Phytochemical screening and In Vitro Antioxidant potential of Memecylon umbellatum Burm leaf extracts

Objective: Different dry extracts of Memecylon umbellatum Burm leaf obtained by various solvents such as petroleum ether, chloroform, ethyl acetate, acetone, methanol and chloroform water (IP) was screened to reap the benefits of its antioxidant and free radical scavenging properties using ascorbic acid as standard antioxidants. Methods: The in vitro free radical scavenging activity was evaluated using diphenyl picryl hydrazyl (DPPH) radical method using various concentrations of dry extract in distilled water (1, 2, 4, 8, 16, 20 μg/ml) against blank with ascorbic acid as a standard in same concentrations. Results: Among the all extracts, Methanol leaf extract has showed higher Antioxidant activity (84.65 ± 0.064 %) having IC50 Value 11.81 ± 0.033 μg/ml at 20 μg/ml. While, IC50 value for ascorbic acid was found to be 8.91 ± 0.084 μg/ml. Conclusion: The results clearly indicate that Methanol leaf extract of Memecylon umbellatum is effective in free radical scavenging. So in future, this may emerge as promising natural herbal source of powerful antioxidant. Keywords: Memecylon umbellatum, DPPH reagent, Antioxidant activity, Ascorbic acid, IC50

Microscopic Evaluation of Leaves of Memecylon umbellatum Burm

Objective. Aim of present work is to perform the microscopic evaluation and physicochemical analysis and to explore the morphology parameters of Memecylon umbellatum Burm leaves. Methods. Fresh, dried and desiccated powdered leaf samples were studied for their morphology, microscopy, organoleptic characters, and an assortment of other WHO recommended methods for standardisation. Results. The microscopy revealed the dorsiventral nature of the leaf. Midrib showed presence of nonlignified phloem, lignified xylem with well-defined xylem fibers, vessels, and parenchyma. Presence of Phloecentric vascular bundles surrounded by endodermis and crystal sheath. Well-defined patches of collenchyma were observed above and below the vascular bundles in the midrib area. Trichomes are mostly absent and stomata (anomocytic) were observed on both epidermal surfaces. Conclusions. It can be concluded that the microscopic analysis and pharmacognostic parameters can serve as tool for developing standards for proper authentication, quality, and purity of Memecylon umbellatum Burm leaves

Towards Environment Friendly Hydrothermally Synthesized Li+, Rb+, In3+ Intercalated Phosphotungstate (PW12O40) Thin Films

In the present investigation, a one-step hydrothermal approach is proposed to synthesize Li+, Rb+, and In3+intercalated PW12O40 (PTA) thin films. The photoelectrochemical performance of the deposited Li3PW12O40 (Li−PTA), Rb3PW12O40 (Rb−PTA), and In3PW12O40 (In−PTA) photocathodes were investigated using a two-electrode cell configuration of FTO/Li3PW12O40/(0.1 M I−/I3−)aq./Graphite. The energy band gaps of 2.24, 2.11, and 2.13 eV were observed for the Li−PTA, Rb−PTA, and In−PTA films, respectively, as a function of Li+, Rb+, and In3+. The evolution of the spinal cubic crystal structure with increased crystallite size was observed for Rb+ intercalation within the PTA Keggin structure, which was confirmed by X-ray diffraction (XRD). Scanning electron microscopy (SEM) revealed a modification in the surface morphology from a rod-like structure to a densely packed, uniform, and interconnected microsphere to small and large-sized microspheres for Li−PTA, Rb−PTA, and In−PTA, respectively. Compositional studies confirmed that the composing elements of Li, Rb, In, P, W, and O ions are well in accordance with their arrangement for Li+, Rb+, In3+, P5+, W6+, and O2− valence states. Furthermore, the J-V performance of the deposited photocathode shows power conversion efficiencies (PCE) of 1.25%, 3.03%, and 1.62%, as a function of the incorporation of Li+, Rb+, and In3+ ions. This work offers a one-step hydrothermal approach that is a prominent way to develop Li+, Rb+, and In3+ ions intercalated PTA, i.e., Li3PW12O40, Rb3PW12O40, and In3PW12O40 photocathodes for competent solar energy harvesting