This study aimed to study the impact of selected common organic solvents on extractable solids, phytochemical composition, and antioxidant capacity of S. chinensis. The results showed that the tested solvents played an important role in extraction of total solid and phytochemical composition as well as antioxidant capacity of S. chinensis. Acetone (50% v/v) was found to be the optimal extraction solvent for extractable solids (12.2%), phenolic compounds (60 mg GAE/g DW), flavonoids (100 mg CE/g DW), proanthocyanidins (47.4 mg CE/g DW), and saponins (754 mg EE/g DW) as well as antioxidant capacity (ABTS 334 mM TE/g DW, DPPH 470 mM TE/g DW, FRAP 347 mM TE/g DW, and CUPRAC 310 mM TE/g DW). The extract prepared from 50% acetone had high levels of bioactive compounds (TPC 555 mg GAE/g CRE, flavonoids 819 mg CE/g CRE, proanthocyanidins 392 mg CE/g CRE, and saponins 1,880 mg EE/g CRE) as well as antioxidant capacity (ABTS 414 mM TE/g, DPPH 407 mM TE/g, FRAP 320 mg TE/g, and CUPRAC 623 mM TE/g), thus further confirming that 50% acetone is the solvent of choice. Therefore, 50% acetone is recommended for extraction of phenolic compounds, their secondary metabolites, saponins, and antioxidant capacity from the root of S. chinensis for further isolation and utilisation.

Blueberry ash (Elaeocarpus reticulatus Sm.) fruit has potential for human nutrition, but there is limited information on this fruit. This preliminary study aimed to characterise blueberry ash fruit and examine the influence of extraction solvents on its phytochemical and antioxidant properties. Blueberry ash fruit is dark blue in colour and is a stone fruit of small size (7 mm) and light weight (0.2 g). However, it has a high portion of flesh (60% of fruit weight), which is edible and can be a potential source of phytochemicals. Water, ethanol, acetonitrile, acetone, and their combination were tested for extraction of phytochemicals from flesh of this fruit. Water or absolute organic solvent was ineffective for extraction of phenolic compounds from this fruit, but mixtures of water and organic solvents were more effective, and 50% acetone was the most suitable extraction solvent. Extraction with 50% acetone, this fruit was found to contain high levels of total phenolic content, flavonoids, proanthocyanidins, and anthocyanins (104 mg GAE/g, 155 mg RUE/g, 78 mg CE/g, and 119 mg CGE/g, respectively). In addition, this fruit was found to possess potent antioxidant properties. Therefore, this fruit should be further studied for identification of its phenolic compounds and further tested for their biological properties.

Mangiferin has been reported to exhibit anti-viral, anti-cancer, anti-diabetic, immunomodulatory and hepatoprotective properties. This study aimed to develop an HPLC method to isolate mangiferin from Salacia chinensis L. root; investigate the impact of solvents on yield; optimise the ultrasound-assisted extraction (UAE) technique; and compare mangiferin yield with continuously shaking extraction (CSE) and decoction techniques. The results showed that mangiferin, with a purity of over 88%, could be achieved by HPLC using a mixture of solvent A (water: acetonitrile: orthophosphoric acid, 96.8:3:0.2 (v/v/v)) and solvent B (acetonitrile). Solvent type significantly affected the extraction yield of mangiferin, and a mixture of acetone and water gave the highest extraction yield, as compared to other solvents or mixtures. UAE conditions, such as ultrasonic power, temperature, time and concentration of acetone significantly affected the extraction of mangiferin. Optimal UAE conditions were at an ultrasonic power of 250 W, temperature of 50 °C, acetone concentration of 40% and extraction time of 60 min. These optimal conditions could extract approximately 92 mg, whereas CSE and decoction only extracted 89.20 mg and 58.71 mg of mangiferin, respectively, from 1 g of S. chinensis root. Therefore, these UAE conditions are recommended for the extraction of mangiferin from S. chinensis root for further utilisation.