BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY
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2021
·Vol. 85
·期 7
·1697-1705
·
IF 2.043
Chen Jianmin,Ran Mengnan,Wang Meixia,Liu Xinying,Liu Siwan,Yu Yue
The related structure–activity relationships of cinnamic acid and its derivates have not been studied in details yet. Herein, antityrosinase and antioxidant activities of 18 compounds were evaluated. The results demonstrated that the substituents on the phenyl ring of cinnamic acid led to the enhancement of the inhibition on monophenolase and the weakening of the inhibition on diphenolase. Among these tested compounds, 9 was first discovered as a tyrosinase inhibitor in a reversible competitive manner with IC50 value of 68.6 ± 4.2 µm. Docking results demonstrated 9 located into the catalytic center of tyrosinase. Antioxidant assay indicated that only 1 hydroxyl group on the phenyl ring was not enough to possess the radical scavenging activity, and the number of hydroxyl groups may be more important. This study will be helpful in the development of new cinnamic acid derivates as tyrosinase inhibitors and antioxidants with higher efficacy.
研究领域:
药理学
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生物化学
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分子生物学
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DOI
PubMed
高影响因子
MOLECULES
·
2020
·Vol. 25
·期 2
·344
·
IF 3.267
Limin Qu,Ke Song,Qi Zhang,Jie Guo,Juan Huang
Tyrosinase inhibitors with excellent inhibitory activities and lower side effects have promising applications in the fields of medicine, agriculture, food sciences and cosmetics. In this study, a method for simultaneous separation and determination of six target compounds (puerarin, daidzin, genistein, daidzein, genistin, and formononetin) inPuerariae LobataeRadix was established by cloud point extraction (CPE) and concentration combined with high performance liquid chromatography (HPLC). To achieve high extraction yields, an ultrasound-assisted extraction method was developed based on a salt-modified Triton X-100 system. The optimal extraction conditions are: surfactant Triton X-100 concentration 0.07 g/mL, liquid-solid ratio 80:1 (mL/g), NaCl addition amount 0.6 g, equilibrium time 40 min, equilibrium temperature 70 °C. Under the optimal conditions, the total maximum extraction yield of the six target isoflavones reached 8.92 mg/g. Usingl-tyrosine andl-dopa as substrates, the effects of puerarin on the monophenolase and diphenolase activity of tyrosinase activity were investigated by the enzyme kinetics method. The results showed that puerarin inhibited monophenolase activity with an IC50of 0.537 mg/mL and activated diphenolase activity. The inhibition type of puerarin on monophenolase and the activation type of puerarin on diphenolase were analyzed by Lineweaver-Burk plots which show that puerarin showed mixed inhibition on monophenolase and mixed activation on diphenolase. Therefore, puerarin can be used as both a tyrosinase inhibitor and a tyrosinase activator.Keywords:Puerariae LobataeRadix;cloud point extractions;tyrosinase inhibitors;tyrosinase activator;kinetic analysis
研究领域:
药理学
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植物化学
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酶学
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DOI
PubMed
高影响因子
TALANTA
·
2019
·
IF 4.916
Yu-Zhu Ding,Wei-Feng Wang,Tian Chai,Yin Qiang,Yan-Ping Shi,Jun-Li Yang
Tyrosinase is the key enzyme in the treatment of vitiligo. Development of rapid, simple, and visual methods for screening bioactive compounds with tyrosinase activity from natural compounds is interesting for new drug discovery. Herein, a novel visual ratiometric fluorescent assay for screening tyrosinase activators and/or inhibitors based on silicon nanoparticles (Si NPs) was explored. Inspired by the changes in both of the solution color and the fluorescence emission due to the sensing between Si NPs and dopamine (DA), we employed tyramine as the model substrate, which can transfer into DA by tyrosinase. It was found that the tyrosinase-incubated tyramine solution exhibited pale yellow under nature light or yellow fluorescence under UV light in the presence of Si NPs, where the color/fluorescence intensity were directly related to the concentration of tyrosinase. The established method showed good detection selectivity , and the LOD for tyrosinase was 0.14 U mL −1 . Eventually, this assay was successfully applied to screen tyrosinase activators or inhibitors from a natural product-like library, and a tyrosinase activator with EC 50 of 2.62 μM, more potent than the commonly used tyrosinase activator 8-MOP, was discovered.
