Swarna Vinodh Kanth | Anna University (original) (raw)

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Papers by Swarna Vinodh Kanth

ABSTRACT Schizophyllum commune is the world′s most extensively disseminated mushroom except in An... more ABSTRACT Schizophyllum commune is the world′s most extensively disseminated mushroom except in Antarctica. Schizophyllan is a polysaccharide fractions isolated from S. commune. The schizophyllan is oxidized to form scleraldehyde to introduce carbonyl group for additional functions. The relationship between structure, kinetic and antioxidant properties of scleraldehyde was studied in order to establish the molecular characteristics related to its maximum radical scavenging activity. In our earlier paper we have reported that scleraldehyde obtained from schizophyllan with the dialdehyde content of 28%. From the absorption studies, it explains there is π–π⁎ excitations involving the benzene groups. Moreover, the structural identification of scleraldehyde were characterized by bands at 1670 and 3600–3200 cm−1, corresponding to the axial deformation of the C=O bond and the angular deformation of the C–H bond respectively. The IR spectrum confirms the identity of aldehyde. The scavenging assays of scleraldehyde was found to be reliant on their reactivity and concentration. Scavenging assays performed indicate that 100 μM of scleraldehyde showed the highest antioxidant activity compared to the ascorbic acid. Furthermore, The reducing ability of the scleraldehyde was 54.81±0.92 μM of Fe(II)/g compared to the control (Ascorbic acid) respectively. The kinetic mechanism of scleraldehyde portrays a competitive inhibition against antioxidant enzymes on calculating for radical scavenging activity. By means of structure determination, kinetic assays and the antioxidant assays that hydroxyl group present in C2, C4 and C6 are the main reactive sites. The hypothesis converse that scleraldehyde can serve as scavenger of aqueous peroxyl radicals near the membrane surface of collagen.

ABSTRACT The interaction of bilirubin with collagen in the significance of jaundice incidence hav... more ABSTRACT The interaction of bilirubin with collagen in the significance of jaundice incidence have been previously reported and investigated. The novel peptide sequences containing bilirubin binding domain was identified and located to develop a basis for further studies investigating the interactions of collagen with bilirubin in the present study. In this study an intricate interaction between bilirubin and collagen was characterized and their binding domain has been established using in-gel digestion and LC–MS/MS analysis based on the collagen sequencing and peptide mass fingerprinting. The biotinylated bilirubin derivatives bind to α1(I) chain but not to α2(I) chains which clearly designates that bilirubin shows greater affinity to α1 chains of collagen. The intact proteins collected after analyzing the resulting complex mixture of peptides was used for peptide mapping. Using the electrospray method, among the other peptide sequence information obtained, the molecular weight of collagen alpha-2(I) chain was obtained by locating a 130 kDa weight peptide sequences with greater pi value (9.14) with 1,364 amino acid residues and collagen alpha-1(I) chain with 1,463 amino acid residues with 138.9 kDa molecular weight. This information leads to locate the exact sequence of these helices focussing on the domain identification. The total charge of the peptide domain sequences infers that the bilirubin participates in the electrostatic mode of interaction with collagen peptide. Moreover, other modes of interactions such as hydrogen bonding, covalent interactions and hydrophobic interactions are possible.

Desalination and Water Treatment, 2013

Dyes and Pigments, 2008

Collagenase enzymes are nontoxic and eco-friendly biocatalysts. Dyeing is an important process in... more Collagenase enzymes are nontoxic and eco-friendly biocatalysts. Dyeing is an important process in the leather industry, which employs many synthetic colorants. Many good dyes suffer from incomplete exhaustion and this causes concern, as the biotreatability of the unexhausted dyes in effluent is normally difficult. Hence in the present study, an attempt has been made to improve the exhaustion of dyes by using bacterial collagenase enzymes as biocatalysts. The effect of process parameters of enzymatic treatment such as pH, temperature and duration on the exhaustion of the dye, levelness of dyeing, shade brightness, dye penetration and color intensity have been studied and the conditions are optimized. Uptake of dye as high as 99% has been observed by the treatment of collagenase. The change in shades due to enzymatic treatment has been quantified by reflectance measurements and compared with the visual assessment data. Scanning electron microscopy analysis showed a well opened-up fibre matrix for the collagenase treated leather. The strength properties are not significantly altered and the bulk properties like softness have been found to be improved by the use of collagenase.

Journal of Natural Fibers, 2008

Leather making involves conversion of a putrefiable skin or hide protein (collagen) into nonputre... more Leather making involves conversion of a putrefiable skin or hide protein (collagen) into nonputrescible material. Environmental concerns have forced the leather industry to develop tanning systems based on natural products. Vegetable tanning is one of the oldest methods of tanning. However, there is limitation in the usage of vegetable tanning materials because of its high organic load in the effluent generated, which is difficult to degrade and leads to high biological and chemical oxygen demand. In this investigation an attempt has been made to design an eco-friendly tanning process of protein fibers using proteolytic enzymes to improve the exhaustion of vegetable tannins by increased uptake of vegetable tannins. The enzymatic treatment of the protein fibers brought in an exhaustion of 97% in the case of the optimized experimental process, compared to 85% in conventional vegetable tanning process. The enzyme treatment before tanning showed slight improvement in hydrothermal stability. Physical and tactile evaluation of leathers was slightly better than conventionally tanned leathers. Surface color values illustrated the variation in color or shade between control and optimized experimental leather was negligible. Experimental leathers showed opened-up fiber structure well coated by vegetable tannins, indicating that the enzymatic tanning process did not bring about any major change on the fiber structure of the leathers. The enzymatic process also benefits from reduction in total solids and chemical oxygen demand (COD) loads by 76% and 25%, respectively from the identified streams.

