Carboxylic Function Research Articles

Comparison between Chemical and Biological Degradation Processes for Perfluorooctanoic Acid

Perfluorooctanoic acid (PFOA) is a perfluoro compound that contains an eight-carbon perfluoroalkyl chain followed by a carboxylic acid function group. The C-F bound possesses a strong bond energy of approximately 485 kJ/mol, rendering PFOA thermally and chemically stable. It has found applications in water-resistant coating and is produced either by degrading other long-chain perfluorinated carboxylic acids or fluorotelomer alcohol. PFOA is challenging to further degrade during water treatment processes, leading to its accumulation in natural systems and causing contamination. Research has been conducted to develop several methods for its removal from the water system, but only a few of these methods effectively degrade PFOA. This review compares the most common chemical degradation methods such as photochemical, electrochemical, and sonochemical methods, to the cutting-edge biodegradation method. The chemical degradation and biodegradation methods both involve the stepwise degradation of PFOA, with the latter capable of occurring both aerobically and anaerobically. However, the degradation efficiency of the biological process is lower when compared to the chemical process, and further research is needed to explore the biological degradation aspect.

Developing a ternary conductive hydrogel of polyacrylamide, polyaniline, and carbon nanotube: A potential chemiresistive gas sensor

Over the past few years, conductive hydrogels have received increasing attention for numerous electronic applications because of the concurrent provision of electrical conductivity, flexibility, and conformability. In the present study, a polyaniline-based conductive hydrogel was synthesized. Carbon nanotubes (CNTs) were associated with the hydrogel to impart higher electrical conductivity to the hydrogel, and ternary composites of polyacrylamide (PAM), polyaniline (PANI), and CNT were developed. To fulfill this, at first, CNT surface was decorated with carboxyl functionalities, and the carboxyl decorated CNT was included into the composition in two manners: firstly, CNTs were included during acrylamide polymerization, whereas in the second manner, CNTs were incorporated during aniline polymerization. The composite hydrogels' chemical, swelling, morphological, and electrical properties were evaluated. The experimental results corroborated that in the latter case, abundant intermolecular interactions were developed between the PANI chains and the CNT surface. Moreover, the swelling value was increased by 9% comapred to the former case. In the former case, a porous microstructure and in the latter case a fibrous microstructure was dominated. And more importantly, the electrical conductivity of the hydrogel in the latter case was 104 folds higher than that in the former case. The ternary composition prepared with the latter manner was employed for sensing the ammonia gas, and the analyses unveiled that the hydrogel represents an appropriate response in the range of 10.43%–16.87% to various concentrations of the target gas and has the potential to be a thriving chemiresistive gas sensor.

Preparation of Starch‐Fatty Acid Esters from Agro‐Based Raw Materials (Corn Starch, Cassava Starch, Coconut Oil, and Castor Seed Oil)

AbstractThe preparation of starch‐fatty acid esters is investigated for corn starch and cassava starch. The fatty acid contents are obtained from the hydrolysis of coconut oil and castor oil respectively and are characterized by GC/MS techniques. The major fatty acid component of coconut oil is found to be lauric acid (34%) while that of castor oil is ricinoleic acid (84%). Four different starch‐fatty esters are prepared, namely cassava starch‐coconut fatty acid esters (CacoFAE), cassava starch‐castor fatty acid ester (CacaFAE), corn starch‐coconut fatty acid ester (CocoFAE), and corn starch‐castor fatty acid ester (CocaFAE). The starch‐fatty acid esters are analyzed using FT‐IR and liquid chromatography‐mass spectrometer techniques. All the esterified starch‐fatty acid esters contain the C=O absorption peak at 1707 cm−1 which is the peak corresponding to the ester group formed between the starch hydroxyl and fatty acid carboxylic functions. The major fatty acid eluted from LC‐MS for CacoFAE and CocoFAE is lauric (dodecanoic) acid with 67.4% and 74% respectively while ricinoleic acid (58%) is obtained for CacaFAE. The data for CocaFAE are mainly dominated by the ester of the fatty acids.

Photocaging of Carboxylic Function Bearing Biomolecules by New Thiazole Derived Fluorophore.

