scholarly journals Urolithin and Reduced Urolithin Derivatives as Potent Inhibitors of Tyrosinase and Melanogenesis: Importance of the 4-Substituted Resorcinol Moiety

2021 ◽  
Vol 22 (11) ◽  
pp. 5616
Author(s):  
Sanggwon Lee ◽  
Heejeong Choi ◽  
Yujin Park ◽  
Hee Jin Jung ◽  
Sultan Ullah ◽  
...  

We previously reported (E)-β-phenyl-α,β-unsaturated carbonyl scaffold ((E)-PUSC) played an important role in showing high tyrosinase inhibitory activity and that derivatives with a 4-substituted resorcinol moiety as the β-phenyl group of the scaffold resulted in the greatest tyrosinase inhibitory activity. To examine whether the 4-substituted resorcinol moiety could impart tyrosinase inhibitory activity in the absence of the α,β-unsaturated carbonyl moiety of the (E)-PUSC scaffold, 10 urolithin derivatives were synthesized. To obtain more candidate samples, the lactone ring in synthesized urolithins was reduced to produce nine reduced urolithins. Compounds 1c (IC50 = 18.09 ± 0.25 μM), 1h (IC50 = 4.14 ± 0.10 μM), and 2a (IC50 = 15.69 ± 0.40 μM) had greater mushroom tyrosinase-inhibitory activities than kojic acid (KA) (IC50 = 48.62 ± 3.38 μM). The SAR results suggest that the 4-substituted resorcinol motif makes an important contribution to tyrosinase inhibition. To investigate whether these compounds bind to human tyrosinase, a human tyrosinase homology model was developed. Docking simulations with mushroom and human tyrosinases showed that 1c, 1h, and 2a bind to the active site of both tyrosinases with higher binding affinities than KA. Pharmacophore analyses showed that two hydroxyl groups of the 4-substituted resorcinol entity act as hydrogen bond donors in both mushroom and human tyrosinases. Kinetic analyses indicated that these compounds were all competitive inhibitors. Compound 2a inhibited cellular tyrosinase activity and melanogenesis in α-MSH plus IBMX-stimulated B16F10 melanoma cells more strongly than KA. These results suggest that 2a is a promising candidate for the treatment of skin pigment disorders, and show the 4-substituted resorcinol entity importantly contributes to tyrosinase inhibition.

2016 ◽  
Vol 16 (1) ◽  
pp. 18 ◽  
Author(s):  
Vidyalakshmi Subramanian ◽  
Dhamodharan Sahithya

Tyrosinase inhibition is an important approach towards controlling hyper pigmentation. We aimed to screen alcoholic extracts of 11 plants extract for their tyrosinase inhibitory activity. These plants have been used traditionally in the treatment of skin ailments and for the improvement of skin complexion. The extracts were quantified for total phenols, alkaloids and tannins. <em>In vitro</em> tyrosinase inhibition was performed with kojic acid as the positive control. Cell viability was tested on B16 F0 melanoma cells. The extracts of <em>Rosa berberifolia</em>, <em>Punica granatum</em> and <em>Casiia angustifolia</em> showed more than 80% inhibition at 500 mg/ml concentration. Nine of the extracts were also shown to have a high phenolic content greater than 200 mg/g of the plant material. The tyrosinase inhibitory activity of the extracts of <em>Cassia angustifolia, Punica granatum </em>and<em> Rosa berberifolia</em> were comparable with that of the control, kojic acid. The three extracts also showed lesser than 50% cytotoxicity at the concentrations tested. From the screening assays, it is seen that three plants have appreciable tyrosinase inhibitory activity. Hence, these plants may be further evaluated for their use in cosmetics and hyper pigmentation.


2020 ◽  
Vol 26 (2) ◽  
pp. 209-213
Author(s):  
Nissha Bharrathi Romes ◽  
Wan Mohd Nuzul Hakimi Wan Salleh ◽  
Hasnah Mohd Sirat ◽  
Zaini Assim

Background: Genus Alpinia are commonly used as spices and ingredients in traditional medicines. In the present study, we attempted to isolate the phytochemicals from Alpinia aquatica and evaluate their tyrosinase inhibitory activity. Methods: Phytochemical constituents of the extract were investigated using various chromatographic and spectroscopic methods. The chemical structures of the isolated phytochemicals were established by analysis of their spectroscopic data, as compared to that of reported data. Tyrosinase inhibitory activity was also tested on the extracts and selected compounds using mushroom tyrosinase as the enzyme. Results: Fractionation and purification of the extracts of Alpinia aquatica afforded seven known compounds which are 5-hydroxy-3,7,4’-trimethoxyflavone (1), 4’,5-dihydroxy-3,7-dimethoxyflavone (2), 2-methoxy-8-(2’,4’,5’-trimethoxyphenyl)-1,4-naphthaquinone (3), cis-3S-(2’,4’,5’-trimethoxyphenyl)-4S-[(E)-2’’’,4’’’,5’’’-trimethoxystyryl]cyclohexene (4), 2,4,5-trimethoxybenzaldehyde (5), stigmasterol (6) and β-sitosterol (7). The ethyl acetate extract of pseudostems possessed the highest tyrosinase inhibition of 31.0% among the extracts, while compound (1) gave tyrosinase inhibition of 48.0%. Conclusion: Compounds (3) and (4) were isolated for the first time from A. aquatica and Alpinia genus. These phytochemical results suggest that the extracts could assist as a potential source of bioactive compounds. Further research is needed in which the extract could possibly be exploited for pharmaceutical use.


