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1.
Curr Res Food Sci ; 8: 100777, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38840809

RESUMO

The novel ß-glucosidase gene (pgbgl1) of glycoside hydrolase (GH) family 1 from the psychrotrophic bacterium Psychrobacillus glaciei sp. PB01 was successfully expressed in Escherichia coli BL21 (DE3). The deduced PgBgl1 contained 447 amino acid residues with a calculated molecular mass of 51.4 kDa. PgBgl1 showed its maximum activity at pH 7.0 and 40 °C, and still retained over 10% activity at 0 °C, suggesting that the recombinant PgBgl1 is a cold-adapted enzyme. The substrate specificity, Km, Vmax, and Kcat/Km for the p-Nitrophenyl-ß-D-glucopyranoside (pNPG) as the substrate were 1063.89 U/mg, 0.36 mM, 1208.31 U/mg and 3871.92/s, respectively. Furthermore, PgBgl1 demonstrated remarkable stimulation of monosaccharides such as glucose, xylose, and galactose, as well as NaCl. PgBgl1 also demonstrated a high capacity to convert the primary soybean isoflavone glycosides (daidzin, genistin, and glycitin) into their respective aglycones. Overall, PgBgl1 exhibited high catalytic activity towards aryl glycosides, suggesting promising application prospects in the food, animal feed, and pharmaceutical industries.

2.
Front Pharmacol ; 15: 1339153, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38841368

RESUMO

Treatment of glomerulonephritis presents several challenges, including limited therapeutic options, high costs, and potential adverse reactions. As a recognized Chinese patent medicine, Tripterygium wilfordii poly-glycosides (TWP) have shown promising benefits in managing autoimmune diseases. To evaluate clinical effectiveness and safety of TWP in treating glomerulonephritis, we systematically searched PubMed, Cochrane Library, Web of Science, and Embase databases for controlled studies published up to 12 July 2023. We employed weighted mean difference and relative risk to analyze continuous and dichotomous outcomes. This meta-analysis included 16 studies that included primary membranous nephropathy (PMN), type 2 diabetic kidney disease (DKD), and Henoch-Schönlein purpura nephritis (HSPN). Analysis revealed that additional TWP administration improved patients' outcomes and total remission rates, reduced 24-h urine protein (24hUP) and decreased relapse events. The pooled results demonstrated the non-inferiority of TWP to glucocorticoids in achieving total remission, reducing 24hUP, and converting the phospholipase A2 receptor (PLA2R) status to negative. For DKD patients, TWP effectively reduced 24hUP levels, although it did not significantly improve the estimated glomerular filtration rate (eGFR). Compared to valsartan, TWP showed comparable improvements in 24hUP and eGFR levels. In severe cases of HSPN in children, significant clinical remission and a reduction in 24hUP levels were observed with the addition of TWP treatment. TWP did not significantly increase the incidence of adverse reactions. Therefore, TWP could offer therapeutic benefits to patients with PMN, DKD, and severe HSPN, with a minimal increase in the risk of side effects.

3.
Phytochemistry ; 224: 114169, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38825030

RESUMO

Continued interest in the bioactive alkaloids led to the isolation of five undescribed alkaloids (1-5), ophiorglucidines A-E, and seven known analogues (6-12) from the water-soluble fraction of Ophiorrhiza japonica. The structures were elucidated based on spectroscopic data and quantum calculations as well as X-ray crystallographic analysis. The structure of 1 was characterized as a hexacyclic skeleton including a double bridge linking the indole and the monoterpene moieties, which is the first report of a single crystal with this type of structure. Moreover, the inhibitory effect of zwitterionic indole alkaloid glycosides on xanthine oxidase was found for the first time. The alkaloids 2 and 3, both of which have a pentacyclic zwitterionic system, were more active than the reference inhibitor, allopurinol (IC50 = 11.1 µM) with IC50 values of 1.0 µM, and 2.5 µM, respectively. Structure-activity relationships analyses confirmed that the carbonyl group at C-14 was a key functional group responsible for the inhibitory effects of these alkaloids.

