A method has been developed for the separation of anthocyanins and anthocyanidins with high performance liquid chromatography (HPLC). Experimental designs were applied for multivariate optimization of the HPLC experimental conditions with using response surface methodology (RSM). Three independent factors, namely formic acid concentration, initial ratio of acetonitrile in gradient program and flow rate, were used to design mathematical models. The responses were resolutions of four peak couples which were the most difficult to separate including: pelargonidin-3-glucoside and delphinidin, delphinidin and peonidin-3-glucoside, peonidin-3-glucoside and malvidin-3-glucoside, peonidin and malvidin. Variance analysis proved a chosen model was highly fit and the RSM method yielded good results in improving separation of anthocyanins and anthocyanidins. The optimized HPLC parameters were as follows: C18 column (250 mm × 4.6 mm × 5 µm), mobile phase is FA 10 % and ACN used as a gradient; flow rate 0.8 mL.min-1. Using these optimum conditions, separation of compounds with good resolutions and a run time of less than 30 min were archived. The results for method validation satisfied the requirement of AOAC, linearity range from 0.2-10 ppm with R 2 ≥ 0.9955, LOD from 0.05-0.1 mg/kg, RSD from 4.79-6.45 % and the recovery is from 85.4-109.6 %. The method was applied to determone anthocyanins and anthocyanidins in some fruits and vegetables samples with the content of anthocyanidins being from 5.74-218.27 mg/100g. Anthocyanins primarily concentrate in peel of fruits and vegetables, black bean peel contains most anthocyanins.
The genetic diversity of five natural populations of milkfish (Chanos chanos) collected in Nghe An, Quang Binh, Binh Dinh, Phu Yen, Khanh Hoa provinces in Vietnam was examined using COI gene sequence analysis. Twelve haplotypes were noted from a total of 50 sequences along with 12 variable sites and 6 parsimony informative sites. The Quang Binh milkfish population had the highest haplotype (0.889 ± 0.060) and nucleotide diversities (0.00301 ± 0.00049). Overall, haplotype and nucleotide diversities were 0.804 ± 0.036 and 0.00212 ± 0.00026, respectively. Genetic differentiation (FST) was high between the milkfish populations of Nghe An – Quang Binh (0.21744) and Nghe An - Phu Yen (0.26215). Haplotype network analysis indicated that milkfish populations shared common haplotypes and each population had its own private haplotypes. Population structure and demographic expansion were not evident for all populations except for Quang Binh. This is the first principal endeavor to understand genetic information of milkfish in Vietnam, thereby providing information for scientists, managers, and the general public to establish timely strategies to explore, protect, and develop milkfish genetic resources in the future.
Alkaloids are among the most important and best-known secondary metabolites as sources of new drugs from medicinal plants and marine organisms. A phytochemical investigation of whole Crinum asiaticum var. sinicum plants resulted in the isolation of seven alkaloids (1–7), including one new compound (1). Their structures were elucidated using NMR and HR-ESI-MS. The absolute configuration of 1 was established by ECD. A molecular docking and molecular dynamics simulation was carried out for the isolated compounds to screen for acetylcholine (AChE) inhibitory activity. The target compounds were evaluated for their inhibitory effects on AChE activity in vitro. The results suggest that these C. asiaticum alkaloids possess the ability to treat Alzheimer’s disease.
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