Molecular Weight Determination Research Articles

Molecular weight determination of adeno-associate virus serotype 8 virus-like particle either carrying or lacking genome via native nES gas-phase electrophoretic molecular mobility analysis and nESI QRTOF mass spectrometry.

Virus‐like particles (VLPs) are proteinaceous shells derived from viruses lacking any viral genomic material. Adeno‐associated virus (AAV) is a non‐enveloped icosahedral virus used as VLP delivery system in gene therapy (GT). Its success as vehicle for GT is due to its selective tropism, high level of transduction, and low immunogenicity. In this study, two preparations of AAV serotype 8 (AAV8) VLPs either carrying or lacking completely genomic cargo (i.e., non‐viral ssDNA) have been investigated by means of a native nano‐electrospray gas‐phase electrophoretic mobility molecular analyzer (GEMMA) (native nES GEMMA) and native nano‐electrospray ionization quadrupole reflectron time‐of‐flight mass spectrometry (MS) (native nESI QRTOF MS). nES GEMMA is based on electrophoretic mobility principles: single‐charge nanoparticles (NPs), that is, AAV8 particle, are separated in a laminar sheath flow of dry, particle‐free air and a tunable orthogonal electric field. Thus, the electrophoretic mobility diameter (EMD) of a bio‐NP (i.e., diameter of globular nano‐objects) is obtained at atmospheric pressure, which can be converted into its MW based on a correlation. First is the native nESI QRTOF. MS's goal is to keep the native biological conformation of an analyte during the passage into the vacuum. Subsequently, highly accurate MW values are obtained from multiple‐charged species after deconvolution. However, once applied to the analysis of megadalton species, native MS is challenging and requires customized instrumental modifications not readily available on standard devices. Hence, the analysis of AAV8 VLPs via native MS in our hands did not produce a defined charge state assignment, that is, charge deconvolution for exact MW determination was not possible. Nonetheless, the method we present is capable to estimate the MW of VLPs by combining the results from native nES GEMMA and native ESI QRTOF MS. In detail, our findings show a MW of 3.7 and 5.0 MDa for AAV8 VLPs either lacking or carrying an engineered genome, respectively.

Validation of an Analytical Method for the Simultaneous Determination of Hyaluronic Acid Concentration and Molecular Weight by Size-Exclusion Chromatography.

The hyaluronic acid (HA) global market growth can be attributed to its use in medical, cosmetic, and pharmaceutical applications; thus, it is important to have validated, analytical methods to ensure confidence and security of its use (and to save time and resources). In this work, a size-exclusion chromatography method (HPLC-SEC) was validated to determine the concentration and molecular distribution of HA simultaneously. Analytical curves were developed for concentration and molecular weight in the ranges of 100–1000 mg/L and 0.011–2.200 MDa, respectively. The HPLC-SEC method showed repeatability and reproducibility greater than 98% and limits of detection and quantification of 12 and 42 mg/L, respectively, and was successfully applied to the analysis of HA from a bacterial culture, as well as cosmetic, and pharmaceutical products.

Comparison of the Properties of Cellulose Obtained from Various Sources

The article discusses the structure, structure and properties of cellulose obtained from various natural sources of plant origin. The physical and mechanical properties of celluloses (content of α–cellulose, determination of the mass fraction of pentosans; determination of the copper number; viscosity characteristics; determination of the degree of purity, moisture content and ash content and determination of the average molecular weight, degree of polymerization and content of aldehyde and carboxyl groups), interaction with nitrogen acid as well as the ability of various cellulose samples to complex formation with copper ions.

Rapid and Nondestructive Determination of Polyacrylonitrile Molecular Weight by Fourier Transform near-Infrared (NIR) Spectroscopy

The molecular weight of polyacrylonitrile (PAN) precursors plays an important role in specifying the properties of prepared carbon fibers. However, it is challenging to rapidly and conveniently determine the accurate molecular weight of PAN. Herein, a practical and facile molecular weight determination model of PAN based on near-infrared spectroscopy (NIR) combined with partial least squares (PLSs) is reported. Using the spectral modeling range from 4000 to 6000 cm−1 with standard normal variate (SNV) or multiplicative scatter correction (MSC) combined with smoothing and first-order differential, the optimized models with main factors number of nine are achieved. The models were systematically evaluated by root mean square error of calibration (RMSEC), root mean square error of prediction (RMSEP), and root mean squares error of cross-validation (RMSECV). In the determination of the molecular weight of the samples based on these optimized models, the value of the relative standard deviation is only 0.9%, and the value of deviation from the established gel permeation chromatography (GPC) method is between −0.037 × 105 and 0.051 × 105. The results show that the reported NIR method has promising potential for the rapid and nondestructive determination of the molecular weight of PAN in production processes.

