Journal of the Chilean Chemical Society

Mn-DOPPED ZnS QUANTUM DOTS AS SENSITIVE SENSOR FOR DETERMINATION OF CIPROFLOXACIN IN PHARMACEUTICAL AND BIOLOGICAL SAMPLES

2021-06-13T02:27:44+00:00

A simple and fast spectrofluorimetric method for determination of ciprofloxacin based on its quenching effect on the fluorescence intensity of colloidal water soluble TGA caped, Mn doped ZnS quantum dots (QDs) has been described. The QDs having characteristic fluorescence spectra with maximum excitation at 315 nm followed by an emission peak at 632 nm were characterized using Energy Dispersive X-Ray and X-ray Diffraction techniques. The effect of various parameters such as concentration of QDs, time, pH, common excipients and metal ions on the quenching phenomenon was investigated. Fluorescence quenching was found to be maximum with 10 µg mL^-1 of QDs at pH 8 and fluorescence intensity was observed to be constant upto 45 min. The Stern-Volmer calibration plot of F⁰/F as a function of ciprofloxacin concentration was found to be linear in the range of 0.5-10 µg mL^-1 with r² = 0.993. Under optimal experimental conditions the method was found to be interference free. The percent relative standard deviation of the proposed method calculated against method blank was found to be 1.10%_. The limit of detection (LOD) and the limit of quantitation (LOQ) for Cf (signal to noise ratio 3:1 for LOD and 10:1 for LOQ) were calculated to be 0.15 and 0.50 μg mL^-1 respectively. Average percent recoveries (±SD) obtained for spiked commercial formulations; ciprol and ciproquine, and serum and urine samples were found to be in the range of 92.2±1.8% to 99.5±1.5%, 90.5±1.2% to 96.7±1.4% and 94.0±1.2% to 98.5±1.4% respectively. The data evidently prove the potential of the proposed sensor QDs in biological analysis.

Ag/CuO/MCM-48 AS A POTENTIAL CATALYST FOR THE SYNTHESIS OF SYMMETRICAL AND UNSYMMETRICAL POLYHYDROQUINOLINES

2021-06-13T21:39:33+00:00

Ag/CuO/MCM-48 as a heterogeneous catalyst was efficiently employed in the synthesis of diversely substituted symmetrical and unsymmetrical polyhydroquinoline by a multi-component reaction of arylaldehyde, dimedone, ethyl cyanoacetate and ammonium acetate. This novel method is simple, environmentally friendly, rapid, use a recyclable catalyst and produce the products in high to excellent yields (83-97%) and lower reaction times (17-35 min). The catalyst can be reused at least 10 times without any appreciable decrease in its catalytic activities.

BENZIMIDAZOLE MOLECULE AS NEW ANTICANCER AGENT; DESIGN, SYNTHESIS AND ADMET PREDICTION

2021-06-20T21:44:51+00:00

A new series of benzimidazole clubbed with oxadiazole ring with second amine (4a-l) were design and synthesize with an intention to search an anticancer lead compound under microwave irradiation in good yields. Further, the synthetic compounds were spectral characterization with modern instrumental techniques such as FTIR, NMR (¹H and ¹³C), MS and elemental analysis. Anticancer activities of synthesized compounds were investigated at the National Cancer Institute (NCI) against NCI 60 cell line panel, results showed good to notable anticancer activity. With the help of molinspiration, drug like properties and bioactivity score for drug targets of synthetic compounds were predicted and found to obey the Lipinski’s rule, and result indicates that the derivatives are orally active molecules. Osiris property explorer was used for the prediction of drug relevant properties and toxicity of synthetic compounds. Pre ADMET and Lazar toxicity was also used to estimate the ADME and toxicity of the synthetic compounds. So that, these new hybrids compounds could serve as potential template to become leads in near future for the discovery and development of new effect orally drugs molecules. Two compounds, 4c [1-(1H-benzo[d]imidazol-2-yl)-3-(5-((4-methylpiperazin-1-yl)methyl)-1,3,4 -oxadiazol-2-yl) propan-1-one] and 4k [3-((5-(3-(1H-benzo[d]imidazol-2-yl) -3-oxopropyl)-1, 3, 4-oxadiazol-2-yl) methyl)-5-methylpyrimidine-2,4(1H, 3H)-dione] were exhibited highest drug score and emerged as lead compounds and motivates for further development of more effective and safer compounds.

