Judul: Struktur dan Aktivitas Antioksidan Fraksi Polar Ekstrak Temu Giring (Curcuma heyneana).
Abstrak: Temu giring (Curcuma heyneana) banyak digunakan untuk mengobati sakit perut dan penyakit kulit. Tujuan penelitian ini adalah melaporkan struktur senyawa dan aktivitas antioksidan dari fraksi polar tumbuhan tersebut. Ekstrak metanol temu giring difraksionasi menggunakan kromatografi cair vakum dengan elusi gradien menghasilkan 10 fraksi. Fraksi 6 dan 8 dipisahkan dengan berbagai teknik kromatografi hingga diperoleh F611 dan F813. Identifikasi F611 dan F813 dengan liquid chromatography-mass spectrophotometry menunjukkan ada 3 senyawa pada F611 dan 2 senyawa pada F813. Kelima senyawa tersebut ialah (1(10)-E,4β,5α,8β)-4,5-epoksi-1(10),11(13)-germakradien-12,8-olida (5), (R)-ar-turmeron (6), kurkumanolida A (12), demetoksikurkumin (14), dan dihidrosuberenol (15). Senyawa (12) dilaporkan terdapat dalam temu giring dan 4 senyawa lainnya terdapat dalam genus yang sama. Hasil pengujian aktivitas antioksidan dengan 1,1-difenil-2-pikrilhidrazil menunjukkan aktivitas antioksidan yang tinggi pada F813 dan ekstrak metanol kasar dengan nilai IC50 maing-masing 59.18 dan 82.16 μg/mL, sedangkan fraksi F611 menunjukkan aktivitas antioksidan yang rendah dengan nilai IC50 >100 μg/mL.
Keyword: aktivitas antioksidan, curcuma heyneana, kromatografi

Judul: Struktur Kimia dan Aktivitas Antibakteri Fraksi Nonpolar Ekstrak Temu Giring (Curcuma heyneana).
Abstrak: Curcuma heyneana yang dikenal sebagai temu giring adalah tanaman obat keluarga Zingiberaceae yang banyak digunakan masyarakat Indonesia sebagai obat cacing, bahan kosmetik, obat demam, obat sakit perut dan obat penyakit kulit. Penelitian ini dilakukan untuk menentukan senyawa akif yang memiliki khasiat antibakteri dalam temu giring. Rimpang temu giring dimaserasi menggunakan metanol dan difraksionasi menggunakan kromatografi cair vakum sehingga diperoleh 10 fraksi. Fraksi 4 dipisahkan menggunakan kromatografi radial dan kromatografi lapis tipis preparatif. Struktur senyawa hasil isolasi diinterpretasi menggunakan spektroskopi inframerah transformasi Fourier, kromatografi gasspektrometer massa, dan spektroskopi resonans magnetik inti sebagai kurkumenol. Aktivitas antibakteri isolat kurkumenol dan ekstrak metanol maserasi diuji pada bakteri Staphylococcus aureus dan hasilnya menunjukkan tidak ada aktivitas antibakteri. Pada bakteri Escherichia coli, aktivitas antibakteri ekstrak metanol maserasi bersifat cukup kuat dan lebih tinggi dibandingkan isolat kurkumenol yang bersifat sedang. Berdasarkan penelitian, aktivitas antibakteri senyawa pada temu giring tidak terlalu kuat.
Keyword: antibakteri, isolasi, kurkumenol, temu giring

Judul: The Construction of Greedy SVP LLL Algorithm
Abstrak: A lattice is a set of all integer linear combination of a set of linearly independent vectors in ℝ𝑛���. The independent vectors are called bases of lattice. Any lattice can be generated from many bases, and these bases have the same cardinality. In the lattice, the most fundamental and renowned problem is the Shortest Vector Problem (SVP). SVP is a tracking problem of the shortest nonzero vector in a lattice with equivalent bases. In two dimensions, SVP problem has resolved exactly by Gauss’ algorithm. When the lattice dimension is higher than two, A.K. Lenstra, H.W. Lenstra and L. Lovasz gave a LLL algorithm to compute approximation of nonzero shortest vector in the lattice. Reduced bases solution obtained from LLL algorithm still be an approximation and has polynomial running time of arbitrary dimension which large enough. In 1994, Schnoor and Euchner modified this LLL algorithm as a new variant which later was named deep insertion LLL algorithm. This algorithm is a modified version of the LLL algorithm to the terms of the exchange step to improve the accuracy of output of LLL reduced bases and applying it to the subset sum problem. The purpose of this research are: (1) Reconstruct the LLL algorithm and deep insertion LLL algorithm using a geometric approach. (2) Construct a greedy SVP LLL algorithm. (3) Implement the three algorithms in a symbolic programming language, and evaluate them experimentally. A bases ℬ=[𝐛���1,𝐛���2,…,𝐛���𝑛���] in ℝ𝑚��� is called reduced LLL with parameter 𝛿��� if satisfies: (a) |𝜇���𝑗���𝑖���|≤12, for every integer 𝑖���,𝑗��� with 1≤𝑖���<𝑗���<𝑛���. (b)𝛿���‖𝜋���𝑗���(𝐛���𝑗���)‖2≤‖𝜋���𝑗���(𝐛���𝑗���+1)‖2, for 𝑗���=1,2,…,𝑛���−1,where 𝛿��� is a reduced parameter of real numbers with 14<𝛿���<1. The first requirement is the reduced basis 𝛿��� must “nearly orthogonal” and in its computation case, this requirement can be reached out by using the Gram-Schmidt’s orthogonalization. While the second requirement is called exchange step, or used to called as Lovasz condition. By using both of these requirements, then they establish the LLL algorithm. Then, Schnoor and Euchner modify the LLL algorithm based on the requirements of the exchange step called the deep insertion LLL algorithm, where the exchange step is based on the comparison of the projected vector in orthogonal complement [𝐛���1,𝐛���2,…,𝐛���𝑘���−1]⊥ after j-th reduction. To construct greedy SVP LLL algorithm, the requirements of the exchange step is based on purely by comparing norm of lattice 𝐛���𝑗��� with norm lattice 𝐛���𝑖��� for 𝑖���=1,2,3…,𝑗���−1. The process of insertion reduced vector after the exchange step also has done greedily. Then, we calculate the number of arithmetic operation in greedy SVP LLL algorithm for further analysis. The result of our exprimentation for three algorithms on the certain matrix size shows that the running time of the three algorithms increases propotional to the size of the matrix. The result also shows that by using 𝛿���=34 for the LLL algorithm and the deep insertion LLL algorithm, and the greedy SVP LLL algorithm which is a new variant made by using no parameter of 𝛿���, outperform of the other of two previous algorithm in terms of speed with the same output.
Keyword: LLL algorithm, LLL deep insertion algorithm, greedy SVP LLL algorithm