Enhanced Photocatalytic Activity of C-doped TiO2 under Visible Light Irradiation: A Comparison of Corn Starch, Honey, and Polyethylene Glycol as a Carbon Sources

Titanium dioxide (TiO2) represents an effective photocatalyst for removal of polluted water; however, it has a limitation of active under small part of ultraviolet light region from sun spectrum. Herein, reported the carbon doping TiO2 (C-doped TiO2) by using various carbon sources such as corn starch, honey, and polyethylene glycol, for improving the electronic and photocatalytic properties of TiO2. The responsed visible light photocatalysis was synthesized via the ultrasonic–assisted sol–gel method and characterized by X-ray diffraction (XRD), fourier transform infrared (FT–IR) and X-ray photoelectron (XPS) spectroscopy, field emission scanning electron microscopy (FE-SEM), energy dispersive X-ray spectroscopy (EDS), and UV−vis spectroscopy. The results showed that the photocatalytic C-doped anatase TiO2 nanoparticles have the narrowest band gap down to 2.71 eV with increase the carbon doping up to 2.0% by weight from corn starch as external carbon source. XPS result reveals carbon substitution of titanium positions in the anatase TiO2 structure and also to precipitate at the surface of TiO2. As compared photodegradation efficiency under ultraviolet light, observed 87 %MB maximum photoremoval in neutral aqueous solution within 1 hour reaction time under visible light irradiation. While doping with other carbon sources, C-doped anatase TiO2 showed low photocatalytic activity. Hence, great strategy of wastewater treatment application in large scale pilot plant, selected low cost of corn starch acted as an external carbon source for promoted an excellent visible light nano-anatase TiO2 photocatalytic immobilization on the modified glass supporter throughout adhesive waterproof glue

Study on the absolute configuration and biological activity of rotenoids from the leaves and twigs of Millettia pyrrhocarpa Mattapha, Forest & Hawkins, sp. Nov

Abstract Background M. pyrrhocarpa is a new plant in the Fabaceae: Faboideae family that is found in Thailand. A literature search revealed that the Milletia genus is rich in bioactive compounds possessing a wide range of biological activities. In this study, we aimed to isolate novel bioactive compounds and to study their bioactivities. Methods The hexane, ethyl acetate, and methanol extracts from the leaves and twigs of M. pyrrhocarpa were isolated and purified using chromatography techniques. These extracts and pure compounds were tested in vitro for their inhibitory activities against nine strains of bacteria, as well as their anti-HIV-1 virus activity and cytotoxicity against eight cancer cell lines. Results Three rotenoids, named 6aS, 12aS, 12S-elliptinol (1), 6aS, 12aS, 12S-munduserol (2), dehydromunduserone (3), and crude extracts were evaluated for antibacterial, anti-HIV, and cytotoxic activities. It was found that compounds 1–3 inhibited the growth of nine strains of bacteria, and the best MIC/MBC values were obtained at 3/ > 3 mg/mL. The hexane extract showed anti-HIV-1 RT with the highest %inhibition at 81.27 at 200 mg/mL, while 6aS, 12aS, 12S-elliptinol (1) reduced syncytium formation in 1A2 cells with a maximum EC50 value of 4.48 μM. Furthermore, 6aS, 12aS, 12S-elliptinol (1) showed cytotoxicity against A549 and Hep G2 cells with maximum ED50 values of 2.27 and 3.94 μg/mL. Conclusion This study led to the isolation of constituents with potential for medicinal application, providing compounds (1–3) as lead compounds against nine strains of bacteria. The hexane extract showed the highest %inhibition of HIV-1 virus, Compound 1 showed the best EC50 in reducing syncytium formation in 1A2 cells, and it also showed the best ED50 against human lung adenocarcinoma (A549) and human hepatocellular carcinoma (Hep G2). The isolated compounds from M. pyrrhocarpa offered significant potential for future medicinal application studies