scholarly journals Diarylalkanoids as Potent Tyrosinase Inhibitors from the Stems of Semecarpus caudata

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Phu H. Dang ◽  
Tho H. Le ◽  
Truong N. V. Do ◽  
Hai X. Nguyen ◽  
Mai T. T. Nguyen ◽  
...  
Keyword(s):  
Amino Acid ◽  
Inhibitory Activity ◽  
Spectroscopic Data ◽  
Data Interpretation ◽  
Docking Studies ◽  
Amino Acid Residues ◽  
Soluble Extract ◽  
Tyrosinase Inhibitory Activity ◽  
Ic50 Values ◽  
Tyrosinase Inhibitors

From a CHCl3-soluble extract of the stems of Semecarpus caudata (Anacardiaceae), two new diarylalkanoids, semedienone (1) and semetrienone (2), were isolated. Their structures were elucidated based on NMR spectroscopic data interpretation. These compounds possess strong tyrosinase inhibitory activity with the IC50 values of 0.033 and 0.11 μM, respectively. Docking studies of 1 and 2 with oxy-tyrosinase were carried out to analyze their interactions. Accordingly, semedienone (1) showed good interactions with the peroxide group and amino acid residues. The biosynthesis of the isolated diarylalkanoids was proposed.

scholarly journals Tyrosinase Inhibitors from the Stems of Streblus Ilicifolius

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Nhan T. Nguyen ◽  
Phu H. Dang ◽  
Hai X. Nguyen ◽  
Truong N. V. Do ◽  
Tho H. Le ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Inhibitory Activity ◽  
Spectroscopic Data ◽  
Soluble Fraction ◽  
Optical Rotation ◽  
Data Interpretation ◽  
Docking Studies ◽  
Ic50 Value ◽  
Stilbene Derivatives ◽  
Tyrosinase Inhibitors

Two new stilbene derivatives, named strebluses C and D, were isolated from the EtOAc-soluble fraction of the stems of Streblus ilicifolius (Moraceae). Its absolute configuration was elucidated based on NMR spectroscopic data interpretation and optical rotation calculation. Streblus C possesses strong tyrosinase inhibitory activity with an IC50 value of 0.01 μM. Docking studies of 1 and 2 with oxy-tyrosinase were carried out to analyze their interactions. The analysis of the docked poses confirmed that 1 showed better binding affinity for oxy-tyrosinase than that of 2.

Tyrosinase Inhibitory Activity of Pyrazole Derivatives

2012 ◽  
Vol 506 ◽  
pp. 194-197
Author(s):  
T. Suwunwong ◽  
T. Kobkeatthawin ◽  
K. Chanawanno ◽  
N. Saewan ◽  
P. Wisitsak ◽  
...  
Keyword(s):  
Inhibitory Activity ◽  
Spectroscopic Data ◽  
Kojic Acid ◽  
Data Interpretation ◽  
Pyrazole Derivatives ◽  
Tyrosinase Inhibitory Activity

A series of 3,5-substituted-4,5-dihydro-1H-pyrazole-1-carbothioamide derivatives were synthesized. Their structures were determined on the basis of spectroscopic data interpretation and their tyrosinase inhibitory activity was determined. The results showed that compound 2 (at 1.00 mg/mL) exhibits significant tyrosinase inhibitory activity with % inhibition of 91.866 ± 2.086 with L-tyrosine as substrate whereas compound 3 (at 1.00 mg/mL) exhibits significant tyrosinase inhibitory activity with % inhibition of 79.266 ± 0.552 and 89.593 ± 1.015 with L-tyrosine and L-DOPA as substrates. The IC50values of compounds 2 and 3 were further determined comparing with kojic acid and resveratrol. It was found that IC50values of compounds 2 and 3 were 0.391 ± 0.017 and 0.259 ± 0.005 mg/mL., with L-tyrosine as substrate, which were lower than those of the standard tyrosinase inhibitory resveratrol (0.965 ± 0.016 mg/mL).

