A fungal endophyte which was identified as a hitherto undescribed member of the family Xylariaceae by sequencing of the ITS region was isolated from fresh and healthy leaves of Lansium domesticum collected on tropical peatland of West Kalimantan, Indonesia. Chromatographic separation of the ethyl acetate extract of the fungus resulted in the isolation of three new arugosin type metabolites, including arugosins O (1), P (2), and Q (3). The structures were determined by analysis of 1D and 2D NMR spectra and HRMS data, and by comparison with data from the literature. Biological activities of those compounds are also reported.

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Limonoid has been isolated from orange seeds of Citrus microcarpa Bunge using extraction and partitioning methods. It is a yellowish-white crystal with a melting point of 276-277 oC. Based on the phytochemical analysis and FTIR spectroscopy, 1H NMR and compared with the literature, the compound is limonin which is a triterpenoid. The purpose of this study was to determine the structure and evaluate antioxidant activity of the limonin. The antioxidant activity by DPPH obtained IC50 value of limonin was 199.18 ppm. Whereas, the test antioxidant activity by FRAP method using a comparative solution of ascorbic acid showed that there was an increasingly blue color change, which meant that antioxidant activity was stronger with activity value of 11.88 mgAAE /g sample.

Eugenol from the isolation of clove leaves oil had been utilized in the synthesis of 7-hydroxy-3',4'-dimethoxy-isoflavone based on deoxybenzoin intermediate. The raw material was firstly converted into methyleugenol using DMS (89.87%). Secondly, methyl eugenol was oxidized using KMnO4 to produce 3,4-dimethoxybenzyl carboxylic acid (21%). Friedel-Craft acylation of it with recorcinol produced 3,4-dimethoxybenzyl-2',4'-dihydroxyphenyl ketone (deoxybenzoin intermediate) in 78% yield. Eventually, cyclization of the intermediate with reagents of BF3.OEt2/DMF/POCl3 yielded 7-hydroxy-3',4'-isoflavone in 85% yield.

Padas stone is one of the natural mineral containing 67.5% of SiO2 compounds. In this research, synthesis of nanosilica was carried out by sol-gel method asistanced by 2.45 GHz microwave radiations with low (10%), medium (50%) and high (100%) power at 30 and 60 minutes of contact times. It was analyzed by XRD, BET, FTIR spectrophotometry and SEM. The synthesized silica was then used as absorbent for total organic carbon (TOC) of palm oil waste. The results show that the synthesized silica was a mixture of cristobalite and quartz type minerals according to ICDD No. 00-003-0271 and 01-083-287. The surface area and silicon dioxide contains are 12.174 m2/g and 76.325% for silica without microwave assistance (SiO2-TPMW); 12.796 m2/gand 86.385% for silica with 30 minutes on 10% microwave assistance(SiO2 -MW 10A); 12.735 m2/gand 86.254% for silica with 60 minutes on 10% microwave assistance (MW 10B); 13,659 m2/gand 87.211% for MW 50A; 13,583 m2/g and 86.684% for MW 50B;7.883 m2/gand 57.527% for MW 100A; also 8.752 m2/g and 37.725% for MW 100B, respectively. The use of silica as an absorbent of TOC shows the effectiveness of 62.89% (TPMW); 63.68% (MW 10A); 62.96% (MW 10B); 65.25% (MW 50A); 64.61% (MW 50B); 62.37% (MW 100A) and 61.18% (MW 100B) from the initial TOC of 1520 mg/L. Keywords: synthesis, nanosilica, padas stone, total organic carbon, oil waste.