研究领域:
生物化学
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药学
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纳米技术
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药物发现
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产品关联
DOI
PubMed
高影响因子
ACS Sensors
·
2025
·
IF 9.1
Zuhua Zeng,Ying Tan,Tiantian Luo,Zhengwei Li,Guihao Hu,Yao Liu,Ling He,Haiyu Wang,Lei Zhong,Haiying Wang,Tianwei Liu,Jiang Zhu
Melanoma is one of the most aggressive forms of skin cancer. Accurate and early diagnosis of melanoma is crucial for improving patient outcomes. This study develops two TYR-activatable molecular probes, Mn-TyrEDTA and Al-18F-TyrEDTA, for the selective detection of melanoma in vivo. In vitro studies reveal that Mn-TyrEDTA exhibits TYR activity-dependent relaxivity enhancement, undergoing TYR-mediated oxidative polymerization, resulting in the formation of paramagnetic oligomers. UV–vis analysis supports this mechanism, showing time- and TYR concentration-dependent increases in broad band absorbance in the UV–vis region, specifically around 475 nm, due to the formation of o-quinone intermediates and melanin-like oligomers. HPLC analysis further confirmed the presence of polar oligomeric products in Mn-TyrEDTA solutions incubated with TYR/O2. MRI studies demonstrate Mn-TyrEDTA’s selective retention and signal enhancement in TYR-expressing melanoma tissues. Furthermore, PET imaging with Al-18F-TyrEDTA conducted using a dual-xenograft mouse model reveals significantly higher uptake and retention of Al-18F-TyrEDTA in TYR-expressing melanoma compared to TYR-negative tumors. This selective retention could be attributed to a TYR-mediated proximity labeling mechanism, where highly reactive quinones form covalent bonds with nearby tumor proteins. In summary, our findings establish Mn-TyrEDTA and Al-18F-TyrEDTA as promising TYR-activatable imaging probes, offering a novel strategy for the early diagnosis and prognosis of melanoma.
研究领域:
医学影像学
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肿瘤学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
PROCESS BIOCHEMISTRY
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2019
·
IF 2.883
Yu-Xia Wang,Wei-Chao Su,Qin Wang,Yu-Feng Lin,Yuan Zhou,Long-Fang Lin,Su Ren,Yan-Ting Li,Qing-Xi Chen,Yan Shi
In this study, the antityrosinase and antioxidant activities of four guanidine compounds (GCs), including guanylthiourea (GT), guanidine thiocyanate (GTC), phenylguanidine (PG), and phenethyldiguanide (PTDG), were investigated. The results showed that the GCs reduced the monophenolase and diphenolase activities of tyrosinase. The IC 50 values of GT, GTC, PG, and PTDG were 0.27, 3.53, 6.68, and 5.18 mM for monophenolase and 0.23, 3.24, 3.97 and 2.50 mM for diphenolase, respectively. The inhibition of diphenolase activity was reversible for the four GCs. The inhibition types of GT and PTDG were competitive, while those of GTC and PG were mixed. FRAP, ABTS, DPPH, and DNA damage protection assays revealed that only GT possessed significant antioxidant activity. Furthermore, GT was found to decrease the melanin content and expression of TYR, MITF and DCT in both B16F10 cells and zebrafish. Overall, our results indicated that GT can inhibit tyrosinase activity in vitro , which suggests that these GCs are potential candidates for novel small-molecule tyrosinase inhibitors and that GT could have broader application prospects.
研究领域:
药理学
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生物化学
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细胞生物学
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分子生物学
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产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
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2011
·Vol. 16
·期 2
·449-456
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IF 2.234
Han Ruixia,Cui Lin,Ai Shiyun,Yin Huanshun,Liu Xianggang,Qiu Yanyan
A tyrosinase (Tyr) biosensor has been constructed by immobilizing tyrosinase on the surface of Mg–Al–CO 3 hydrotalcite-like compound film (HTLc) modified glassy carbon electrode (GCE) for the determination of polyphenols. The negatively charged tyrosinase was adsorbed firmly on the surface of a positively charged HTLc/GCE by electrostatic interactions and retained its activity to a great degree. The modified electrode was characterized by cyclic voltammetry and AC impedance spectra. Polyphenols were determined by a direct reduction of biocatalytically generated quinone species. The different parameters, including pH, temperature, and enzyme loading were investigated and optimized. Under the optimum conditions, Tyr/HTLc electrode gave a linear response range of 3–300, 0.888–444, and 0.066–396 μM with a detection limit (S/N = 3) of 0.1, 0.05, and 0.003 μM for catechol, caffeic acid, and quercetin, respectively. In addition, the repeatability and stability of the enzyme electrode were estimated. Total polyphenol contents of real samples were also determined to study the potential applicability of the Tyr/HTLc/GCE biosensor.