Inhibition of Protein Tyrosine Phosphatase 1B by Lutein Derivatives isolated from Mexican Oregano (Lippia graveolens)

2018 ◽  
Vol 17 (3) ◽  
pp. 134-139
Author(s):  
R.M. Perez-Gutierrez
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Inhibitory Activity ◽  
Spectroscopic Data ◽  
Methanol Extract ◽  
Tyrosine Phosphatase ◽  
Positive Control ◽  
Protein Tyrosine Phosphatase 1B ◽  
Protein Tyrosine ◽  
Ic50 Value ◽  
Ic50 Values

Methanol extract from Lippia graveolens (Mexican oregano) was studied in order to identify inhibitory bioactives for protein tyrosine phosphatase 1B (PTP1B). Known flavone as lutein (1), and another flavone glycoside such as lutein-7-o-glucoside (2), 6-hydroxy-lutein-7-ohexoside (3) and lutein-7-o-ramnoide (4) were isolated from methanol extract of aerial parts of the Lippia graveolens. All isolates were identified based on extensive spectroscopic data analysis, including UV, IR, NMR, MS and compared with spectroscopic data previously reported. These flavones were evaluated for PTP1B inhibitory activity. Among them, compounds 1 and 3 displayed potential inhibitory activity against PTP1B with IC50 values of 7.01 ± 1.25 μg/ml and 18.4 μg/ml, respectively. In addition, compound 2 and 4 showed moderate inhibitory activity with an IC50 value of 23.8 ± 6.21 and 67.8 ± 5.80 μg/ml respectively. Among the four compounds, luteolin was found to be the most potent PTP1B inhibitor compared to the positive control ursolic acid, with an IC50 value of 8.12 ± 1.06 μg/ml. These results indicate that flavonoids constituents contained in Lippia graveolens can be considered as a natural source for the treatment of type 2 diabetes.

Evaluation of Cytotoxic and Tyrosinase Inhibitory Activities of 2-phenoxy(thiomethyl) pyridotriazolopyrimidines: In Vitro and Molecular Docking Studies

2020 ◽  
Vol 20 (14) ◽  
pp. 1714-1721
Author(s):  
Hatem A. Abuelizz ◽  
El Hassane Anouar ◽  
Mohamed Marzouk ◽  
Mizaton H. Hasan ◽  
Siti R. Saleh ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Kojic Acid ◽  
Docking Studies ◽  
Breast Adenocarcinoma ◽  
Amino Acid Residues ◽  
New Class ◽  
Structure Activity ◽  
Tyrosinase Inhibitors ◽  
Mcf 7

Background: The use of tyrosinase has confirmed to be the best means of recognizing safe, effective, and potent tyrosinase inhibitors for whitening skin. Twenty-four 2-phenoxy(thiomethyl)pyridotriazolopyrimidines were synthesized and characterized in our previous studies. Objective: The present work aimed to evaluate their cytotoxicity against HepG2 (hepatocellular carcinoma), A549 (pulmonary adenocarcinoma), MCF-7 (breast adenocarcinoma) and WRL 68 (embryonic liver) cell lines. Methods: MTT assay was employed to investigate the cytotoxicity, and a tyrosinase inhibitor screening kit was used to evaluate the Tyrosinase (TYR) inhibitory activity of the targets. Results: The tested compounds exhibited no considerable cytotoxicity, and nine of them were selected for a tyrosinase inhibitory test. Compounds 2b, 2m, and 5a showed good inhibitory percentages against TYR compared to that of kojic acid (reference substance). Molecular docking was performed to rationalize the Structure-Activity Relationship (SAR) of the target pyridotriazolopyrimidines and analyze the binding between the docked-selected compounds and the amino acid residues in the active site of tyrosinase. Conclusion: The target pyridotriazolopyrimidines were identified as a new class of tyrosinase inhibitors.

scholarly journals Design and Synthesis of Pyrazole-3-one Derivatives as Hypoglycaemic Agents

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Prasanna A. Datar ◽  
Sonali R. Jadhav
Keyword(s):  
Amino Acid ◽  
Docking Studies ◽  
Diabetic Rats ◽  
Hypoglycemic Activity ◽  
Amino Acid Residues ◽  
Docking Score ◽  
Design And Synthesis ◽  
Hypoglycaemic Agents ◽  
Standard Compound

Pyrazole-3-one compounds were designed on the basis of docking studies of previously reported antidiabetic pyrazole compounds. The amino acid residues found during docking studies were used as guidelines for the modification of aromatic substitutions on pyrazole-3-one structure. Depending on the docking score, the designed compounds were selectively prioritized for synthesis. The synthesized compounds were subjected to in vivo hypoglycemic activity using alloxan induced diabetic rats and metformin as a standard. Compound 4 having sulphonamide derivative was found to be the most potent compound among the series.

scholarly journals Components from the Leaves and Twigs of Mangrove Lumnitzera racemosa with Anti-Angiogenic and Anti-Inflammatory Effects

