Synthesis and Critical View on the Structure-Activity Relationships of N-(Substituted phenyl)-/N-Diphenylmethyl-piperazine-Based Conjugates as Antimycobacterial Agents

This research focused on a three-step synthesis, analytical, physicochemical, and biological evaluation of hybrid molecules 6a–g, containing a lipophilic 3-trifluoromethylphenyl moiety, polar carbamoyloxy bridge, 2-hydroxypropan-1,3-diyl chain and 4-(substituted phenyl)-/4-diphenylmethylpiperazin-1-ium-1-yl fragment. The estimation of analytical and physicochemical descriptors (m/zmeasured via HPLC-UV/HR-MS, log ε2 (Ch–T) from UV/Vis spectrophotometry and log kw via RP-HPLC) as well as in vitro antimycobacterial and cytotoxic screening of given compounds were carried out (i.e., determination of MIC and IC50 values). These highly lipophilic molecules (log kw = 4.1170–5.2184) were tested against Mycobacterium tuberculosis H37Ra ATCC 25177 (Mtb H37Ra), M. kansasii DSM 44162 (MK), M. smegmatis ATCC 700084 (MS), and M. marinum CAMP 5644 (MM). The impact of the 6a–g set on the viability of human liver hepatocellular carcinoma (HepG2) cells was also investigated. 1-[2-Hydroxypropyl-{(3-trifluoromethyl)- phenyl}carbamoyloxy]-4-(3,4-dichlorophenyl)piperazin-1-ium chloride (6e) and 1-[2-hydroxy- propyl-{(3-trifluoromethyl)phenyl}carbamoyloxy]-4-(4-diphenylmethyl)piperazin-1-ium chloride (6g) most effectively inhibited the growth of Mtb H37Ra (MIC < 3.80 μM). The substance 6g also showed interesting activity against MM (MIC = 8.09 μM). All obtained data served as input values for structure-activity relationship evaluations using statistical principal component analysis. In fact, the toxicity of both 6e (IC50 = 29.39 μM) and 6g (IC50 = 22.18 μM) in HepG2 cells as well as selectivity index (SI) values (SI < 10.00) prevented to consider these promising antimycobacterials safe.

Synthesis, Anticancer Assessment, and Molecular Docking of Novel Chalcone-Thienopyrimidine Derivatives in HepG2 and MCF-7 Cell Lines

Heterocycles containing thienopyrimidine moieties have attracted attention due to their interesting biological and pharmacological activities. In this research article, we reported the synthesis of a series of new hybrid molecules through merging the structural features of chalcones and pyridothienopyrimidinones. Our results indicated that the synthesis of chalcone-thienopyrimidine derivatives from the corresponding thienopyrimidine and chalcones proceeded in a relatively short reaction time with good yields and high purity. Most of these novel compounds exhibited moderate to robust cytotoxicity against HepG2 and MCF-7 cancer cells similar to that of 5-fluorouracil (5-FU). The results indicated that IC50 of the two compounds (3b and 3g) showed more potent anticancer activities against HepG2 and MCF-7 than 5-FU. An MTT assay and flow cytometry showed that only 3b and 3g had anticancer activity and antiproliferative activities at the G1 phase against MCF-7 cells, while six compounds (3a-e and 3g) had cytotoxicity and cell cycle arrest at different phases against HepG2 cells. Their cytotoxicity was achieved through downregulation of Bcl-2 and upregulation of Bax, caspase-3, and caspase-9. Although all tested compounds increased oxidative stress via increment of MDA levels and decrement of glutathione reductase (GR) activities compared to control, the 3a, 3b, and 3g in HepG2 and 3b and 3g in MCF-7 achieved the target results. Moreover, there was a positive correlation between cytotoxic efficacy of the compound and apoptosis in both HepG2 ( R 2 = 0.531 ; P = 0.001 ) and MCF-7 ( R 2 = 0.219 ; P = 0.349 ) cell lines. The results of molecular docking analysis of 3a-g into the binding groove of Bcl-2 revealed relatively moderate binding free energies compared to the selective Bcl-2 inhibitor, DRO. Like venetoclax, compounds 3a-g showed 2 violations from Lipinski’s rule. However, the results of the ADME study also revealed higher drug-likeness scores for compounds 3a-g than for venetoclax. In conclusion, the tested newly synthesized chalcone-pyridothienopyrimidinone derivatives showed promising antiproliferative and apoptotic effects. Mechanistically, the compounds increased ROS production with concomitant cell cycle arrest and apoptosis. Therefore, regulation of the cell cycle and apoptosis are possible targets for anticancer therapy. The tested compounds could be potent anticancer agents to be tested in future clinical trials after extensive pharmacodynamic, pharmacokinetic, and toxicity profile investigations.

