Haplophyton cimicidum alkaloids

The Mexican cockroach plant, Haplophyton cimicidum A.DC. (Apocyanaceae), was first investigated by Snyder and his collaborators, who isolated two insecticidal alkaloids, haplophytine and cimicidine (1-4). Both alkaloids were reported to be toxic to a wide variety of insects, but most of the toxicity of the plant appeared to be owing to the haplophytine content (1). 

Haplophyton cimicidum thus joins the interesting group of plants which produce both the aspidospermine and the biogenetically intimately related eburnamine types of alkaloids. 

Cimicine and cimicidine were reported from Haplophyton cimicidum A. DC. by Cava et al. in 1963 (55), and some of their chemistry has been described earlier in this series (Volume VIII, p. 451). More recently, a paper (59) has appeared on these alkaloids including data leading to the stereoformulas 110 and 111 for cimicine and cimicidine, respectively. 

Cimiciphytine and norcimiciphytine are two minor, lactonic alkaloids isolated from Haplophyton cimicidum. ° Both alkaloids contain an unrearranged canthiphytine unit, since cimiciphytine (269) can be obtained by mild reduction of haplophytine in acid solution (Zn-AcOH), and norcimiciphytine (270) affords... 

Haplophytine (183), (Fig. 8), a polycyclic indole alkaloid, was first isolated by Snyder and coworkers in 1952, and identified as the principle bioactive component of the wild Mexican flower Haplophyton cimicidum A.D.C. (Apocynaceae) [72-77]. Haplophytine is of comparable toxicity to several widely used insecticides, and it was found to be toxic to a wide range of insects including European com borers, Mexican bean beetle larvae, Colorado potato beetle larvae and adults, grasshoppers, egg-plant lace bugs, and codling moths [75]. 

Rogers EF, Snyder HR, Fischer RF (1952) Plant insecticides. II. The alkaloids of Haplophyton cimicidum. J Am Chem Soc 74 1987-1989... 

Scheme 1. The structures of haplophytine (2) and aspidophytine (1), biologically active indole alkaloids obtained from the dried leaves of the plant Haplophyton cimicidum.

An extract of Haplophyton crooksii (Apocynaceae) is said to be an effective poison for such insects as cockroaches, flies, mosquitoes, fleas, and lice (Correll and Johnston, 1970). This plant contains yohimbine and norcimiphytine (Mroue and Alam, 1988). Cimiphytine (42) and norcimiphytine (43) are two minor, lactonic alkaloids isolated from Haplophyton cimicidum (Fig. 34.10) (Specialist Periodic Reports 1981). 

---