Marine Drugs ◽  
2018 ◽  
Vol 16 (11) ◽  
pp. 404 ◽  
Author(s):  
Szu-Yin Yu ◽  
Shih-Wei Wang ◽  
Tsong-Long Hwang ◽  
Bai-Luh Wei ◽  
Chien-Jung Su ◽  
...  
Keyword(s):  
Spectroscopic Data ◽  
Methanolic Extract ◽  
Data Interpretation ◽  
Tube Formation ◽  
Biosynthesis Pathway ◽  
Angiogenic Effect ◽  
Ic50 Values ◽  
Anti Inflammatory ◽  
Lumnitzera Racemosa

One new neolignan, racelactone A (1), together with seven known compounds (2−8) were isolated from the methanolic extract of the leaves and twigs of Lumnitzera racemosa. The structure of racelactone A (1) was determined on the basis of the mass and NMR spectroscopic data interpretation. With respect to bioactivity, compound 1 displayed an anti-angiogenic effect by suppressing tube formation. Furthermore, compounds 1, 4, and 5 showed significant anti-inflammatory effects with IC50 values of 4.95 ± 0.89, 1.95 ± 0.40, and 2.57 ± 0.23 μM, respectively. The plausible biosynthesis pathway of racelactone A (1) was proposed.

α-Glucosidase Inhibitory and Anti-Inflammatory Coumestans from the Roots of Dolichos trilobus

Planta Medica ◽  
2018 ◽  
Vol 85 (02) ◽  
pp. 112-117 ◽  
Author(s):  
Meng-Yuan Jiang ◽  
Ming Luo ◽  
Kai Tian ◽  
Yan-Hong Li ◽  
Jing-Xian Sun ◽  
...  
Keyword(s):  
Spectroscopic Data ◽  
Data Interpretation ◽  
Raw 264.7 Cells ◽  
Raw 264.7 ◽  
Nitric Oxide Production ◽  
Murine Macrophage ◽  
Cytotoxic Effects ◽  
Ic50 Values ◽  
Anti Inflammatory ◽  
Related Compounds

AbstractFour new coumestans dolichosins A – D (1–4) were isolated from the roots of Dolichos trilobus, together with four known compounds: isosojagol (5), phaseol (6), psoralidin (7), and 4″,5″-dehydroisopsoralidin (8). Their structures were elucidated on the basis of spectroscopic data interpretation, mass spectrometric analyses, and the comparison with literature data of related compounds. The anti-inflammatory activity of these compounds (1–8) was evaluated through the inhibition of nitric oxide production in lipopolysaccharide-activated murine macrophage RAW 264.7 cells, in which compounds 1 and 6 displayed moderate inhibitory activity and no cytotoxic effects. In a α-glucosidase inhibitory assay, compounds 1 and 5–8 exhibited appreciable inhibition on α-glucosidase. Especially compounds 1, 7, and 8 showed IC50 values lower than 20.0 µM.

scholarly journals The functional dyad of scorpion toxin Pi1 is not itself a prerequisite for toxin binding to the voltage-gated Kv1.2 potassium channels

2004 ◽  
Vol 377 (1) ◽  
pp. 25-36 ◽  
Author(s):  
Stéphanie MOUHAT ◽  
Amor MOSBAH ◽  
Violeta VISAN ◽  
Heike WULFF ◽  
Muriel DELEPIERRE ◽  
...  
Keyword(s):  
Amino Acid ◽  
Scorpion Toxin ◽  
Xenopus Laevis Oocytes ◽  
Amino Acid Residues ◽  
Voltage Gated ◽  
Toxin Binding ◽  
Ic50 Values

Pi1 is a 35-residue scorpion toxin cross-linked by four disulphide bridges that acts potently on both small-conductance Ca2+-activated (SK) and voltage-gated (Kv) K+ channel subtypes. Two approaches were used to investigate the relative contribution of the Pi1 functional dyad (Tyr-33 and Lys-24) to the toxin action: (i) the chemical synthesis of a [A24,A33]-Pi1 analogue, lacking the functional dyad, and (ii) the production of a Pi1 analogue that is phosphorylated on Tyr-33 (P-Pi1). According to molecular modelling, this phosphorylation is expected to selectively impact the two amino acid residues belonging to the functional dyad without altering the nature and three-dimensional positioning of other residues. P-Pi1 was directly produced by peptide synthesis to rule out any possibility of trace contamination by the unphosphorylated product. Both Pi1 analogues were compared with synthetic Pi1 for bioactivity. In vivo, [A24,A33]-Pi1 and P-Pi1 are lethal by intracerebroventricular injection in mice (LD50 values of 100 and 40 µg/mouse, respectively). In vitro, [A24,A33]-Pi1 and P-Pi1 compete with 125I-apamin for binding to SK channels of rat brain synaptosomes (IC50 values of 30 and 10 nM, respectively) and block rat voltage-gated Kv1.2 channels expressed in Xenopus laevis oocytes (IC50 values of 22 µM and 75 nM, respectively), whereas they are inactive on Kv1.1 or Kv1.3 channels at micromolar concentrations. Therefore, although both analogues are less active than Pi1 both in vivo and in vitro, the integrity of the Pi1 functional dyad does not appear to be a prerequisite for the recognition and binding of the toxin to the Kv1.2 channels, thereby highlighting the crucial role of other toxin residues with regard to Pi1 action on these channels. The computed simulations detailing the docking of Pi1 peptides on to the Kv1.2 channels support an unexpected key role of specific basic amino acid residues, which form a basic ring (Arg-5, Arg-12, Arg-28 and Lys-31 residues), in toxin binding.

