https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:29969 Phyllanthus amarus (P. amarus) is a herbal plant used in the treatment of various diseases such as hepatitis, diabetes, and cancer. Efficiency of its bioactive compounds extraction and therefore the biological activity of the extracts are significantly influenced by both solvent character and extraction method. This study is aimed at the determination of the influence of six various solvents (water, acetonitrile, ethanol, methanol, ethyl acetate, and dichloromethane) and nine different extraction methods (conventional, ultrasound-assisted, microwave-assisted, and six novel methods) on the extraction efficiency and antioxidant capacity of P. amarus. The results indicated that water extracted the maximal amount of phenolics from P. amarus and had the highest antioxidant capacity, while microwave-assisted extraction provided the highest yields of phenolics and saponins, and the highest antioxidant capacity with the lowest energy consumption when compared to the other extraction methods. These findings implied that water and microwave-assisted extraction are recommended as the most effective solvent and method for the extraction of bioactive compounds from P. amarus for potential application in the pharmaceutical and nutraceutical industries.]]> Wed 19 Jan 2022 15:19:25 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24691 Phyllanthus amarus is known as a healing herb which has traditionally been used in the treatment of various diseases such as hepatitis, diabetes and cancer. The extraction parameters have great effects on the extraction efficiency of bioactive compounds and pharmacological activity of the extracts. This study sought to optimise the microwave-assisted extraction parameters for phenolic compounds-enriched extracts and antioxidant capacity from P. amarus using response surface methodology (RSM). The results showed that the optimal microwave-assisted extraction parameters were an extraction time of 30 min, an irradiation time of 14 s min⁻¹ and a ratio of solvent to sample of 150 mL g⁻¹. The total phenolic content, phenolic extraction efficiency, saponin content, 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging capacity, 2,2-diphenyl-1-picryl-hydrazil (DPPH) radical scavenging capacity and ferric reducing antioxidant power of the P. amarus achieved under these optimal parameters were 87.3 mg of gallic acid equivalents (GAE) per gram of dried sample, 69.7 %, 134.9 mg of escin equivalents (EE) per gram of dried sample, 997.8, 604.7 and 437.3 all in mg of trolox equivalents (TE) per gram of dried sample, respectively, which were not significantly different from the predicted values (86.9 mg of GAE per gram of dried sample, 67.3 %, 123.5 mg of EE per gram of dried sample, 1013.3 mg of TE per gram of dried sample, 530.6 mg of TE per gram of dried sample and 423.5 mg of TE per gram of dried sample, respectively). Accordingly, the optimal microwave-assisted extraction parameters of 30 min, 14 s min⁻¹ and 150 mL g⁻¹ are recommended for the extraction of enriched phenolics from P. amarus for potential application in the nutraceutical and pharmaceutical industries.]]> Wed 09 Feb 2022 15:54:22 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:52893 Wed 07 Feb 2024 14:23:53 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:34077 Helicteres hirsuta Lour. The results revealed that all the three powdered extracts from the leaves and the stems possessed high levels of phenolics (177.07–241.03 mg GAE g⁻¹), flavonoids (158.03–280.06 mg CE g⁻¹) and saponins (165.77–1035.33 mg ESE g⁻¹) and exhibited strong antioxidant capacity. HPLC analysis identified nine major compounds in the leaf powder crude extract; however, the leaf aqueous fraction had three extra compounds; whereas, the saponin-enriched butanol leaf fraction had seven extra compounds. For the stems, twelve main compounds were evident in either the powdered crude extract or the aqueous fraction, and five new compounds were revealed in the saponin-enriched butanol fraction. The findings revealed that the powdered aqueous fractions and saponin-enriched butanol fractions are potential sources of biologically active compounds for further investigation and industrial utilisation.]]> Wed 06 Feb 2019 14:24:17 AEDT ]]>