Synthesis, structural characterization, in vitro antimicrobial and anticancer activity studies of ternary metal complexes containing glycine amino acid and the anti-inflammatory drug lornoxicam

Synthesis and DFT calculations of metal(II) oxime complexes bearing cysteine as coligand and investigation of their biological evolutions in vitro and in silico

New complexes with the formula of [ML(Cys)(H2O)2] were obtained as a result of the reaction between the oxime ligand [HL: 4-(4-bromophenylaminoisonitrosoacetyl)biphenyl], cysteine (Cys), and the metal(II) salts (Mn, Ni, Co, Zn, Cu). The newly synthesized compounds were characterized using conventional techniques such as molar conductance, magnetic measurements, elemental analysis, infrared spectroscopy, and thermal analysis (TGA/DTA). Based on the conductivity measurements in DMF, it was determined that the complexes were non-electrolytes. The TGA/DTA analysis was performed to examine the thermal stability and degradation behavior of all samples, and results demonstrated that metal oxides or sulfides formed as a result of the decompositions. In conjunction with other data obtained, the elemental analysis confirmed the octahedral coordination of the complexes with deprotonated oxime (O, O-donor) and amino acid (N, S-donor) ligands and two coordinated waters. The compounds' optimized geometries, molecular electrostatic potential diagrams, and frontier molecular orbitals were computed at the DFT/B3LYP level using the 6-311 G(d,p) and LANL2DZ basis sets. The antibacterial and DNA cleavage activities of all synthesized compounds were also screened, and molecular docking simulations were performed. According to the results of molecular docking studies conducted with three different proteins, the best interaction was found to be between HL-1HNJ with a binding energy of -9.5 kcal/mol. The stability of the HL-1HNJ complex was also verified by a molecular dynamics simulation performed for 50 ns.Communicated by Ramaswamy H. Sarma.

Biological Applications, In Vitro Cytotoxicity, Cellular Uptake, and Apoptotic Pathway Studies Induced by Ternary Cu (II) Complexes Involving Triflupromazine with Biorelevant Ligands

The novel mixed-ligand complexes derived from the parent antidepressant phenothiazine drug triflupromazine (TFP) were synthesized along with the secondary ligands glycine and histidine. [Cu(TFP)(Gly)Cl]·2H2O (1) and [Cu(TFP)(His)Cl]·2H2O (2) were examined for their in vitro biological properties. Cyclic voltammetry was used to study the binding of both complexes to CT-DNA. The two complexes were examined for antiviral, antiparasite, and anti-inflammatory applications. An in vitro cytotoxicity study on two different cancer cell lines, MCF-7, HepG2, and a normal cell line, HSF, shows promising selective cytotoxicity for cancer cells. An investigation of the cell cycle and apoptosis rates was evaluated by flow cytometry with Annexin V-FITC/Propidium Iodide (PI) staining of the treated cells. Gene expression and western blotting were carried out to determine the expression levels of the pro-apoptotic markers and the anti-apoptotic marker Bcl2. The tested complexes decreased cell viability and triggered apoptosis in human tumor cell lines. Molecular docking was also used to simulate Bcl2 inhibition. Finally, complex (2) has potent antitumor effects on human tumor cells, especially against HepG2 cells, as seen in the cellular drug uptake assay. Consequently, complex (2) may prove useful against cancer, especially liver cancer. For further understanding, it needs to be explored in vivo.

Short Fragmented Peptides from Pardachirus Marmoratus Exhibit Stronger Anticancer Activities in In Silico Residue Replacement and Analyses

BACKGROUND

Cancer is a worldwide issue. It has been observed that conventional therapies face many problems, such as side effects and drug resistance. Recent research reportedly used marine-derived products to treat various diseases and explored their potential in treating cancers.

OBJECTIVE

This study aims to discover short-length anticancer peptides derived from pardaxin 6 through an in silico approach.