scholarly journals A New Tyrosinase Inhibitor from the Red Alga Symphyocladia latiuscula (Harvey) Yamada (Rhodomelaceae)

Marine Drugs ◽  
2019 ◽  
Vol 17 (5) ◽  
pp. 295 ◽  
Author(s):  
Pradeep Paudel ◽  
Aditi Wagle ◽  
Su Hui Seong ◽  
Hye Jin Park ◽  
Hyun Ah Jung ◽  
...  
Keyword(s):  
Methyl Ether ◽  
Inhibitory Activity ◽  
Biological Activities ◽  
Docking Study ◽  
Red Alga ◽  
Moderate Activity ◽  
Molecular Docking Study ◽  
Tyrosinase Inhibitory Activity ◽  
Ic50 Values ◽  
Catalytic Hydrogen

A marine red alga, Symphyocladia latiuscula (Harvey) Yamada (Rhodomelaceae), is a rich source of bromophenols with a wide array of biological activities. This study investigates the anti-tyrosinase activity of the alga. Moderate activity was demonstrated by the methanol extract of S. latiuscula, and subsequent column chromatography identified three bromophenols: 2,3,6-tribromo-4,5-dihydroxybenzyl methyl alcohol (1), 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether (2), and bis-(2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether) (3). Bromophenols 1 and 3 exhibited potent competitive tyrosinase inhibitory activity against l-tyrosine substrates, with IC50 values of 10.78 ± 0.19 and 2.92 ± 0.04 μM, respectively. Against substrate l-3,4-dihydroxyphenylalanine (l-DOPA), compounds 1 and 3 demonstrated moderate activity, while 2 showed no observable effect. The experimental data were verified by a molecular docking study that found catalytic hydrogen and halogen interactions were responsible for the activity. In addition, compounds 1 and 3 exhibited dose-dependent inhibitory effects in melanin and intracellular tyrosinase levels in α-melanocyte-stimulating hormone (α-MSH)-induced B16F10 melanoma cells. Compounds 3 and 1 were the most effective tyrosinase inhibitors. In addition, increasing the bromine group number increased the mushroom tyrosinase inhibitory activity.

scholarly journals Dimeric 1,4-benzoquinone Derivatives with Cytotoxic Activities from the Marine-Derived Fungus Penicillium sp. L129

Marine Drugs ◽  
2019 ◽  
Vol 17 (7) ◽  
pp. 383 ◽  
Author(s):  
Zhang ◽  
Ju ◽  
Li ◽  
Sun ◽  
Peng ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Cell Lines ◽  
Inhibitory Activity ◽  
Spectroscopic Data ◽  
Cytotoxic Activities ◽  
Penicillium Sp ◽  
Ic50 Values ◽  
Cytotoxicity Activities ◽  
Mic Value ◽  
Mcf 7

Two new dimeric 1,4-benzoquinone derivatives, peniquinone A (1) and peniquinone B (2), a new dibenzofuran penizofuran A (3), and a new pyrazinoquinazoline derivative quinadoline D (4), together with 13 known compounds (5–17), were isolated from a marine-derived fungus Penicillium sp. L129. Their structures, including absolute configurations, were elucidated by extensive spectroscopic data and electronic circular dichroism calculations. Compound 1 exhibited cytotoxicity against the MCF-7, U87 and PC3 cell lines with IC50 values of 12.39 µM, 9.01 µM and 14.59 µM, respectively, while compound 2 displayed relatively weak cytotoxicity activities against MCF-7, U87 and PC3 cell lines with IC50 values of 25.32 µM, 13.45 µM and 19.93 µM, respectively. Furthermore, compound 2 showed weak quorum sensing inhibitory activity against Chromobacterium violaceum CV026 with an MIC value of 20 μg/well.

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