Enhanced Production of Nargenicin A1 and Generation of Novel Glycosylated Derivatives

Abstract

Nargenicin A1, an antibacterial polyketide macrolide produced by Nocardia sp. CS682, was enhanced by increasing the pool of precursors using different sources. Furthermore, by using engineered strain Nocardia sp. ACC18 and supplementation of glucose and glycerol, enhancement was ~7.1 fold in comparison to Nocardia sp. CS682 without supplementation of any precursors. The overproduced compound was validated by mass spectrometry and nuclear magnetic resonance analyses. The novel glycosylated derivatives of purified nargenicin A1 were generated by efficient one-pot reaction systems in which the syntheses of uridine diphosphate (UDP)-α-D-glucose and UDP-α-D-2-deoxyglucose were modified and combined with glycosyltransferase (GT) from Bacillus licheniformis. Nargenicin A1 11-O-β- D-glucopyranoside, nargenicin A1 18-O-β-D-glucopyranoside, nargenicin A111 18-O-β-D- diglucopyranoside, and nargenicin 11-O-β-D-2-deoxyglucopyranoside were generated. Nargenicin A1 11-O-β-D-glucopyranoside was structurally elucidated by ultra-high performance liquid chromatography-photodiode 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 nargenicin A1 glycosides were characterized by UPLC-PDA and HR-QTOF ESI-MS/MS analyses. The overall conversion studies indicated that the one-pot synthesis system is a highly efficient strategy for production of glycosylated derivatives of compounds like macrolides as well. Furthermore, assessment of solubility indicated that there was enhanced solubility in the case of glycoside, although a substantial increase in activity was not observed.

Synthesis of Curcumin Glycosides with Enhanced Anticancer Properties Using One-Pot Multienzyme Glycosylation Technique

“…The analyses of OPME reactions with curcumin revealed that the formation of monoglycosides was favored at higher concentration of substrate, whereas the lower concentration of substrate was favorable for diglycosides. These OPME systems have proven their efficiency by successful glycosylation of α-mangostin [28] and nargenicin A(1) [31].…”

“…The one-pot multienzyme (OPME) approaches are often employed for the synthesis of diverse kinds of glycoconjugates. Our group has successfully developed and applied the efficient OPME systems for the synthesis of glycosides of α-mangostin [28], nargenicin A(1) [31], and resvera-A [32]. Such methods are more efficient and cheaper than the chemical methods, which involve several protection/deprotection steps before any product can be obtained.…”

Herboxidiene biosynthesis, production, and structural modifications: prospect for hybrids with related polyketide

“…Similarly, heterologous expression of acetyl-CoA carboxylase complex from S. coelicolor A3 (2) in Nocardia sp. CS682 resulted in a substantial increase in the pool of malonyl-CoA (Maharjan et al 2012), and subsequent feeding led to the enhancement of nargenicin A1 Dhakal et al 2015). With herboxidiene, the introduction of an expression cassette containing the ACC complex from S. coelicolor A3 (2) in a pSET152 vector (Bierman et al 1992) reduced the herboxidiene yield.…”

“…The heterologous expression of the metK1-sp gene from S. peucetius enhanced the production of pikromycin from S. venezuelae (Maharjan et al 2008) and that of Nargenicin A1 from Nocardia sp. CS682 Dhakal et al 2015). In herboxidiene, the polyketide is decorated with a methyl ester at 25-OH (Fig.…”

Coalition of Biology and Chemistry for Ameliorating Antimicrobial Drug Discovery

“…While NPs exhibit a wide range of pharmacophores and a high degree of stereochemistry (Harvey et al, 2015), novel NPs with better activities still need to be developed. Versatile biological knowledge based synthetic-biology approaches, system-biology guided metabolic engineering techniques, enzymatic modifications, and synthetic chemistry methods can be utilized to maximize the benefit of NPs from the source organism (Dhakal et al, 2015, 2016). Thus, the optimum application of NPs can only be improved with considerable effort based on precise screening, higher production, and desirable structural diversification (Dhakal and Sohng, 2015).…”