Bioresource Technology, 2009

In the present investigation, kinetics of dyeing involving pretreatment with acid protease has be... more In the present investigation, kinetics of dyeing involving pretreatment with acid protease has been presented. Application of acid protease in dyeing process resulted in increased absorption and diffusion of dye into the leather matrix. Enzyme treatment at 1% concentration, 60 min duration and 50°C resulted in maximum of 98% dye exhaustion and increased absorption rate constants. The final exhaustion (C 1 ) for the best fit of CI Acid Black 194 dye has been 98.5% with K and r 2 values from the modified Cegarra-Puente isotherm as 0.1033 and 0.0631. CI Acid Black 194 being a 2:1 metal complex acid dye exhibited higher absorption rate than the acid dye CI Acid Black 210. A reduction in 50% activation energy calculated from Arrhenius equation has been observed in enzyme assisted dyeing process of both the dyes that substantiates enhanced dye absorption. The absorption rate constant calculated with modified Cegarra-Puente equation confirm higher rate constants and faster kinetics for enzyme assisted dyeing process. Enzyme treated leather exhibited richness of color and shade when compared with control. The present study substantiates the essential role of enzyme pretreatment as an eco-friendly leather dyeing process.

Carbohydrate Research, 2010

The present study investigates the antimicrobial activity of oxidized schizophyllan (scleraldehyd... more The present study investigates the antimicrobial activity of oxidized schizophyllan (scleraldehyde) against Gram-positive and Gram-negative bacteria by diffusion and tube dilution analysis. Schizophyllan is a natural polysaccharide produced by fungi of the genus Schizophyllum. Periodate oxidation specifically cleaves the vicinal glycols in scleraldehyde to form their dialdehyde derivatives. The antibacterial activity exhibited by scleraldehyde was defined using various tests such as the disc diffusion assay, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). MIC and MBC values were found to be in the range of 3.0-8.0 mg/mL. Hence, the present studies establish that the scleraldehyde possesses effective antibacterial properties and can be used as a biopreservative for preservation of raw hides and skins.

Carbohydrate Polymers

Schizophyllan is a natural polysaccharide, produced by fungi of the genus Schizophyllum. Periodat... more Schizophyllan is a natural polysaccharide, produced by fungi of the genus Schizophyllum. Periodate oxidation specifically cleaves the vicinal glycols in schizophyllan to form their dialdehyde derivatives. The present study investigates the interaction of scleraldehyde with Type I collagen membrane. The formation of the inter and intra interaction between scleraldehyde and the collagen fibres results in significant increase in viscosity of collagen. Crosslinking efficiency of scleraldehyde was found to increase with concentration of scleraldehyde. Scleraldehyde interacted collagen membrane exhibited an increase in thermal stability by 29 • C at pH 8. The gelling time of collagen fibrils was found to decrease with increase in concentration of scleraldehyde due to shift in nucleation centre. Swelling degree of collagen membrane was also found to decrease with increase in concentration of scleraldehyde. Scleraldehyde treated collagen membrane exhibited 93% resistance to collagenase. The modified collagen membrane exhibited non-toxicity towards the fibroblasts cells. The modified collagen membrane by scleraldehyde finds application as a stabilizing agent in scaffold preparation.

Process Biochemistry, 2009

Journal of Macromolecular Science, Part A, 2012

The present study explains the molecular level interaction of valeraldehyde with collagen. Valera... more The present study explains the molecular level interaction of valeraldehyde with collagen. Valeraldehyde is a monoaldehyde, which involves crosslinking with protein through covalent linkages. The role of valeraldehyde as a crosslinking agent for collagen stabilization was studied. Molecular modeling approaches was used to understand the interaction of collagen like peptide with valeraldehyde, which mimic the aldehyde tanning processes involved in protein stabilization. Crosslinking efficiency of valeraldehyde was found to increase with an increase in concentration due to the higher availability of aldehydic groups involved in crosslinking with collagen. Valeraldehyde interacted collagen membrane showed an increase in thermal stability by 25°C at pH 8. In the presence of valeraldehyde, collagen fibrils nucleation center was shifted from a lower to a higher range. Shift in the nucleation center was observed in the reduction of gelling time. Water accessibility in valeraldehyde interacted collagen membrane was reduced due to a higher crosslinking rate in the collagen. Modified collagen membrane by valeraldehyde at incubation of about 96 h showed higher resistance to collagenolytic activity of 81%. The amino groups reacting appear to be involved in crosslinking with valeraldehyde. Several interaction sites were identified and the docking energy obtained was −5.539 kcal/mol. The participation of the aldehyde group with amino groups in collagen was observed, which plays a dominant role in the stabilization of peptide by valeraldehyde. It was found that complexes exhibit covalent bonding, hydrogen bonding and electrostatic interaction in the process of stabilization.