研究领域:
生物传感器
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酶学分析
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电化学检测
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DOI
高影响因子
TALANTA
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2016
·
IF 4.035
Yun Guan,Lanjunzi Liu,Chao Chen,Xiuzhi Kang,Qingji Xie
The facile preparation of poly( l -DOPA)-tyrosinase (PD M -Tyr) composite and its application both in substrate (phenol) and inhibitor (atrazine) sensing is reported here for the first time. Effective immobilization of enzyme is realized via in-situ entrapping Tyr in poly( l -DOPA) (PD M ), which is formed by Tyr catalytic polymerization of l -DOPA. The Tyr modified electrode is simply prepared by dipping the PD M -Tyr composite on an Au electrode and then covered by Nafion. The thus-prepared Tyr-immobilized electrode exhibits excellent performance superior to most Tyr-based electrochemical biosensors, the sensitivity to phenol is as high as 5122 μA mM −1 in the linear range of 10 nM~1.25 μM, the apparent Michaelis-Menten constant ( K M app ) determined as low as 3.13 μM indicates strong substrate binding and high catalytic activity of the immobilized Tyr. The biosensor also works well in atrazine biosensing, with a linear detection range of 50 ppb~30 ppm and a low detection limit of 10 ppb obtained. In addition, the biosensor shows excellent stability, precision, high sensitivity and fabrication simplicity.
研究领域:
生物化学
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环境科学
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分析化学
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DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 111
·109730-109741
·
IF 3.289
Yi Tao,Dandan Su,Yingshan Du,Weidong Li,Baochang Cai,Liuqing Di,Liyun Shi,Lihong Hu
Tyrosinase is the rate-limiting enzyme for controlling the production of melanin. A very precise, sensitive and convenient solid-phase extraction based approach was developed for extract and analysis of tyrosinase binders from San-Bai decoction. Tyrosinase binders were captured by using tyrosinase conjugated magnetic beads. The retained tyrosinase binders were dissociated and analyzed by high performance liquid chromatography and quadrupole-time-of-flight mass spectrometry. The powder X-ray diffraction (XRD), transmission electron microscopy (TEM), vibration sample magnetometer (VSM) and Fourier transform infrared (FT-IR) spectroscopy techniques were used for the characterization of tyrosinase conjugated magnetic beads. A variety of experimental conditions such as incubation temperature, buffer pH and ion strength, which may affect extraction yield, were optimized through Box–Behnken statistical design and response surface methodology by using paeoniflorin as a model compound. The optimal incubation conditions were as follows: wash times: 4, wash solvent: 10% acetonitrile–water, incubation time: 30 min, temperature: 34.84 °C, ion strength: 193.67 mM, pH: 6.98. The established approach was successfully applied for the extraction of tyrosinase binders from San-Bai decoction. The tyrosinase inhibitory assay was employed for validation of the activities of these identified binders. Fifteen tyrosinase inhibitors were identified, and nine of which, including benzoylpaeoniflorin, benzoyloxypaeoniflorin, galloylpaeoniflorin, paeonolide, oxypaeoniflora, albiflorin, ononin, mudanpioside C and apiopaeonoside, were reported for the first time.
研究领域:
分析化学
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药理学
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中药学
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生物化学
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产品关联
DOI
高影响因子
RSC Advances
·
2019
·Vol. 9
·期 35
·20029-20034
·
IF 3.049
Jianzhong Zhang,Yuyuan Chen,Zongfu Zheng,Zhenzhen Wang,Yanjie Zheng,Xinhua Lin,Shaohuang Weng
As a vital, copper-containing oxidase, tyrosinase (TYR) is useful as a biomarker for the screening of skin diseases. In this paper, a convenient and sensitive homogeneous fluorescence detection platform for the assay of TYR activity without any modified steps is described. Inspired by the fact that carbon dots (CDs) with excellent properties can be obtained through some surface modification, amine rich carbon dots (N-CDs) using a nitrogen doping process were developed as the fluorescent probe for this assay. The effect and the response mechanism of the degree of nitrogen doping in relation to the response of different CDs to the sensing of TYR activity using dopamine (DA) as a substrate were investigated. The DA was oxidized to o-dopaquinone with the catalyzation of TYR and quenched the fluorescence of the N-CDs by direct interaction. By using a set concentration of DA and other optimized reaction conditions, the fluorescence intensity of the N-CDs was directly applied to monitor the TYR activity. This assay for TYR activity showed a broad linear range from 0.05 to 6.0 U mL−1 with a detection limit of 0.039 U mL−1. The satisfactory recovery of the sensor for TYR activity in diluted human serum illustrated a potential clinical application.
