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For the full development and utilization of Sophora tonkinensis Gagnep., this study was primarily intended to established a simple and efficient approach for the preparative purification of total flavonoids from S. tonkinensis by macroporous resin column chromatography (MRCC). The adsorption and desorption characteristics of the total flavonoids on ten macroporous resins were first studied, and AB-8 resin was chosen as the most suitable, and the adsorption data were best fitted to the pseudo-second-order kinetics model and Langmuir isotherm model. Furthermore, the technological parameters for the purification of the total flavonoids were optimized using column chromatography. After a sample one-step purification procedure, the content of the total flavonoids increased by about 4.76-fold from 12.14% to 57.82%, with a recovery yield of 84.93%. In addition, the comparative analysis of the flavonoid extracts before and after purification was performed by high-performance liquid chromatography coupled with photodiode-array detection (HPLC-PAD). The results showed that the contents of six major flavonoids in the purified product were all higher than before the purification. Therefore, the AB-8 MRCC established in this work was a promising method for the industrial-scale purification of the total flavonoids from S. tonkinensis.

In the present work, the ultrasonic-assisted extraction (UAE) of total flavonoids (TF) from Pteris cretica L. was optimized by response surface methodology (RSM) on the basis of a single-factor experiment. The optimized UAE parameters were as follows: Ethanol concentration 56.74%, extraction time 45.94 min, extraction temperature 74.27 &deg, C, and liquid/solid ratio 33.69 mL/g. Under the optimized conditions, the total flavonoids yield (TFY) was 4.71 &plusmn, 0.04%, which was higher than that obtained by heat reflux extraction (HRE). The extracts were further analyzed by HPLC, and five major flavonoids, including rutin, quercitrin, luteolin, apigenin, and luteolin-7-O-glucoside, were identified and quantified. Furthermore, the results of the antioxidant test showed that the TF extract obtained under optimized UAE conditions exhibited good 2,2-diphenyl-1-picrylhydrazyl radical (DPPH&bull, ) and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS+&bull, ), nitric oxide radical (NO&bull, ) scavenging activities, and ferrous ion (Fe2+) chelating capacity, with IC50 values of 74.49, 82.92, 89.12, and 713.41 &micro, g/mL, respectively. Results indicated that the UAE technique developed in this work was an efficient, rapid, and simple approach for the extraction of flavonoids with antioxidant activity from P. cretica.

The objective of this study was to develop an ultrasonic-assisted procedure for the extraction of total phenolics from Citrus aurantium L. blossoms (CAB) and evaluate the free radical scavenging activity and anti-HMG-CoA reductase activity of the total phenolics. In this work, a Box&ndash, Behnken design based on single-factor experiments was used to explore the optimum extraction process. Under the optimum conditions (extraction solvent 70.31% ethanol, extraction temperature 61.94 &deg, C, extraction time 51.73 min, and liquid-to-solid ratio 35.63 mL/g), the extraction yield of total phenolics was 95.84 mg gallic acid equivalents (GAE)/g dry matter (DM), which was highly consistent with the theoretical value (96.12 mg GAE/g DM). The higher contents of total phenolics and five main phenolic compounds obtained from the optimized ultrasonic-assisted extraction (UAE) proved its efficiency when compared with conventional heat reflux extraction (HRE). The total phenolic extract showed excellent free radical scavenging properties against 1,1-diphenyl-2-picrylhydrazyl radical (DPPH&middot, ), 2,2&prime, azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid) radical (ABTS+&middot, ), hydroxyl radical (&middot, OH) and superoxide anion radical (&middot, O2&minus, ), with IC50 values of 197.007, 83.878, 218.643, and 158.885 &mu, g/mL, respectively, the extracts also showed good inhibition of &beta, hydroxy-&beta, methylglutaryl-CoA reductase (HMG-CoA reductase) activity, with an IC50 value of 117.165 &mu, g/mL. Total phenolics from CAB could be a potential source of natural free radical scavenger and HMG-CoA reductase inhibitor.

A systematic phytochemical investigation of Pteris wallichiana J. Agardh resulted in the isolation of twenty compounds, including five sesquiterpenes (1–5), six flavonoids (6–11), seven phenolic acids (12–18) and two fatty acids (19 and 20). Their structures were deduced from MS, NMR and ORD data. This is the first report of compounds dehydropterosin B (2), (2R,3S)-pterosin C (4), (2R,3R)-pterosin L (5), apigenin (6), luteolin (7), luteolin-7-O-glucoside (10), caffeic acid (13), vanillin (14), 3,4-dihydroxybenzaldehyde (15), chlorogenic acid (17), 3,5-dicaffeoylquinic acid (18), suberic acid (19) and azelaic acid (20) from P. wallichiana and of compounds 15, 19 and 20 from the family Pteridaceae. Furthermore, a chemotaxonomic study of the isolates was performed.

Phytochemical study of Pteris ensiformis Burm. resulted in the isolation of eleven compounds, including three sesquiterpenoids (1–3), one alkaloid (5), one amino acid (6), one flavonoid (7), four phenolic acids (4, 8, 9 and 10), and one coumarin (11). Structures of these compounds were deduced from the ESI-MS and NMR data. This is the first report on the isolation of compounds 1, 2, 7 and 11 from P. ensiformis, compounds 6 and 9 from the genus Pteris, and compound 5 from the family Pteridaceae. In addition, a detailed discussion of the chemotaxonomic significance of these compounds was presented.

Phytochemical study on the roots of Sophora tonkinensis Gagnep. led to the isolation of fifteen compounds, including eleven flavonoids (1–11) and four phenolic acids (12–15). The structures of these compounds were elucidated based on NMR and HR-ESIMS analysis, further supported by comparison with previous literatures. Among them, compounds 2, 3, 4, 6, 9, 12 and 13 were firstly discovered from S. tonkinensis, compound 8 was firstly discovered from the genus Sophora. Furthermore, the chemotaxonomic significance of the obtained compounds was discussed in detail.