4.
Angew Chem Int Ed Engl ; : e202409004, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38837495

RESUMO

Previous N-glycosylation approaches have predominately involved acidic conditions, facing challenges of low stereoselectivity and limited scope. Herein, we introduce a radical activation strategy that enables versatile and stereoselective N-glycosylation using readily accessible glycosyl sulfinate as a donor under basic conditions and exhibits exceptional tolerance towards various N-aglycones containing alkyl, aryl, heteroaryl and nucleobase functionalities. Preliminary mechanistic studies indicate a pivotal role of iodide, which orchestrates the formation of a glycosyl radical from the glycosyl sulfinate and subsequent generation of the key intermediate, a configurationally well-defined glycosyl iodide, which is subsequently attacked by an N-aglycone in a stereospecific SN2 manner to give the desired N-glycosides. An alternative route involving the coupling of a glycosyl radical and a nitrogen-centered radical is also proposed, affording the exclusive 1,2-trans product. This novel approach promises to broaden the synthetic landscape of N-glycosides, offering a powerful tool for the construction of complex glycosidic structures under mild conditions.

5.
Fitoterapia ; : 106049, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38838827

RESUMO

Three undescribed seco-iridoid glycosides, one undescribed flavonoid glycoside, and three known glycosides were isolated and identified from Gentiana olivieri Griseb. The structures of these compounds were determined through spectroscopic analysis and ECD calculations. Olivierisecosides NP (1-3) were identified as aromatic conjugated seco-iridoid glucosides, among them olivierisecoside N was representing a particularly rare subtype known as the morroniside seco-iridoids. The compounds 2, 3, 5, and 6 exhibited significant inhibition of COX-2 expression, particularly compound 5 which demonstrated the most pronounced inhibitory activity with IC50 value of 23.33 ±â€¯0.51 µM. This study provides evidence for the potential development and utilization of G. olivieri as a source of anti-inflammatory components.

6.
Nat Prod Res ; : 1-11, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38832521

RESUMO

Three undescribed compounds including two furosteroid glycosides (perfoloside and 22-O-methylperfoloside) and one stilbenedimer (perfolostilbene) together with 21 known compounds were isolated from the roots of Smilax perfoliata. The structural elucidation was established by extensive uses of HRMS, 1D and 2D spectroscopic techniques. The assignment of the stereocenters in perfolostilbene was based on NOESY data and ECD calculation. Among the isolates, two compounds showed marginal cytotoxic activity against KB and Hela cell lines while seven stilbenoids showed strong to weak antiacetylcholinesterase and antibutyrylcholinesterase activities with IC50 ranging between 2-197 µM.

7.
Nat Prod Res ; : 1-9, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38770927

RESUMO

The Marsdenia tenacissima, has been used as traditional Chinese medicine for six hundred years. Our chemical investigation on the stem of Marsdenia tenacissima led to the isolation of one new pregnane glycoside, namely, marsdeoside J (compound 1) and twelve known compounds. The structure of the new compound was elucidated by spectroscopic analysis including 1D and 2D NMR, HRESIMS, IR, and UV. The absolute configurations of the sugar moiety were identified by comparing the specific optical rotations and Rf values with those of the commercially available standards and the data reported in the literature. Compound 1 showed cytotoxicities against five human cancer cell lines, with IC50 values ranging from 6.5 to 18.1 µM and certain inhibitory activities on NO production.

8.
Antioxidants (Basel) ; 13(5)2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38790637

RESUMO

Apart from being utilized as a commercial fiber at maturity, kenaf shoots have potential as a food and feed source because of their diverse bioactivities. Previous studies have focused on mature stems because of their high biomass, whereas the antioxidant activities (AA) and the destination of AA contributors of kenaf stems and their high-yielding byproduct leaves during the growth stage have rarely been studied. Therefore, we investigated changes in AA and its relative components in kenaf leaves and stems during the four vital growth stages. Higher ABTS radical cation and DPPH radical scavenging abilities and ferric reducing antioxidant power, total phenolic content, total flavonoid content, and total polysaccharide content were observed at all leaf stages and in the late stem stages. Chlorogenic acid (CGA) and kaempferol glycosides, especially kaempferitrin (Kfr), were identified as representative phenolic acids and flavonoids in both kenaf leaves and stems. The content of CGA in both leaves and stems increased corresponding to the plant's growth stage, whereas kaempferol glycosides were enhanced in leaves but declined in stems. The highest correlation was observed between TPC and AA in all organs. Further evaluation of CGA and Kfr verified that CGA was the predominant contributor to AA, surpassing Kfr. These findings suggest that kenaf leaves increase antioxidant levels as they grow and can be a useful source of stem harvesting byproducts.

