants of Peganum harmala. Zeitschrift fur Naturforschung C-A Journal of Biosciences, 60(5-6) 451 58. 

There is a little bit of interesting history connected with the melting point of harmaline. A report appeared that described an alkaloid from Peganum harmala... 

But do remember, with the harmaline and harmine content of the seeds of Peganum harmala, you are also accepting an equal weight of quinazoline alkaloids with pharmacological properties that are quite different from those of the carbolines. 

An alkaloid obtained from peganum, the dried seeds of Peganum harmala (Zygophyllaceae). It is also found, together with harmine, in the South American hallucinogenic drink caapi , also known as Yage and ayahuasca . 

In 1888, Hooper first investigated the pharmacological action of an extract of Adhatoda vasica Nees containing compound 184. In 1925, Ghose and Sen isolated this component and named it vasicine. In 1934, Spath and Nikawitz isolated an alkaloid from Peganum harmala and named it pe-ganine, but soon afterward Sp th and Kuffner showed it to be identical with vasicine. This alkaloid (184) was found not only in Adhatoda... 

Khashimov, H.N. etal. 1971. The dynamics of the accumulation of alkaloids in Peganum harmala Chemistry of Natural Compounds 3 364—365. 

Because there is no ethnographic literature on the use of Peganum harmala seeds as an inebriant, it was necessary to conduct self-experiments to establish the active dose and nature of effects. In all experiments ground seeds were extracted twice by boiling 15 minutes in 30% lime juice in water, followed by jSltration. This resulted in efficient extraction of the alkaloids, and it was determined that 15 grams... 

Fig. 12. Transverse section through testa and endosperm of seed of Peganum harmala a epidermis 6 small-celled layer c alkaloid-bearing layer d disintegrated perisperm e endosperm. After Barth (44).

Close examination of Peganum harmala, especially by Soviet scientists, resulted in the discovery and spectral detection of some new quinazoline alkaloids in low yield from different plant parts. Peganidine (44) 116) shows UV absorptions [X-max of 226 (4.04) and 297 (3.96) nm and IR bands at 1350, 1700,... 

E. Merck (Darmstadt), where it was obtained from the mother liquors remaining from the technical preparation of the principal harmala alkaloids. The material from this source, which was named peganine, was investigated by E. Spath and his school (1929-1938) (35), and its identity with vasicine soon became apparent (6, 7). In accordance with custom, the name peganine should therefore be abandoned in favor of the older name recognition of the occurrence of the alkaloid in Peganum harmala is made, however, in the retention of the convenient systematic nomenclature introduced by Sp th (16), which is based on the name pegan for the parent tricyclic system (IV). 

In the course of basic studies in the germination metabolites of Peganum harmala seeds, it was discovered that the alkaloidal constituents are located in the husk and the kernel yields 20% of oil comparable in its constants and constituents to those of cotton seed oil [9]. However, the economic viability of harmal seeds as a new source of edible oil would largely depend on the utilization of alkaloids from the husk which constitutes 50% of the whole seed and contain ca. 7% of the alkaloidal bases. In view of this fact, intensive studies have been undertaken on the chemistry of the two main alkaloids of harmala, namely harmine, harmidine, and their derivatives, and a whole series of new potentially pharmacophoric derivatives of these bases have been prepared [10]. 

Vasicinone (37) is an oxidation product of vasicine. Mehta et al. 136) have found that the crude total alkaloids from Adhatoda vasica contain predominantly vasicine, but that gradual conversion of vasicine to vasicinone takes place during countercurrent distribution and partition chromatography, probably as a result of autooxidation. Pure vasicine similarly undergoes autooxidation to vasicinone. (37) has also been isolated from the seeds 121, 122, 136) and other parts 163, cf. 775) of Peganum harmala as well as Linaria transiliensis 164). The physical properties are as follows uv, max 227, 272, 302 and 315 nm ir, the short wavenumber part of the spectrum contains absorptions at 3115, 2924, 1658, 1454, 1385, 1331, 1291, 1209, 1179, 1104, 1080, 1028, 987, 970, 896, 883, 867, 854, 774, 749, 720, 694 cm H-nmr (CF3COOH), 5 7.3—7.8, aromatic protons 8.05, C8-H 5.56, C3-H 2.64-h2.21, C2-H2 3.92-h4.32, CI-H2. 

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