The Effect of Trifluoroacetic Acid on Molecular Weight Determination of Polyesters: An in Situ NMR Investigation

Due to the poor solubility of aromatic polyesters in common organic solvents, trifluoroacetic acid is usually used as a co-solvent to increase their solubility for characterizations. However, only few works have reported the side reactions induced by it. We present here the application of in-situ 1H NMR techniques to explore its effect on the hydroxyl end-groups, which are usually used for the molecular weight determination of polyesters by end-group estimation method. Using bis(2-hydroxyethyl) terephthalate (BHET) as model compound, 1H quantitative NMR results show the peak integration of hydroxyethyl end-groups decreased with time via a pseudo-first-order kinetics in d-trifluoroacetic acid/d-chloroform mixture solvent (1:10 in volume). This is due to the esterification of hydroxyethyl groups with trifluoroacetic acid, revealed by the 1H-13C gradient-enhanced heteronuclear multiple bond correlation (gHMBC) spectrum. The mixtures of dimethyl terephthalate and BHET with different molar ratio were used to represent poly(ethylene terephthalate) (PET) with different degree of polymerization, and the effect of trifluoroacetic acid on the estimation of hydroxyethyl groups and subsequent molecular weight determination of polyesters was studied. Our results show that if a relative error of 5% is allowed, the NMR measurements must be finished within 1.3 h of solution preparation at 25 C in the mixture solvent. The results were confirmed in PET sample, while in poly(ethylene adipate), the obtained esterifaction constant is faster that those in aromatic system. The results can be applied to other polymer systems with alcohol functionalized groups, and used as a guideline for the characterization of polyesters and polyethers by end-group estimation method.

The HMG-CoA Reductase Inhibitor Activities of Soy Protein Hydrolysates from Papain Hydrolysis

The search for an HMG-CoA reductase inhibitor agent as a safe and inexpensive alternative treatment for hypercholesterolemia has been carried out using soy protein hydrolysates as one of the bioactive peptide sources. This study was conducted to explore the potency of soy protein hydrolysates as an anti hypercholesterolemia agent by an in vitro assay, through the inhibition capacity of the HMG-CoA (3-hydroxy-3-methyl glutaryl-coenzyme A) reductase enzyme as a key component of cholesterol biosynthesis. Sample preparation started with soy protein isolation through acid precipitation and separated by centrifugation. The samples were analyzed the proximate content and hydrolyzed by papain enzyme at concentration 0.2% (w/v), for 0-6 hours and at 37, 50, and 55 oC. The protein hydrolysates were subsequently evaluated for hydrolysis degree (% DH), hydrolysates profile with SDS-PAGE (Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis), and anti-cholesterol assay through HMG-CoA reductase inhibition tests. The sample with the highest inhibition activity was fractionated using gel filtration chromatography (Sephadex G-10) and the molecular weight of fractions was characterized by LCMS QTOF (Liquid Chromatography-Mass Spectrometry Quadrupole Time-of-Flight) for molecular weight determination. The results indicated the optimum hydrolysis conditions of soy protein isolates were obtained at 3 hours incubation, at 50 °C with DH 33.39% and the inhibition value was 95.65% (protein concentration 39.21 μg / mL). LCMS data showed the molecular weight of fractionated peptides were 1514 and 2029 Da. We assumed that both peptides have the same affinity as previous peptides in inhibiting HMG-CoA reductase.

Synthesis, identification, density functional and Hirshfeld surface studies of 2,2'-disulfanediylbis(tetrahydro-4H-cyclopenta[d][1,3,2]dioxaphosphole-2-sulfide).