9.
ACS Synth Biol ; 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38820348

RESUMO

Glycosylation is a ubiquitous modification present across all of biology, affecting many things such as physicochemical properties, cellular recognition, subcellular localization, and immunogenicity. Nucleotide sugars are important precursors needed to study glycosylation and produce glycosylated products. Saccharomyces cerevisiae is a potentially powerful platform for producing glycosylated biomolecules, but it lacks nucleotide sugar diversity. Nucleotide sugar metabolism is complex, and understanding how to engineer it will be necessary to both access and study heterologous glycosylations found across biology. This review overviews the potential challenges with engineering nucleotide sugar metabolism in yeast from the salvage pathways that convert free sugars to their associated UDP-sugars to de novo synthesis where nucleotide sugars are interconverted through a complex metabolic network with governing feedback mechanisms. Finally, recent examples of engineering complex glycosylation of small molecules in S. cerevisiae are explored and assessed.

10.
Carbohydr Res ; 541: 109164, 2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38815342

RESUMO

Stereoselective synthesis is essential for propelling mainstream academia toward a relentless pursuit of novel and cutting-edge strategies for constructing molecules with unparalleled precision. Naturally derived benzopyrans, benzopyrones, and flavonoids are an essentially prominent group of oxa-heterocycles, highly significant targets in medicinal chemistry owing to their extensive abundance in biologically active natural products and pharmaceuticals. The molecular complexity and stereoselectivity induced by heterocycles embedded with C-glycosides have attracted considerable interest and emerged as a fascinating area of research for synthetic organic chemists. This present article emphasizes the existing growths in the strategies involving the diastereoselective synthesis of C-glycosylated benzopyrans, benzopyrones, and flavonoids using naturally acquired glycones as chiral synthons.

11.
Zhongguo Zhong Yao Za Zhi ; 49(7): 1882-1887, 2024 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-38812200

RESUMO

Chemical constituents from the ethanol extract of Picrorhiza scrophulariiflora were isolated and purified by column chromatography. Their structures were identified by HR-MS, 1D and 2D-NMR, and their cytotoxicity was assessed by CCK-8 assay. Four compounds were isolated and identified as follows: 2ß-D-glucosyloxy-3ß,16α,20ß-trihydroxy-9-methyl-19-norlanosterol-5,25-diene-22-one(1), 2ß-D-glucosyloxy-3ß,16α,20ß-trihydroxy-9-methyl-19-norlanosta-5,24-diene-22-one(2), 25-acetoxy-2ß-glucosyloxy-3ß,16α,20ß-trihydroxy-9-methyl-19-norlanosta-5-ene-22-one(3) and 25-acetoxy-2ß-glucosyloxy-3ß,16α,20ß-trihydroxy-9-methyl-19-norlanosta-5,23-(E)-diene-22-one(4). Compound 1 represents a new cucurbitane glycoside. The half inhibitory concentrations of the 4 compounds exceeded 100 µmol·L~(-1) against four tumor cell lines, indicating no significant cytotoxicity.