The design and synthesis of a new fluorophore containing an arylidene thiazole scaffold resulted in a compound with good photophysical characteristics. Furthermore, the thiazole C5-methyl group was easily modified into specific functional groups (CH2 Br and CH2 OH) for the formation of a series of photocourier molecules containing model compounds (benzoic acids), as well as prodrugs, including salicylic acid, caffeic acid, and chlorambucil via a "benzyl" linker. Spectral characteristics (1 H, 13 C NMR, and high-resolution mass spectra) corresponded to the proposed structures. The photocourier molecules demonstrated absorption with high values of coefficient of molar extinction, exhibited contrasting green emission, and showed good dark stability. The mechanism of the photorelease was investigated through spectral analysis, HPLC-HRMS, and supported by TD-DFT calculations. The photoheterolysis and elimination of carboxylic acids were proved to occur in the excited state, yielding a carbocation as an intermediate moiety. The fluorophore structure provided stability to the carbocation through the delocalization of the positive charge via resonance structures. Viability assessment of Vero cells using the MTT-test confirmed the weak cytotoxicity of prodrugs without irradiation and it increase upon UV-light.

Designing of molecularly imprinted polymer with carboxylic acid functionality for chiral separation of (±)‐3,4‐methylenedioxymethamphetamine

AbstractIn this work, we discuss the development of a long‐lasting enantioselective material for the effective enantio‐recognition of S‐3,4‐methylenedioxymethamphetamine (S‐MDMA) and chiral separation of the (±)‐MDMA racemate using a crosslinked poly(acrylic acid‐4‐vinylpyridine) copolymer. The first step was the synthesis and characterization of an acryloyl‐S‐MDMA amide. After that, the free radical initiator azobisisobutyronitrile was used to copolymerize the synthesized chiral amide with 4‐vinylpyridine and divinylbenzene. The incorporated S‐MDMA species were extracted from the polymeric particles by heating them with sodium hydroxide, followed by rinsing with hydrochloric acid. This developed the molecularly imprinted S‐MDMA particles, which were visualized with a scanning electron microscope and Fourier transform infrared spectroscopy. The selectivity parameters indicated a higher affinity of the fabricated S‐MDMA imprinted particles toward S‐MDMA, around 10‐fold higher than that related to R‐MDMA. Results from Langmuir adsorption experiments at pH 6 demonstrated a maximal capacity of 142 mg g−1. In addition, the values of enantiomeric excess were found to be 94.5% and 79.4% for R‐ and S‐MDMA in the loading and eluant solutions, respectively, after optical separation was done using the column technique. © 2023 Society of Industrial Chemistry.

Equilibrium Thermodynamics of Macropa Complexes with Selected Metal Isotopes of Radiopharmaceutical Interest.

To pursue the design of in vivo stable chelating systems for radiometals, a concise and straightforward method toolbox was developed combining NMR, isothermal titration calorimetry (ITC), and europium time-resolved laser-induced fluorescence spectroscopy (Eu-TRLFS). For this purpose, the macropa chelator was chosen, and Lu3+, La3+, Pb2+, Ra2+, and Ba2+ were chosen as radiopharmaceutically relevant metal ions. They differ in charge (2+ and 3+) and coordination properties (main group vs lanthanides). 1H NMR was used to determine four pKa values (±0.15; carboxylate functions, 2.40 and 3.13; amino functions, 6.80 and 7.73). Eu-TRLFS was used to validate the exclusive existence of the 1:1 Mn+/ligand complex in the chosen pH range at tracer level concentrations. ITC measurements were accomplished to determine the resulting stability constants of the desired complexes, with log K values ranging from 18.5 for the Pb-mcp complex to 7.3 for the Lu-mcp complex. Density-functional-theory-calculated structures nicely mirror the complexes' order of stabilities by bonding features. Radiolabeling with macropa using ligand concentrations from 10-3 to 10-6 M was accomplished by pointing out the complex formation and stability (212Pb > 133La > 131Ba ≈ 224Ra > 177Lu) by means of normal-phase thin-layer chromatography analyses.

