Effect of Some Natural Uv-Absorbers on the Photostabilization of Active Ingredients in German Chamomille Floral Extracts: Part I

Abstract

The effect of some natural UV absorbers on the photostabilization of spiroketal enol ethers (en-yn-dicycloethers) present in German Chamomille extracts precoated on glass plates (solid phase) was examined. Plates were exposed to sunlight radiation from a UV-sun radiation lamp, in the presence and absence of gallic acid, cinnamic acid, caffeic acid, ferulic acid and aloin, all natural UV absorbers. At particular intervals the remaining concentration of the en-yn-dicycloethers was analyzed by HPLC. Using first-order kinetic equation, the dissipation half-life values (DT 50 ) for the degradation of the en-yn-dicycloethers under UV-sun radiation were obtained. The results showed that the addition of cumaric acid and caffeic acid provided moderate degree of photostabilization of the en-yndicycloethers and that addition of ferulic acid provided the best photostabilization among the UV absorbers studied. Photostabilization effect appears to be due to a competitive energy absorption of UV photons by the absorber molecules.

Chitosan‐hydroxycinnamic acid conjugates: Synthesis, photostability and phytotoxicity to seed germination of barley

“…Most of the secondary metabolites of plants with a great potential for use as the basis of eco‐friendly products for horticulture from biopesticides and insecticides to stimulants and growth regulators are highly photolabile 34,35 . A lot of attention is certainly paid to compounds with a photosensitizing toxic effect as a basis for plant pesticides.…”

The influence of after-treatments on dyeability of raw and bleached cotton with curcumin, and visibility of anthotype produced motifs

“…Vzorce smo osvetljevali 14 ur pri oddaljenosti žar-nice od vzorca 50 cm. Ena ura obsevanja z žarnico ustreza 16-urni izpostavljenosti neposredni sončni svetlobi [15].…”

“…Glede na način ustvarjanja motivov s tehniko antotipije na tekstilu lahko predvidevamo, da bo le-ta s časoma zbledela. Trajnost motivov se lahko podaljša ob primernem shranjevanju in z uporabo UV-absorberja, ki zašči-ti pred fotodegradacijo [15]. …”

Evaluation of the Effect of Refined Extracts of <i>Matricaria recutita L</i> and <i>Chrysanthemum coronarium L</i>, Proposed as Bio-Pesticides for Agricultural Use, Determining the Variation of Biomarkers of Oxidative and Hepatotoxic Stress in Acutely Exposed Rats

“…On the basis of the above, the insecticidal properties of hexanic extracts of flowers of M. recutita and C. coronarium have been studied in search of new alternatives such as biopesticides. In addition, experimental studies of their toxicity, induced by Chrysanthemum coronarium extract against house flies and red spider mites, points to sub-lethal and lethal effects of both, in addition to anti-feeding behavior [13]. Research has also been performed on lethal toxic effects of chamomile against Tetranychus urticae Koch, with extract obtained by Soxhlet extraction, where this extract and its purified fraction showed, like C. coronarium extracts, both lethal and sublethal effects [14].…”