The new compound 2,2'-disulfanediylbis (tetrahydro-4H-cyclo penta[d][1,3,2]dioxaphosphole 2-sulfide), the dimeric form of 2-mercaptotetrahydro-4H-cyclopenta[d] [1,3,2] dioxaphosphole 2-sulfide, has been synthesized and characterized by elemental analysis, molecular weight determination and spectral data (1 H-NMR, 13 C-NMR, 31 P-NMR, FTIR). The molecular geometry was confirmed by single X-Ray crystallography. The ground state property was examined by PBE0 and B3LYP density functionals using aug-cc-pV(Q+d)Z basis set in the gas phase and in DMSO solution. The preference of PBE0 functional was statistically established. Thermodynamic parameters and standard heat of dissociation reaction ( ) have been established. The calculated equilibrium constants at different temperatures reflect the stability of the dimer over the monomers at low temperatures and vice versa. Valency and Fukui indices calculations showed that the monomer is more reactive than the dimer. 2D-fingerprint revealed that, while the H…X; [X=H, O and S] nonbonding intermolecular interactions and reciprocals play a crucial role in strengthening of molecules packing in the crystal unit cell while the S…S ones contribute negatively on it.

Synthetic, structural and biochemical approach of the macro cyclic complexes of manganese (II) and tin (II)

This study presents a brief account of the synthesis, spectroscopic and biochemical aspects of tetraazamacrocyclic complexes of managenese (II) and tin (II). The complexes of manganese (II) and tin (II) were prepared by the template condensation of metal salts with phthalic acid and diamines (1,3-diaminobutane and 1,4- diaminobutane) in 1:2:2 molar ratio. All the complexes are soluble in polar solvent. The structures were investigated using elemental analyses, molecular weight determinations, conductivity measurements, electronic, infrared and X-Ray diffraction spectral studies. The elemental analyses are consistent with the formation of complexes of the type [M(Macn)Cl2] (where, n=1-2, M=Mn(II), Sn (II)). An octahedral geometry around the metal ion is suggested for these complexes. All the complexes were screened against several fungi and bacteria to assess its biological properties and results are discussed.The importance of this method includes shorter reaction time and high yield.

Protein and glycan molecular weight determination of highly glycosylated HIV-1 envelope trimers by HPSEC-MALS

High Performance Size-Exclusion Chromatography coupled with Multi-Angle Light Scattering detection (HPSEC-MALS) is an important tool to provide a reliable molecular weight measurement for a large complex biomolecule. A recent HIV-1 soluble envelope trimer vaccine candidate, BG505 DS-SOSIP.664, is among the most glycosylated proteins to enter a clinical trial to date, and determination of its protein and glycan molecular weight is one of the key attributes in pre-clinical characterization. However, protein and glycans possess disparate dndcvalues making molecular weight measurement inaccurate in conventional SEC-MALS. To overcome these challenges, a simple mathematically guided experiment was explored, and a composite dndcvalue was established by utilizing protein and glycan mass contributions for the HIV-1 envelope trimer. This establishment was further verified by an orthogonal mass spectrometry analysis. This innovative, simple, and quick analytical approach can be applied broadly to measuring the molecular weight of various composite molecular structures, such as complex glycoconjugates.

Synthesis and evaluation of polymeric dispersant based on vegetable oils their application as cutting fluid

In this work, a novel vegetable oil-based polymeric agents were prepared by epoxidation of rapeseed oil (RO) and castor oil (CO) followed by ring opening reaction of epoxidized products, (epoxidized rapeseed oil and epoxidized castor oil) (ERO) and (ECO) with polyethylene glycol with different molecular weights (400, 600 and 10000 g/mole). The prepared polymers were characterized by 1H NMR, FTIR and GPC for determination of molecular weight. The properties of epoxidized vegetable oil (EVO) and Polymeric vegetable oils (polymeric dispersant of rapseed (PDR) and (polymeric dispersant of castor (PDC) were studied. The prepared polymers were employed as emulsifiers for metal working cutting fluids (MWCF) application.

Anticancer Efficacy of Purified Extracellular L-asparaginase from Aspergillus niger and Yield Enhancement by Agro-industrial Wastes

