The synthesis of novel amino alcohol derivatives based on cardanol and glycerol were achieved in good yields and characterized by 1 H and 13 C NMR (nuclear magnetic resonance) and MS (mass spectrometry). In addition, we evaluated the in vitro antimicrobial activity against Gram-positive (Staphylococcus aureus, standard and clinical strains), Gram-negative (Escherichia coli) and M. tuberculosis bacterial strains. The bioassay results indicated that four compounds showed activity against S. aureus, including the clinical resistant strain, with MIC (minimum inhibitory concentration) ranging from 3.90 to 15.60 µg mL -1 and M. tuberculosis, with MIC 90 (minimum inhibitory concentration required to inhibit the growth of 90% of organisms) ranging from 3.18 to 7.36 µg mL -1 .Keywords: CNSL, cardanol, amino alcohols, epoxide ring opening, antimicrobial activity
IntroductionThe synthesis of fine chemicals from natural renewable resources has received great interest in synthetic community and is becoming a significant and challenging theme for researchers of both the academic and industrial sectors. Among the renewable materials, cardanol has attracted considerable attention due to its unique nature.1 Cardanol is a low cost, naturally occurring renewable non-isoprenoic phenolic lipid-mixture of cashew nut shell liquid (CNSL). The structural benefits of cardanol are carrying reactive phenolic group and hydrophobic alkyl/alkenyl side chain at meta-position of phenolic group. With these unique structural features, cardanol and its derivatives are renowned amphiphilic building blocks and precursors of high-value fine chemicals and supramolecular structures. Its derivatives present many biological activities such as: fungicidal, bactericidal, molluscicidal, larvicidal, anti-inflammatory, antioxidant and, towards serious disorders like cancer and obesity. [2][3][4][5][6][7][8][9] It is also described in the literature in recent years, that cardanol frameworks are involved to build phenolic resins, 10-12 bio-based polymers, 13 epoxy curing resins, 14-16 reactive diluents, 17,18 and fluorescent compounds. 19,20 Similarly, glycerol is another important renewable material used in the synthesis of higher value-added fine chemicals through green chemistry procedures in the last years. It may be applied, for instance, to generate hydrogen gas, 21 Synthesis, Antibacterial and Antitubercular Evaluation of Cardanol and Glycerol-Based β-Amino Alcohol Derivatives J. Braz. Chem. Soc. 640 Cardanol and glycerol can be starting materials to prepare β-amino alcohols which is a vital interesting class of organic intermediates due to their abundant existence in nature and they are useful in the preparation of wide range of biologically active natural and synthetic frameworks, pharmaceuticals (e.g. β-blockers), unnatural β-amino acids, pesticides and chiral auxiliaries. [29][30][31][32] Additionally, β-amino alcohols have many applications as antibiotics, anti-bacterial drugs and, steroids.33 One of the most classical approaches toward the syn...