2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Zhao-Hui Sun ◽  
Jing Chen ◽  
Yun-Qing Song ◽  
Tong-Yi Dou ◽  
Li-Wei Zou ◽  
...  

Abstract Background Human carboxylesterases (hCES) are key serine hydrolases responsible for the hydrolysis of a wide range of endogenous and xenobiotic esters. Although it has been reported that some ginsenosides can modulate the activities of various enzymes, the inhibitory effects of ginsenosides on hCES have not been well-investigated. Methods In this study, more than 20 ginsenosides were collected and their inhibitory effects on hCES1A and hCES2A were assayed using the highly specific fluorescent probe substrates for each isoenzyme. Molecular docking simulations were also performed to investigate the interactions between ginsenosides and hCES. Results Among all tested ginsenosides, Dammarenediol II (DM) and 20S-O-β-(d-glucosyl)-dammarenediol II (DMG) displayed potent inhibition against both hCES1A and hCES2A, while protopanaxadiol (PPD) and protopanaxatriol (PPT) exhibited strong inhibition on hCES2A and high selectivity over hCES1A. Introduction of O-glycosyl groups at the core skeleton decreased hCES inhibition activity, while the hydroxyl groups at different sites might also effect hCES inhibition. Inhibition kinetic analyses demonstrated that DM and DMG functioned as competitive inhibitors against hCES1A-mediated d-luciferin methyl ester (DME) hydrolysis. In contrast, DM, DMG, PPD and PPT inhibit hCES2A-mediated fluorescein diacetate (FD) hydrolysis via a mixed manner. Conclusion The structure–inhibition relationships of ginsenosides as hCES inhibitors was investigated for the first time. Our results revealed that DM and DMG were potent inhibitors against both hCES1A and hCES2A, while PPD and PPT were selective and strong inhibitors against hCES2A.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Larissa Lavorato Lima ◽  
Rebeca Mól Lima ◽  
Annelisa Farah da Silva ◽  
Antônio Márcio Resende do Carmo ◽  
Adilson David da Silva ◽  
...  

This research has been an effort to develop synthetic resveratrol analogs in order to improve the depigmenting potential of natural resveratrol. Six resveratrol analogs were synthesized and tested for tyrosinase inhibitory activityin vitro, by qualitative and quantitative steps. The results showed the analogCas being the most powerful tyrosinase inhibitor (IA50= 65.67 ± 0.60 μg/mL), followed by the analogsB,E,F,A, andD, respectively. The analogCpresented a tyrosinase inhibition potential better than natural resveratrol (P<0.001). The best depigmenting activity was provided by the presence of hydroxyl in the orthoposition on the second phenolic ring.


2011 ◽  
Vol 2011 ◽  
pp. 1-7 ◽  
Author(s):  
Shang-Jun Yin ◽  
Yue-Xiu Si ◽  
Guo-Ying Qian

Tyrosinase inhibition studies are needed due to the medicinal applications such as hyperpigmentation. For probing effective inhibitors of tyrosinase, a combination of computational prediction and enzymatic assay via kinetics was important. We predicted the 3D structure of tyrosinase, used a docking algorithm to simulate binding between tyrosinase and phthalic acid (PA), and studied the reversible inhibition of tyrosinase by PA. PA inhibited tyrosinase in a mixed-type manner with a Ki=65.84±1.10 mM. Measurements of intrinsic and ANS-binding fluorescences showed that PA induced changes in the active site structure via indirect binding. Simulation was successful (binding energies for Dock6.3=-27.22 and AutoDock4.2=-0.97 kcal/mol), suggesting that PA interacts with LEU73 residue that is predicted commonly by both programs. The present study suggested that the strategy of predicting tyrosinase inhibition based on hydroxyl groups and orientation may prove useful for screening of potential tyrosinase inhibitors.


Author(s):  
Reema Abu Khalaf ◽  
Shorooq Alqazaqi ◽  
Maram Aburezeq ◽  
Dima Sabbah ◽  
Ghadeer Albadawi ◽  
...  

