Isolation of quaternary benzo[c]phenanthridine alkaloids from Macleaya microcarpa (MAXIM.) FEDDE: comparison of maceration, Soxhlet extraction and pressurised liquid extraction

Application of Central Composite Design-Based Response Surface Methodology in Optimization of the Preparation Process of Sanguinarine Chitosan Microspheres

We designed the present experiment to prepare the sanguinarine chitosan microspheres. First, using the chitosan as a carrier, we prepared sanguinarine microspheres by emulsion cross-linking method, and determined the drug loading and encapsulation efficiency of sanguinarine microspheres by high performance liquid chromatography (HPLC). Then, taking the particle size as the evaluation indicator, we optimized the preparation process by the central composite design-based response surface methodology (CCD-based RSM). Finally, we performed in vitro release test to examine the cumulative release of sanguinarine microspheres. As a result, the optimal process conditions: 0.06 g for sanguinarine dosage, 0.07 g for chitosan dosage, 2% for acetic acid concentration, 3:10 for volume ratio of oil to water, 40 °C for emulsion cross-linking temperature, 500 r/min for rotation speed, and 5% for emulsifier dosage. Under such conditions, the sanguinarine microspheres had round shape, the average particle size was (8.14±0.13) μm, the particle size distribution was 2–20 μm, the drug loading was (4.58±0.93)%, and the encapsulation efficiency was (54.64±0.39)%, the cumulative release within 24 h was (78.34±1.08)%. In conclusion, we successfully prepared the sanguinarine chitosan microspheres, and they have excellent morphology, suitable particle size, and good sustained-release effect.

Phytochemical Constituents and Biological Activities of the Unexplored Plant Rhinanthus angustifolius subsp. grandiflorus

In the present study, a total of 12 extracts of Rhinanthus angustifolius subsp. grandiflorus, an understudied hemiparasitic species, were obtained using different extraction techniques, namely, homogenizer-assisted extraction (HAE), maceration (MAC), soxhlet (SOX), infusion, and solvents (ethyl acetate, methanol, ethanol, and water), and were evaluated for their in vitro antioxidant and enzyme-inhibiting properties. Additionally, untargeted profiling based on high-resolution mass spectrometry targeted different phytochemical classes, namely, polyphenols, terpenoids, and alkaloids. The highest total phenolic and flavonoid contents were detected using methanol as the extraction solvent. Multivariate statistics following the untargeted profiling revealed that the extraction solvent had a hierarchically higher impact than the extraction method when considering the recovery of bioactive compounds. The methanolic extracts displayed the highest radical-scavenging antioxidant capacity, as provided by CUPRAC and FRAP assays. On the other hand, the water extracts (MAC and HAE) and the infusion extract showed the highest activity as metal chelators (25.66–27.51 mg EDTAE/g). Similarly, the water extract obtained by HAE and the infusion extract revealed the highest phosphomolybdenum activity (3.92 ± 0.14 and 3.71 ± 0.01 mmol TE/g, respectively). The different extracts also exhibited different enzyme inhibition potentials. For instance, HAE and MAC ethanolic extracts inhibited only α-amylase (0.69 ± 0.01 and 0.70 ± 0.01 mmol ACAE/g), while all the other extracts showed a dual inhibition against both carbohydrate-hydrolyzing enzymes tested (i.e., α-amylase: 0.07–0.69 mmol ACAE/g; α-glucosidase: 0.03–1.30 mmol ACAE/g). Nevertheless, the other extracts inhibited acetyl-, butyryl-cholinesterases, or both; MAC–water extract displayed no inhibition against the enzymes. Additionally, all the studied extracts were found to inhibit tyrosinase, ranging from 10.62 to 52.80 mg KAE/g. In general, the water extracts showed weaker inhibition towards the enzymes than the other extracts. This study demonstrated that R. angustifolius is an excellent source of natural antioxidants and enzyme inhibitors that could be further investigated and exploited for pharmaceutical purposes.

The impact of chirality on the analysis of alkaloids in plant

Most of the alkaloids are chiral compounds and are clinically administered as the racemic mixture, even though its enantiomers have been known to exert different pharmacological activity. The determination of the enantiomeric composition of alkaloid-containing plants is subject to severe attention from pharmacological and toxicological points of view. This review gives an overview of the chiral analysis of alkaloids that were used in theoretical studies and applications for plants in recent years.

Sediment-water interactions of pharmaceutical residues in the river environment

To assess the environmental fate and risks of pharmaceuticals, the determination of their distributions between sediment and water is crucial as a controlling process. In this paper, the concentrations of 9 selected pharmaceuticals were determined in water and sediment samples from the River Medway, Kent, UK between December 2009 and December 2010. In the water phase, there was a spatial variation of concentration with the highest concentrations being detected in the sewage outfall, indicating it being an important point source in the river. In terms of seasonal variations, the highest concentrations (13-878 ng L(-1)) were detected in June 2010. In the surface sediment phase, the highest concentrations (5.3-33.6 ng g(-1) dry weight) were observed at the sewage outfall, although in February 2010 the highest concentrations were detected downstream of the sewage outfall indicating a delayed response in sediment accumulation of pharmaceuticals in relation to the water phase. The partition coefficient of pharmaceuticals between surface sediment and water was variable, reflecting a dynamic process of sediment-water interaction and the varying nature of sediments. Overall the partition coefficient was shown to decrease with an increase in suspended sediment concentration. The organic carbon normalized partition coefficient of the pharmaceuticals was shown to be positively related to their molecular weight (MW), suggesting that sediment-water interactions were partly a partition process favoring large molecules.