Publications by authors named "Shuju Guo"

We herein report a novel dibenzo[,]phenazine-based fluorescent probe with fast response to thiophenols over a wide pH range from 5 to 13. The probe possesses a large Stokes shift (120 nm). More importantly, it displays a high selectivity and sensitivity for thiophenols in the presence of other analytes such as biothiols and common metal ions.

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Astaxanthin (AST) is a xanthophyll carotenoid widely distributed in aquatic animals, which has many physiological functions such as antioxidant, anti-inflammatory, anti-hypertensive and anti-diabetic activities. AST has three optical isomers, including a pair of enantiomers (3S,3'S and 3R,3'R) and a meso form (3R,3'S). Different optical isomers have differences in a variety of physiological functions.

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Astaxanthin (AST) characteristics and pigment productivity of , one of the few AST-producing higher plants, have not yet been studied extensively. In this study, the geometrical and optical isomers of AST in different parts of the flower were determined in detail, followed by a separation of the all- AST using HPLC chromatography. AST extracted from the flower accounted for 1.

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Protein tyrosine phosphatase 1B (PTP1B) is a well-validated target in therapeutic interventions for type 2 diabetes mellitus (T2DM), however, PTP1B inhibitors containing negatively charged nonhydrolyzable pTyr mimetics are difficult to convert to the corresponding in vivo efficacy owing to poor cell permeability and oral bioavailability. In this work, molecules bearing less acidic heterocycle 2,4-thiazolidinedione and hydantoin were designed, synthesized and evaluated for PTP1B inhibitory potency, selectivity and in vivo antidiabetic efficacy. Among them, compound 5a was identified as a potent PTP1B inhibitor (IC = 0.

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Gut microbiota has a critical role in metabolic diseases, including type 2 diabetes mellitus (T2DM). 3-bromo-4,5-bis(2,3-dibromo-4,5-dihydroxybenzyl)-1,2-benzenediol (BDB) is a natural bromophenol isolated from marine red alga . Our latest research showed that BDB could alleviate T2DM in diabetic BKS db mice.

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Background And Purpose: Protein tyrosine phosphatase (PTP) 1B (PTP1B) plays a critical role in the regulation of obesity, Type 2 diabetes mellitus and other metabolic diseases. However, drug candidates exhibiting PTP1B selectivity and oral bioavailability are currently lacking. Here, the enzyme inhibitory characteristics and pharmacological benefits of 3-bromo-4,5-bis(2,3-dibromo-4,5-dihydroxybenzyl)-1,2-benzenediol (BDB) were investigated in vitro and in vivo.

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Protein tyrosine phosphatase 1B (PTP1B) is a highly validated target for the treatment of type 2 diabetes and obesity. Previous studies have shown that bromophenols from marine red alga Rhodomela confervoides can inhibit PTP1B activity. However, traditional in vitro enzymatic assays may result in false positive activity.

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Triple negative breast cancer (TNBC) is the most aggressive cancer in women, and despite improved treatments, it remains a major cause of morbidity and mortality. We and others have demonstrated that different hybrid compounds targeting PARP/MAPK or other pathways to inhibit cancer progression may lead to promising therapeutic results. We introduced fluorine to alter the physical properties of the compounds.

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PTP1B is a key negative regulator of insulin signaling transduction, and the inhibition of PTP1B has emerged as a potential therapeutic strategy to treat T2DM. 3,4-Dibromo-5-(2-bromo-6-(ethoxymethyl)-3,4-dihydroxybenzyl)benzene-1,2-diol (BPN), a natural bromophenol isolated from marine red alga , was found to inhibit PTP1B activity in our previous study. Herein, we identified that BPN functioned as a competitive PTP1B inhibitor and enhanced phosphorylation of IRβ, IRS-1 and Akt in palmitate acid-induced insulin-resistant HepG2 cells.

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Two efficient chalcone fluorescent probes (probe-KCN1 and probe-KCN2) were developed for the detection of thiophenols. Upon gradual addition of thiophenols to the fluorescent probes, the fluorescence intensity of the emission band at 550 nm is enhanced about 40-fold, with a large Stokes shift (130 nm). Probe-KCN1 responds to thiophenols with a good range of linearity and a detection limit of 79 nΜ (R = 0.

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A study on the secondary metabolites of sp. XNM-4, which was derived from marine algae (Chordariaceae), led to the identification of one previously undescribed () and seventeen known compounds (2-18). Their planar structures were established by extensive spectroscopic analyses, while the stereochemical assignments were defined by electronic circular dichroism (ECD) calculations.

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Protein tyrosine phosphatase 1B (PTP1B) is a widely confirmed target of the type 2 diabetes mellitus (T2DM) treatment. Herein, we reported a highly specific PTP1B inhibitor 2,2',3,3'-tetrabromo-4,4',5,5'-tetrahydroxydiphenylmethane (compound 1), which showed promising hypoglycemic activity in diabetic BKS db mice. With the IC value of 2.