Background: Diabetes mellitus is a chronic metabolic disorder, characterized by hyperglycemia over a prolonged period, disturbance of fat, protein and carbohydrate metabolism, resulting from defective insulin secretion, insulin action or both. Dipeptidyl peptidase-IV (DPP-IV) inhibitors are relatively a new class of oral hypoglycemic agents that reduces the deterioration of gut-derived endogenous incretin hormones that are secreted in response to food ingestion to stimulate the secretion of insulin from beta cells of pancreas. Objective: In this study, synthesis, characterization, and biological assessment of twelve novel phenanthridine sulfonamide derivatives 3a-3l as potential DPP-IV inhibitors was carried out. The target compounds were docked to study the molecular interactions and binding affinities against DPP-IV enzyme. Methods: The synthesized molecules were characterized using 1H-NMR, 13C-NMR, IR, and MS. Quantum-polarized ligand docking (QPLD) was also performed. Results: In vitro biological evaluation of compounds 3a-3l reveals comparable DPP-IV inhibitory activities ranging from 10%-46% at 100 µM concentration, where compound 3d harboring ortho-fluoro moiety exhibited the highest inhibitory activity. QPLD study shows that compounds 3a-3l accommodate DPP-IV binding site and form H-bonding with the R125, E205, E206, S209, F357, R358, K554, W629, S630, Y631, Y662, R669 and Y752 backbones. Conclusion: In conclusion, phenanthridine sulfonamides could serve as potential DPP-IV inhibitors that require further structural optimization in order to enhance their inhibitory activity.


2021 ◽  
Author(s):  
Sucheewin Krobthong ◽  
Yodying Yingchutrakul ◽  
Pawitrabhorn Samutrtai ◽  
Kiattawee Choowongkomon

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1254 ◽  
Author(s):  
Xi Chen ◽  
Dong Chen ◽  
Linyuan Huang ◽  
Xiaoling Chen ◽  
Mei Zhou ◽  
...  

The peptides from the ranacyclin family share similar active disulphide loop with plant-derived Bowman–Birk type inhibitors, some of which have the dual activities of trypsin inhibition and antimicrobial. Herein, a novel Bowman–Birk type trypsin inhibitor of the ranacyclin family was identified from the skin secretion of broad-folded frog (Sylvirana latouchii) by molecular cloning method and named as SL-BBI. After chemical synthesis, it was proved to be a potent inhibitor of trypsin with a Ki value of 230.5 nM and showed weak antimicrobial activity against tested microorganisms. Modified analogue K-SL maintains the original inhibitory activity with a Ki value of 77.27 nM while enhancing the antimicrobial activity. After the substitution of active P1 site to phenylalanine and P2′ site to isoleucine, F-SL regenerated its inhibitory activity on chymotrypsin with a Ki value of 309.3 nM and exhibited antiproliferative effects on PC-3, MCF-7 and a series of non-small cell lung cancer cell lines without cell membrane damage. The affinity of F-SL for the β subunits in the yeast 20S proteasome showed by molecular docking simulations enriched the understanding of the possible action mode of Bowman–Birk type inhibitors. Further mechanistic studies have shown that F-SL can activate caspase 3/7 in H157 cells and induce apoptosis, which means it has the potential to become an anticancer agent.


2017 ◽  
Vol 15 (1) ◽  
pp. 332-343 ◽  
Author(s):  
Karolina A. Wojtunik-Kulesza ◽  
Katarzyna Targowska-Duda ◽  
Katarzyna Klimek ◽  
Grażyna Ginalska ◽  
Krzysztof Jóźwiak ◽  
...  

AbstractAlzheimer’s disease (AD) is by far the most prevalent of all known forms of dementia. Despite wide-spread research, the main causes of emergence and development of AD have not been fully recognized. Natural, low-molecular, lipophilic terpenoids constitute an interesting group of secondary plant metabolites, that exert biological activities of possible use in the prevention and treatment of AD. In order to identify secondary metabolites possessing both antioxidant activity and the potential to increase the level of acetylcholine, selected terpenoids have been screened for possible acetylcholinesterase inhibitory activity by use of two methods, namely Marston (chromatographic assay) and Ellman (spectrophotometric assay). In order to describe the interaction between terpenes and AChE active gorge, molecular docking simulations were performed. Additionally, all analyzed terpenes were also evaluated for their cytotoxic properties against two normal cell lines using MTT assay. The obtained results show that: carvone (6), pulegone (8) and γ-terpinene (7) possess desirable AChE inhibitory activity. MTT assay revealed low or lack of cytotoxicity of these metabolites. Thus, among the investigated terpenes, carvone (6), pulegone (8) and y-terpinene (7) can be recognized as compounds with most promising activities in the development of multi-target directed ligands.


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