title: Modification of emodin and aloe-emodin by glycosylation in engineered Escherihia coli.
abstract: Glycosyltransferase from Bacillus licheniformis DSM13 (YjiC) was used for enzymatic modification of emodin and aloe-emodin in vitro and in vivo. In order to increase the availability of UDP-glucose, three genes involved in the production of precursors of NDP-sugar in Escherichia coli BL21 (DE3) viz. D-glucose phosphate isomerase (pgi), D-glucose-6-phosphate dehydrogenase (zwf), and UDP-sugar hydrolase (ushA) were deleted and glucose-1-phosphate urididyltransferase (galU) gene was over expressed. To improve the yield of the products; substrate, time and media parameters were optimized, and the production was scaled up using a 3 L fermentor. The maximum yield of glycosylated products of emodin (emodin-O-β-D-glucoside) and aloe-emodin (aloe-emodin-O-β-D-glucoside) were approximately 144 µM (38 mg/L) and 168 µM (45 mg/L) respectively, representing almost 72 % and 84 % bioconversion of emodin and aloe-emodin when 200 µM of emodin and aloe-emodin were supplemented in the culture. Additionally, the emodin and aloe emodin major glycosylated products exhibited the highest stability at pH 8.0 and the stability of products was up to 70 °C and 60 °C respectively. Furthermore, the biological activities of emodin and its major glucoside (P1) were compared and their anti-cancer activities were assayed in several cancer cell lines. The results demonstrate that YjiC has the capacity to catalyze the glycosylation of these aromatic compounds and that glycosylation of anthraquinones enhances their aqueous solubility while retaining their biological activities.
authors: Department of BT-Convergent Pharmaceutical Engineering, Institute of Biomolecule Reconstruction, Sun Moon University, 70 Sunmoon-ro 221, Tangjeong-myeon, Asan-si, Chungnam, 336-708, Republic of Korea.
authors: Gopal Prasad
authors: GP
authors: Ghimire
authors: Niranjan
authors: N
authors: Koirala
authors: Ramesh Prasad
authors: RP
authors: Pandey
authors: Hye Jin
authors: HJ
authors: Jung
authors: Jae Kyung
authors: JK
authors: Sohng
mesh_terms: D000504:Aloe / Q000378:metabolism; D000880:Anthraquinones / Q000378:metabolism*; D004642:Emodin / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism*; D006031:Glycosylation; D060847:Metabolic Engineering
chemical_list: D000880:Anthraquinones; C518327:aloe emodin; D004642:Emodin