A quantitative method for fluoride determination using RP HPLC and UV detection was developed. The method is based on the reaction of fluoride with triphenylhydroxysilane in highly acidic conditions and extraction of the reaction product into n-heptane. Chromatographic conditions as well as the derivatization parameters were optimized. LOQ for fluoride ion was evaluated as 0.25 μM (4.75 ppb) and linear range of response up to 75 μM (1.42 ppm) was obtained. The method was developed as a part of a procedure designed for the determination of total organic fluorine in natural waters, using SPE on a carbon sorbent and sodium biphenyl reagent for the defluorination reaction. LOD for a model compound, perfluorooctanoic acid, calculated for the complete procedure with 2000-fold preconcentration, is 20 ppt (n=4). Initial results show feasibility of total organic fluorine determination for environmental purposes.
Chelidonium majus L. is a latex-bearing plant used in traditional folk medicine to treat human papillomavirus (HPV)-caused warts, papillae, and condylomas. Its latex and extracts are rich in many low-molecular compounds and proteins, but there is little or no information on their potential interaction. We describe the isolation and identification of a novel major latex protein (CmMLP1) composed of 147 amino acids and present a model of its structure containing a conserved hydrophobic cavity with high affinity to berberine, 8-hydroxycheleritrine, and dihydroberberine. CmMLP1 and the accompanying three alkaloids were present in the eluted chromatographic fractions of latex. They decreased in vitro viability of human cervical cancer cells (HPV-negative and HPV-positive). We combined, for the first time, research on macromolecular and low-molecular-weight compounds of latex-bearing plants in contrast to other studies that investigated proteins and alkaloids separately. The observed interaction between latex protein and alkaloids may influence our knowledge on plant defense. The proposed toolbox may help in further understanding of plant disease resistance and in pharmacological research.
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