Microwave-assisted extraction of Taxol and 10-Deacetyl baccatin III from the leaves and branches of red pine (Taxus wallichiana Zucc.)

Abstract

Taxol has been by far the most well-known worldwide as an effective anticancer natural drug. With the great treatment abilities at low concentration, Taxol is a considerable interest of many scientists in various fields. The commercial products of Taxol can be isolated directly from Taxus species or can be synthesized from 10-deacetylbaccatin III (10-DAB III) or baccatin III (BC III), which are known as precursors of Taxol, by using semisynthetic methods. In this study, the extraction of Taxol and 10-DAB III from the leaves and branches of red pine cultivated in Lam Dong Province, Vietnam was carried out. Some traditional methods such as Soxhlet, maceration as well as the modern methods such as microwave-assisted extraction (MAE), ultrasonic-assisted extraction (UAE) were used to extract and evaluate the extraction efficiency. The concentration of 10-DAB III experienced at over 90% as compared to maceration and the amount of Taxol accounted for approximately 80% of Soxhlet. MAE was thus more suitable for recovering both Taxol and 10-DAB III than the others because of its short time and less solvent consumption. Besides, four parameters including solvent nature (MeOH and EtOH), extraction time, material/solvent ratio (1:10, 1:15, 1:20 and 1:25) and microwave power (40W, 240W and 440W) were investigated the effects of these elements on the content of 10-DAB III and Taxol. The results illustrated that the optimal conditions providing 95.85% 10-DAB III were as follows: 240W, 1:15 ratio and 20 minutes for extraction. To get the highest amount of Taxol (79.83%), extraction was subjected at these conditions concluding 40W, 1:25 ratio and 20 minutes. Diaion, NP-silicagel were used to enrich taxol and 10-DAB III from methanol extract and chloroform extract, respectively. The highest concentration of Taxol and 10-DAB III constituted at 0.64% and 19.76% with NP-silicagel (PE: aceton, 7:3).