A NEW SYNTHETIC THIO-CHALCONE INTENDED AS A LIGAND FOR POLYMETALLIC COORDINATION COMPOUNDS: STRUCTURAL, ELECTROCHEMICAL AND THEORETICAL STUDY.

2021-06-13T21:41:59+00:00

The new chalcone, 1-(PYRIDIN-2-YL)-3-(THIOPHEN-2-YL)PROPENONE, has been synthesized and its crystal and molecular structure determined. An electrochemical characterization of the molecule disclosed some reversible and irreversible processes in its cathodic/anodic reactions. A density functional study was carried out in order to calculate the frontier molecular orbitals and the diffusion coefficient, which showed very good agreement with the experimental data.

THERMODYNAMIC RESEARCH ON THE INHIBITORS OF CORONAVIRUS THROUGH DRUG DELIVERY METHOD

2021-06-13T02:27:45+00:00

Based on CoVs, the genomic structure is arranged in a +ssRNA with approximately 30 kb in length which is the biggest known RNA viruses including a 5′-cap structure and 3′-poly-A tail. CoVs, (positive stranded RNA viruses), can infect humans and multiple species of animals, cause enteric, respiratory, and central nervous system diseases in many species. These viruses are important for anti-CoV drug delivery through a pivotal function in viral gene expression and replication through the proteolytic processing of replicase polyproteins.

In this paper, it has been illustrated the linkage of 6 inhibitors of N-[[4-(4-methylpiperazin-1-yl)phenyl]methyl]-1,2-oxazole-5-carboxamide, “inh1”, NSC 158362, “inh2”,JMF 1586 ,“inh3”,(N-(2-aminoethyl)-1-1ziridine-ethanamine) , “inh4” ,[(Z)-1-thiophen-2-ylethylideneamino]thiourea, “inh5” and Vanillinbananin, “inh6”, to CoVs by forming the complexes of “inhibitor- CoV” in water phase through the H-bonding using some physico-chemical properties including heat of formation , Gibbs free energy , electronic energy , charge distribution of active parts in the hydrogen bonding ,NMR estimation of inhibitor jointed to the database amino acids fragment of Tyr-Met-His as the selective zone of the CoV, positive frequency and intensity of different normal modes of these structures.

The theoretical calculations were done at various levels of theory in water simulated medium to gain the more accurate equilibrium geometrical results, and infrared spectral data for each of the complex proposed drugs of N-terminal or O-terminal auto-cleavage substrate were individually determined to elucidate the structural flexibility and substrate binding of six inhibitors including jointed to TMH, inh[1-6]-TMH. A comparison of these structures with two configurations provides new insights for the design of substrate-based inhibitors targeting CoV. This indicates a feasible model for designing wide-spectrum inhibitors against CoV-associated diseases.

The structure-based optimization of these structures has yielded two more efficacious lead compounds, N and O atoms through forming the hydrogen bonding (hydrogen-bonding) with potent inhibition against CoV (Tyr160-Met161-His162) because of water polar medium which has been abbreviated as TMH in this paper.

COMPUTATIONAL INVESTIGATION OF METHYL α-D-GLUCOPYRANOSIDE DERIVATIVES AS INHIBITOR AGAINST BACTERIA, FUNGI AND COVID-19 (SARS-2)