The Monoterpenoid Perillyl Alcohol: Anticancer Agent and Medium to Overcome Biological Barriers

Perillyl alcohol (POH) is a naturally occurring monoterpenoid related to limonene that is present in the essential oils of various plants. It has diverse applications and can be found in household items, including foods, cosmetics, and cleaning supplies. Over the past three decades, it has also been investigated for its potential anticancer activity. Clinical trials with an oral POH formulation administered to cancer patients failed to realize therapeutic expectations, although an intra-nasal POH formulation yielded encouraging results in malignant glioma patients. Based on its amphipathic nature, POH revealed the ability to overcome biological barriers, primarily the blood–brain barrier (BBB), but also the cytoplasmic membrane and the skin, which appear to be characteristics that critically contribute to POH’s value for drug development and delivery. In this review, we present the physicochemical properties of POH that underlie its ability to overcome the obstacles placed by different types of biological barriers and consequently shape its multifaceted promise for cancer therapy and applications in drug development. We summarized and appraised the great variety of preclinical and clinical studies that investigated the use of POH for intranasal delivery and nose-to-brain drug transport, its intra-arterial delivery for BBB opening, and its permeation-enhancing function in hybrid molecules, where POH is combined with or conjugated to other therapeutic pharmacologic agents, yielding new chemical entities with novel mechanisms of action and applications.

Novel Structural Hybrids of Pyrrole and Thiazole Moieties: Synthesis and Evaluation of Antibacterial and Antifungal Activities

One of the best ways to design new biocidal agents is synthesizing hybrid molecules by combining two or more bioactive moieties in a single molecular scaffold. So, new series of pyrroles bearing a thiazole moiety were synthesized using 1-methyl-1H-pyrrole-2-carbaldehyde thiosemicarbazones 1a–c. Cyclization of thiosemicarbazone derivatives 1a–c with ethyl chloroacetate, ethyl 2-chloropropanoate, chloroacetone and phenacyl bromide afforded the corresponding thiazolidin-4-ones 2a–c, 5-methylthiazolidin-4-ones 3a–c, 4-methyl-2,3-dihydrothiazoles 4a–c, and 4-phenyl-2,3-dihydrothiazoles 5a–c, respectively. The antimicrobial activity of the new thiazole derivatives was evaluated.

Density Functional Theory Investigation of the Doping Effects of Bromine and Fluorine on the Electronic and Optical Properties of Neutral and Ionic Perylene

Perylene and its derivatives are some of the promising organic semiconductors. They have found vast applications in many areas such as photovoltaic systems, organic light-emitting diodes, and so on. The instability of organic molecules under ambient conditions is one factor deterring the commercialization of organic semiconductor devices. Currently, most of the investigation of Perylene and its derivatives concentrated on its diimide and bisimide derivatives. In this work, an investigation of the effects of doping Bromine and Fluorine on the electronic and non-linear optical properties was carried out based on Density Functional Theory (DFT) as implemented in the Gaussian 09 software package. We computed the Molecular geometries of the molecules, HOMO-LUMO energy gap, global chemical indices and non-linear optical properties using the same method. The bond lengths and angles of the mono-halogenated molecules at different charge states were found to be less than that of the isolated Perylene. 1-fluoroperylene was found to be the most stable amongst the studied molecule for having the least bond angles and bond lengths. In the calculation of the energy bandgap neutral 1-fluoroperylene was observed to have the highest energy gap 3.0414 eV and 3.0507 eV for 6-31++G(d,p) and 6-311++G(d,p) basis sets respectively. These results were found to agree with the existing literature. This reconfirmed 1-fluoroperylene as the most stable molecule. The computations of the ionic molecules reported small values of the energy gap. The molecule with the most chemical hardness was obtained to be the neutral 1-fluoroperylene with a chemical hardness of 1.5253eV. All the ionic molecules results were found to be more reactive than their neutral form for having lower values of chemical hardness. For NLO calculations, the results showed an increment in their values with the ionic hybrid molecules having the largest values. In the case of first-order hyper-polarizability, 1-bromoperylene (neutral), 1-fluoroperylene (neutral), 1-bromoperylene (anionic), 1-fluoroperylene (anionic), 1-bromoperylene (cationic) and 1-fluoroperylene (cationic) were found to be 73.93%, 1.71%, 83.9%, 39.2%,38.7% and 41.7% larger than that of Urea respectively. These calculated results make these hybrid molecules suitable for a wide range of optoelectronic applications.

