Subcritical Water Extraction Technique for Selective Extraction of Pentacyclic Triterpenoids from Dry Loquat (Eriobotrya japonica) Leaves
Erasto Mlyuka, Shuang Zhang, Zongping Zheng, Zhiyong He, Maomao Zeng, Martha Mbifile and Jie Chen** Author for corresponding; e-mail address: chenjie@jiangnan.edu.cn
Volume: Vol.44 No.4 (October 2017)
Research Article
DOI:
Received: 18 August 2015, Revised: -, Accepted: 15 November 2015, Published: -
Citation: Mlyuka E., Zhang S., Zheng Z., He Z., Zeng M., Mbifile M., et al., Subcritical Water Extraction Technique for Selective Extraction of Pentacyclic Triterpenoids from Dry Loquat (Eriobotrya japonica) Leaves, Chiang Mai Journal of Science, 2017; 44(4): 1534-1547.
Abstract
Subcritical water extraction (SWE) is a novel alternative to conventional organic solvent extraction method (CE) for isolating corosolic acid (CA) and ursolic acid (UA) from loquat leaves (Eriobotrya japonica). SWE were performed in a subcritical water condition at a system pressure 4-10 MPa with the flow rate 33.33-50.00 mL/min, temperatures 100-250°C, and extraction time 5-90 min. The static mode, dynamic mode and static-dynamic mode for the extraction of CA and UA were optimized separately. LC/MS was employed for the quantification of total pentacyclic triterpenoids (PTTs). The results showed high yields of PTTs (25.02±0.71 mg/g) obtained at SWE conditions of 200°C, 41.67 mL/min and extraction time of 30 min (10 min static mode and 20 min dynamic mode) compared to 4 h extraction with CE (14.39±1.12 mg/g). CA (9.63±0.33 mg/g) and UA (15.04±0.81 mg/g) were the main PTTs obtained from dry loquat leaves at 180°C and 200°C, respectively using static-dynamic mode. Findings from this study suggest that SWE at 150 to 200°C, 10 MPa and 30 to 60 min might be a potential green technology to obtain PTTs from dry loquat leaves.