Buchi rotavapor r 300

Amaranthus dried and crushed leaf samples (1.5 g) were combined with 30 mL of 80% [v/v] methanol [28 (link),51 ,52 (link)]. Aqueous extract was prepared by combining 1.5 g of sample with 30 mL of water. The extraction was carried out on a Eumax Ultrasonic bath for 1 h at room temperature for both methanol and aqueous extracts. The mixtures were centrifuged at 4000 rpm for 10 min. The supernatants were filtered through a 0.45 µm PTFE membrane filter.
Methanol was evaporated using a rotary evaporator (BUCHI Rotavapor^® R-300, BÜCHI Labortechnik AG, 9230 Flawil, Switzerland). The methanol extract was concentrated using a SpeedVac concentrator (Thermo Scientific™ Savant™ SpeedVac Concentrator SPD121P 115, Waltham, MA, USA).
The collected filtrate of the aqueous extract was frozen overnight at −80 °C and the frozen extract was freeze-dried using a Virtis freeze dryer (SP Scientific, Gardiner, NY, USA). The dried extracts were kept at 4 °C and they were used as crude extracts for analyses of total phenolic content (TPC), total flavonoid content (TFC) and total antioxidant activity (TAC). All extractions were performed in triplicate using independent samples.

Three different plants, Olea europaea leaves, Ficus carcia leaves, and Salvadora persica roots, were washed thoroughly with water, dried in air for 6 days at room temperature, and ground using a blender into a fine powder. A standardized amount (80 g) from each plant powder was placed into a Soxhlet extractor (Carl Roth GmbH + Co. KG, Karlsruhe, Germany) separately and an extraction process was carried out using 250 mL of ethyl alcohol (70%) at 75 °C. The resultant product of each process was then filtered using Whatman filter paper no. 1 and mixed together to prepare an extract mixture. A rotary evaporator (Buchi Rotavapor R-300, Buchi Labor Technik GmbH, Essen, Germany) was used to evaporate the solvent at 37 °C, leaving a concentrated crude mixture that was stored at 4 °C in a glass bottle until usage [58 (link)].