Methodology for evaluating the mechanical performances of a bonded assembly through complementary mechanical tests

ABSTRACT Bifunctional polymers have been studied as bonding layers (BL) on aluminum surfaces to promote adhesion of adhesives for structural bonding applications. The BL are located at the interface between the aluminum substrate and the adhesive. The mechanical performances of the BL in a bonded assembly were evaluated via several complementary mechanical tests, before and after ageing cycle: single lap shear, Arcan test, three-point bending test, and micro-scratch. The results of these four mechanical tests were compared with those of a raw reference (without any treatment) and a reference that had undergone standard surface preparation (cleaning and etching), in order to assess the mechanical performances of the surface treatment products (BL), and to value these products on the surface treatment market. In order to follow a methodology for selecting the best surface treatments, the mechanical results were compared with each other, and even correlated for samples with bonding layers (containing phosphorus and carboxylic acid functions). The correlation of the results obtained from the four mechanical tests (single lap shear, Arcan, three-point bending, and micro-scratch tests) therefore makes it possible to validate the methodology for evaluating these surface treatments.

Synthesis of nanostructured In2O3 ceramics via a green and chemical method for the mineralization of crystal violet dye: A comparative study

Herein, the photocatalytic capabilities of indium oxide nanoparticles obtained by Aerva javanica extract synthesis and surfactant-mediated co-precipitation synthesis were studied using crystal violet (CV) as a model dye. Indium oxide nanoparticles synthesized via green (In2O3-G) and chemical route (In2O3-C) were characterized through different spectroscopic, structural, electrical and morphological analyses. The plant extract’s metabolites (flavonoids) effectively reduce the indium metal and induce oxygen vacancies, which develop sub-energy levels below the conduction band and hence increase the current conductivity and reduce the optical band of the photocatalyst. The above-mentioned structural modifications improve the In2O3-G photocatalyst's light-harvesting capacity and charge transport characteristics. Optical and current–voltage measurements show that the In2O3-G photocatalyst has more outstanding electrical conductivity (σ = 1.76 × 10-3 Sm−1) and bandgap (Eg = 2.93 eV) more compatible with the visible light than its counterpart (In2O3-C). Due to their amine, carboxyl, and hydroxyl functionalities, the plant extract's metabolites controlled and facilitated the synthesis of In2O3-G in the nanosized range. The integration of some crucial features such as higher surface area, faster charger transport properties, and a visible light-compatible band gap enable our In2O3-G photocatalyst to mineralize 93.75% CV dye in just 80 min with 0.027 min−1 rate-constant. This research demonstrates that a green approach to producing ceramic photocatalysts is preferable to chemical methods, which are more costly and create additional environmental issues.

Organic compounds as corrosion inhibitors for reinforced concrete: a review

Abstract With the goal of preventing concrete deterioration by means of destructive corrosion processes, the use of single organic compounds or mixtures as organic corrosion inhibitors (OCIs) instead of inorganic chemicals is becoming a very attractive practice. As OCIs are more ecologically friendly in their production and environmental fate, they have several advantages over well-known inorganic additives such as metallic nitrites, chromates, or arsenates. In this article, the application of different single organic compounds (of either natural or synthetic origin) as well as mixtures that have been used to lengthen the lifespan of concrete structures is reviewed. After a small exemplification of the use of single organic compounds bearing amino, hydroxy, formyl, or carboxylic functionalities, the more often used OCIs are reviewed according to their principal functional group. Afterward, the application of compound mixtures of either synthetic or natural origin, the use of natural extracts, and biomass are surveyed. Finally, the effects of functional groups within the top 10 inhibitor molecules, the toxicity of OCIs, their effects on the physical-mechanical properties of concrete, and their long-term performance are discussed.

Efficient Photocatalytic Selective Oxidation of Benzylamines over Cobalt Molecular Catalyst Covalently Bonded to Carboxyl Functionalized Carbon Nitride

Photocatalysis is accepted as a promising method for selective oxidative coupling of amine to imine. However, owing to the rapid dehydrogenation of the generated imine intermediate of α‐amino hydrogen to butyronitrile, it remains a huge challenge to fabricate an exquisite catalyst with enhanced conversion and selectivity. Herein, a novel heterogeneous catalyst (Bpy‐CoCl2/CNCOOH) is developed, where carboxyl functionalized carbon nitride (CNCOOH) serves as a substrate material and couples with highly efficient cobalt‐aminopyridine (Bpy‐CoCl2) molecular catalyst through covalent bonding. The catalyst not only effectively facilitates the transfer of photogenerated charges, but also generates mildly oxidatively active species of superoxide radicals, which can effectively oxidize various functionalized benzylamines to corresponding imines in the presence of oxygen with at least 78.5% conversion and >99% selectivity using O2 as oxygen source, especially for the unmodified benzylamine with >99% conversion and >99% selectivity. This unique combination of a selective molecular catalyst and a simple and robust semiconducting material open new avenues for the selective oxidative coupling of amines.