2021-06-13T02:27:45+00:00

For employing computational tools for drug discovery in the area of medicinal chemistry by carbohydrates, methyl a-D-glucopyranoside and its ten acylated derivatives have picked up. At first, the HOMO, LUMO, and its energy gap have been obtained by the DFT method, as well as the chemical reactivity and global descriptors, such as global softness, electron affinity, ionization potential, electronegativity, global hardness, global electrophilicity index, and chemical potential have calculated from HOMO and LUMO data. From this data, it is illustrated that the HOMO-LUMO energy gap is -9.756 to -7.756 kcal/mol while the compound 12 shows the highest energy gap and compound 10 is opposite, and the softness has recorded the range from 0.208 to 0.255, showing a small difference, while the lower softness is picked up for 12, but 09 is reverse. The key and vital part of this study are noted as molecular docking against four pathogens proteins, such as Bacillus cereus, E Coli, Lanosterol 14alpha demethylase, SARS-02, and it is obtained the most expected and impactful result as an inhibitor. It is mentioned that the result of molecular docking score is -9.6 for compounds 09 and 11 against Bacillus cereus which is the highest score. But it is slightly different for E Coli -9.5 and -9.3 of compounds 10 and 07. On the other hand, it is precious and lavish work against COVID-19 protein whereas all of the tested compounds can show good and standard inhibitor with value more than -6.0, and the -9.1, 9.0, and 8.5 for compounds 09, 07, and 08, respectively. It may be revealed that methyl α-D-glucopyranoside and its ten acylated derivatives are also found as a good inhibitor against SARS-02 protein than bacteria and fungi. Moreover, all of these are non–carcinogenic and low toxic in the case of both aquatic and non-aquatic species which says us for safe use in drug discovery.

MOLECULARLY IMPRINTED POLYMER FOR THE BINDING AND RECOGNITION OF BASIC BLUE 41 DYE

2021-06-13T02:27:45+00:00

This study reports a novel imprinted molecular poly(ethylene terephatalate) (MIP_BB41) for the binding and selective recognition of an azoic dye (basic blue 41) by a non-covalent imprinting approach. Basic blue 41 (BB₄₁) was chosen as the template molecule, acrylic acid-grafted polyethylene terephthalate (PET-g-AA), and N,N’-methylene-bis-acrylamide (MBA) were used as the functional polymer and crosslinking reagent respectively. To determine the binding capacity of MIP_BB41, several adsorption studies were performed. The adsorption isotherm was described by the Langmuir model, and the maximum adsorption capacity of MIP_BB41 toward basic blue 41 reached 144.8 mg g^-1in water at pH 6.2. The fabricated MIP showed good recognition properties. In a further experiment, the adsorption capacity of the MIP was compared to the non-imprinted polymer (NMIP), and a recognition coefficient of 3.14 was obtained.

SYNTHESIS OF 6-TERT-OCTYL AND 6,8-DITERT-BUTYL COUMARINS, TWO COUMARINS OF BIOLOGICAL INTEREST

2021-06-13T02:27:45+00:00

In this study, the synthesis of new coumarins with aliphatic chains is discussed. The incorporation of the 6-tert-octyl and 6,8-ditert-butyl chains into a coumarin structure from alkylphenols, allows obtaining hydrophobic coumarins with good yields. These coumarins can be potential modulators of TRPV1 receptors. Synthesis and spectroscopic data of these new coumarins are analyzed.

EVALUATION OF BEHAVIOR OF CONNECTIONS THROUGH AUTOFLOWING SCREWS IN TREATED RADIATA PINE WOODEN PRESERVATIVES

2021-06-13T21:44:24+00:00

Wood is a great material, it has a disadvantage of early deterioration due to external agents. For this reason, it is interesting to create a new wooden preservative. It was studied one based on a natural polymer (chitosan) and nanoparticles (Si and Ti). Tests were carried out to characterize physical (density, moisture content, swelling and absorption) and mechanical properties (flexion, compression and hardness) of wood specimens with and without impregnation, and their joints with two types of self-drilling screws. Simple and lateral extraction test were carried out. Improvements in hardness and perpendicular compression are highlighted obtained, results indicate a stiffening of the fibers. This treatment achieves the material cross section hardening, coating it with components that help to delay the ignition and provide greater duration against external agents. From the extraction of screws, the impregnated wood allowed more rigid unions, with smaller displacements in comparison to the wood without treatment.

PHYTOCHEMICAL ANALYSIS AND ANTIBACTERIAL ACTIVITY OF ERYNGIUM PYRAMIDALE BOISS. & HAUSSKN.

