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TiO2 material is composited with silica obtained from natural sand with indirect sonochemistry method. The addition of SiO2 increase the photocatalyst activity of TiO2 as an antibacterial against S. aureus and P. aeruginosa.

The complex compound of [Mn(salen)OAc] can serve as mSOD and its activity has been determined nonenzymatically in vitro through riboflavin photoreduction. The complex was synthesized from Mn(OAc)2.4H2O and H2salen. Based on the elemental analysis, the C=56.69%; H=4.21%; and N=7.52% content are corresponding to the chemical formula of MnC18H17N2O4. The functional groups and ionic species in the complex have been analyzed by infrared spectroscopy and ESI-MS. SOD activity was determined by mixing complex at various concentrations with riboflavin and nitroblue tetrazolium (NBT), then the mixture was lighted with 20 watts tungsten lamp for 15 minutes in a closed box. Then the reduced NBT absorptions were measured at λ 560 nm. The difference of absorbance between standard and sample solutions (without and with riboflavin, respectively) was multiplied by 100% to obtain %inhibition of each various sample concentration against NBT. SOD activity was obtained from IC50 data defined as a 50% inhibition of the plot curve of % inhibition to the concentration of the complex. The result obtained for this compound is IC50 = 2.7 ± 0.1 µM as well as enzymatic method. Therefore, this method can be used to determine the SOD activity by giving more stability and accuracy of IC50 value.Keywords: [Mn(salen)OAc], SOD, non-enzymatic, photoreduction, riboflavin ABSTRAK Senyawa kompleks [Mn(salen)OAc] dapat berfungsi sebagai mSOD dan aktivitasnya telah ditentukan secara in vitro non-enzimatik melalui fotoreduksi riboflavin. Kompleks ini disintesis dari Mn(OAc)2.4H2O dan H2salen. Berdasarkan analisis unsur diperoleh kadar unsur C=56,69%; H=4,21%; dan N=7,52% yang sesuai dengan rumus kimia MnC18H17N2O4. Gugus fungsi dan spesi ion dalam kompleks tersebut telah dianalisis dengan spektroskopi inframerah dan ESI-MS. Aktivitas SOD ditentukan dengan mencampurkan kompleks pada berbagai konsentrasi dengan riboflavin dan nitroblutetrazolium (NBT), yang kemudian campuran tersebut disinari oleh lampu wolfram 20 watt selama 15 menit pada kotak tertutup. Setelah itu serapan NBT tereduksi diukur pada λ 560 nm. Perbedaan absorbansi antara larutan standar dan sampel (masing-masing tanpa dan dengan adanya riboflavin) dikalikan dengan 100% untuk mendapatkan % inhibisi dari setiap variasi konsentrasi sampel terhadap NBT. Aktivitas SOD diperoleh dari data IC50 yang ditentukan sebagai 50% inhibisi pada kurva aluran persen inhibisi terhadap konsentrasi kompleks. Hasil yang diperoleh untuk kompleks ini adalah IC50 = 2,7 ± 0,1 µM sama seperti pada metode enzimatik. Oleh karena itu metode ini dapat digunakan untuk menentukan aktivitas SOD dengan memberikan nilai IC50 yang lebih stabil dan akurat.

Uncaria gambir Roxb. is a plant from Southeast Asia and is widely used as an alternative medicine with various applications. This plant has been widely used in traditional medicine. This paper aims to provide information on U. gambir, a summary of data on phytochemicals and on medical and nonmedical activities. Phytochemical studies reveal biologically active constituents such as flavonoids, phenolics, and alkaloids. Various studies have shown that extracts and compounds obtained from U. gambir have medical uses for their antioxidant, antibacterial, anti-helminthic, anticancer, antifungal, anti-inflammatory, anti-hyperglycemic, anti-hyperuricemic, anti-lipid peroxidation, antihyperlipidemic and other properties. In addition, this extract has other uses, such as adsorbent for dyes and metal ions, as well as corrosion inhibition. Thus, U. gambir, which is commonly used in traditional medicine, is a potential plant for many therapeutic applications and prospects for drug development as well as other applications such as adsorbent and corrosion inhibition.