Assuntos
Glicosídeos , Picrorhiza , Glicosídeos/química , Glicosídeos/isolamento & purificação , Humanos , Linhagem Celular Tumoral , Picrorhiza/química , Estrutura Molecular , Espectroscopia de Ressonância Magnética , Medicamentos de Ervas Chinesas/química , Triterpenos
12.
Food Chem ; 453: 139622, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-38761729

RESUMO

For health and safety reasons, the search for green, healthy, and low-calorie sweeteners with good taste has become the demand of many consumers. Furthermore, the need for sugar substitutes of natural origin has increased dramatically. In this review, we briefly discussed the safety and health benefits of stevia sweeteners and enumerated some examples of physiological functions of steviol glycosides (SGs), such as anti-inflammatory, anti-obesity, antihypertensive, anti-diabetes, and anticaries, citing various evidence related to their application in the food industry. The latest advances in emerging technologies for extracting and purifying SGs and the process variables and operational strategies were discussed. The impact of the extraction methods and their comparison against the conventional techniques have also been demonstrated. These technologies use minimal energy solvents and simplify subsequent purification stages, making viable alternatives suitable for a possible industrial application. Furthermore, we also elucidated the potential for advancing and applying the natural sweeteners SGs.


Assuntos
Diterpenos do Tipo Caurano , Extratos Vegetais , Stevia , Edulcorantes , Stevia/química , Diterpenos do Tipo Caurano/isolamento & purificação , Diterpenos do Tipo Caurano/química , Edulcorantes/isolamento & purificação , Edulcorantes/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Humanos , Glucosídeos/isolamento & purificação , Glucosídeos/química , Animais , Glicosídeos/isolamento & purificação , Glicosídeos/química
13.
J Agric Food Chem ; 72(20): 11617-11628, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38728580

RESUMO

When grapes are exposed to wildfire smoke, certain smoke-related volatile phenols (VPs) can be absorbed into the fruit, where they can be then converted into volatile-phenol (VP) glycosides through glycosylation. These volatile-phenol glycosides can be particularly problematic from a winemaking standpoint as they can be hydrolyzed, releasing volatile phenols, which can contribute to smoke-related off-flavors. Current methods for quantitating these volatile-phenol glycosides present several challenges, including the requirement of expensive capital equipment, limited accuracy due to the molecular complexity of the glycosides, and the utilization of harsh reagents. To address these challenges, we proposed an enzymatic hydrolysis method enabled by a tailored enzyme cocktail of novel glycosidases discovered through genome mining, and the generated VPs from VP glycosides can be quantitated by gas chromatography-mass spectrometry (GC-MS). The enzyme cocktails displayed high activities and a broad substrate scope when using commercially available VP glycosides as the substrates for testing. When evaluated in an industrially relevant matrix of Cabernet Sauvignon wine and grapes, this enzymatic cocktail consistently achieved a comparable efficacy of acid hydrolysis. The proposed method offers a simple, safe, and affordable option for smoke taint analysis.


Assuntos
Frutas , Cromatografia Gasosa-Espectrometria de Massas , Glicosídeo Hidrolases , Glicosídeos , Fenóis , Fumaça , Vitis , Hidrólise , Glicosídeos/química , Glicosídeos/metabolismo , Glicosídeos/análise , Fumaça/análise , Glicosídeo Hidrolases/metabolismo , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/genética , Fenóis/química , Fenóis/metabolismo , Vitis/química , Frutas/química , Frutas/enzimologia , Vinho/análise , Incêndios Florestais , Biocatálise
14.
Acta Pharm Sin B ; 14(5): 2333-2348, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38799633

RESUMO

Enzymatic malonylation of natural glycosides provides a promising alternative method for drug-like malonylated glycosides supply. However, the catalytic potential and structural basis of plant malonyltransferase are far from being fully elucidated. This work identified a new malonyltransferase CtMaT1 from Cistanche tubulosa. It displayed unprecedented mono- and/or di-malonylation activity toward diverse glucosides with different aglycons. A "one-pot" system by CtMaT1 and a malonyl-CoA synthetase was established to biosynthesize nine new malonylated glucosides. Structural investigations revealed that CtMaT1 possesses an adequately spacious acyl-acceptor pocket capable of accommodating diverse glucosides. Additionally, it recognizes malonyl-CoA through strong electrotactic and hydrogen interactions. QM/MM calculation revealed the H167-mediated SN2 reaction mechanism of CtMaT1, while dynamic simulations detected the formation of stable hydrogen bonds between the glucose-6-OH group and H167, resulting in its high malonylation regiospecificity. Calculated energy profiles of two isomeric glycosides highlighted lower reaction energy barriers towards glucoside substrates, emphasizing CtMaT1's preference for glucosides. Furthermore, a mutant CtMaT1H36A with notably increased di-malonylation activity was obtained. The underlying molecular mechanism was illuminated through MM/GBSA binding free energy calculation. This study significantly advances the understanding of plant acyltransferases from both functional and protein structural perspectives, while also providing a versatile tool for enzymatic malonylation applications in pharmacology.

