Nanopowders of Centella asiatica (L.) were produced using planetary ball mill in order to investigate the differences of water extraction yield of asiatic acid as compared to micropowders of Centella asiatica. Effect of extraction time (20–60 min) on extraction yield of asiatic acid from Centella asiatica was examined. Results showed that water extraction of asiatic acid using Centella asiatica nanopowders exhibits was almost 50% higher extraction yield with 7.09 mg/g as compared to the micropowders of Centella asiatica. It was concluded that nanopowders contributed in enhancing water extraction yield of asiatic acid as compared to micropowders. Thereby utilizing nanopowders in water extraction could improve the extraction of asiatic acid via clean, eco-friendly, and less expensive process.

Centella asiatica (C. Asiatica) is a traditional herb that has been used in raditional medicine especially in Asia region. Recently the pharmalogical study of Asiatic acid (AA) which is one of bioactive constituents in C. Asiatica has been studied and revealed that this compound has a potential to be use in medicine area. The objective of this paper is to produce nanoparticles C. Asiatica by Planetary Ball Mill (PBM) and determined the effect of nanonization on extraction yield of asiatic acid. The particles were analyzed using particle sizer to determine size of particle produce and the morphology was evaluated through FESEM. As a result, the mean particles size of nanopowders was 501.10 nm and the extraction of asiatic acid using nanopowders showed 82.09 % higher than original powder.

The present study reports an eco-friendly, biosynthesis of silver nanoparticles (AgNPs) using stem bark extract of Diospyros montana. Initially, the synthesis of AgNPs was confirmed by visual observation as color change. Further, the morphology of the biosynthesized nanoparticles, average size and presence of elemental silver were characterized by UV-Visible spectroscopy, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray and dynamic light scattering spectrometer. Qualitative phytochemical screening and FTIR spectral peaks supported the role of phytochemicals in bark extract for the metal reduction, stabilization and capping of silver nanoparticles. XRD studies demonstrated that crystalline nature and their average size of nanoparticles was 28 nm as determined by Scherrer's formula. The antioxidant ability of AgNPs and plant extract was analyzed using DPPH and Hydrogen peroxide assay. The percentage of DPPH and H 2 O 2 activity was increased with increasing concentration of AgNPs. In vitro antibacterial effect of various concentration of AgNPs was investigated against both Gram positive (B.subtilis and S.aureus) and Gram negative (E.coli and K.aerogenes) bacterial strains. The result shows that biosynthesized AgNPs have significant antibacterial activity.

Ball milling is a top down approach and a method to reduce size of particle while Zeolite is a valuable inorganic materials having wide variety of applications. In this paper, ball milling of commercial synthetic Zeolite powder was studied with their time varied. Wet ball milling was selected as a potential means to decrease the particle size of Zeolite over dry grinding. The parameters that included in this study were rotational speed, balls to powder ratio, water to powder ratio and milling time. These nanozeolite were characterized via Zeta-sizer nanoseries of particle sizer, FESEM, and also FTIR. Results showed that commercial synthetic Zeolite powder with particle size larger than 45 μm may be reduced into the size range between 0.2 0.3 μm by planetary ball mill.

Centella asiatica (C. Asiatica) contains asiatic acid as one of bioactive constituent that has the commercial medicinal value such as anticancer and also possess wound healing property. The ball milling process was carried out at 0.5, 4 and 8 hours. The effects of ball milling at different times were characterized using particles size analysis (Photon Correlation Spectroscopy) and Fourier Transform infra red (FTIR) Spectroscopy. The surface morphology was characterized by Field-Emission Scanning Electron Microscope (FESEM). As a result, smallest particles size by mean 279.5 nm was produced at a longest milling time (8 hr) and FTIR spectra shows there is no obvious change in the structure of C. asiatica nanopowders as compared to the micropowders. Centella asiatica nanopowders shows good extraction yield of asiatic acid with 5.5 μg/ml of yield but poor inhibition of DPPH as compared to micropowders.