An efficient synthesis of O- and N- alkyl derivatives of 4-aminobenzoic acid and evaluation of their anticancer properties

Abstract

A series of twenty alkyl derivatives (2-21) of 4-amino benzoic acid (1, PABA) have been prepared using potassium carbonate and respective alkylating agents under simple and mild reaction conditions. Compounds (16-21) are reported for the first time. Electron impact mass spectrometry (EIMS), fourier transform infrared (FTIR) and Proton nuclear magnetic resonance ( 1 H-NMR) spectroscopic techniques were adopted for the characterization of these analogues. In the present study, the cytotoxic screening of sixteen compounds (3, 5-11, 13, 15-21) was also achieved against lung (NCI-H460) and oral squamous carcinoma (CAL-27) cell lines. Compounds 20 and 21 have shown magnificent inhibitory properties against NCI-H460 cell line (IC50 15.59 and 20.04 µM, respectively) at a lower dose than that of control (cisplatin; IC50 21.00 µM). One-way analysis of variance (ANOVA), t-test and pearson correlation coefficient (PCC) have been performed to determine the reliability of current data through statistical package for the social sciences (SPSS). This is the first report for the evaluation of cytotoxic activity of these compounds. In a nutshell, further investigation on O-and N-alkyl analogues of PABA might be advantageous in the preparation of new and potent antiproliferative agents.

Microwave-assisted synthesis of green fluorescent copper nanoclusters: a novel approach for sensing of hydroxyl radicals and pyrophosphate ions via a “turn-off–on” mechanism

“…The FT-IR data showed the sharp peak at 1632 and 3439 cm −1 with a little shift and decrease in intensity after adding ˙OH in coffee-Tryp-CuNCs, suggesting that the interaction occurs at –CO and –OH functional groups. These results indicate that significant structural changes in coffee-Tryp-CuNCs occurred due to the powerful oxidation ability of ˙OH, which might damage the trypsin by fragmenting its structure 35 or causing the oxidation at C 4 C 5 double bond of caffeine present on the surface of the coffee-Tryp-CuNCs (Fig. S15 of ESI†).…”