研究领域:
生物化学
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医学诊断
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
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2014
·
IF 3.259
Yajie Wang,Guowen Zhang,Jiakai Yan,Deming Gong
Tyrosinase is a key enzyme in the production of melanin in the human body, excessive accumulation of melanin can lead to skin disorders. Morin is an important bioactive flavonoid compound widely distributed in plants and foods of plant origin. In this study, the inhibitory kinetics of morin on tyrosinase and their binding mechanism were determined using spectroscopic and molecular docking techniques. The results indicate that morin reversibly inhibited tyrosinase in a competitive manner through a multi-phase kinetic process. Morin was found to bind to tyrosinase at a single binding site mainly by hydrogen bonds and van der Waals forces. Analysis of circular dichroism spectra revealed that the binding of morin to tyrosinase induced rearrangement and conformational changes of the enzyme. Moreover, molecular docking results suggested that morin competitively bound to the active site of tyrosinase with the substrate levodopa.
研究领域:
生物化学
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药理学
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DOI
高影响因子
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2025
·
IF 3.5
Yan-Xia Li,He Ma,Le Shi,Zhong-Fei Zhang,Yu-Meng Wu,Chao Yan,Yan Chen,Yong-Ming Lu
BACKGROUND Polysaccharides from Pleurotus citrinopileatus exhibit diverse bioactivities, yet their efficacy against ultraviolet B (UVB)-induced photoaging remains unexplored. This study aimed to purify and characterize a specific PCP and assess its protective effects using a UVB-induced zebrafish model. RESULTS A polysaccharide, designated as PCP-2, was isolated from P. citrinopileatus through hot-water extraction, ultrafiltration and chromatography. PCP-2 is a galactoglucan with a molecular weight of 1.52 × 10 6 Da, predominantly composed of 1,4-linked glucopyranosyl and 1,4,6-linked galactopyranosyl residues. In UVB-exposed zebrafish, PCP-2 administration resulted in a significant reduction of reactive oxygen species and malondialdehyde levels, alongside enhanced activities of antioxidant enzymes, including superoxide dismutase, catalase and glutathione peroxidase. Additionally, PCP-2 inhibited apoptosis by upregulating Bcl-2 expression and downregulating caspase-3. It also attenuated cellular senescence, as indicated by decreased β -galactosidase activity and increased telomerase activity. Moreover, PCP-2 promoted the synthesis of type I and III collagen by suppressing matrix metalloproteinases MMP-1 and MMP-3 and reduced melanin production through the downregulation of tyrosinase expression. Mechanistic studies suggested that these protective effects are mediated via activation of the Nrf2/HO-1 signaling pathway. CONCLUSION PCP-2 from P. citrinopileatus effectively mitigates UVB-induced photoaging, primarily by activating the Nrf2/HO-1 pathway. These findings suggest PCP-2's potential as an anti-photoaging agent in both food and pharmaceutical industries. © 2025 Society of Chemical Industry.
研究领域:
生物化学
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药理学
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食品科学
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产品关联
DOI
PubMed
高影响因子
SENSORS
·
2016
·Vol. 16
·期 1
·135
·
IF 2.033
Jiexia Chen,Yifan Liu,Guang-Chao Zhao
A novel photoelectrochemical biosensor for step-by-step assay of tyrosinase and thrombin was fabricated based on the specific interactions between the designed peptide and the target enzymes. A peptide chain with a special sequence which contains a positively charged lysine-labeled terminal, tyrosine at the other end and a cleavage site recognized by thrombin between them was designed. The designed peptide can be fixed on surface of the CdTe quantum dots (QDs)-modified indium-tin oxide (ITO) electrode through electrostatic attraction to construct the photoelectrochemical biosensor. The tyrosinase target can catalyze the oxidization of tyrosine by oxygen into ortho-benzoquinone residues, which results in a decrease in the sensor photocurrent. Subsequently, the cleavage site could be recognized and cut off by another thrombin target, restoring the sensor photocurrent. The decrease or increase of photocurrent in the sensor enables us to assay tyrosinase and thrombin. Thus, the detection of tyrosinase and thrombin can be achieved in the linear range from 2.6 to 32 μg/mL and from 4.5 to 100 μg/mL with detection limits of 1.5 μg/mL and 1.9 μg/mL, respectively. Most importantly, this strategy shall allow us to detect different classes of enzymes simultaneously by designing various enzyme-specific peptide substrates.Keywords:tyrosinase;thrombin;peptide;photoelectrochemical biosensor
研究领域:
生物化学
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医学检测
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纳米技术
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）