Haplophyton crooksii

Since oxidized derivatives of secodine appear to be involved as late intermediates in the biosynthesis of the aspidospermidine and pseudoas-pidospermidine alkaloids, it is logical to begin with those secodine derivatives that have been found to occur naturally. Tetrahydrosecodine (1) occurs in the root bark of Aspidosperma marcgravianum Woodson (5) and has been detected in cell-suspension cultures of Rhazya stricta Decaisne (6) its demethoxycarbonyl derivative (2) also occurs in A. marcgravianum (5), and in Haplophyton crooksii L. Benson (7,8) and the roots of R. stricta (9). The two isomeric carbonyl derivatives, 2-ethyl-3-[2-(3-acetyl-V-piperidino)ethyl]indole (3) and crooksidine (4), occur, respectively, in A. marcgravianum (5) and H. crooksii (7,8). 

Crooksidine (4), the alkaloid of Haplophyton crooksii, has been synthesized by two groups of workers. The first of these (272) consists of a very straightforward route in which condensation of 2-ethyltryptamine with methyl 4-formylhexanoate gave the dihydropyridone derivative 425. Reduction followed by oxidation then gave crooksidine (4) (Scheme 3S). 

Ablordeppy SY, Hufford CD, Bourne RF, Dwuma-Badu D (1990) Proton NMR and carbon-13 NMR assignments of cryptolepine, a 3 4-benzo-d-carboline derivative isolated from Cryptolepis sanguinolenta. Planta Med 56 416-417 Alam M, Mroue M (1991) Crooksiine, a bisindole alkaloid from Haplophyton crooksii. Phytochemistry 30 1741-1744... 

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). 

Mroue, M. and M. Alam, Chemical investigation of alkaloids of Haplophyton crooksii, Phytochemical Society of North i mer-ica, Abstracts, Annual Meeting, 1988. 

---