Potencialidades e aplicações biotecnológicas do latex de Himatanthus drasticus (mart.) Plumel

Abstract

Active natural substances can be obtained through folk medicine. Due to the great demand for herbal medicines that are more accessible to the poorest population and the great use of these plants in the northeast region of Brazil for different therapeutic purposes, it is important to check the chemical composition and try to prove the biological effects and pharmacological actions attributed to plants medicines. The objective of this work was to prove the effects of latex and its chemical constituents against the enzymes α-amylase and αglucosidase in addition to the bioinsecticidal potential of the compounds identified in the latex of Himatanthus drasticus. The phytochemical identification of compounds presents in the ethanolic fraction (FHDHA) of H. drasticus latex was made possible by analysis by 1 H, 13C NMR spectroscopy, mass spectrometry and comparison with literature data. The identified compounds were: α-ethyl-glycoside, protocatechuic acid, 3-O-caffeoylquinic acid, 15- demethylplumieride acid, 5-O-caffeoylquinic acid, caffeic acid, vanillic acid, plumieride and catechin. IC50 results obtained from the FHDHA fraction from liquid-liquid fractionation with solvents of increasing polarity, from the ethanolic subfraction FHDHA1 from the separation in SPE C18 eluted with MeOH: H2O (0: 100) and from the plumieride from fractionation in Sephadex column LH-20 of the ethanolic subfraction FHDHA3 eluted with MeOH against the α-amylase enzyme were 36.46, 72.61, 33.87 µg/mL, respectively. These enzymes are involved in the glucose absorption process. The presence of substances that inhibit the α-amylase and αglucosidase enzymes, made it possible to verify bioinsecticidal activity against Callosobruchus maculatus, which is one of the most harmful storage pests of cowpea and other legumes. Results of the FHDHA fraction and the plumieride showed LC50 lethal concentrations very close to FHDHA (0.109%) and plumieride (0.106%), respectively. The FHDHA fraction and the plumieride at a concentration of 0.25%, there was no development of larvae and larval mortality was 100%. Plumieride (major compound) damaged the intestinal cells of the larvae, since no larvae managed to develop in the artificial beans. The results of the bioassays carried out by direct application to the bean seeds of the FHDHA fraction showed a percentage decrease in mass loss and for the samples treated with FHDHA (2.00%) managed to protect the beans from infestation by C. maculatus, which demonstrates its bioinsecticidal action and its biotechnological potential.