The aqueous extract of various plants like Coriandrum sativum (AECS), Alternanthera tenella colla (AEAT), Spermacoce hispida (AESH) and Mollugo verticillata (AEMV) was studied for its hexavalent chromium (CrVI) reduction property. Even though antioxidant activity was present, AEAT, AESH and AEMV did not reduce CrVI. AECS showed rapid and dose-dependent CrVI reduction. The efficient reduction of 50 mg/L of CrVI using AECS was attained in the presence of 250 µg/mL of starting plant material, incubating the reaction mixture at pH 2, 30°C and agitation at 190 rpm. Under such conditions, about 40 mg/L of CrVI was reduced at 3 h of incubation. FT-IR analysis revealed the involvement of phenols, alcohols, alpha-hydroxy acid and flavonoids present in the AECS for the CrVI reduction. These results indicate that not all the plant extracts with rich antioxidants are capable of reducing CrVI. Using the conditions standardized in the present study, AECS reduced about 80% of CrVI present in the tannery effluent. These results signify the application of AECS as an eco-friendly method in the wastewater treatment.
Silver nanoparticles (AgNPs) were biosynthesized using Bauhinia variegata flower extract (BVFE). The BVF-AgNPs was found to be spherical shaped with the size of 5-15 nm. The phytoconstituents analysis and FTIR spectrum indicated that bioactive compounds like, phenols, flavonoids, benzophenones, nitro compounds, aromatics and aliphatic amines from BVFE might absorb on the surface of BVF-AgNPs. The synthesized BVF-AgNPs showed potent antioxidant property and α-amylase enzyme activity inhibition. The IC50 value of BVF-AgNPs was found to be 4.64 and 16.6 µg/ml for DPPH and ferric reducing power assay, respectively. The IC50 value of BVF-AgNPs for α-amylase inhibition was found to be 38 µg/ml. The Ki value of BVF-AgNPs for α-amylase inhibitory effect was found to be 21 µg/ml with the non-competitive mode of inhibition. These results suggest that BVF-AgNPs might be an effective nano-drug to treat diabetic conditions.
Two high-copy-number insertion sequences, IS2404 and IS2606, were recently identified in Mycobacterium ulcerans and were shown by Southern hybridization to possess restriction fragment length polymorphism between strains from different geographic origins. We have designed a simple genotyping method that captures these differences by PCR amplification of the region between adjacent copies of IS2404 and IS2606. We have called this system 2426 PCR. The method is rapid, reproducible, sensitive, and specific for M. ulcerans, and it has confirmed previous studies suggesting a clonal population structure of M. ulcerans within a geographic region. M. ulcerans isolates from Australia, Papua New Guinea, Malaysia, Surinam, Mexico, Japan, China, and several countries in Africa were easily differentiated based on an array of 4 to 14 PCR products ranging in size from 200 to 900 bp. Numerical analysis of the banding patterns suggested a close evolutionary link between M. ulcerans isolates from Africa and southeast Asia. The application of 2426 PCR to total DNA, extracted directly from M. ulcerans-infected tissue specimens without culture, demonstrated the sensitivity and specificity of this method and confirmed for the first time that both animal and human isolates from areas of endemicity in southeast Australia have the same genotype.