Synthesis and antibacterial activity of novel coumarinyl azo-chalcones

Coumarinyl azo-chalcone is one of the coumarin derivatives containing moiety of chalcone. This coumarinyl azo-chalcones were prepared by introduction of substituents (N(CH2CH3)2, OH, Br and OCH3) on coumarin ring. The coumarinyl azo-chalcones (122-126) were synthesised by Claisen-Schmidt condensation reaction of coumarin and benzaldehydes derivatives. The coumarin precursors have been prepared through Knoevenagel Condensation reaction yielded 3-acetyl-7-(diethylamino)coumarin (111), 3-acetyl-7-hydroxycoumarin (112), 3-acetyl-6-bromocoumarin (113) and 3-acetyl-7-methoxycoumarin (114). Meanwhile, benzaldehydes derivatives were prepared by coupling reaction of azo compound under cold condition, afforded 2-hydroxy-5-((4'-nitrophenyl)diazenyl)benzaldehyde (118), 2-hydroxy-5-((4'-chlorophenyl)diazenyl)benzaldehyde (119), and 2-hydroxy-5-((4'-methylphenyl)diazenyl)benzaldehyde (120). Five coumarinyl azo-chalcones were synthesised and identified as 3-((2E)-(3-(2'-hydroxy-5'-((4"-nitrophenyl)diazenyl)phenyl)acryloyl)-6-bromo-2H-chromen-2-one (122), 3-((2E)-(3-(2'-hydroxy-5'-((4"-chlorophenyl)diazenyl)phenyl)acryloyl)-6-bromo-2H-chrom-en-2-one (123), 3-((2E)-(3-(2'-hydroxy-5'-((4"-methylphenyl)diazenyl)-phenyl)acryloyl)-6-bromo-2H-chrom-en-2-one (124), 3-((2E)-(3-(2'-hydroxy-5'-((4"-chlorophenyl)diazenyl)phenyl)acryloyl)-7-methoxy-2H-chromen-2-one (125), and 3-((2E)-(3-(2'-hydroxy-5'-((4"-methylphenyl)diazenyl)phenyl)acryloyl)-7-methoxy-2H-chromen-2-one (126). The compounds obtained were characterized by infrared and nuclear magnetic resonance (1D and 2D NMR) spectroscopy. All coumarinyl azo-chalcones (122-126) were tested for the antibacterial activity against Gram-positive and Gram-negative bacteria. Coumarinyl azo-chalcone (124) showed moderate activity towards all Gram-positive and Gram-negative bacteria

Chemical constituents and antioxidant activity of garcinia parvifolia Miq. stem bark

The chemical constituents of GarciniaparvifoliaMiq.stem bark have been studied. The dried samples have been extracted using Soxhlet apparatus to give the crude products. The constituents were separated and purified by using vacuum column chromatography, gravity column chromatography and recrystallisation. The chemical compounds obtained were elucidated by infrared (IR) and nuclear magnetic resonance (NMR) spectroscopy. Two compounds namely as 1,6,7-trihydroxy-3-methoxyxanthone and 3,8''-binaringenin were isolated from the ethyl acetate crude extracts of G. parvifoliaMiq. The free-radical scavenging activity of the crude extracts were determined by the 2,2- diphenyl-1-picrylhydrazyl (DPPH) assay. The ethyl acetate extract was found to be the most active free radical scavenger with IC50 value of 4.2 ppm, followed by methanol extract (IC50 96 ppm) and petroleum ether extract (IC50 200 ppm)

IoT based dual axis solar tracker implementation for polycrystalline photovoltaic with energy storage

This project has been identified as IoT Based Dual Axis Solar Tracker Implementation for Polycrystalline Photovoltaic with Energy Storage that has two degrees of freedom that act as axes of rotation, both horizontal and vertical. Polycrystalline panel is great in both diffuse light and specular light and yet known for its minimal cost. This motorized servo-motor system based final year project is a self-orient the solar panel towards the maximum intensity of sunlight using Light Dependent Resistor (LDR) and hence, it will generate supply to the load. The main system that use to control the movement of motor and sense the LDR is Arduino Uno. This portable 10W solar project can be used anywhere at any time as its main concern to educate people of basic solar tracker concept aside to help supplying 5V Direct Current (DC) load. An Internet of Things (IoT) is therefore added as a feature for this project to monitor the performance of photovoltaic voltage through Blynk application in cell phon