No abstract

This paper describes the synthesis of novel molecularly imprinted polymers (MIPs), prepared by a noncovalent imprinting approach, for cleanup and preconcentration of curcumin (CUR) and bisdemethoxycurcumin (BDMC) from medicinal herbal extracts and further analysis by high-performance liquid chromatography with fluorescence detection (HPLC-FLD). Two molecular mimics, a mixture of reduced BDMCs and 4-(4-hydroxyphenyl)-2-butanone (HPB), have been synthesized and applied as templates for MIP synthesis. The polymers were prepared using N-(2-aminoethyl) methacrylamide (EAMA) as functional monomer, ethylene glycol dimethacrylate (EDMA) as the cross-linker (in a 1:5 molar ratio), and a mixture of acetonitrile/dimethylsulfoxide (90%, v/v) as porogen. MIPs prepared using a mixture of reduced BDMCs as template showed higher selectivity for CUR and BDMC than those obtained with HPB, with imprinting factors of 3.5 and 2.7 for CUR and BDMC, respectively, using H2O/acetonitrile (65:35, v/v) as mobile phase. The adsorption isotherms for CUR in the MIP and the nonimprinted polymer (NIP) were fitted to the Freundlich isotherm model, and the calculated average binding affinities for CUR were (17 ± 2) and (8 ± 1) mM(-1) for the MIP and the NIP, respectively. The polymers were packed into solid-phase extraction (SPE) cartridges, and the optimized molecularly imprinted solid-phase extraction (MISPE-HPLC) with fluorescence detection (FLD) method allowed the extraction of both curcuminoids from aqueous samples (50 mM NH4Ac, pH 8.8) followed by a selective washing with acetonitrile/NH4Ac, 50 mM at pH 8.8 (30:70%, v/v), and elution with 3 × 1 mL of MeOH. Good recoveries and precision ranging between 87 and 92%, with relative standard deviation (RSD) of <5.3% (n = 3), were obtained after the preconcentration of 10-mL solutions containing both CUR and BDMC at concentrations in the range of 0-500 μg L(-1). The optimized method has been applied to the analysis of both curcuminoids in medicinal herbal extracts.

Objective: Andrographis paniculata, widely used as an antidiabetic in Indonesian traditional medicines (jamu), contains chemical compounds whose concentration is related to its therapeutic effects. The concentration of solvents used for extraction will also affect the number of compounds extracted. Therefore, a quality control method is needed to ensure consistency in quantifying these compounds in A. paniculata to improve its therapeutic application. High-performance liquid chromatography fingerprint analysis combined with chemometrics was used to evaluate extracts from different solvent extraction treatments. The content of andrographolide, the main bioactive compound in A. paniculata, and the level of α-glucosidase inhibition activity, an indicator of its antidiabetic activity, were also determined. Results: Fingerprint chromatograms of A. paniculata extracts from different treatments exhibited a similar pattern with several peaks in common, only differing in area and intensity value. The A. paniculata extracts were classified using HPLC fingerprint and principal component analysis to allow grouping according to their respective solvent extraction treatments. The highest andrographolide content and α-glucosidase inhibition activity occurred in the 50% ethanol extract and the lowest in the water extract. HPLC fingerprint analysis could be used for identifying A. paniculata extracts based on solvent extraction, thus improving quality control for their therapeutic application.

Andrographis paniculata is known as the king of bitter and it has been widely used as a medicinal plant. The properties of A. paniculata are generally determined by the metabolite composition, which may be influenced by several factors, one of which is the part of the plant extracted. The objectives of this research are to identify putatively the metabolite composition of the stem and the leaves extracts using LC-MS/MS and classify them using PCA. The stem and the leaves samples were separated and extracted using sonication with 70% ethanol. A total of 31 metabolite compounds has been putatively identified. All compounds were identified in the stem and the leaves extracts, which only differed in their intensity. These metabolite compounds were divided into diterpene lactones, flavonoids, and phenolic acid groups. By using the peak intensities of the 18 compounds identified, the leaves and stem extracts were grouped using PCA.