Synthesis, Molecular Docking, and Antimalarial Activity of Hybrid 4-Aminoquinoline-pyrano[2,3-c]pyrazole Derivatives

Widespread resistance of Plasmodium falciparum to current artemisinin-based combination therapies necessitate the discovery of new medicines. Pharmacophoric hybridization has become an alternative for drug resistance that lowers the risk of drug–drug adverse interactions. In this study, we synthesized a new series of hybrids by covalently linking the scaffolds of pyrano[2,3-c]pyrazole with 4-aminoquinoline via an ethyl linker. All synthesized hybrid molecules were evaluated through in vitro screenings against chloroquine-resistant (K1) and -sensitive (3D7) P. falciparum strains, respectively. Data from in vitro assessments showed that hybrid 4b displayed significant antiplasmodial activities against the 3D7 strain (EC50 = 0.0130 ± 0.0002 μM) and the K1 strain (EC50 = 0.02 ± 0.01 μM), with low cytotoxic effect against Vero mammalian cells. The high selectivity index value on the 3D7 strain (SI > 1000) and the K1 strain (SI > 800) and the low resistance index value from compound 4b suggested that the pharmacological effects of this compound were due to selective inhibition on the 3D7 and K1 strains. Molecular docking analysis also showed that 4b recorded the highest binding energy on P. falciparum lactate dehydrogenase. Thus, P. falciparum lactate dehydrogenase is considered a potential molecular target for the synthesized compound.

The antibacterial activity of isatin hybrids

: Bacterial infections which cause a wide range of host immune disorders leading to local and systemic tissue damage, are still one of the main causes of patient morbidity and mortality worldwide. Treatment of bacterial infections is challenging, which is mainly attributed to the rapidly evolving resistance mechanisms, creating an urgent demand to develop novel antibacterial agents. Hybridization is one of the most promising strategies in the development of novel antibacterial drugs with the potential to address drug resistance since different pharmacophores in the hybrid molecules could modulate multiple targets and exert synergistic effects. Isatin, distributed widely in nature, can exert antibacterial properties through acting on diverse enzymes, proteins, and receptors. Accordingly, hybridization of isatin pharmacophores with other antibacterial pharmacophores in one molecule may provide novel antibacterial candidates with broad-spectrum activity against various pathogens, including drug-resistant forms. This review aims to outline the recent advances of natural and synthetic isatin hybrids with antibacterial potential and summarize the structure-activity relationship (SAR) to provide an insight for the rational design of more active candidates, covering articles published between January 2012 and June 2021.

Synthesis and Anticancer Activity of Novel Hydrazone Linkage-Based Aryl Sulfonate Derivatives as Apoptosis Inducers

In the present study, the various 28 hybrid molecules containing hydrazone and sulfonate moiety were synthesized and characterized by FTIR, 1H-NMR, 13C-NMR spectroscopy and LC-MS spectrometry, besides elemental analysis. The compounds were evaluated for their antiproliferative effects against six cancer cell lines, namely A549 (non-small cell lung cancer), MCF-7 (breast cancer), HT-29 (colorectal adenocarcinoma cancer), PC-3 (androgen-independent prostate adenocarcinoma), Hep3B (hepatocellular carcinoma cancer), and HeLa (epitheloid cervix carcinoma cancer). Among all the target compounds, compounds 4g and 4h exhibited more promising effects on MCF-7 cell lines (IC50=17.8 mM and 21.2 mM, respectively) with high selectivity. Further mechanistic studies proposed that compounds 4g and 4h induced apoptosis is mediated through the intrinsic apoptotic pathway with changes in mitochondrial membrane potential by finally activating caspase-9 and caspase-3. The results have been encouraging enough to merit further investigation.