15.
Phytomedicine ; 129: 155681, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38718638

RESUMO

BACKGROUND: Infertility patients account for an astonishing proportion of individuals worldwide. Due to its complex etiology and challenging treatment, infertility has imposed significant psychological and economic burdens on many patients. C. Herba (Cistanche tubulosa (Schenk) Wight and Cistanche deserticola Ma), renowned as one of the most prominent Chinese herbal medicines (CHMs), is abundant in diverse bioactive compounds that exhibit therapeutic effects on many diseases related to oxidative stress (OS) and disorders of sex hormone levels. OBJECTIVE: Due to the limited drugs currently used in clinical practice to improve reproductive outcomes and their inevitable side effects, developing safe and effective new medications for infertility is of significance. This article comprehensively reviewed the phytochemicals of C. Herba, focusing on their efficacy and mechanisms on infertility and their safety for the first time, aiming to offer valuable insights for the development and application of C. Herba, and for developing novel strategies for treating infertility. METHODS: We used "Cistanche" and its known bioactive components in combination with "sperm", "testicles", "epididymis", "ovaries", "uterus", and "infertility" as keywords to search in PubMed, Web of Science, Scopus and CNKI up to November 2023. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guideline was followed. RESULTS: The therapeutic effects of C. Herba on infertility are mainly attributed to echinacoside (ECH), verbascoside (VB), salidroside (SAL), polysaccharides, and betaine. They can effectively improve spermatogenic dysfunction, gonadal dysfunction and erectile dysfunction (ED) by exerting anti-oxidation, sex hormones regulation and anti-hypoxia. Moreover, they can also improve premature ovarian failure (POF), ovarian and uterine cancer, oocyte maturation by exerting anti-oxidation, anti-apoptosis, and anti-cancer. C. Herba and its active ingredients also exhibit pleasing safety. CONCLUSION: C. Herba is a promising source of natural medicine for infertility. Additionally, compared to current therapeutic drugs, its favorable safety also supports its development as a nutritional supplement. However, high-quality clinical studies are required to validate its effectiveness for the development of novel therapeutic strategies.


Assuntos
Cistanche , Medicamentos de Ervas Chinesas , Animais , Feminino , Humanos , Masculino , Cistanche/química , Medicamentos de Ervas Chinesas/farmacologia , Medicamentos de Ervas Chinesas/uso terapêutico , Medicamentos de Ervas Chinesas/química , Glucosídeos/farmacologia , Glucosídeos/uso terapêutico , Glicosídeos , Infertilidade/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Fenóis/farmacologia , Fenóis/uso terapêutico , Compostos Fitoquímicos/farmacologia , Compostos Fitoquímicos/uso terapêutico , Polifenóis , Reprodução/efeitos dos fármacos
16.
Heliyon ; 10(9): e30507, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38737284

RESUMO

Three previously unidentified dihydrostilbene glycosides, named oleiferaside A (1), oleiferaside B (2), and oleiferaside C (3), were discovered through a phytochemical exploration on Camellia oleifera Abel. leaves. Additionally, nine known secondary metabolites (4-12) were also identified. The undescribed secondary metabolites 1-3 were elucidated as 3,5-dimethoxydihydrostilbene 4'-O-α-l-arabinofuranosyl-(1 â†’ 6)-ß-d- glucopyranoside, 3,5-dimethoxydihydrostilbene 4'-O-α-l-arabinopyranosyl-(1 â†’ 6)-ß-d- glucopyranoside and 3,5-dimethoxydihydrostilbene 4'-O-ß-d-apiofuranosyl-(1 â†’ 6)-ß-d- glucopyranoside, respectively. HR-MS and NMR spectroscopy were utilized for determining the structures of the isolates. The natural products were assessed for their anti-inflammatory effect using RAW264.7 macrophage stimulated by LPS. The findings demonstrated that compounds 1-4 exhibited inhibitory activities on NO and PGE2 production without causing cytotoxicity. These observations suggest that these compounds may have potential anti-inflammatory properties.

