Alstonia constricta

Alstonia constricta F. Muell. Alstonine (chlorogenine), alstonidine,... 

Alstonia constricta F. Muell. (36) alstonine, R. vomitoria (37) aricine, Aspidosperma marcgravianum Woodson (37) reserpiline, R. decurva Hook. (38) isoreserpiline, R. cambodiana Pierre (39), R. decurva, and Ochrosia poweri F. M. Bailey serpentinine, R. vomitoria (37) and R. javanica (34). 

Source Alstonia constricta. Molecular formula C21 H12 N2 O3. Molecular weight 349.44. Biological activity Not confirmed. 

Zeyer s alkaloid was almost certainly an impure sample of the bisbenzylisoquinoline berbamine (1), the principal alkaloid of the plant, but nearly a century went by before it was reisolated from sassafras and its structure fully elucidated (2. Shortly after Zeyer s study, a second alkaloid, alstonine (2), was obtained in an impure form from another Australian plant, Alstonia constricta (Apocynaceae) [3]. This work was also done in Germany, and a similar period elapsed before the complete structure and stereochemistry of alstonine were established [4,443],... 

In a study23 of the minor alkaloids of Alstonia constricta the structure (13) for alstonidine was confirmed and the stereochemistry deduced from a detailed n.m.r. examination. The absence of a complex overlapping pattern for aliphatic hydrogens in such / -carbolines facilitates a complete analysis (see ref. la and below). This study also showed vincamajine, 17-0-(3,4,5-trimethoxycinnamoyl)-vincamajine, 17-0-(3,4,5-trimethoxybenzoyl)quebrachidine, and alstonilidine (14) to be present. The structure of the last was again susceptible to n.m.r. analysis... 

The mixed sulfates of the alkaloids of Alstonia constricta F. Mnoll resemble the cinchona alkaloids in many of their pharmacological actions. Oxytocic activity has been reported by both Sharp (171) and Keogh and Shaw (172). On the isolated uterus of the rat and guinea pig, both a stimulant and depressant action was observed, but the effect was always similar to that of quinine on any one particular preparation. Powerful contraction of the cat uterus in situ was produced by doses of 20.0 mg. administered intravenously. 

International free name for methyl 18-0-(3,4,5-tri-methoxybenzoyO-reserpate, Cj3H4 209> Mr 608.69 prismatic, cryst., decomp, at 265 C, soluble in chloroform, poorly soluble in water, LD50 (mouse i.v.) 20 mg/kg (dog i. v.) 0.5 mg/kg (rat p.o.) 420 mg/kg. R. is a Rauvolfia alkaloid ( indole alkaloids, mono-terpenoid indole alkaloids) from the roots of the Indian Rauvolfia serpentina, the Mexican R. heterophylla, and the Australian Alstonia constricta. 

Some Australian native plants had been associated with the treatment and/or prevention of mosquito-borne disease. There have been suggestions that the bark of tropical rainforest tree Alstonia scholaris (L.) R. Br. (dita bark) has been used as an antimalarial, but clinical trials have shown that alkaloids in the bark of this, and the closely related species Alstonia constricta F. Muell. (bit-terbark), have little antimalarial activity. Eucalyptus globulus Labill (Tasmanian blue gum) had sometimes been referred to as fever prevention tree with a belief that the use of the oil prevented malaria. Similarly, many anecdotal reports of Melaleuca quinquenervia (Cav.) S. T. Blake (broadleaved paperbark) may prevent disease by repelling mosquitoes. Unfortunately, there is no current evidence that Australian native plants provide a suitable treatment for malaria. ... 

---