Refined waxy product from the residues of pyrethrins processing: contents, compositions and skin-whitening effects

Pyrethrins is one of the most important botanical insecticides. In recent years, due to the demand for pyrethrins, factories use dried flowers of cultivated pyrethrum as raw materials to produce pyrethrin. During this process, a large amount of wax is produced. In order to avoid resource waste and environmental pollution, better development and utilization of pyrethrum wax is required. Therefore, in this study, refined pyrethrum wax unsaponifiables (RPWU) were prepared from pyrethrum wax wastes by silica gel column chromatography and saponification. The compositions and contents of main components in the RPWU were studied by GC and GC-MS. RPWU contained rich long-chain fatty alcohols, in which eicosanol, docosanol, tetracosanol and hexacosanol were the main components, accounting for 71.3%. In addition, it contained a small amount of odd carbon long-chain fatty alcohols (tricosanol and pentacosanol), accounting for 7.5%, which is very rare in plants. Meanwhile, RPWU showed inhibitory effect on tyrosinase, suggesting that RPWU could have skin-whitening effect. Therefore, RPWU obtained from pyrethrum wax waste has potential bioavailability value, which will promote the development and utilization of pyrethrum wax waste.