Centella asiatica has been known for its significant medicinal properties due to abundance of bioactive constituents like triterpenoids and flavonoids. Nevertheless, an appropriate solvent system and extraction technique is still lacking to ensure optimized extraction of bioactive constituents present in C. asiatica. Recently, scientists are more focused towards application of green sustainable extraction techniques for the valuable components from plant matrix owing to their eco-friendly and safe nature. Among these, ultrasonication (US) is known as a valuable strategy for separation of bioactive components from medicinal plants. Hence, current research was performed to observe the effect of ultrasonication in the presence of five different solvents (Water, Hexane, Methanol, Chloroform, and Ethyl acetate) on total phenolic contents (TPC), total flavonoid contents (TFC), antioxidant properties (DPPH, ABTS, Nitric oxide radical activity, and Superoxide anion assay), and four major triterpenoid contents in C. asiatica leaves. Herein, ultrasound assisted methanolic extract (UAME) possessed maximum amount of TPC (129.54 mg GAE/g), TFC (308.31 mg QE/g), and antioxidant properties (DPPH: 82.21 % & FRAP: 45.98 µmol TE/g) followed by ultrasound-assisted Water extract (UAWE), ultrasound-assisted ethyl acetate extract (UAEAE), ultrasound-assisted n-hexane extract (UAHE), and ultrasound-assisted chloroform extract (UACE), respectively. Moreover, the superoxide radical and nitric oxide assays depicted a similar trend, revealing the highest percent inhibition for UAME (SO: 83.47 % & NO: 66.76 %) however, the lowest inhibition was displayed by UACE (63.22 % & 50.21 %), respectively. Highest content of major terpenoids were found in UAME of C. asiatica leaves as madecassoside (8.21 mg/g) followed by asiaticoside (7.82 mg/g), madecassic acid (4.44 mg/g), and asiatic acid (3.38 mg/g). Ultrasound-assisted extraction technique can be an efficient extraction method for bioactive compounds present in C. asiatica. However, ultrasonication along with methanol as an extraction solvent can surely enhance the extraction of valuable constituents. The results of this study provide an insight into major terpenoids, and antioxidants present in extracts of C. asiatica, implicating its use in ancient medicine systems and future drug development.

中文翻译：

---

超声辅助溶剂萃取积雪草叶中的酚类物质、类黄酮和主要三萜类化合物：一项比较研究


积雪草因其丰富的生物活性成分（如三萜类化合物和类黄酮）而以其重要的药用特性而闻名。然而，仍然缺乏合适的溶剂系统和提取技术来确保对 C. asiatica 中存在的生物活性成分进行最佳提取。最近，由于其环保和安全的特性，科学家们更加关注将绿色可持续提取技术应用于植物基质中的宝贵成分。其中，超声 （US） 被认为是从药用植物中分离生物活性成分的宝贵策略。因此，目前的研究旨在观察在五种不同溶剂（水、己烷、甲醇、氯仿和乙酸乙酯）存在下超声处理对积雪草叶片中总酚含量 （TPC）、总类黄酮含量 （TFC）、抗氧化特性 （DPPH、ABTS、一氧化氮自由基活性和超氧阴离子测定） 和四种主要三萜类化合物含量的影响。在此，超声辅助甲醇提取物（UAME）具有最多的TPC（129.54毫克GAE/g），TFC，308.31毫克QE/g）和抗氧化性能（DPPH：82.21%和FRAP：45.98μmol TE/g），其次是超声波辅助水提取物（UAWE），超声波辅助乙酸乙酯提取物（UAEAE），超声波辅助正己烷提取物（UAHE）和超声波辅助氯仿提取物（UACE）。此外，超氧自由基和一氧化氮测定也呈现出类似的趋势，显示对UAME的抑制百分比最高（SO（83.47%和NO（66.76%），然而，UACE的抑制率最低（分别为63.22%和50.21%）。在 C. asiatica 叶的 UAME 中发现主要萜类化合物含量最高，即羟基积雪草苷 （8.21 mg/g），其次是积雪草苷 （7.82 mg/g）、羟基积雪草酸 （4.44 mg/g） 和积雪草酸 （3.38 mg/g）。超声辅助提取技术可以成为 C. asiatica 中存在的生物活性化合物的有效提取方法。然而，超声处理与甲醇一起作为提取溶剂肯定可以提高对有价值成分的提取。这项研究的结果提供了对积雪草提取物中存在的主要萜类化合物和抗氧化剂的见解，暗示其在古代医学系统和未来药物开发中的应用。