METHODS

Fragmented peptides ranging from 5 to 15 amino acids were derived from the pardaxin 6 parental peptide. These peptides were further replaced with one residue and, along with the original fragmented peptides, were predicted for their SVM scores and physicochemical properties. The top 5 derivative peptides were further examined for their toxicity, hemolytic probability, peptide structures, docking models, and energy scores using various web servers. The trend of in silico analysis outputs across 5 to 15 amino acid fragments was further analyzed.

RESULTS

Results showed that when the amino acids were increased, SVM scores of the original fragmented peptides were also increased. Designed peptides had increased SVM scores, which was aligned with previous studies where the single residue replacement transformed the non-anticancer peptide into an anticancer agent. Moreover, in vitro studies validated that the designed peptides retained or enhanced anticancer effects against different cancer cell lines. Interestingly, a decreasing trend was observed in those fragmented derivative peptides.

CONCLUSION

Single residue replacement in fragmented pardaxin 6 was found to produce stronger anticancer agents through in silico predictions. Through bioinformatics tools, fragmented peptides improved the efficiency of marine-derived drugs with higher efficacy and lower hemolytic effects in treating cancers.

Revelation of potential bioactive water-soluble Boc-L-valine and imidazole appended metal complexes {M = Co(II), Cu(II) & Zn(II)}: synthesis, characterization, ct-DNA binding, pBR322 cleavage, SOD mimetic, and cytotoxicity studies

Bio-compatible water-soluble conjugates of Co(II), Cu(II) and Zn(II) (1-3), [Co(Boc-L-valine)2(imidazole)2], [Cu(Boc-L-valine)2(imidazole)2], and [Zn(Boc-L-valine)2(imidazole)2], were synthesized and comprehensively characterized by various spectroscopic techniques (UV-visible, FT-IR, ESI-MS, EPR, 1H NMR, 13C NMR) and single crystal X-ray diffraction which showed that the complexes 1-3 crystallized in an orthorhombic crystal system, in a slightly distorted octahedral geometry having the space group P21212. Density functional theory calculations were performed to correlate the energy of frontier molecular orbitals with the stability and reactivity of the complexes. In vitro DNA binding interaction studies of complexes were performed by employing various biophysical techniques and their corroborative results revealed (i) the electrostatic mode of binding in the groove region of DNA, (ii) pBR322 plasmid cleavage at a low concentration of 5-12.5 μM via an oxidative pathway in complexes 1 and 2 and the hydrolytic mechanism in the case of 3, (iii) changes in the 1H NMR chemical shift values of the NH2 group of GMP after interaction with complex 3, (iv) alteration in the EPR parameters of complex 2 after complexation with DNA, (v) SOD mimetic activity of complex 2 with the IC50 value of 2.08 μM and (vi) a good and selective cytotoxicity profile against chemo-resistant MCF-7 and MDA-MB-231 cancer cell lines by complex 1. Molecular docking studies complemented the spectroscopic results and confirmed the electrostatic interaction of complexes in the groove region of DNA.

Manganese complexes and manganese-based metal-organic frameworks as contrast agents in MRI and chemotherapeutics agents: Applications and prospects

Manganese-based Metal-organic Frameworks (Mn-MOFs) represents a unique sub-class of MOFs with low toxicity, oxidative ability, and biocompatibility, which plays vital role in the application of this class of MOFs in medical field. Mn-MOFs show great potential in biomedical applications, and has been extensively studied as compared to other MOFs in transition metal series. They are important in medical applications because Mn(II) possess large electron spin number and longer electron relaxation time. They display fast water exchange rate and could be employed as a potential MRI contrast agent because of their strong targeting ability. Manganese complexes with different ligands also display prospective applications in area such as carrier for drug targeting in anti-tumor and antimicrobial therapy. In the review presented herewith, the application of Mn-based complexes and Mn-MOFs have been emphasized in the area such as imaging viz. MRI, multimodal imaging, antitumor activities such as chemodynamic therapy, photodynamic therapy, sonodynamic therapy and antimicrobial applications. Also, how rational designing and syntheses of targeted Mn-based complexes and Mn-MOFs can engender desired applications.

