Antibacterial potential of the Cistus incanus L. phenolics as studied with use of thin-layer chromatography combined with direct bioautography and in situ hydrolysis.

摘要: The main aim of this study was to detect and identify antibacterial components fraction I derived from eleven commercial C. incanus herbal teas. Fraction obtained by a well-established phytochemical protocol multi-step extraction expected contain flavonoid aglycons alone. Antibacterial profile demonstrated means thin-layer chromatography - direct bioautography (TLC-DB) using Gram positive B. subtilis negative A. fischeri strain. Six chromatographic zones exhibited well pronounced potential. In qualitative terms, good agreement observed among fingerprints the corresponding bioautograms samples. compounds isolated six were analyzed HPLC- diode array detector (DAD)-electrospray ionization (ESI)-MS. High numerical m/z values valid for certain constituents these isolates suggested that some selected are, unexpectedly, glycosides. order confirm suggestion, three independent HPTLC methods (multi-development on amino phase two two-dimensional developments silica gel phase) devised in situ hydrolyze glycosides then separate visualize liberated glucose other building blocks zones' components. Additionally, sensitivity detection with p-aminobenzoic acid reagent enhanced paraffin. way, presence kaempferol (and not only aglycones alone) confirmed. Beside kaempferol, p-coumaric as block unit shown HPLC-DAD-MS analysis hydrolyzed isolates. Results proved apigenin, kaempferide acylated (cis- trans-tiliroside their conjugates acid) be I. Because isomers coumaric conjugated tiliroside detected crude extract, they are regarded artifacts produced through fractionation.