Surface chemistry analysis of acidified and nickel impregnated carbon for desulfurization of fuels

Emission norms tend to reduce sulfur content in transport fuels to 10ppm. Considering this new method like adsorptive desulfurization are widely researched. The main motive in adsorptive desulfurization is to selectively adsorb Dibenzothiophene (DBT) and 4,6-DimethylDBT. Considering this adsorbent with nickel impregnation and acidic surface functionalities were developed. Topographical and surface chemical features were studied of developed carbon adsorbents. Presence of carboxylic surface functionalities and reduced solid nickel was confirmed on adsorbents surfaces. In addition to this formation of nickel complexes due to neutralization of nickel ion and carboxylic groups was confirmed. This type of adsorbents can act as potential adsorbents for adsorption of DBT and 4,6-dimethyl DBT.

Peptide nucleic acid-zirconium coordination nanoparticles

Ideal drug carriers feature a high loading capacity to minimize the exposure of patients with excessive, inactive carrier materials. The highest imaginable loading capacity could be achieved by nanocarriers, which are assembled from the therapeutic cargo molecules themselves. Here, we describe peptide nucleic acid (PNA)-based zirconium (Zr) coordination nanoparticles which exhibit very high PNA loading of >,94% w/w. This metal-organic hybrid nanomaterial class extends the enormous compound space of coordination polymers towards bioactive oligonucleotide linkers. The architecture of single- or double-stranded PNAs was systematically varied to identify design criteria for the coordination driven self-assembly with Zr(IV) nodes at room temperature. Aromatic carboxylic acid functions, serving as Lewis bases, and a two-step synthesis process with preformation of Zr_{6} O_{4} (OH)_{4} turned out to be decisive for successful nanoparticle assembly. Confocal laser scanning microscopy confirmed that the PNA-Zr nanoparticles are readily internalized by cells. PNA-Zr nanoparticles, coated with a cationic lipopeptide, successfully delivered an antisense PNA sequence for splicing correction of the beta-globin intron mutation IVS2-705 into a functional reporter cell line and mediated splice-switching via interaction with the endogenous mRNA splicing machinery. The presented PNA-Zr nanoparticles represent a bioactive platform with high design flexibility and extraordinary PNA loading capacity, where the nucleic acid constitutes an integral part of the material, instead of being loaded into passive delivery systems.

(Invited) nanoengineered Surfaces for Modulating Cell-Surface Interaction and Sensing Applications

The greatest challenge in the field of biomaterials is the understanding and prediction of long-term biological responses in patients receiving implantable materials. Reconstructing and detailing these mechanisms may allow for more targeted approaches and highlights how immune processes are amenable to manipulation by synthetic biomaterials. Surface nanotopography and chemistry are critical factors in integrating implanted devices into tissues and in the satisfactory resolution of the wound healing process. However, how the interplay between surface chemistry and nanotopography may influence inflammatory and wound-healing pathways remains unanswered. To address this gap, 2D and 3D surfaces with nanotopography of controlled height (16, 38, and 68 nm) and lateral spacing with uniform outermost surface chemistry tailored with plasma polymerized amines (NH2), carboxyl (COOH-) and hydrocarbon (CH3-) functionalities were fabricated. These surfaces were employed to study cellular responses responsible for implant encapsulation, wound healing, and tissue regeneration. The data shows that the right combination of chemistry and nanotopography can modulate cellular adhesion, proliferation, self-differentiation, collagen deposition, and the expression of anti and pro-inflammatory signals.Furthermore, our surface engineering expertise was utilized to fabricate metal ion sensors and biosensors based on nanoporous anodic alumina (NAA) and gold nanoclusters (AuNCs). We anticipate that future explorations in this field of research will facilitate the rational design of biomedical implants and devices with physicochemical surface characteristics tailored at the nanoscale that will enhance utility and function and improve clinical outcomes.

Preparation of Amino-Functionalized Poly(N-isopropylacrylamide)-Based Microgel Particles.

