Extract from balloon flower root (Platycodi radix) containing platycosides as saponins is a beneficial food additive and is used for their savory taste and the alleviation of respiratory diseases. Deglycosylated platycosides show greater pharmacological effects than glycosylated platycosides. However, there are no reports on the conversion of glycosylated platycosides into deapiosylated platycosides. In this study, we showed that the crude enzyme from Rhizopus oryzae, a generally recognized as safe (GRAS) fungus isolated from meju (fermented soybean brick), completely converted glycosylated platycosides in Platycodi radix extract into deapiosylated platycosides: deapiosylated platycodin D (deapi-PD), deapiosylated platycodin A (deapi-PA), deapiosylated polygalacin D (deapi-PGD), and deapiosylated platyconic acid A (deapi-PCA). Among these, deapi-PA and deapi-PCA were first identified using liquid chromatography/mass spectrometry. The anti-inflammatory and antioxidant effects of deapiosylated platycosides were greater than those of the precursor glycosylated platycosides. These deapiosylated platycosides could improve the properties of functional food additives.
-Allose is a potential medical sugar because it has anticancer, antihypertensive, anti-inflammatory, antioxidative, and immunosuppressant activities. Allose production from fructose as a cheap substrate was performed by a one-pot reaction using -allulose 3-epimerase (FP-DAE) and ribose 5-phosphate isomerase (CT-RPI). The optimal reaction conditions for allose production were pH 7.5, 60°C, 0.1 g/l FP-DAE, 12 g/l CT-RPI, and 600 g/l fructose in the presence of 1 mM Co. Under these optimized conditions, FP-DAE and CT-RPI produced 79 g/l allose for 2 h, with a conversion yield of 13%. This is the first biotransformation of fructose to allose by a two-enzyme system. The production of allose by a one-pot reaction using FP-DAE and CT-RPI was 1.3-fold higher than that by a two-step reaction using the two enzymes.
d-Tagatose, a low-calorie functional sweetener, is biotransformed from lactose via galactose. The discovery of an enzyme with 4-epimerization activity toward d-fructose to produce d-tagatose has been a major goal in the sugar industry. However, no enzymes used for the direct production of d-tagatose from d-fructose have been identified until now. Here, we identified a tagaturonate 3-epimerase from Thermotoga petrophila with latent 4-epimerization activity toward d-fructose. We developed this enzyme into tagatose 4-epimerase by increasing the 4-epimerization activity toward d-fructose using structure-based engineering, including favorable interaction analysis and active-site modifications, and random mutagenesis, including saturation mutagenesis and DNA shuffling after error-prone PCR. The developed tagatose 4-epimerase, which showed 184-fold higher 4-epimerization activity toward d-fructose than that of tagaturonate 3-epimerase, produced 213 g/L d-tagatose using d-fructose in 2 h. Our results suggest that the tagatose 4-epimerase is an alternative enzyme for d-tagatose production via a different biocatalytic route.
In the human body, docosahexaenoic acid (DHA) contained in fish oil is converted to trace amounts of specialized pro-resolving mediators (SPMs) as the principal bioactive metabolites for their pharmacological effects. Protectin Dx (PDX), an SPM, is an important medicinal compound with biological activities such as modulation of endogenous antioxidant systems, inflammation pro-resolving action, and inhibition of influenza virus replication. Although it can be biotechnologically synthesized from DHA, it has not yet been produced quantitatively. Here, we found that 15S-lipoxygenase from Burkholderia thailandensis (BT 15SLOX) converted 10S-hydroxydocosahexaenoic acid (10S-HDHA) to PDX using enzymatic reactions, which was confirmed by LC-MS/MS and NMR analyses. Thus, whole-cell reactions of Escherichia coli cells expressing BT 15SLOX were performed in flasks to produce PDX from lipase-treated DHA-enriched fish oil along with E. coli cells expressing Mus musculus (mouse) 8S-lipoxygenase (MO 8SLOX) that converted DHA to 10S-HDHA. First, 1 mM DHA (DHA-enriched fish oil hydrolysate, DFOH) was obtained from 455 mg/L DHA-enriched fish oil by lipase for 1 h. Second, E. coli cells expressing MO 8SLOX converted 1 mM DHA in DFOH to 0.43 mM 10S-HDHA for 6 h. Finally, E. coli cells expressing BT 15SLOX converted 0.43 mM 10S-HDHA in MO 8SLOX-treated DFOH to 0.30 mM (108 mg/L) PDX for 5 h. Consequently, DHA-enriched fish oil at 455 mg/L was converted to 108 mg/L PDX after a total of 12 h (conversion yield: 24% (w/w); productivity: 4.5 mg/L/h). This study is the first report on the quantitative production of PDX via biotechnological approaches.
Platycodon grandiflorus A.DC., known as bellflower or balloon flower, belongs to the genus Platycodon of the family Campanulaceae. It is a perennial herb native to East Asia. Platycodi radix (PR), the root of Platycodon grandiflorum, contains a mixture of different chemical compounds that may act individually, additively, or synergistically to improve human health. The main bioactive compounds of PR are platycodin saponins. PR is eaten as a side dish in Korean cuisine and is also used in desserts, teas, flavored liquors, and as a dietary supplements for the treatment of pulmonary diseases and respiratory disorders such as cough, asthma, bronchitis, cold, sore throat, tonsillitis, tuberculosis, inflammation, and chest congestion [1]. Furthermore, PR has been used as a traditional herbal treatment for hyperlipidemia, hypertension, and diabetes [2]. The root extract is reported to have hepatoprotective [3], anti-inflammatory [3], anti-lipidemic [4], anti-hypercholesterolemic [5], and antiobesity properties [6]. PR extract-derived platycosides are composed of pentacyclic triterpenes with two side sugar moieties. One of the sugars is a β-glucopyranose residue that is linked by a glycosidic bond at C-3 in the triterpenoid structure, whereas the other is an oligosaccharide (apiofuranosyl-xylopyranosyl-rhamnopranosylarabinofuranosyl residue) attached to the ester linkage at C-28.There are three types of saponins, each determined by the type of residue at C-24 in the triterpenoid structure. Platycodigenin-type saponins, one of the three, have a hydroxymethyl group at C-24 (Fig. 1A). Another, polygalacic acid-type saponins, have a methyl group at C-24 (Fig. 1B). The last, platyconic acid-type saponins, have a carboxyl group at C-24 (Fig. 1C). All three types share the same structure except for the residue in C-24, while the differences in functionality depend on the residue of C-24 in the triterpenoid structure.Deglycosylated saponins, obtained through the biotransformation of glycosylated saponins, exert stronger biological effects than their glycosylated forms [7,8]. Glycosylated saponins with more than three sugar residues are poorly absorbed in the intestine, whereas deglycosylated saponins, with less than two sugar residues, function Platycodon grandiflorum (balloon flower) root (Platycodi radix, PR) is used as a health supplement owing to its beneficial bioactive properties. In the present study, the anti-inflammatory, antioxidant, and whitening effects of deglycosylated platycosides (saponins) from PR biotransformed by pectinase from Aspergillus aculeatus were investigated. The bioactivities of the platycosides improved when the number of sugar moieties attached to the aglycone platycosides was decreased. The deglycosylated saponins exhibited higher lipoxygenase inhibitory activities (anti-inflammatory activities) than the precursor platycosides and the anti-inflammatory compound baicalein. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the pectinasetreated PR extract was higher than that of...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.