Judul: Produksi Flavonoid Daun Dewa (Gynura pseudochina (L.) DC) Asal Kultur in Vitro pada Kondisi Naungan dan Pemupukan
Abstrak: Daun dewa (Gynura pseudochina (L.) DC) adalah tumbuhan obat yang menghasilkan senyawa bioaktif berupa golongan senyawa flavonoid yang telah digunakan sebagai bahan obat tradisional alami untuk mengobati beberapa jenis penyakit khususnya tumor atau kanker pada manusia. Upaya untuk meningkatkan kadar senyawa bioaktif dalam tanaman dilakukan melalui perbaikan kualitas bahan tanam, optimalisasi pemanfaatan cahaya dan pemupukan. Untuk memenuhi hal tersebut, dilakukan percobaan dalam empat tahap masing-masing mempelajari : (1) multiplikasi tunas secara in vitro, (2) induksi akar dan antosianin secara in vitro, (3) pertumbuhan dan kandungan bioaktif bahan tanam asal in vitro dan setek pucuk pada berbagai periode pencahayaan dan (4) produksi flavonoid bahan tanam asal in vitro pada berbagai periode pencahayaan dan pemupukan. Pada hasil studi in vitro diperoleh komposisi media kultur terbaik yang menghasilkan plantlet dengan kandungan antosianin yang tinggi. Komposisi media MS dengan penambahan IAA 0.5 ppm dan sukrosa 30 g/l menghasilkan plantlet terbanyak (2.7) dan kandungan antosianin tertinggi (0.07%). Pada proses pertumbuhan di lapang yang menggunakan berbagai periode pencahayaan, bahan tanam asal kultur in vitro adalah bahan tanam terbaik yang menghasilkan pertumbuhan dan kandungan antosianin lebih tinggi (0.05%) dibanding setek pucuk (0.03%). Pada penelitian ini juga ditemukan periode pencahayaan yang menghasilkan pertumbuhan dan produksi flavonoid tertinggi, serta aspek mekanisme adaptasi fisiologi dan morfo-anatomi tanaman. Pada naungan 50% selama 3 bulan dan 1 bulan cahaya 100%, dihasilkan produksi total flavonoid (1.61g/tanaman) dan kuersetin (0.02g/tanaman) tertinggi, sedangkan produksi antosianin tertinggi (0.17%) diperoleh pada naungan 25% selama 2 bulan dan 2 bulan cahaya 100%. Adaptasi tanaman pada kondisi naungan juga menyebabkan peningkatan kandungan klorofil, aktivitas enzim SOD, tumpukan grana dan ukuran butir pati dari kloroplas serta penurunan jumlah stomata, trichoma dan ketebalan daun di akhir percobaan. Pada percobaan pemupukan diperoleh komposisi media tanam terbaik yang menghasilkan produksi flavonoid tertinggi. Perbaikan media tanam dengan pemupukan semakin meningkatkan pertumbuhan dan produksi flavonoid bahan tanam asal in vitro. Penggunaan dosis maksimum dari pupuk kandang ayam 100g + SO4 0.8g/tanaman menghasilkan produksi total flavonoid per tanaman (1.61g/tanaman) dan antosianin per tanaman (0.17g/tanaman) tertinggi, sedangkan produksi kuersetin per tanaman tertinggi (0.02g/tanaman) dihasilkan pada dosis pupuk kandang ayam 50g + SO4 0.4g/tanaman. Dari seluruh hasil penelitian yang diperoleh, bahan tanam daun dewa asal kultur in vitro menghasilkan pertumbuhan, produksi total flavonoid, antosianin dan kuersetin lebih tinggi pada kondisi naungan dan pemupukan dibanding cahaya 100% dan tanpa pemupukan.
Keyword: Shading, Fertilizing, Flavonoid production, Authocyanin, Quercetin

Judul: Isolasi Komponen Bioaktif Flavonoid dari Tanaman Daun Dewa (Gynura pseudochina (Lour) DC)
Abstrak: This research was including of isolation of flavonoid component from leaf and rhizoma of daun dewa plant, followed by bioassay test of larvae mortality of Artemia salina Leach and antikhamir to Saccharomyces cerevisiae. Extraction process of antocyanin flavonoid was done by maceration using HCl in MeOH solvent, whereas another flavonoid was done maceration too, but with two steps, first, using MeOH – H2O (9:1) and second, using MeOH – H2O (1:1). Filtrate obtained from these steps was collected together and dried using rotavapour. Extract that obtained from this process was partitied using n-hexan, chloroform, diethylether, ethylacetic and n-buthanol solvent, respectively. Its residue was soxhletated using petroleum ether and methanol. The existency of flavonoid was traced by phytochemical test, its bioavailabiolity was traced by toxicity test using A. salina Leach larvae (BSLT test) and antikhamir activity test to Saccharomyces cerevisiae with spectrometer UV-Vis and FTIR, GC-MS and HPLC. The result of phitochemical test of fresh leaf extract of daun dewa plant could not detect the anthocyanin flavonoid group. The result of BSLT test of leaf powder extract showed that buthanol fraction has the highest value of LC50 = 832.12297 ppm, in rhizoma powder extract, the ethylacetic showed the highest value of LC50 was 723.44205 ppm, but in those both extract did not show antikhamir activity to S. cerevisiae khamir. Separation of buthanol fraction was using TLC preparative with silica gel 60 F254 as a stationer phase and BAW as a mobile phase. It was resulted 7 fractions. Fraction 4 and 7 had LC50 value 7.80408 and 208.51563 ppm, respectively. The result of structure identification of fraction 4 and 7 with spectrometer UV-Vis and FTIR gave a clue that fraction 4 and 7 could be presumed contain of flavonoid group compound and these fractions had functional group such as OH, C=O ketone, C=C aromatic and C-O. The results of GC and HPLC showed fraction 4 and 7 obtained was not pure. From the result of HPLC analysis, the content of quercetine in fraction 4 was 2.7458 mg/g.
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Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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