Responsive cationic microgels are a promising building block in several diagnostic and therapeutic applications, like transfection and RNA or enzyme packaging. Although the direct synthesis of cationic poly(N-isopropylacrylamide) (PNIPAm) microgel particles has a long history, these procedures typically resulted in low yield, low incorporation of the cationic comonomer, increased polydispersity, and pure size control. In this study, we investigated the possibility of the post-polymerization modification of P(NIPAm-co-acrylic acid) microgels to prepare primary amine functionalized microgels. To achieve this goal, we used 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide hydrochloride (EDC) mediated coupling of a diamine to the carboxyl groups. We found that by controlling the EDC excess in the reaction mixture, the amine functionalization of the carboxyl functionalized microgel could be varied and as much as 6-7 mol% amine content could be incorporated into the microgels. Importantly, the reaction was conducted at room temperature in an aqueous medium and it was found to be time efficient, making it a practical and convenient approach for synthesizing primary amine functionalized PNIPAm microgel particles.

Design and Synthesis of Novel 1‐((1‐Phenyl‐1H‐1,2,3‐triazol‐4‐yl)methyl)pyridin‐2(1H)‐one Derivatives

AbstractThe synthesis of a new class of compounds, namely 1‐((1‐phenyl‐1H‐1,2,3‐triazol‐4‐yl)methyl)pyridin‐2(1H)‐one derivatives starting from 2‐hydroxynicotinic acid was reported. Initially, the carboxylic acid functionality connected to the pyridinone ring was converted to either the ester, amide or aldehyde functionality to obtain the precursor for the propargylation step. The incorporation of a propargyl group into the nitrogen atom of pyridinones was achieved in the presence of K2CO3 as a base. Different organic azides were also synthesized starting from the corresponding aniline derivatives. To obtain target molecules, the facile click cycloaddition reactions of alkynes with aryl azide derivatives in the presence of copper(I) catalyst were applied. Using this protocol, novel 1‐((1‐phenyl‐1H‐1,2,3‐triazol‐4‐yl)methyl)pyridin‐2(1H)‐one derivatives with different substitution patterns were prepared in good to excellent yields under the mild reaction conditions. The structures of the compounds were confirmed by 1D and 2D NMR, FTIR, and HRMS analysis data. Overall, this protocol offers a straightforward method for synthesizing these novel compounds.

Total Synthesis of a Structurally Complex Tetrasaccharide Repeating Unit of Vibrio cholerae O43.

Herein we report the first total synthesis of a densely functionalized tetrasaccharide repeating unit of Vibrio cholerae O43, which contains rare deoxy amino sugars d-quinovosamine and d-viosamine attached with the rare amino acid N-acetyl-l-allothreonine. Synthesis of orthogonally protected rare sugars and unnatural amino acid building blocks, stereoselective construction of three consecutive 1,2-cis glycosidic linkages, amide coupling, and the presence of five nitrogen atoms dispersed over four sugar units as well as the carboxylic acid functionality make the total synthesis a formidable task.

Development of Novel Peptide-Modified Silver Nanoparticle-Based Rapid Biosensors for Detecting Aminoglycoside Antibiotics.

The detection and monitoring of aminoglycoside antibiotics (AGAs) have become of utmost importance due to their widespread use in human and animal therapy, as well as the associated risks of exposure, toxicity, and the emergence of antimicrobial resistance. In this study, we successfully synthesized casein hydrolysate peptides-functionalized silver nanoparticles (CHPs@AgNPs) and employed them as a novel colorimetric analytical platform to demonstrate remarkable specificity and sensitivity toward AGAs. The colorimetric and spectral response of the CHPs@AgNPs was observed at 405 and 520 nm, showing a linear correlation with the concentration of streptomycin, a representative AGA. The color changes from yellow to orange provided a visual indication of the analyte concentration, enabling quantitative determination for real-world samples. The AgNP assay exhibited excellent sensitivity with dynamic ranges of approximately 200-650 and 100-700 nM for streptomycin-spiked tap water and dairy whey with limits of detection found to be ∼98 and 56 nM, respectively. The mechanism behind the selective aggregation of CHPs@AgNPs in the presence of AGAs involves the amine groups of the target analytes acting as molecular bridges for electrostatic coupling with hydroxyl or carboxyl functionalities of adjacent NPs, driving the formation of stable NP aggregates. The developed assay offers several advantages, making it suitable for various practical applications. It is characterized by its simplicity, rapidity, specificity, sensitivity, and cost-effectiveness. These unique features make the method a promising tool for monitoring water quality, ensuring food safety, and dealing with emergent issues of antibiotic resistance.

