This work aims to develop a rapid and reliable method by HPLC-QqQ-MS/MS for identification and quantification of Kaurenoic acid (KA) in extract, tincture and syrup from Mikania glomerata. The developed method allows identifying and quantifying KA in complex samples obtained from extract marketed in pharmaceutical industry, a tincture prepared with the leaves from plant and two syrups purchased in the local market. The quantification was performed using standard addition calibration curve. An accurate method for Kaurenoic acid determination in M. glomerata samples was developed. The concentrations of KA found in M. glomerata were 0.19 mg mL-1 in the commercial extract, 0.93 mg mL-1 in the tincture, 3.00 x 10-3 mg mL-1 in the syrup B and in syrup A was not possible to quantify due to the concentration is below the detection limit. Since most reports describe the quantification of the main active constituent (coumarin) and do not provide relevant information on the quantification of KA in these sample types (syrup and tincture), the developed method represents an excellent alternative for agile and efficient analysis of the KA in complex matrices from simple dilution.

In this work, we describe the synthesis of a novel 9-aminoacridine derivative that presents surprisingly different colors when exposed to neutral, acidic or basic mediums with potential application as pH indicator in organic solvents. Furthermore, pKa and molar absorptivity values were determined and theoretical studies supported by density functional theory (DFT) calculations were performed to elucidate the different structures of this compound.