Nowadays L-asparaginase enzyme is of great importance medically as an anticancer agent and in the food industry through acrylamide mitigation so this work aimed to screen thirty-one fungal isolates recovered from rhizosphere soil by using the dilution plate method for L-asparaginase production. Twenty-four isolates (77.4%) were L-asparaginase producers. Aspergillus niger and A. quadrilineatus were the highest producers with enzyme activity 9.808±0.18930 and 7.348±0.12328 U/ml, respectively. The optimum conditions for enzyme production were at 30 °C for 72 h, pH 6 at 160 rpm, and 0.1% of KH2PO4 in presence of 2% glucose and 1.5% sucrose as carbon source and 1% L-asparagine by A. niger and A. quadrilineatus, respectively. Ammonium sulfate precipitation, Sphedax G-200, and SDS-PAGE were performed for L- asparaginase purification and molecular weight determination. Purified L-asparaginase molecular weights were approximately 50.36 KDa from A. niger with specific activity 50.4 U/mg and 27.8 KDa from A. quadrilineatus with specific activity 37.4 U/mg. Purified L-asparaginase significantly inhibited the proliferation of HCT-116, HePG-2, and MCF-7cell lines with IC50 concentrations of 28.9, 36.1, and 82.6 µg/ml, respectively and did not exhibit any antibacterial efficacy. Enhancement of L-asparaginase production using agro-industrial wastes was evaluated. Maximum yield (23.548 ± 0.00000 U/ml) was obtained by cultivation of A. niger on a mixture of onion and pomegranate peels powder (50%: 50% w/w) and cultivation of A. quadrilineatus on pomegranate peels only.

Photoluminescent studies of 2, 2’-dihydroxybiphenyl, ethylenediamine - formaldehyde copolymer

Polymer resin-II (2,2’-DBPEDF) synthesized by the condensation polymerization of 2,2’-dihydroxybiphenyl (DBP), ethylenediamine (ED) and formaldehyde (F) in acidic medium with molar ratio 2:1:3 of monomer and refluxing in oil bath at 120°C for 5 hr. Synthesized copolymer as a ligand is combined with metal particles such as Ni2+, Cu2+ and Zn2+ ions is in 2:1 molar proportion to get metal complex. The reaction has been finished with refluxed at 60°C for three hour. Composition and structure of organic polymer resin-II have been determined by elemental analysis and molecular weight determination by non-aqueous conductometric titration. The UV-visible, FTIR, proton nuclear magnetic resonance and surface feature and crystalline behaviour of ligand and its complexes were analysed by SEM. Newly synthesized copolymer with metal complexes with copper and zinc metal may be used as supporting material for luminescence 2,2’-DBPEDF-Cu show higher photoluminescence than 2,2’-DBPEDF-Zn.

Comparative extraction of bromelain and bioactive peptides from pineapple byproducts by ultrasonic‐ and microwave‐assisted extractions

AbstractUltrasonic‐assisted extraction (UAE) and microwave‐assisted extraction (MAE) were used for the extraction of bioactive peptides from pineapple byproducts. Independent extraction parameters for UAE were ultrasonic amplitude (60–100%), extraction time (10–30 min), and solvent to material ratio (20–40 mL/g), whereas for MAE independent variables were microwave power (100–300 W), irradiation time (5–15 min), and feed to solvent ratio (1:8–1:12 g/mL). The optimized extraction conditions were 99.96%, 26.83 min, and 20.96 mL/g for UAE and 100 W, 8.99 min, and 1:8 g/mL for MAE. The optimized extraction resulted in total sugar, protein content, and proteolytic activity of 15.71 ± 0.03 mg/mL, 4.01 ± 0.04 mg/mL, and 196.46 ± 3.29 U/mL, respectively, whereas 33.87 ± 0.03 mg/mL, 2.50 ± 0.01 mg/mL, and 154.08 ± 1.49 U/mL for MAE, respectively. Scanning electron microscopy was used to observe the morphology of sample during extraction. Molecular weight determination showed that the major protein band in the extracts (UAE and MAE) was at ∼23 kDa which corresponded to bromelain. Furthermore, pineapple crown protein extract obtained by UAE showed high proteolytic activity (>80% relative). The present study indicated that bromelain and other bioactive peptides from pineapple byproducts have potential in food, feed, and pharmaceutical products development.Practical ApplicationsThe conventional extraction techniques for bioactive compounds are time‐consuming and less efficient. The use of advance extraction techniques like microwave‐ and ultrasonication‐assisted extraction techniques can increase the extraction yield with better recovery of bioactive compounds. Pineapple byproducts are rich source of bioactive compounds and bromelain. The effective utilization of pineapple byproducts for the extraction of bromelain and other bioactive peptides will offer an effective solution for minimizing the organic waste and provide an efficient source of bioactive peptides for application in various food products.

