Herein, the extraction of antioxidant compounds from Brazilian orchid tree leaves (Bauhinia forficata Link), also known as “pata-de-vaca” or “pezuña-de-vaca,” is optimized using thermal-assisted solid-liquid extraction. The combination of operational conditions including the temperature (32–74 °C), ethanol percentage (13–97 %), and solid/liquid ratio of leaves and ethanol (1:10–1:60; w/v) was employed using a rotational central composite design. The extracts were evaluated for total phenolic compounds (TPC), total flavonoid compounds (TFC), and antioxidant capacities by the radical monocation reduction of 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺), free radical scavenging activity of 2,2′-diphenyl-β-picrylhydrazyl radical (DPPH), and ferric reducing/antioxidant power (FRAP). The phenolic profile of the optimized extract was also obtained using ultra-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry. The statistically evaluated results revealed that the optimal operational conditions for the recovery of antioxidant compounds from plant leaves included 73.5 °C, 51 % ethanol, and a solid/liquid ratio of 1:40. Under these conditions, the obtained values were 74 milligrams of rutin equivalent per gram of dried material (mg RE/g dm), 45 mg RE/g dm, 128 micromoles of Trolox equivalent per gram of dried material (μmol TE/g dm), 121 μmol TE/g dm, and 380 micromoles of Fe²⁺ per gram of dried material (μmol Fe²⁺/g dm) for TPC, TFC, and ABTS⁺, DPPH, and FRAP assays, respectively. The optimized extract mainly comprised kaempferol and quercetin derivatives, indicating that Bauhinia forficata Link leaves are an important source of antioxidant compounds.

在此，使用热辅助固液萃取法优化了从巴西兰花叶（紫荆花链接）（也称为“ pata-de-vaca”或“pezuña-de-vaca”）中提取抗氧化剂化合物的过程。结合使用操作条件，包括温度（32–74°C），乙醇百分比（13–97％）以及叶片和乙醇的固液比（1：10–1：60； w / v），使用旋转中央复合设计。通过2,2'-叠氮基双-（3-乙基苯并噻唑啉-6-磺酸）（ABTS ⁺）的自由基单阳离子还原，对提取物的总酚类化合物（TPC），总类黄酮化合物（TFC）和抗氧化能力进行了评估， 2,2'-二苯基-β-甲基肼基自由基（DPPH）的自由基清除活性），以及还原铁/抗氧化能力（FRAP）。还使用超高效液相色谱-四极杆/飞行时间质谱仪获得了优化提取物的酚类特征。统计评估的结果表明，从植物叶片中回收抗氧化剂化合物的最佳操作条件包括73.5°C，51％的乙醇和1:40的固/液比。在这些条件下，获得的值为每克干燥材料74毫克芦丁当量（mg RE / g dm），45 mg RE / g dm，128微摩尔Trolox当量每克干燥材料（μmolTE / g dm） ，对于TPC，TFC和ABTS ⁺，DPPH ，每克干燥物料中含121μmolTE / g dm和380微摩尔Fe ²⁺（μmolFe ²⁺ / g dm）和FRAP分析。优化的提取物主要包含山奈酚和槲皮素衍生物，表明紫荆花连叶是抗氧化剂化合物的重要来源。