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A turn-on florescent probe (probe-KCP) was developed for highly selective detection of thiophenols based on a donor-excited photo-induced electron transfer mechanism. Herein, the synthesis of the probe, a chalcone derivative, through a simple straightforward combination of a carbazole-chalcone fluorophore with a 2,4-dinitrophenyl functional group. In a kinetic study of the probe-KCP for thiophenols, the probe displayed a short response time (~30 min) and significant fluorescence enhancement.

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A series of novel pyrimidinedione derivatives were designed and evaluated for in vitro dipeptidyl peptidase-4 (DPP-4) inhibitory activity and in vivo anti-hyperglycemic efficacy. Among them, the representative compounds 11, 15 and 16 showed excellent inhibitory activity of DPP-4 with IC values of 64.47 nM, 188.

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Diabetes is a fast growing chronic metabolic disorder around the world. Dipeptidyl peptidase-4 (DPP-4) is a new promising target during type 2 diabetes glycemic control. Thus, a number of potent DPP-4 inhibitors were developed and play a rapidly evolving role in the management of type 2 diabetes in recent years.

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Bromophenol is a type of natural marine product. It has excellent biological activities, especially anticancer activities. In our study of searching for potent anticancer drugs, a novel bromophenol derivative containing indolin-2-one moiety, 3-(4-(3-([1,4'-bipiperidin]-1'-yl)propoxy)-3-bromo-5-methoxybenzylidene)-N-(4-bromophenyl)-2-oxoindoline-5-sulfonamide (-) was synthesized, which showed excellent anticancer activities on human lung cancer cell lines.

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A series of bromophenol hybrids with N-containing heterocyclic moieties were designed, and their anticancer activities against a panel of five human cancer cell lines (A549, Bel7402, HepG2, HCT116 and Caco2) using MTT assay in vitro were explored. Among them, thirteen compounds (, , , , , , , , , , , , and ) exhibited significant inhibitory activity against the tested cancer cell lines. The structure-activity relationships (SARs) of bromophenol derivatives were discussed.

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Thiosemicarbazone, a class of compounds with excellent biological activity, especially antitumor activity, have attracted wide attention. In this study, a novel fluorinated thiosemicarbazone derivative, 2-(3,4-difluorobenzylidene) hydrazinecarbothioamide (compound 1) was synthesized and its antitumor activities were further investigated on a non-small cell lung cancer cell line (A549) along with its underlying mechanisms. Compound 1 showed significant anti-proliferative activity on A549 cells, which was further proved by colony formation experiment.

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A series of novel carbohydrate-modified antitumor compounds were designed based on glucose transporter 1 (GLUT1), and evaluated for their anticancer activities against four cancer cell lines. The ribose derivatives (compound 9 and 10) exhibited modest inhibitory activity. The compound 9 significantly inhibited the migration of A549 cell and induced A549 cell apoptosis in a concentration-dependent manner.

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Protein tyrosine phosphatase 1B (PTP1B) is a key negative regulator of insulin signaling pathway. Inhibition of PTP1B is expected to improve insulin action. Appropriate selectivity and permeability are the gold standard for excellent PTP1B inhibitors.

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In an effort to develop novel small molecule PTP1B inhibitors, a series of bromophenol derivatives were designed, synthesized and evaluated in vitro and in vivo. All of the synthesized compounds displayed weak to potent PTP1B inhibitory activities (5.62-96.

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3,4-Dibromo-5-(2-bromo-3,4-dihydroxy-6-(isopropoxymethyl)benzyl)benzene-1,2-diol (HPN) is a synthetic analogue of 3,4-dibromo-5-(2-bromo-3,4-dihydroxy-6-(ethoxymethyl)benzyl)benzene-1,2-diol (BPN), which is isolated from marine red alga Rhodomela confervoides with potent protein tyrosine phosphatase 1B (PTP1B) inhibition (IC(50) = 0.84 μmol/L). The in vitro assay showed that HPN exhibited enhanced inhibitory activity against PTP1B with IC(50) 0.

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A series of bromophenol derivatives were synthesized and evaluated as protein tyrosine phosphatase 1B (PTP1B) inhibitors in vitro and in vivo based on bromophenol 4e (IC(50)=2.42 μmol/L), which was isolated from red algae Rhodomela confervoides. The results showed that all of the synthesized compounds displayed weak to good PTP1B inhibition at tested concentration.

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3-Bromo-4,5-bis(2,3-dibromo-4,5-dihydroxybenzyl)-1,2-benzenediol (BDB) is a bromophenol purified from the marine red alga Rhodomela confervoides and exhibits potent protein tyrosine phosphatase 1B (PTP1B) inhibition (IC(50)  = 1.7 µmol/L). In an effort to improve the PTP1B inhibitory activity, a series of derivatives were designed, synthesized, and evaluated in vitro.

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Objective: To synthesize (2'-bromo-4',5'-dimethoxy-phenyl)-( 2,3- dibromo-4,5-dimethoxy-phenyl)-methane (6) as protein tyrosine phosphatase 1B (PTP1B) inhibitor.

Method: Compound 6 was synthesized by Friedel-Crafts reaction, bromination and decarbonylation and screened inhibitory activity against PTP1B by the colorimetric assay. The structure of synthetic intermediates and target product were identified on the basis of spectral analysis.

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