Improving Aqueous Solubility of Natural Antioxidant Mangiferin through Glycosylation by Maltogenic Amylase from Parageobacillus galactosidasius DSM 18751

Abstract

Mangiferin is a natural antioxidant C-glucosidic xanthone originally isolated from the Mangifera indica (mango) plant. Mangiferin exhibits a wide range of pharmaceutical activities. However, mangiferin’s poor solubility limits its applications. To resolve this limitation of mangiferin, enzymatic glycosylation of mangiferin to produce more soluble mangiferin glucosides was evaluated. Herein, the recombinant maltogenic amylase (MA; E.C. 3.2.1.133) from a thermophile Parageobacillus galactosidasius DSM 18751T (PgMA) was cloned into Escherichia coli BL21 (DE3) via the expression plasmid pET-Duet-1. The recombinant PgMA was purified via Ni2+ affinity chromatography. To evaluate its transglycosylation activity, 17 molecules, including mangiferin (as sugar acceptors), belonging to triterpenoids, saponins, flavonoids, and polyphenol glycosides, were assayed with β-CD (as the sugar donor). The results showed that puerarin and mangiferin are suitable sugar acceptors in the transglycosylation reaction. The glycosylation products from mangiferin by PgMA were isolated using preparative high-performance liquid chromatography. Their chemical structures were glucosyl-α-(1→6)-mangiferin and maltosyl-α-(1→6)-mangiferin, determined by mass and nucleic magnetic resonance spectral analysis. The newly identified maltosyl-α-(1→6)-mangiferin showed 5500-fold higher aqueous solubility than that of mangiferin, and both mangiferin glucosides exhibited similar 1,1-diphenyl-2-picrylhydrazyl free radical scavenging activities compared to mangiferin. PgMA is the first MA with glycosylation activity toward mangiferin, meaning mangiferin glucosides have potential future applications.

Fisetin glycosides synthesized by cyclodextrin glycosyltransferase from Paenibacillus sp. RB01: characterization, molecular docking, and antioxidant activity

“…For example, 6-O-α-rhamnosyl-βglucosidase from Acremonium sp. retained only 57% of initial activity in 30% (v/v) DMSO ( Mazzaferro et al, 2019 ), β-fructosidase from Arthrobacter nicotianae XM6 retained 25% of catalytic activity in 20% (v/v) DMSO ( Wu et al, 2013 ), and maltogenic amylase from Parageobacillus galactosidasius DSM 18751 exhibited less than 50% of initial activity in 30% (v/v) DMSO ( Wu et al, 2021 ). Commonly, cosolvent was used to improve the solubility of flavonoids for enhancing the transglycosylation yield ( Ji et al, 2020 ).…”

Enzymatic Synthesis of Novel and Highly Soluble Puerarin Glucoside by Deinococcus geothermalis Amylosucrase

“…The purification process followed a previously described method [33]. To purify compound (1), the biotransformation reaction was scaled up to 40 mL (1 mL per tube), and the 40-vial reactions were incubated with 180 rpm of shaking at 40 • C for 24 h. After the reaction, compound (1) was purified by a preparative YoungLin HPLC system.…”

Application of Biotransformation-Guided Purification in Chinese Medicine: An Example to Produce Butin from Licorice

“…Recombinant BmTYR was prepared according to a previous study [24]. The recombinant E. coli harboring the recombinant expression plasmid pETDuet-BmTYR was cultivated in Luria-Bertani medium to an optical density at 560 nm (OD 560 ) of 0.6 and then induced with 0.2 mM isopropyl β-D-1-thiogalactopyranoside (IPTG) and 1 mM CuSO 4 .…”

“…The purification process had been previously described [24]. To purify compound (1), the biotransformation reaction containing the F2 fraction extract was scaled up to 100 mL (0.5 mL per tube), and the 200-vials reactions were incubated with 200 rpm of shaking at 50 • C for 1.5 h. After reaction, compound (1) was purified by a preparative YoungLin HPLC system.…”

“…DPPH assay was performed as previously described, with minor modifications [24]. The tested sample (dissolved in DMSO) was added to the DPPH solution (1 mM in methanol) to a final volume of 0.1 mL.…”