scholarly journals C7-Prenylation of Tryptophan-Containing Cyclic Dipeptides by 7-Dimethylallyl Tryptophan Synthase Significantly Increases the Anticancer and Antimicrobial Activities

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3676
Author(s):  
Rui Liu ◽  
Hongchi Zhang ◽  
Weiqiang Wu ◽  
Hui Li ◽  
Zhipeng An ◽  
...  

Prenylated natural products have interesting pharmacological properties and prenylation reactions play crucial roles in controlling the activities of biomolecules. They are difficult to synthesize chemically, but enzymatic synthesis production is a desirable pathway. Cyclic dipeptide prenyltransferase catalyzes the regioselective Friedel–Crafts alkylation of tryptophan-containing cyclic dipeptides. This class of enzymes, which belongs to the dimethylallyl tryptophan synthase superfamily, is known to be flexible to aromatic prenyl receptors, while mostly retaining its typical regioselectivity. In this study, seven tryptophan-containing cyclic dipeptides 1a–7a were converted to their C7-regularly prenylated derivatives 1b–7b in the presence of dimethylallyl diphosphate (DMAPP) by using the purified 7-dimethylallyl tryptophan synthase (7-DMATS) as catalyst. The HPLC analysis of the incubation mixture and the NMR analysis of the separated products showed that the stereochemical structure of the substrate had a great influence on their acceptance by 7-DMATS. Determination of the kinetic parameters proved that cyclo-l-Trp–Gly (1a) consisting of a tryptophanyl and glycine was accepted as the best substrate with a KM value of 169.7 μM and a turnover number of 0.1307 s−1. Furthermore, docking studies simulated the prenyl transfer reaction of 7-DMATS and it could be concluded that the highest affinity between 7-DMATS and 1a. Preliminary results have been clearly shown that prenylation at C7 led to a significant increase of the anticancer and antimicrobial activities of the prenylated derivatives 1b–7b in all the activity test experiment, especially the prenylated product 4b.

Author(s):  
Asghar Davood ◽  
Aneseh Rahimi ◽  
Maryam Iman ◽  
Parisa Azerang ◽  
Soroush Sardari ◽  
...  

Objective(s): Azole antifungal agents, which are widely used as antifungal antibiotics, inhibit cytochrome P450 sterol 14α-demethylase (CYP51). Nearly all azole antifungal agents are N-substituted azoles. In addition, an azolylphenalkyl pharmacophore is uniquely shared by all azole antifungals. Due to importance of nitrogen atom of azoles (N-3 of imidazole and N-4 of triazole) in coordination with heme in the binding site of the enzyme, here a group of N- un-substituted azoles in which both of nitrogen is un-substituted was reported. Materials and Methods: Designed compounds were synthesized by reaction of imidazole-4-carboxaldehyde with appropriate arylamines and subsequently reduced to desired amine derivatives. Antifungal activity against Candida albicans and Saccharomyces cervisiae were done using a broth micro-dilution assay. Docking studies were done using AutoDock. Results: Antimicrobial evaluation revealed that some of these compounds exhibited moderate antimicrobial activities against tested pathogenic fungi, wherein compound 3, 7 and 8 were potent. Docking studies propose that all of the prepared azoles interacted with 14α-DM, wherein azole-heme coordination play main role in drug-receptor interaction. Conclusion: Our results offer some useful references in order to molecular design performance or modification of this series of compounds as a lead compound to discover new and potent antimicrobial agents.


Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 712
Author(s):  
Ali Salama ◽  
Ammar Almaaytah ◽  
Rula M. Darwish

(1) Background: Antimicrobial resistance represents an urgent health dilemma facing the global human population. The development of novel antimicrobial agents is needed to face the rising number of resistant bacteria. Ultrashort antimicrobial peptides (USAMPs) are considered promising antimicrobial agents that meet the required criteria of novel antimicrobial drug development. (2) Methods: Alapropoginine was rationally designed by incorporating arginine (R), biphenylalanine (B), and naproxen to create an ultrashort hexapeptide. The antimicrobial activity of alapropoginine was evaluated against different strains of bacteria. The hemolytic activity of alapropoginine was also investigated against human erythrocytes. Finally, synergistic studies with antibiotics were performed using the checkerboard technique and the determination of the fractional inhibitory index. (3) Results: Alapropoginine displayed potent antimicrobial activities against reference and multi-drug-resistant bacteria with MIC values of as low as 28.6 µg/mL against methicillin-resistant S. aureus. Alapropoginine caused negligible toxicity toward human red blood cells. Moreover, the synergistic studies showed improved activities for the combined conventional antibiotics with a huge reduction in their antimicrobial concentrations. (4) Conclusions: The present study indicates that alapropoginine exhibits promising antimicrobial activity against reference and resistant strains of bacteria with negligible hemolytic activity. Additionally, the peptide displays synergistic or additive effects when combined with several antibiotics.


