To develop a new antioxidant, antibacterial and natural cosmetic ingredient\r\nwithout cytotoxicity to skin cells, bioactive molecules contained in Kalanchoe pinnata leaf\r\nmethanolic extract were targeted using semi-preparative HPLC fractionation linked to\r\nbiological activity tests. Chromatographic effluent was collected at the column outlet into\r\na 96 deep-well microplate, filling successively all the wells. After freeze-drying, the\r\nmicroplate was ready to use for different biological tests such as antimicrobial activity on\r\nmicroorganisms, skin cell viability and antioxidant activity on human keratinocyte cells.\r\nThe injection of only 2.64 mg of crude extract into the HPLC system reveals a good\r\ncorrelation between the chromatographic peaks and the different biological activities.\r\nOne fraction is mainly of interest since good antibacterial and antioxidant activities without\r\ncytotoxicity are observed. The analysis of this fraction using mass spectrometry allows the\r\nidentification of glycoside derivatives of quercetin, isorhamnetin and kaempferol. Thus, a\r\ncorrelation between biological activity and the presence of these flavonoids is obtained.\r\nThis screening method allows a rapid fractionation associated with a biological activity\r\nevaluation and a first molecular identification, saving time by limiting sample treatments\r\nand solvent consumption.
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