Synthesis, antimicrobial activity, molecular docking and ADMET study of a caprolactam-glycine cluster

Density functional theory calculations were performed with DFT method using both b3lyp/6-311++G(d,p) and wb97xd/6-311++G(d,p) levels of theory to predict the molecular geometry, to evaluate the molecular electrostatic potential and frontier molecular orbitals of synthesized a new compound: caprolactam-glysine cluster (CL-Gly). Molecular docking study of the CL-Gly was carried out to clarify the interaction and the probable binding modes, between the title compound and DNA. The antibacterial activities of CL-Gly cluster against Gram-positive and Gram-negative bacteria was determined. In silico ADMET study was also performed for predicting pharmacokinetic and toxicity profile of the synthesized cluster which expressed good drug-like behavior and non-toxic nature. It was revealed that the compound has importance in drug discovery process.Communicated by Ramaswamy H. Sarma.

Design of Novel Oligomeric Mixed Ligand Complexes: Preparation, Biological Applications and the First Example of Their Nanosized Scale

A successful oligomerization of ternary metal complexes, cobalt (II), nickel (II), copper (II), zinc (II), chromium (III) and ferric sulfate (III) with nitrilotriacetic acid (NTA) as a primary ligand and glutamic acid as a secondary ligand, has been demonstrated. The formation of oligomers arose from the presence of the sulfate moiety, which operates as a bridged bidentate ligand that coordinates with other metal moieties. The novel oligomers exhibited octahedral structures, which bonded together through the sulfate moiety. In silico predictions were conducted to gauge the bioactivity, physico-chemical and pharmacokinetic properties. The biological activities of these oligomers as well as their tumor inhibitory behavior have been explored. This work also presents a facile and novel method of preparing these materials in nanosize, using Cetyltrimethylammonium bromide (CTAB) and polyvinyl alcohol (PVA) as capping ligands. The size and shape of the nanomaterials have been confirmed using the transmission electron microscope (TEM) and the scanning electron microscope (SEM).

Synthesis, structure, and biological evaluation of a copper(ii) complex with fleroxacin and 1,10-phenanthroline

A novel mixed-ligand Cu(ii) complex combined with the quinolone drug fleroxacin and 1,10-phenanthroline was synthesized in this work. The crystal structure of the complex was characterized via X-ray crystallography, which was the first reported single crystal complex of fleroxacin. Results showed that Cu(ii) was coordinated through pyridone oxygen and one carboxylate oxygen atom of fleroxacin, as well as two nitrogen atoms from 1,10-phenanthroline. Various characterization methods, including Fourier transform infrared, elementary analysis, thermogravimetry, and X-ray powder diffraction, were applied. The Cu(ii)-quinolone complex exhibited favorable biological activities, and was proved to be capable of transforming supercoiled PUC19 DNA into nicked form under hydrolytic conditions. The obtained pseudo-Michaelis-Menten kinetic parameter was 12.64 h(-1), which corresponded to a million-fold rate enhancement in DNA cleavage. In addition, the interaction capacity of the complex with human serum albumin (HSA) was investigated. The results demonstrated a moderately intense combination between HSA and the complex. The complex evidently quenched the fluorescence of HSA. Approximately 19.2% of the quenching was attributed to Förster resonance energy transfer (FRET), whereas the rest was caused by ground-state complex formation (molar ratio of HSA : complex = 1 : 2). The energy of the complex was excited during FRET, which increased the fluorescence of the complex by approximately 18%.

Synthesis, structure, and calf-thymus DNA binding of ternary fleroxacin–Cu(ii) complexes

The interaction between the synthesized fleroxacin complexes and CT DNA was investigated.