Phenanthridine derivatives as promising new anticancer agents: synthesis, biological evaluation and binding studies

The Effective Synthesis of New Benzoquinoline Derivatives as Small Molecules with Anticancer Activity

In this study, some novel benzo[c]quinoline derivatives were synthesized, their structural characteristics were described, and their in vitro anticancer efficacy was investigated. The synthesis involves an initial quaternization of the nitrogen atom from benzo[c]quinoline and then a [3+2] dipolar cycloaddition reaction of the in situ formed ylide. The effectiveness of synthesis using traditional thermal heating (TH) compared to microwave (MW) and ultrasound (US) irradiation was investigated in detail. The setup of a reaction under MW or US irradiation offers a number of additional benefits: higher yields, a reduction in the amount of solvent used compared to TH, a reduction in the reaction time from hours to minutes, and a reduction in the amount of energy consumed. The structure of all the obtained compounds was proved by several spectral techniques (FTIR, HRMS, and NMR). All benzo[c]quinoline derivatives (quaternary salts and cycloadducts) along with ten other benzo[f]quinoline derivatives (quaternary salts and cycloadducts), previously obtained, were tested in an in vitro single-dose anticancer experiment. The results demonstrated that the cycloadducts 5a-c and 6a-c exhibit stronger anticancer activity than quaternary salts 3a-c. The most active compound is compound 5a, with anticancer activity on most of the cell lines studied, while the second most active compound is 6c, showing significant lethality for the SR leukemia cell line (17%). Structure-activity relationship (SAR) correlations are also included in the study.

Visible-Light-Mediated Annulation/Thiolation of 2-Isocyanobiaryls with Disulfides to Organoylthiophenanthridines Derivatives

A visible-light-induced annulation/thiolation of 2-isocyanobiaryls with dialkyl(aryl)disulfides has been established, delivering a sustainable and atom-economic route to 6-organoylthiophenanthridines with wild functional group tolerance and good to excellent yields under oxidant-, base-, and transition-metal-free conditions.

Design, synthesis and biological evaluation of phenanthridine amide and 1,2,3-triazole analogues against Mycobacterium tuberculosis

The phenanthridine core exhibits antitubercular activity, according to reports from the literature. Several 1,2,3-triazole-based heterocyclic compounds are well-known antitubercular agents. A series of twenty-five phenanthridine amide and 1,2,3-triazole derivatives are synthesized and analyzed using ESI-MS, 1HNMR, and 13CNMR on the basis of our earlier findings that phenanthridine and 1,2,3-triazoles shown good antitubercular activity. The synthesized phenanthridine amide and 1,2,3-triazole analogues were tested in vitro against Mycobacterium tuberculosis H37Rv and minimum inhibitory concentration (MIC) values were determined utilizing non-replicating and replicating low-oxygen recovery assay (LORA) and microplate Alamar Blue assay (MABA) methodologies. The phenanthridine amide derivative PA-01 had an MIC of 61.31 μM in MABA and 62.09 μM in the LORA technique, showing intense anti-TB activity. Amongst the phenanthridine triazole derivatives, PT-09, with MICs of 41.47 and 78.75 μM against the tested strain of Mtb in both MABA and LORA was the most active one. The final analogues' drug-likeness is predicted using absorption, distribution, metabolism, excretion, and toxicity (ADMET) studies. The most active compounds PA-01 and PT-09 were further subjected to in silico docking studies. Using the Glide module of Schrodinger, molecular docking analysis was carried out to estimate the plausible binding pattern of PA-01 and PT-09 at the active site of Mycobacterial DNA topoisomerase II (PDB code: 5BS8). Further, molecular dynamics studies of PA-01 and PT-09 were also carried out.

Anti-AChE and Anti-BuChE Screening of the Fermentation Broth Extracts from Twelve Aspergillus Isolates and GC-MS and Molecular Docking Studies of the Most Active Extracts

Nowadays, the administration of cholinesterase enzyme (acetylcholinesterase: AChE and butyrylcholinesterase: BuChE) inhibitors is very common for the symptomatic treatment of Alzheimer's disease and the other forms of dementia and CNS disorders. In this paper, the anti-AChE and anti-BuChE activities of the fermentation broth ethyl acetate extracts from twelve Aspergillus isolates were evaluated by Ellman method. The results showed that A1 (Aspergillus flavus) and A5 (Aspergillus tubingensis, isolate 1) extracts with IC50 values of 46.77 μg/mL and 75.85 μg/mL possess the greatest ability to inhibit AChE and BuChE, respectively. GC-MS analysis of the extracts (A1 and A5) demonstrated that two alkaloids named 14-methyl-16-azabicyclo[10.3.1]hexadeca-1(15),12(16),13-triene (MAHT) and 6-chloro-2-methyl-7,8,9,10-tetrahydro-phenanthridine (CMTP) account for the highest percentage of A1 (26.95%) and A5 (25.5%) extracts, respectively. A 2-pyrazoline derivative, 5-hydroxy-3-(4-pyridinyl)-5-trifluoromethyl-1-(2,4,6-trimethylphenoxyacetyl)- (PHPTT), also constituted the high percentage (9.54%) of A5 extract. The anticholinesterase and neuroprotective effects of some 2-pyrazoline derivatives have been previously reported. The interaction study of MAHT with human AChE and CMTP and PHPTT with human BuChE using molecular docking indicated that these alkaloids bind to the active site gorge of the enzymes with high affinity. The best docking scores of MAHT, CMTP, and PHPTT were -7.1, -8.2, and -9.7 kcal/mol, respectively.

Updates on drug designing approach through computational strategies: a review

The drug discovery and development (DDD) process in pursuit of novel drug candidates is a challenging procedure requiring lots of time and resources. Therefore, computer-aided drug design (CADD) methodologies are used extensively to promote proficiency in drug development in a systematic and time-effective manner. The point in reference is SARS-CoV-2 which has emerged as a global pandemic. In the absence of any confirmed drug moiety to treat the infection, the science fraternity adopted hit and trial methods to come up with a lead drug compound. This article is an overview of the virtual methodologies, which assist in finding novel hits and help in the progression of drug development in a short period with a specific medicinal solution.

Phenanthridine derivatives as potential HIV-1 protease inhibitors

In the present study, the antiviral activity of phenanthridine derivatives was assessed. In total, the inhibitory effect of eight structurally similar low-molecular-weight hydrophobic compounds on HIV-1 protease (HIVp) was investigated. HIVp is a key enzyme in the HIV-1 life cycle. Surface plasmon resonance technology was used for affinity assessment of compounds binding with either monomeric or dimeric forms of HIVp. HIVp enzyme inhibition assays with chromogenic substrate VII were also used to determine the IC₅₀ values. The most potent compound was 3,3,9,9-tetramethyl-3,4,9,10-tetrahydro-2H,8H-phenanthridine-1,7-dione which binds to monomeric and dimeric forms of HIVp (apparent dissociation constant, 2-7 µM; IC₅₀, 36 µМ), while possessing the most favorable Absorption, Distribution, Metabolism and Excretion parameters. Molecular docking simulations highlighted certain differences in the binding patterns of the phenanthridine derivatives with HIVp amino acid residues forming the flaps domain, monomer/monomer interfaces and the active site cavity of HIVp. Thus, it was hypothesized that the inhibitory effect of phenanthridine compounds on the enzymatic activity of HIVp may be due to restriction of substrate access to the HIVp active site.