Enzymatic Synthesis and Antimicrobial Activity of Oligomer Analogues of Medicinal Biopolymers from Comfrey and Other Species of the Boraginaceae Family

Maia Merlani,Lali Gogilashvili,Dieter M Scheibel,Valentina Catania,Lela Amiranashvili,Vakhtang Barbakadze,Ivan Gitsov,Athina Geronikaki,Domenico Schillaci,Giuseppe Gallo

doi:10.3390/pharmaceutics14010115

Abstract

This study reports the first enzymatic synthesis leading to several oligomer analogues of poly[3-(3,4-dihydroxyphenyl)glyceric acid]. This biopolymer, extracted from plants of the Boraginaceae family has shown a wide spectrum of pharmacological properties, including antimicrobial activity. Enzymatic ring opening polymerization of 2-methoxycarbonyl-3-(3,4-dibenzyloxyphenyl)oxirane (MDBPO) using lipase from Candida rugosa leads to formation of poly[2-methoxycarbonyl-3-(3,4-dibenzyloxyphenyl)oxirane] (PMDBPO), with a degree of polymerization up to 5. Catalytic debenzylation of PMDBPO using H2 on Pd/C yields poly[2-methoxycarbonyl-3-(3,4-dihydroxyphenyl)oxirane] (PMDHPO) without loss in molecular mass. Antibacterial assessment of natural polyethers from different species of Boraginaceae family Symhytum asperum, S. caucasicum, S. grandiflorum, Anchusa italica, Cynoglossum officinale, and synthetic polymers, poly[2-methoxycarbonyl-3-(3,4-dimethoxyphenyl)oxirane (PMDMPO) and PMDHPO, reveals that only the synthetic analogue produced in this study (PMDHPO) exhibits a promising antimicrobial activity against pathogenic strains S.aureus ATCC 25923 and E.coli ATCC 25922 the minimum inhibitory concentration (MIC) being 100 µg/mL.

Highlights

IntroductionSeveral plants from the Boraginaceae family such as Symphytum officinale L
This is the first attempt to produce a synthetic analogue of natural polymer poly[2methoxycarbonyl-3-(3,4-dihydroxyphenyl)oxirane], isolated from the roots and stems of A. italica (AI)
The novelty of the synthetic strategy is that the targeted compound was prepared by enzymatic ROP of methyl 3-(3,4-dibenzyloxyphenyl)glycidate using lipase from C

Summary

Introduction

Several plants from the Boraginaceae family such as Symphytum officinale L. Comfrey was used in traditional medicine for bone breakages, sprains and rheumatism, liver problems, gastritis, ulcers, skin disorders, joint pain and contusions, wounds, gout, hematomas, and thrombophlebitis [1], while A. italica-as stimulant, tonic, demulcent, in bilious complaints, fever, cough, asthma and as diuretic in bladder and kidney stones, as diaphoretic, narcotic, hypnotic, antiarthritis, antirheumatic, and cathartic [4].

Methods

Results

Conclusion