Protein-drug binding study addresses a broad domain of biological problems associating molecular functions to physiological processes composing and modifying safe and coherent drug therapeutics. Comparison of the binding and thermodynamic aspect of sulfa drugs, sulfamethazine (SMZ) and sulfadiazine (SDZ) with the protein, lysozyme (Lyz) was carried out using spectroscopic, molecular docking, and dynamic simulation studies. The fluorescence quenching and apparent binding constant for the binding reaction were calculated to be in the order of 10 4 M À1 , slightly higher for SMZ as compared to that of SDZ and the binding stoichiometry values show 1:1 drug binding with each protein molecule. The binding was an enthalpy-driven spontaneous exothermic reaction favored by a negative enthalpy and a positive entropy contribution for both the complexes. The binding from the fluorescence quenching data suggests a static quenching mechanism dominated by non-polyelectrolytic components. Synchronous fluorescence denoted a conformational change in the tryptophan moiety of the protein. Molecular docking and dynamic simulation study provided a clearer view of the interaction pattern, where the drug resides on the binding pocket of the protein structure. Overall the protein, Lyz binding of SMZ was slightly more favored over SDZ.

Qualitative and quantitative analysis of bioactive constituents of a plant is necessary for determination of potential pharmacological activity. In this study, the qualitative and quantitative analysis of the petroleum ether, chloroform and methanolic extract of Ageratina adenophora leaves were performed. A. adenophora, also called Eupatorium adenophorum, belongs to the family Asteraceae and it is an invasive species in many tropical and subtropical countries, including northeastern India, China, Sri Lanka, and Nigeria. The plant has high reproductive capacity which is partly due to the well-developed root system. From the roots, important bioactive compounds such as benzofuran derivatives, chromene derivative and a monoterpene glucoside and sesquiterpenoid have been identified. Qualitative phytochemical analysis in the present study revealed the presence of carbohydrates, alkaloids, phenols, flavonoids, xanthoprotein, glycosides, tannins, steroids and terpenoids. Quantification of the total tannins, total alkaloids and total phenols were determined for the methanolic extracts of the leaves. High amount of tannins and phenols was detected.

Ageratum conyzoides L., belonging to the family Asteraceae, is an annual herbaceous plant and is an invasive weed. It contains bioactive compounds that are reported to possess therapeutic properties. The species has been studied widely owing to its biological properties and its potential application in medicine and agriculture. It is used in the treatment of burns and wounds, arthrosis, malaria, asthma, leprosy and dermatitis. It also has insecticidal activity against a range of major pests of field crops. Chromatographic analyses have identified pyrrolizidine alkaloids, phenolic acids, coumarin and polymethoxyflavones. The present study was conducted to determine the qualitative and quantitative properties of the crude extracts of the leaves. Extracts were prepared by using petroleum ether, chloroform and methanol solvents. The yield of extract was calculated for all the three solvents and they are studied for qualitative analysis of phytochemical compounds and quantitative analysis. The qualitative phytochemical tests exhibited the presences of alkaloids, carbohydrates, phenols, tannins, steroids, terpenoids, glycosides, saponins, and amino acid. Quantitative analysis suggests the presence of tannins, alkaloids and phenols in the leaves and this can be utilized for further investigations.

Characterization of natural products based on the antioxidant activity gains tremendous interest in the past decade. In the current work, the antioxidant activity of the methanolic extract of Ageratina adenophora and Ageratum conyzoides leaves were determined. Both plants belong to the family Asteraceae and are invasive species in many tropical and subtropical countries, including northeastern India, China, Sri lanka, Nigeria. A. conyzoides is an annual herbaceous plant having a number of bioactive compounds. A. conyzoides is typically found in cultivated fields and other disturbed ecosystems; and is known for its medicinal use in the treatment of burns and wounds, arthritis, asthma, dermatitis, leprosy, malaria, and as an insecticide. Notable compounds include toxic pyrrolizidine alkaloids, phenolic acids, cumarin and polymethoxyflavones. In this study, antioxidant activity of the plant leaves was characterized for DPPH (2, 2-diphenyl-1-picrylhydrazy) and hydrogen peroxide radical scavenging activity. Antioxidant activity determines the potential of a compound to scavenge a free radical generated during oxidative stress in the body. The result suggests that A. adenophora and A. conyzoides leaves extracts showed potential antioxidant activity in terms of both DPPH and hydrogen peroxide scavenging activity.

Ageratina adenophora (Asteraceae), commonly known as Crofton weed or sticky snakeroot, leaves are used for various health conditions in traditional medicines. They are used for treatment such as wound, itching, measles, skin diseases, uterine bleeding and also acts as antibacterial and astringent activity. Macroscopic and quantitative microscopic methods were applied to determine the diagnostic features for the identification and standardization of the fresh leaf samples of A. adenophora. Macroscopically, the leaves were found to have an opposite trowel-shaped serration that are 6-10 cm long by 3-6 cm in width. They have a mild characteristic smell and bitter in taste. They are dark-green in colour, while the stems are reddish in colour. The flowers are creamy white coloured followed by a small brown seed with a white feathery parachute. The light and electron microscope images of cross-section of leaf revealed useful diagnostic features. They have anomocytic type of stomata. The stomatal number, stomatal index, vein islet and vein termination number were determined. In the transverse section of the leaf, collenchyma cells, parenchyma cells, vascular bundles, trichomes, palisade cells, upper and lower epidermis were observed. These findings are helpful in authentication of A. adenophora, as well as in laying down its pharmacopoeial standards.