Molecular weight distribution and corrosion inhibitor activity of 4-vinylpyridine oligomer synthesized using low concentration hydrogen peroxide as the initiator

Low molecular weight 4-vinylpyridine oligomer or O(4-VP) has been synthesized using 0.25 M hydrogen peroxide as the initiator. The resulting O(4-VP) was characterized by Fourier transform infrared (FTIR) spectroscopy for identification of functional groups, and mass spectroscopy (MS) for determination of molecular weights. O(4-VP) was tested as a corrosion inhibitor of mild steel in a corrosive solution saturated with carbon dioxide using wheel test and electrochemical methods, i.e., electrochemical impedance spectroscopy (EIS) and Tafel plots. Mild steel surface analysis was performed by scanning electron microscopy (SEM). The product of the synthesis is a viscous orange compound. The mass spectrum showed that O(4-VP) had a mass (m/z) of 100–900, which is in accordance with the chain length of 1–9 monomer units, where the chain length of 4 (tetramer) is the most abundant fraction. The FTIR results show no significant difference between the monomer and O(4-VP). The wheel test as a screening test showed that O(4-VP) exhibited corrosion inhibitor activity. This activity was confirmed by the results of EIS and Tafel analyses, which also demonstrated that protection increased with increasing concentration of O(4-VP) and temperature. At temperature 70°C and a concentration of 150 mg L –1 , the protection by O(4-VP) reached 81.9% (based on EIS) and 87.8% (based on Tafel plots). Protection of mild steel was also confirmed by the surface morphology of the sample obtained by SEM characterization.

Effect of the Polymer Structure Diversity on the Eddies Suppression of Basrah Light Crude Oil Turbulent Flow

Poly(pentaerythritol adipate), poly(pentaerythritol sebacate), and poly(pentaerythritol hexadecandioate) derivatives containing different length alkyl branches were synthesized by two subsequent steps; the reaction of pentaerythritol with (C8-C16) linear aliphatic monocarboxylic acids and then, polymerization of products with (C6-C16) linear aliphatic dicarboxylic acids, using 1% para toluene sulfonic acid as a catalyst. The products were purified and characterized by FTIR, 1H NMR, and 13C NMR spectroscopy. End group analysis was also used as a molecular weight determination technique. The drag-reducing properties of those polymers were investigated in the turbulent flow of Basrah light crude oil using a closed-loop circulation system. Some were found to perform very well DRA and drag reduction efficacy of polymer was further found to be dependent on flowrate, polymer concentration, medium-temperature, and its chemical structure. Also, the effect of the imposed mechanical shear on the polymer stability as a function of time has been investigated using a cylindrical rotator device. It was observed that distance between branch points plays a direct role in contributing to the polymer performance and its mechanical stability.

Expression, purification, crystallization and preliminary X-ray crystallographic studies of a mitochondrial membrane-associated protein Cbs2 from Saccharomyces cerevisiae

BackgroundMitochondria are unique organelles that are found in most eukaryotic cells. The main role of the mitochondria is to produce ATP. The nuclear genome encoded proteins Cbs1 and Cbs2 are located at the mitochondrial inner membrane and are reported to be essential for the translation of mitochondrial cytochrome b mRNA. Genetic studies show that Cbs2 protein recognizes the 5′ untranslated leader sequence of mitochondrial cytochrome b mRNA. However, due to a lack of biochemical and structural information, this biological process remains unclear. To investigate the structural characteristics of how Saccharomyces cerevisiae (S. cerevisiae) Cbs2 tethers cytochrome b mRNA to the mitochondrial inner membrane, a preliminary X-ray crystallographic study was carried out and is reported here.MethodsThe target gene from S. cerevisiae was amplified by polymerase chain reaction. The PCR fragment was digested by the NdeI and XhoI restriction endonucleases and then inserted into expression vector p28. After sequencing, the plasmid was transformed into Escherichia coli C43 competent cells. The selenomethionine derivative Cbs2 protein was overexpressed using M9 medium based on a methionine-biosynthesis inhibition method. The protein was first purified to Ni2+-nitrilotriacetate affinity chromatography and then further purified by Ion exchange chromatography and Gel-filtration chromatography. The purified Se-Cbs2 protein was concentrated to 10 mg/mL. The crystallization trials were performed using the sitting-drop vapor diffusion method at 16 °C. The complete diffraction data was processed and scaled with the HKL2000 package and programs in the CCP4 package, respectively.ResultsCbs2 from S. cerevisiae was cloned, prokaryotic expressed and purified. The analysis of the size exclusion chromatography showed that the Cbs2 protein peaked at a molecular weight of approximately 90 KDa. The crystal belonged to the space group C2, with unit-cell parameters of a = 255.11, b = 58.10, c = 76.37, and β = 95.35°. X-ray diffraction data was collected at a resolution of 2.7 Å. The Matthews coefficient and the solvent content were estimated to be 3.22 Å 3 Da-1 and 61.82%, respectively.ConclusionsIn the present study Cbs2 from S. cerevisiae was cloned, expressed, purified, and crystallized for structural studies. The molecular weight determination results indicated that the biological assembly of Cbs2 may be a dimer.The preliminary X-ray crystallographic studies indicated the presence of two Cbs2 molecules in the asymmetric unit. This study will provide an experimental basis for exploring how Cbs2 protein mediates cytochrome b synthesis.