Surface Modification of Kraft Lignin by Mechanochemical Processing with Sodium Percarbonate.

In this article, we present a novel one-pot mechanochemical reaction for the surface activation of lignin. The process involves environmentally friendly oxidation with hydrogen peroxide, depolymerization of fractions with high molecular mass, and introduction of new carbonyl functions into the lignin backbone. Kraft lignin was ground with sodium percarbonate and sodium hydroxide in a ball mill at different time intervals. Analyses by infrared spectroscopy (IR), nuclear magnetic resonance spectroscopy (NMR), size exclusion chromatography (SEC), dynamic vapor sorption (DVS), and small-angle X-ray scattering (SAXS) showed significant improvements. After only 5 min of reaction, there was a 47% reduction in mass-average molecular weight and an increase in carboxyl functionalities. Chemical activation resulted in an approximately 2.8-fold increase in water adsorption. Principal component analysis (PCA) provided further insight into the correlations between IR spectra and SAXS parameters.

Luminescent dye molecules-embedded zirconium based metal-organic framework as a bifunctional dual-ratiometric responsive sensor for Cu2+/Fe3+ detection

Luminescent dye molecules have attracted enormous research interest, whereas, there are inherent drawbacks that limit their utilization across a broad variety of fields. Herein, a novel dual-luminescent carboxylic acid functionalization Eu3+/Hoc@UIO-66(H3BTC) (Hoc = 7-hydroxycoumarin) was prepared by introducing luminescent dye molecules (Hoc) into the UiO-66-type dual-ligand metal−organic frameworks (MOFs) utilize the encapsulation approach and postsynthetic modification (PSM). UIO-66(H3BTC) was constructed using 1,4-dicarboxybenzene (TPA) as the first ligand, which can restrict the aggregation-induced quenching of Hoc dyes and maintains the Hoc dyes stably included after preparation. 1,3,5-benzenetricar boxylic acid (H3BTC) was used as a second ligand to sensitize Eu3+ ions for the antenna effect emission and provide detection sites. Eu3+/Hoc@UIO-66(H3BTC) material possesses blue luminescence from Hoc molecules as well as red luminescence from Eu3+ when irradiated by UV lamp, which can be used for ratiometric luminescence detection of Cu2+/Fe3+ through reference to the intensity ratios of two emitting peaks. Eu3+/Hoc@MOFs(H3BTC) as a luminescence sensor, displays an ultrahigh sensitivity (Cu2+:4.58 μM, Fe3+:18 μM), strong ant-interference ability, and fast response for detecting analytes. This project demonstrates that the dual-ligand Zr-based MOFs and luminescence dyes offers a novel ratiometric luminescence detection platform for heavy metal ions visible identification.

Employing comparative QSAR techniques for the recognition of dibenzofuran and dibenzothiophene derivatives toward MMP-12 inhibition

Among various matrix metalloproteinases (MMPs), MMP-12 is one of the potential targets for cancer and other diseases. However, none of the MMP-12 inhibitors has passed the clinical trials to date. Therefore, designing potential MMP-12 inhibitors as new drug molecules can provide effective therapeutic strategies for several diseases. In this study, a series of dibenzofuran and dibenzothiophene derivatives were subjected to different 2D and 3D-QSAR techniques to point out the crucial structural contributions highly influential toward the MMP-12 inhibitory activity. These techniques identified some structural attributes of these compounds that are responsible for influencing their MMP-12 inhibition. The carboxylic group may enhance proper binding with catalytic Zn2+ ion at the MMP-12 active site. Again, the i-propyl sulfonamido carboxylic acid function contributed positively toward MMP-12 inhibition. Moreover, the dibenzofuran moiety conferred stable binding at the S1′ pocket for higher MMP-12 inhibition. The steric and hydrophobic groups were found favourable near the furan ring substituted at the dibenzofuran moiety. Besides these ligand-based approaches, molecular docking and molecular dynamic (MD) simulation studies not only elucidated the importance of several aspects of these MMP-12 inhibitors while disclosing the significance of the finding of these QSAR studies and their influences toward MMP-12 inhibition. The MD simulation study also revealed stable and compact binding between such compounds at the MMP-12 active site. Therefore, the findings of these validated ligand-based and structure-based molecular modeling studies can aid the development of selective and potent lead molecules that can be used for the treatment of MMP-12-associated diseases. Communicated by Ramaswamy H. Sarma