Antimicrobial Activity of Catechol-Containing Biopolymer Poly[3-(3,4-dihydroxyphenyl)glyceric Acid] from Different Medicinal Plants of Boraginaceae Family.

This study reports the antimicrobial activities of the biopolymers poly[3-(3,4-dihydoxyphenyl)glyceric acid] (PDHPGA) and poly[2-methoxycarbonyl-3-(3,4-dihydroxyphenyl)oxirane] (PMDHPO), extracted from the six plants of Boraginaceae family: (), (), and (), (), (), and () collected in various parts of Georgia. The study revealed that the antibacterial activities were moderate, and biopolymers from only three plants showed activities against all tested bacteria. Biopolymers from stems as well as and did not show any activity except low activity against a resistant strain, which was the most resistant among all three resistant strains. On the other hand, the antifungal activity was better compared to the antibacterial activity. Biopolymers from stems exhibited the best activities with MIC/MFC at 0.37-1.00 mg/mL and 0.75-1.5 mg/L, respectively, followed by those from stems. Biopolymers from and roots showed antifungal activities against all six fungi, in contrast to the antibacterial activity, while biopolymers from stems and roots had activities against four fungi and one fungus, respectively. The sugar-based catechol-containing biopolymers from stems demonstrated the best activities among all tested biopolymers against , , , and (MIC 0.37 mg/mL). In addition, biopolymers from stems were half as active against and as ketoconazole. Biopolymers from all plant materials except for stems showed higher potency than ketoconazole against For the first time, it was shown that all plant materials exhibited better activity against , one of the most dreadful fungal species.