Judul: Isolation and identification of α-glucosidase inhibitor compound from the leaves extracts of takokak (Solanum torvum).
Abstrak: This study aimed to isolate the alpha-glucosidase inhibitor compounds on leaves and fruit of takokak (Solanum torvum). The leaves and fruit were extracted with n-hexane, ethylacetate, methanol and water and determined the activity of α- glucosidase inhibitors. Leaves extract has properties as an inhibitor, while no activity was found in the fruits extract. The IC50 values of methanol extract of Solanum torvum leaves was 100 ppm. Fractionation performed on leaf extracts using silica gel column chromatography. Fractionation results obtained six fractions (1-6) and the most active fraction was fraction 2 (IC50 18.28 ppm). Fraction 2 was separated further by preparative thin layer chromatography and obtained ten fractions. One fraction has the highest activity of α-glucosidase inhibitors with IC50 of 67.02 ppm. Phytochemical assay, ultraviolet visible spectroscopy and infrared spectroscopy on the fraction with the highest activity showed that the active compound as inhibitors was flavon.
Keyword: 

Judul: Metabolomic application for identification bioactive components: antibacterial components from takokak fruit extracts (Solanum torvum Swart).
Abstrak: Solanum torvum Swartz, commonly known as Takokak, has been traditionally used in Indonesia to cure several diseases. Fruits of Solanum torvum Swartz are used to cure anti-edemic, as analgesic, to improve blood circulation, to alleviate pain, as antitusive, as anti-inflammatory, to relieve stomach pain, toothache, cataracts, menstruation disorders, hemorrhoids, sore breasts, influenza, swelling, ulcers, soreness, sore waist, high uric acid, bone loss, heart palpitations, and for detoxification (Andarwulan et al. 2012). The antibacterial activity of Takokak fruit has been reported as well (Chah et al. 2000, Bari et al. 2010, Sivapriya et al. 2011). However, up to now no reports yet on compounds responsible for takokak’s antibacterial activity. Metabolomics has been found to be more efficient for identification tool of active principles in a complex mixture such as plant extract than the conventional way, which is known as bioassay guided isolation. To achieve this, a specific extraction method that is able to extract the widest possible range of metabolites, and a suitable analytical tool to detect them are required (Yuliana et al. 2011). From 4507,5 g fresh Takokak fruits 376 g dried powder was obtained. Extraction and fractionation with diverse polarity of solvents gave 5,62 g of methanol extract (M), 3,09 g of n-hexane fraction (H), 1,37 g of chloroform fraction (K), 2,59 g of ethyl acetate fraction (E), and 11,78 g of water fraction (A). The result of antibacterial activity indicated that among all the tested extracts and fractions, M extract and K fraction exhibited medium antibacterial activity against Staphylococcus aureus while others did not. Inhibition zone diameters of M extract were between 4-4,5 mm and K fraction were between 6,5–6,8 mm. The results of TLC showed 6 spots of M extract, 1 spot of H fraction, 10 spots of K fraction, 3 spots of E fraction, and 1 spot of A fraction. The TLC spots appearance (blue fluorescence in UV 366 and 254 nm) suggested that steroid components are probably the active components of Takokak fuit. Furthermore analysis to provide chemical compoisition of the extract and fractions was conducted by with HPLC. The chromatograms of each sample were converted into excel file and then were correlated to its antibacterial activity. There are several possible plots as OPLS outputs to be used to interpret the results. In this study we used score plot, Y-related coefficient plot, and X varian plot. The score plot showed good separation between active and non-active takokak extracts and fractions therefore the study was promising to conduct further. Next, the OPLS Y-related coefficient plot was evaluated. In this study, we are interested to find peak of 17,76 – 18,08 min retention time with a high positive correlation value, which means that the higher peak intensity or the higher peak area value implicates to the higher antibacterial activity as well. In further analysis, we used X varian plot to identify the extract or the fraction where the peak of 17,76 – 18,08 min retention time was dominant. It was discovered that the peak was dominant in fractions K measured at UV λ = 310 nm. Therefore, we chose
Keyword: metabolomics, Takokak, antibacterial activity, OPLS, torvoside

Judul: Analisis Struktur Atas Gedung Diploma IPB terhadap Beban Gempa Berdasarkan SNI 03-1726-2002 dan SNI 03-1726-2012
Abstrak: Gedung Diploma IPB masih menggunakan SNI 03-1726-2002 dalam perencanaan strukturnya. SNI tersebut kemudian diubah seiring dengan keluarnya peraturan baru yang termuat dalam SNI 03-1726-2012. Tujuan dari penelitian ini adalah mengetahui ketahanan struktur atas gedung Diploma IPB terhadap beban gempa ditinjau berdasarkan waktu getar alami dan partisipasi massa, mengetahui besarnya gaya geser dasar seismik, dan membandingkan besarnya simpangan berdasarkan kedua SNI. Partisipasi massa arah X yang dihasilkan yaitu sebesar 0.9417 pada modal ke 9 dan 0.9006 pada modal ke 12 pada arah Y. Kedua nilai tersebut telah memenuhi kedua standar SNI. Waktu getar alami telah memenuhi standar SNI 2002, namun belum memenuhi standar SNI 2012. Gaya geser dasar dinamik yang dihasilkan berdasarkan SNI 2012 sebesar 1599.6606 kN akibat gempa arah X dan 1223.5794 kN akibat gempa arah Y, sedangkan berdasarkan SNI 2002 untuk arah X sebesar 1544.5109 kN dan untuk arah Y sebesar 1544.8304 kN. Simpangan antar lantai telah memenuhi persyaratan kedua standar SNI. Struktur Gedung Diploma IPB telah memiliki kekakuan yang cukup dan terhitung boros, sehingga seharusnya dapat direncanakan dengan lebih hemat biaya.
Keyword: beban gempa, gaya geser dasar, simpangan, struktur atas