Vasicine and related alkaloids

Vasicine has been found to possess slight anticholinesterase activity 124), and recently it has come into prominence as an uterine stimulant and uterotonic abortifacient, comparable to oxytocin and methergine 80, 232). Some discrepancies in the results of the pharmacological tests of vasicine and related alkaloids and their interpretations need further clarification. The text by Atal (72) is a leading reference on the pharmacology of vasicine. 

Vasicine, a constituent of the Indian shrub Adhatoda vasica (Acanthaceae), possesses the same quinazoline skeleton as febrifugine and related alkaloids described in Section 9.5. A. vasica is used as an antiasthma drug in traditional medicine in India, and bronchodilation activity was observed... 

These five optically inactive alkaloids were isolated in low yields from Anisotes sessiliflorus C. B. Cl. (9). Formulas are listed in Chart 2. Anisotine has also been isolated from Adhatoda vasica (95). The main alkaloid in both species is vasicine and the minor alkaloids are closely related. Their... 

Alkaloid vasicine and structurally related quinazohnes 13MCR1. Amatyllidaceae and Sceletium alkaloids 13NPR849. 

The alkaloid vasicine was first isolated from Adhatoda vasica in 1925 but the structure (996) was elucidated only after a great amount of work, culminating in two independent syntheses in 1935 (B-53MI21301). It was made subsequently by a simple route from 2-aminobenzaldehyde and 4-amino-2-hydroxybutyraldehyde (994) followed by dehydration of the tricyclic intermediate (995) (60TL(25)44>. Vasicine has bronchodilatory activity of a low order. Two related unnamed alkaloids (997) and (998) were obtained in 1965 from members of the Araliaceae family, viz. Mackinlaya subulata and M. macrosciadia both had been synthesized earlier (66AJC151). 

Vasicine was also isolated from the seeds of Peganum harmala (Zygophyl-laceae) [2] consequendy, the same alkaloid is also known as peganine. Two groups reported the total synthesis of d/-vasicine (peganine) [3,4]. The related quinazoline alkaloids, vasicinone and desoxyvasicinone, were also isolated from P. harmala [5]. 

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