2021-06-13T02:27:45+00:00

Eryngium pyramidale Boiss. & Hausskn. is one of the species of the Apiaceae family, which is used as a spice in Iranian food. In this work, we aim to assess the phytochemical profile and antibacterial activity of the aerial parts of Eryngium pyramidale. The essential oil was obtained by hydrodistillation using a Clevenger apparatus. Then, it was qualitatively and quantitatively analyzed by GC-MS and GC-FID respectively. The antibacterial activity of the essential oil was evaluated against six gram-positive and three gram-negative bacteria by the disc diffusion method and the broth microdilution assay. The phenolic and flavonoid contents of the methanolic extract were assessed using the UV spectrophotometry and HPLC-DAD. A total of 56 compounds representing 94.08% of the total oil were identified, among which sesquicineole (28.49 ± 1.2%) and (Z)-falcarinol (18.04 ± 0.7%) were the major ones. Based on the results, the oil was active against both gram-positive and gram-negative bacteria in comparison with standards. The phytochemical screening of the extracts revealed the presence of flavonoids, steroids, glycosides, and phenols in the methanolic, ethyl acetate, and n-hexane extracts. The total phenolic content of the methanolic extract was 0.36 ± 0.01 mg of gallic acid equivalents per g of dry plant materials, and the total flavonoid content of the methanolic extract was 0.90 ± 0.05 mg of quercetin equivalent (QE) per gram of dry plant materials. Five phenolic and flavonoid compounds in the methanolic extract including naringenin, rutin, apigenin, caffeic acid, and gallic acid were identified and quantified.

DEVELOPMENT IN SYNTHESIS AND COATING APPLICATIONS OF POLYURETHANE

2021-06-13T02:27:45+00:00

Polyurethanes as one of the leading elastomers are explored in academics as well as in industry. These are segmented macromolecules having alternate sequence of soft and hard segments. Structure-property correlation between these segments has been extensively reported in the literature. PUs are used widely in coatings, varnishes, glues, foams, adhesives, sealants, automobile parts, synthetic leather etc. Its application in biomedical devices is also growing rapidly. It is therefore need to highlights the recent developments in this fast growing field. The present article is summarized the conventional and ecofriendly synthetic routes for the preparation of PUs. Conventionally, PUs was synthesized by isocyanates route, later shortcoming of this method explore new synthesis method in which either used biobased polyol or non isocyanates route for preparation of ecofriendly PUs. The applications of different types of PUs coating in various fields are also highlighted in this review.

APPROACHES FOR CHEMICAL SYNTHESIS AND DIVERSE PHARMACOLOGICAL SIGNIFICANCE OF PYRAZOLONE DERIVATIVES: A REVIEW

2021-06-13T21:40:53+00:00

Pyrazolone is a five-membered lactam ring containing two Nitrogens and one ketonic group in its structure. Numerous pyrazolone derivatives were exhibited with diverse biological, pharmacological, and chemical applications. When pyrazolones were discovered, they were only known as NSAIDs but in recent times they play a versatile role in several complications like cerebral ischemia, cardiovascular diseases, antibacterial, antioxidant, anticancer and several other pharmacological activities. Over the last few decades, pyrazolone derivatives have been used for various biochemical applications. Some of these derivatives such as metamizole, phenazone, aminopyrine, and propyphenazone, are widely used as anti-inflammatory and analgesics. The chemistry of pyrazolone has gained increasing attention due to its diverse pharmacological properties such as anticancer, analgesic, anti-inflammatory, antimicrobial, antioxidant, antifungal, antiviral, antidiabetic, and several other biological activities. Thus, keeping because of their importance, synthetic strategies for existing as well as novel pyrazolone derivatives have been developed and explored their biochemical utility. This review deals with the various pharmacological properties of different pyrazolone derivatives and puts chemical synthetic schemes.

SECONDARY METABOLITES AND BIOLOGICAL PROFILES OF DATURA GENUS

2021-06-13T02:27:45+00:00

Solanaceae is an important family of plants where many species of this family are source for food, industrial products, ornamental and medicinal uses. Within the family of Solanaceae, the genus Datura is one of the most interesting, in principle for its known medicinal and psychotropic uses against different pathologies. Multiple biological activities of Datura species have been documented. The species of the genus are attributed with insecticide, fungicide, antioxidant, antimicrobial, hypoglycemic, and immune response enhancing activity against cancer cells. These activities are related to the presence of different secondary metabolites such us: terpenoids, flavonoids, withanolides, tannins, phenolic compounds and tropane alkaloids, the main secondary metabolite of the genus Datura, being the most abundant atropine and scopolamine. The propose of this review is to identify the main phytochemical compounds isolated from the genus Datura and describe their biological activities associated to different secondary metabolites.