Improving SDS-PAGE method for monoclonal antibodies: The advantages of Tris-Acetate over Tris-Glycine SDS-PAGE system and comparison with CE-SDS method

Present study compares two different buffer systems for the electrophoretic separation of the IgG1 and IgG2 Monoclonal Antibodies using SDS-PAGE method. A modified Tris-acetate system was shown to be superior for separation of these proteins in a 6–20% gradient gel as compared with the traditionally used Tris-glycine method. This modified Tris-acetate buffer system showed sharper bands, more accurate determination of molecular weight, higher resolution, and better estimation of sub-fragments with closer results to those obtained by Capillary Gel Electrophoresis. Also in a parallel experiment, effect of IgG deglycosylation by PNGase-F enzyme was investigated and revealed no significant improvement on the SDS-PAGE results.

Rheological determination of molecular weight of honey adulterated with high fructose corn syrup

Adulteration of honey represents an essential quality assurance concern in the utilisation of this natural product. Honey was serially diluted with high fructose corn syrup and analysed for its rheological profiles at 27 °C. Pure honey at ambient temperatures exhibits a peculiar non-Newtonian rheological behaviour while the behaviour of fructose syrup tends towards Newtonian. The adulteration of honey with this material drags its viscosity towards Newtonian flow behaviour. The results show that the Carreau-Yasuda model correlates the rheology of pure honey samples. Parameters of the Carreau-Yasuda model were observed to reflect the quality of the samples and thus aided their classification. Modified with the insertion of the Mark-Houwink’s relation, the Carreau-Yasuda model yielded average molecular weight data on the samples. The Structural Kinetic Model was utilised to give rheological structural information and a second independent assessment of average molecular weight from the rheograms. The average molecular weight of 202 g/mol was obtained using the Structural Kinetic model, while 205 g/mol was obtained using the amended Carreau-Yasuda model.

Characterization of Protein-Nucleic Acid Complexes by Size-Exclusion Chromatography Coupled with Light Scattering, Absorbance, and Refractive Index Detectors.

Size-exclusion chromatography (SEC) coupled with multiangle light scattering detection (SEC/MALS) enables determination of the molecular weight, oligomeric state, and stoichiometry of protein-nucleic acid complexes in solution. Often such complexes show anomalous behavior on SEC, thus presenting a challenge in determination of molecular weight and stoichiometry based solely on the elution position from SEC. In contrast to analytical ultracentrifugation, the SEC/MALS analysis is not affected by the shape of the complex. Here we describe the use of SEC/MALS for characterization of the stoichiometry of the complex between thereverse transcriptase (RT) domain from group II intron-maturase from Eubacterium rectale and intron RNA, and for monitoring protein dimerization that is driven by interaction between single-stranded DNA upstream of the P1 promoter, known as FUSE and FUSE binding protein-interacting repressor (FIR).

Syntheses, Characterization, Antimicrobial and DNA Cleavage Activity of Cr(III) Complexes with Coumarin based Schiff Base Ligands

A series of biologically important complexes of chromium(III) have been synthesized by the reaction of 3-formyl-4-chlorocoumarin hydrazinecarbothioamide (L1H) and 3-formyl-4-chlorocoumarin hydrazinecarboxamide (L2H) with CrCl3·6H2O in 1:1 and 1:2 molar ratio. All the complexes have been characterized by elemental analysis, molecular weight determination, melting point, conductivity measurements, electronic, IR, 1H NMR, 13C NMR and EPR spectroscopic techniques and X-ray diffraction. In vitro biological screening effects of the compounds were tested against the pathogenic bacterial and fungal species. Further, free ligands and their metal complexes have been screened for their DNA cleavage activity. A comparative study of the biological activities of the Schiff base ligands and their Cr(III) complexes indicates that the complexes exhibit higher antimicrobial and DNA cleavage activity than the free ligands. Physico-chemical studies and spectral data suggested a hexa-coordinated environment around the central metal ion.