The insecticidal constituents of pachyrrhizus erosus urban. I

Abstract

AbstractA review of the literature concerning investigations, chemical as well as insecticidal of the seeds of Pachyrrhizus erosus Urban is given. The fatty‐oil content and the content of material that may be extracted with ether have been determined for a number of samples and recorded in a table. The oil extract varied from 20.0–22.9 per cent, the ether extract from 1.0–2.0 per cent. The latter has been found to be very toxic for caterpillars of the cabbage butterfly. Chemical investigation of the ether extract led to the isolation of several substances, one of which, called pachyrrhizone, had the composition C21H16O7, with a melting point of 248° C and a specific optical rotation in chloroform of − 95°. An oxime was prepared, with a melting point of 269–272°C. One OCH3 group was present. A dehydro compound C21H16O7 was formed by treatment with iodine and sodium acetate, ring‐fission probably taking place. A compound called pachyrrhizonic acid C21H16O11 was obtained by the action of alcoholic potash, a tentative formula for this derivative is given. On oxidation with potassium permanganate a substance C9H10O5, melting point 183–184° C. was formed, to which the constitution of 2‐methoxyhydroquinone‐4‐hydroxy acetic acid was given. The investigation is to be continued.