Background: Extraction temperature influences the total phenolic content (TPC), total flavonoid content (TFC) of medicinal plant extracts to a great extend. TPC and TFC are the principle activity constituents present in the plant. The effects of extraction temperature on TPC, TFC and free radical-scavenging capacity of Gynura divaricata leaf extracts are worth to study. Materials and Methods: Folin-Ciocalteu and aluminum chloride colorimetric assay were used to determine the TPC and TFC of Gynura divaricata leaf extracts at different temperatures. The antioxidant and free radical-scavenging activity were measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and phosphomolybdenum methods. Results: TPC and TFC were significantly elevated with increasing extraction temperature (from 40°C to 100°C). However, TPC and TFC were not significantly different (P > 0.05) at the extraction temperatures 90°C and 100°C. Also, the extracts obtained at a higher temperature exhibited a significant free radical-scavenging activity compared with extraction at lower temperatures (P < 0.05). The TPCs (13.95-36.68 mg gallic acid equivalent/g dry material) were highly correlated with DPPH (R² = 0.9229), ABTS (R² = 0.9951) free radical-scavenging capacity, and total antioxidant activity (R² = 0.9872) evaluated by phosphomolybdenum method. Conclusion: The TPC and TFC of G. divaricata leaf was significantly influenced by the extraction temperatures, which were the main antioxidant constituents present in the G. divaricata plant.

Background: Phenolic constituents were the principle bioactivity compounds exist in Gynura divaricata, little phenolic compounds were reported from the plant previously. Materials and Methods: 60% ethanol extract from the leaves of Gynura divaricata were isolated and purified by column chromatography of Silica gel, ODS and Sephadex LH-20, the structures of the isolated compounds were identified by UV, 1H-NMR, 13C-NMR and MS spectroscopic techniques. Additionally, a high-performance liquid chromatography-diode array detector-electrospray ionization-mass (HPLC-DAD-ESI-MS) analytical method was developed to identify some minor constituents in the n-butanol fraction of the ethanol extract of Gynura divaricata. Results: Six flavonols and one Dicaffeoylquinic acid were isolated from the leaves of Gynura divaricata, and these compounds were identified as follows: quercetin (1), kaempferol (2), kaempferol-3-O-β-D-glucopyranoside (3), quercetin-3-O-rutinoside (4), kaempferol-3,7-di-O-β-D-glucopyranoside (5), kaempferol-3-O-rutinoside-7-O-β-D-glucopyranoside (6), and 3,5-dicaffeoylquinic acid (7). A total of 13 compounds, including 9 flavonol glycosides and 4 phenolic acids, were tentatively identified by comparing their retention time (RT), UV, and MS spectrum values with those that had been identified and the published data. Conclusion: This was the first time to use the HPLC-DAD-ESI-MS method to identify the phytochemicals of the genera Gynura. Moreover, compounds (6) and (7) have been isolated for the first time from the genus Gynura.

• Unpetaled pomegranate flowers are usually discarded, rich in resources and valuable for exploitation. • Ultrasound-assisted extraction of active ingredients from pomegranate flowers. • Ultrasound-assisted extraction of active ingredients from pomegranate flowers.

A simple, precise, rapid and accurate, binary-phase high performance liquid chromatographic method has been developed for the determination of oleanolic acid and ursolic acid contents in the Ziziphora clinopodioides Lam. with short run time. Chromatographic separation is achieved by using HPLC system consisting of a Shimadzu LC-6AD and Kromasil C ₁₈ column (150 Χ 4.6 mm, 10 ΅m, with pre-column), the mobile phase consists of methanol and 0.03 M phosphate buffer (pH = 3, 90:10). Detection wavelength is 214 nm. The speed of flow is 0.5 ml/min. The specimen handing quantity is 10 μl. The oleanolic acid's linearity range is 0.4~1.2 mg/ml (r = 0.9996). The ursolic acid's linearity range is 0.6~1.8 mg/ml (r = 0.9996), and the linear relationship is accurate. The average recovery (n = 6) of oleanolic acid is 99.5% (RSD = 1.19%) and ursolic acid is 102.3%(RSD = 1.25%). The content of oleanolic acid and ursolic acid in Ziziphora clinopodioides are 0.76 mg/g and 1.176 mg/g, respectively. The developed HPLC method can therefore be applied to both in vitro studies of oleanolic acid and ursolic acid formulations as well as drug estimation in biological samples.

Objective: This paper investigates the total polyphenolic and flavonoid content as well as the antioxidant activity of Ziziphora clinopodioides Lam. extracts of different polarity. Materials and Methods: The total polyphenolic content was analysed using the Folin-Ciocalteu method. Total flavonoid content analysis was performed using the colorimetric method. Results: The total polyphenolic content of Z. clinopodioides is concentrated in parts of ethyl acetate (19.27%), chloroform (4.99%) and n-butanol extracts (3.94%) containing a small amount of the total polyphenolic content. The petroleum ether (0.23%) and ethanol extracts (1.64%) contain almost no polyphenolic content. The total flavonoid content of Z. clinopodioides is concentrated in parts of ethyl acetate (65.61%), chloroform (14.36%) and n-butanol extracts (10.76%) containing a small amount of the total polyphenolic content. The Z. clinopodioides Lam. ethyl acetate extract exhibits a good antioxidant activity. Conclusion: Ethyl acetate extracts contain a large number of polyphenolic compounds (19.27%) and flavonoids (65.61%) owing to good antioxidant capacity.