Author(s):  
SURENDRA BABU LAGU ◽  
RAJENDRA PRASAD YEJELLA

Objective: Investigation, the series of newer 2‐amino-pyridine‐3‐carbonitrile and 2‐amino-4H-pyran‐3‐carbonitrile derivative were synthesized and evaluated antimicrobial activities and antioxidant activity. Methods: Novel synthesized chalcones were further condensation to give 2-amino-3-cyanopyridine and 2-amino-3-cyanopyrans in the presence of malononitrile, pyridine, and ammonia acetate. The product is characterized by conventional and instrumental methods. Pyridine and 4-H-Pyran and their analogs occupy prime position due to their diverse applications. Results: The compounds A3C and B3C exhibited marked zone of inhibition with 30.02±0.02 mm and 29.06±0.01 mm, respectively. Docking studies suggested possible interactions with dihydrofolic reductase 4 with 9.15 and −9.67 kcal/mol, respectively. The IC50 30.28±0.01 exhibited A3C by 2,2-diphenylpicrylhydrazyl methods which is better among the series. The 2-amino-3-cyanopyridine derivatives were found good activity than 2-amino-3-cyanopyrane derivative. Among all synthesized compounds few having potent activity and some are near to the standard. Conclusion: Antimicrobial activity and antioxidant of the newly synthesized pyrans and pyridines derivatives will definitely inspire future researchers for the preparation of new analogs.


2018 ◽  
Vol 44 (4) ◽  
pp. 473-481
Author(s):  
Elif Ayazoglu Demir ◽  
Ahmet Colak ◽  
Aylin Kalfa ◽  
Ahmet Yasar ◽  
Olcay Bekircan ◽  
...  

Abstract Background Tyrosinase plays a central role in the biosynthesis pathway of melanin pigment. Melanin protects human skin against radiation and its unusual levels cause some skin disorders such as pregnancy scar, oldness spots and melanoma. Tyrosinase has also been linked to Parkinson’s and other neurodegenerative diseases. In addition, melanin plays a critical role as a defense molecule for insects during wound healing and is important for their life. Therefore, determination of inhibitor molecules for tyrosinase has a promising potential for therapies of some diseases and is an alternative method for keeping insects under control. Material and methods In this study, 1-hepthyl-3-(4-methoxybenzyl)-4H-1,2,4-triazole-5-one derivative (A6, A8, A15) and 3-(4-chlorophenyl)- 5-(4-methoxybenzyl)-4H-1,2,4-triazole (B5, B9, B13) derivative compounds were evaluated in terms of their potential for mushroom tyrosinase inhibition. IC50 values of these six molecules were determined. Results It was seen that B9 molecule was the most effective inhibitor. Docking studies also nearly supported this end result. Tyrosinase inhibition type and Ki value were found to be uncompetitive and 370.7±0.3 μM, respectively, in the presence of B9 compound. Conclusion These results suggest that B9 compound is a potential tyrosinase inhibitor.


2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
K. Savithri ◽  
B. C. Vasantha Kumar ◽  
H. K. Vivek ◽  
H. D. Revanasiddappa

A bidentate (N- and O-) imine-based ligand (L1) and its metal complexes of types [CuII(L1)2] (C1), [CuII(L1)(Phen)] (C2), [CoIII(L1)2] (C3), and [CoIII(L1)(Phen)] (C4) (L1 = 2-((E)-(6-fluorobenzo[d]thiazol-2-ylimino)methyl)-4-chlorophenol and phen = 1,10-phenanthroline) were synthesized as potential chemotherapeutic drug candidates. The prepared complexes were structurally characterized by spectral techniques (NMR, FT-IR, LC-MS, EPR, and electronic absorption), thermogravimetric analysis (TGA/DTA), magnetic moment, and CHNO elemental analysis. Spectroscopic studies suggested the distorted octahedral structure for all complexes. In vitro bioassay studies include binding and nuclease activities of the ligand and its complexes with target calf thymus- (CT-) DNA were carried out by employing UV-Vis, fluorescence spectroscopy, viscosity, and gel electrophoresis techniques. The extent of binding propensity was determined quantitatively by Kb and Ksv values which revealed a higher binding affinity for C2 and C4 as compared to C1 and C3. In addition, the scavenging superoxide anion free radical (O∙-2) activity of metal complexes was determined by nitroblue tetrazolium (NBT) light reduction assay. Molecular docking studies with DNA and SOD enzyme were also carried out on these compounds. The antimicrobial study has shown that all the compounds are potential antibacterial agents against Gram-negative bacterial strains and better antifungal agents with respect to standard drugs used.


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