Antimicrobial properties of tannin extracts

Tanini predstavljajo vodotopne polifenole, ki so sposobni obarjanja proteinov iz raztopin, v čemer se razlikujejo od drugih fenolnih spojin. Kemijska sestava taninskih ekstraktov je izredno kompleksna, struktura taninov pa zelo raznolika, kar je vzrok za težko določitev komponent s protimikrobnim učinkom. Naš cilj je bila izolacija posameznih komponent iz kostanjevega ekstrakta. S kolonsko kromatografijo s Sephadex LH-20 smo izolirali vzorca z visoko vsebnostjo kastalagina (KAS71) in z visoko vsebnostjo veskalagina (VES56). Sestavo vzorcev smo okarakterizirali z analitskimi metodami TLC, HPLC, GC in titracijo po Karl Fischerju. Določali smo tudi protimikrobno aktivnost vzorcev Farmatan, mimoza, kvebračo, Colistizer, taninska kislina, galna kislina, VES56 in KAS71 na rast bakterije E. coli. Izmerili smo optično gostoto in jim določili minimalno inhibitorno koncentracijo (MIC) ter odvisnost hitrosti rasti in generacijskega časa od koncentracije taninov.Tannins are water-soluble polyphenols with the ability to precipitate proteins from the solution, which differentiates them from other phenol solutions. The chemical composition of tannins is extremely diverse and therefore, it is hard to determine the exact components with antimicrobial activity. Our goal was to isolate individual components from the chestnut extract. With column chromatography using Sephadex LH-20 we isolated samples with a high content of castalagin (KAS71) and with a high content of vescalagin (VES56). Characterization of the samples was performed using analytical methods HPLC, TLC, GC and Karl Fischer titration. We also determined the antimicrobial activity of samples Farmatan, mimosa, quebracho, Colistizer, tannic acid, gallic acid, VES56 and KAS71 against E. coli. Using optical density we determined the sample\u27s minimal inhibitory concentration (MIC) and dependence of generation time and growth rate from the concentration of tannins