17.
Phytother Res ; 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38649260

RESUMO

Knee osteoarthritis (KOA) is a prevalent degenerative joint disease that is primarily managed by improving the destroyed cartilage and reversing subchondral bone remodeling. Total glucosides of white paeony (TGP) capsule primarily contains extracts from the white peony root and has been shown to have various pharmacological effects, but its role in KOA still requires comprehensive evaluation. In this study, we aimed to investigate the protective effect of TGP on knee cartilage and subchondral bone, as well as elucidate the underlying molecular mechanisms. The effect of TGP on KOA progression was evaluated in the destabilization of the medial meniscus (DMM)-induced KOA model of mouse and interleukin (IL)-1ß-induced KOA model of primary mouse chondrocytes. In vivo and in vitro experiments demonstrated that TGP had a protective effect on the cartilage. Treatment with TGP could induce the synthesis of critical elements in the cartilage extracellular matrix and downregulate the synthesis of degrading enzymes in the extracellular matrix. Regarding the underlying mechanisms, TGP inhibited the phosphorylation and nuclear translocation of p65 by regulating the nuclear factor-kappa B (NF-κB) signaling pathway. In addition, TGP could reduce the secretion of IL-1ß, IL-6, and tumor necrosis factor-α (TNF-α). Moreover, it has a sustained effect on coupled subchondral bone remodeling through regulation of the OPG/RANKL/RANK pathway. In conclusion, TGP may protect articular cartilage by downregulating the NF-κB signaling pathway and may support coupled subchondral bone remodeling by regulating OPG/RANKL/RANK signaling pathway in the DMM-induced KOA model of mouse, suggesting a new therapeutic potential for KOA treatment.

18.
Phytochem Anal ; 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38659238

RESUMO

INTRODUCTION: The sesquiterpene glycosides (SGs) from Dendrobium nobile Lindl. have immunomodulatory effects. However, there are no studies on the growth conditions affecting its contents and quantitative analysis methods. OBJECTIVE: In the present study, a quantitative analysis method for six SGs from D. nobile was established. We explored which growth conditions could affect the contents of SGs, providing a basis for the cultivation and clinical application of D. nobile. METHODS: Firstly, based on the optimization of mass spectrometry parameters and extraction conditions for six SGs in D. nobile, a method for the determination of the contents of six SGs was established using high-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (HPLC-QqQ-MS/MS) in multiple reaction monitoring (MRM) mode. Then, the methodology of the established method was validated. Secondly, the established method was applied to determine the contents of six SGs from 78 samples of D. nobile grown under different growth conditions. Finally, chemometrics analysis was employed to analyze the results and select optimal growth conditions for D. nobile. RESULTS: The results indicated significant variations in the contents of SGs from D. nobile grown under different growth conditions. The primary factors influencing SG contents included age, geographical origin, altitude, and epiphytic pattern. CONCLUSION: Therefore, the established method for determining SG contents from D. nobile is stable. In particular, the SG contents were relatively high in samples of 3-year-old D. nobile grown at an altitude of approximately 500 m on Danxia rocks in Chishui, Guizhou.

