Enzymatic synthesis of epothilone A glycosides

Abstract

Epothilones are extremely cytotoxic chemotherapeutic agents with epoxide, thiazole, and ketone groups that share equipotent kinetic similarity with taxol. The in vitro glycosylation catalyzed by uridine diphosphate glucosyltransferase (YjiC) from Bacillus licheniformis generated six novel epothilone A glycoside analouges including epothilone A 7-O-β-D-glucoside, epothilone A 7-O-β-D-galactoside, epothilone A 3,7-O-β-D-digalactoside, epothilone A 7-O-β-D-2-deoxyglucoside, epothilone A 7-O-β-L-rhamnoside, and epothilone A 7-O-β-L-fucoside. Epothilone A 7-O-β-D-glucoside was structurally elucidated by ultra-high performance liquid chromatography-photo diode array (UPLC-PDA) conjugated with high resolution quantitative time-of-flight-electrospray ionization mass spectroscopy (HR-QTOF ESI-MS/MS) supported by one-and two-dimensional nuclear magnetic resonance studies whereas other epothilone A glycosides were characterized by UPLC-PDA and HR-QTOF ESI-MS/MS analyses. The time dependent conversion study of epothilone A to epothilone A 7-O-β-D-glucoside found to be maximum (~26%) between 3 h to 5 h incubation.

Enhanced Production of Nargenicin A1 and Generation of Novel Glycosylated Derivatives

“…Previously, YjiC has been characterized for its promiscuous activity toward various small molecules such as flavonoids [15,40,41] and macrolides [42,43] for multiple glycoside derivatives. This method was successfully applied for efficient glycosylation of these compounds not only with glucose but also with 2-deoxyglucose.…”

Bacillus licheniformis escapes from Myxococcus xanthus predation by deactivating myxovirescin A through enzymatic glucosylation

“…The constructed plasmid was transformed into E. coli BL21 (DE3), and an E. coli BLp28aY transformant was cultured in liquid LB containing 40 mg l –1 Kan at 37°C with shaking at 180 rpm. YjiC was purified as previously reported (Parajuli et al ., ). Briefly, a final concentration of 500 μM IPTG was added when the optical density of the culture at 600 nm reached 0.6–0.8, after which the transformant was grown for 20 h at 18°C.…”

“…The constructed plasmid was transformed into E. coli BL21 (DE3), and an E. coli BLp28aY transformant was cultured in liquid LB containing 40 mg l -1 Kan at 37 C with shaking at 180 rpm. YjiC was purified as previously reported (Parajuli et al, 2014). Briefly, a final concentration of 500 μM IPTG was added when the optical density of the culture at 600 nm reached 0.6-0.8, after which the transformant was grown for 20 h at 18 C. The cell pellets were harvested at 8000 rpm for 5 min and washed twice with lysis buffer (50 mM Tris-HCl and 10% glycerol at pH 7.4) before being resuspended in lysis buffer and lysed by sonication.…”

Anticancer Antibiotics

“…The discovery of epothilones goes back to 1987, when some strains of myxobacterium such as Sorangium cellulosum were found to produce these polyketide macrolide lactones, which possessed antifungal activity (Cheng et al 2008;Demain and Vaishnav 2011;Parajuli et al 2014). Epothilones seem to demonstrate similarities with taxanes in their mechanism of anti-tumor activity as well as their side effects (Fornier 2007).…”

“…Epothilones B and D have served as interesting lead structures in cancer research due to their considerable effects, and also simplicity of their chemical structures (Taylor and Chen 2001). In 2007 ixabepilone (15), a semi synthetic analog of epothilone B, was approved by FDA (Parajuli et al 2014). Furthermore, ixabepilone (ixempra) has been approved for treatment of metastatic and locally advanced breast cancer (Zhang et al 2014).…”