19.
Appl Environ Microbiol ; 90(5): e0020524, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38625022

RESUMO

Dye-decolorizing peroxidases are heme peroxidases with a broad range of substrate specificity. Their physiological function is still largely unknown, but a role in the depolymerization of plant cell wall polymers has been widely proposed. Here, a new expression system for bacterial dye-decolorizing peroxidases as well as the activity with previously unexplored plant molecules are reported. The dye-decolorizing peroxidase from Amycolatopsis 75iv2 (DyP2) was heterologously produced in the Gram-positive bacterium Streptomyces lividans TK24 in both intracellular and extracellular forms without external heme supplementation. The enzyme was tested on a series of O-glycosides, which are plant secondary metabolites with a phenyl glycosidic linkage. O-glycosides are of great interest, both for studying the compounds themselves and as potential models for studying specific lignin-carbohydrate complexes. The primary DyP reaction products of salicin, arbutin, fraxin, naringin, rutin, and gossypin were oxidatively coupled oligomers. A cleavage of the glycone moiety upon radical polymerization was observed when using arbutin, fraxin, rutin, and gossypin as substrates. The amount of released glucose from arbutin and fraxin reached 23% and 3% of the total substrate, respectively. The proposed mechanism suggests a destabilization of the ether linkage due to the localization of the radical in the para position. In addition, DyP2 was tested on complex lignocellulosic materials such as wheat straw, spruce, willow, and purified water-soluble lignin fractions, but no remarkable changes in the carbohydrate profile were observed, despite obvious oxidative activity. The exact action of DyP2 on such lignin-carbohydrate complexes therefore remains elusive. IMPORTANCE: Peroxidases require correct incorporation of the heme cofactor for activity. Heterologous overproduction of peroxidases often results in an inactive enzyme due to insufficient heme synthesis by the host organism. Therefore, peroxidases are incubated with excess heme during or after purification to reconstitute activity. S. lividans as a production host can produce fully active peroxidases both intracellularly and extracellularly without the need for heme supplementation. This reduces the number of downstream processing steps and is beneficial for more sustainable production of industrially relevant enzymes. Moreover, this research has extended the scope of dye-decolorizing peroxidase applications by studying naturally relevant plant secondary metabolites and analyzing the formed products. A previously overlooked artifact of radical polymerization leading to the release of the glycosyl moiety was revealed, shedding light on the mechanism of DyP peroxidases. The key aspect is the continuous addition, rather than the more common approach of a single addition, of the cosubstrate, hydrogen peroxide. This continuous addition allows the peroxidase to complete a high number of turnovers without self-oxidation.


Assuntos
Amycolatopsis , Corantes , Glicosídeos , Corantes/metabolismo , Corantes/química , Glicosídeos/metabolismo , Amycolatopsis/metabolismo , Amycolatopsis/genética , Amycolatopsis/enzimologia , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/química , Peroxidases/metabolismo , Peroxidases/genética , Peroxidase/metabolismo , Peroxidase/química , Peroxidase/genética , Streptomyces lividans/metabolismo , Streptomyces lividans/genética , Streptomyces lividans/enzimologia , Especificidade por Substrato
20.
Carbohydr Res ; 539: 109105, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38583285

RESUMO

Herein, we report the development of a diastereoselective and efficient route to construct sugar-derived pyrano[3,2-c]quinolones utilizing 1-C-formyl glycal and 4-hydroxy quinolone annulation. This methodology will open a route to synthesize nature inspired pyrano[3,2-c]quinolones. This is the first report for the stereoselective synthesis of sugar-derived pyrano[3,2-c]quinolones, where 100% stereoselectivity was observed. A total of sixteen compounds have been synthesized in excellent yields with 100% stereoselectivity. The molecular docking of the synthesized novel natural product analogues demonstrated their binding modes within the active site of type II topoisomerase. The results of the in-silico studies displayed more negative binding energies for the all the synthesized compounds in comparison to the natural product huajiosimuline A, indicating their affinity for the active pocket. Ten out of the sixteen novel synthesized compounds were found to have comparative or relatively more negative binding energy in comparison to the standard anti-cancer drug, doxorubicin. Additionally, the scalability and viability of this protocol was illustrated by the gram scale synthesis.


Assuntos
Produtos Biológicos , Simulação de Acoplamento Molecular , Quinolonas , Produtos Biológicos/química , Produtos Biológicos/síntese química , Estereoisomerismo , Quinolonas/química , Quinolonas/síntese química , DNA Topoisomerases Tipo II/metabolismo , DNA Topoisomerases Tipo II/química
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