Judul: Pendekatan Metabolomik terhadap Aktivitas Antioksidan Ekstrak dan Fraksi Daun Sirih Merah (Piper crocatum Ruiz & Pav)
Abstrak: Tanaman herbal yang memiliki potensi sebagai antioksidan adalah sirih merah (Piper crocatum Ruiz & Pav). Daun sirih merah (Piper crocatum Ruiz & Pav) mengandung flavanoid, tanin, dan alkaloid. Secara empiris zat aktif tersebut berperan sebagai antioksidan. Penelitian ini bertujuan menentukan aktivitas antioksidan tertinggi dari ekstrak dan fraksi daun sirih merah. Penelitian ini menganalisis peranan fenolik, tanin dan flavonoid terhadap aktivitas antioksdian DPPH dan MDA menggunakan analisa multivariat. Aktivitas antioksidan tertinggi terdapat pada fraksi n-heksan dengan nilai IC50 72.85 μg/mL. Analisis PCA total fenolik, aktivitas antioksidan mampu mengelompokkan sampel berdasarkan nilai IC50 dengan nilai PC total sebesar 84.04%. Fraksi n-heksana memiliki komponen tanin yang tinggi sebesar 98 mg/g dan aktivitas antioksidan MDA yang tinggi dengan IC50 72.85 μg/mL. Fraksi etil asetat memiliki komponen flavonoid yang tinggi sebesar 107.5 mg/g dan aktivitas antioksidan DPPH yang tinggi dengan IC50 13.14 ppm, sedangkan ekstrak etanol dan air memiliki kadar tanin sebesar 86 mg/g dan 32 mg/g dan flavonoid sebesar 47.72 mg QE/g dan 14.11 mg QE/g dan termasuk antioksidan sedang.
Keyword: Daun Sirih Merah, Antioksidan, Analisis PCA, Komponen

Judul: Aktivitas Antioksidan Ekstrak dan Fraksi Daun Sirih Merah (Piper crocatum) dengan Metode Ferric Reducing Antioxidant Power
Abstrak: Sirih merah (Piper crocatum) merupakan tanaman yang berperan sebagai sumber antioksidan yang telah banyak diteliti aktivitasnya. Penelitian ini bertujuan mengukur kandungan kuersetin dan menentukan aktivitas antioksidan ekstrak etanol, fraksi n-heksan, fraksi etil asetat dan fraksi air daun sirih merah dengan metode Ferric Reducing Antioxidant Power (FRAP). Ekstraksi dilakukan dengan metode maserasi menggunakan pelarut etanol 70%. Ekstrak etanol difraksinasi menggunakan tiga pelarut berdasarkan tingkat kepolarannya, yaitu n-heksana, etil asetat, dan air. Pengukuran kandungan kuersetin dilakukan menggunakan HPLC dan uji antioksidan dilakukan dengan metode Ferric Reducing Antioxidant Power (FRAP). Fraksi etil asetat memiliki kandungan kuersetin tertinggi sebesar 3.887 mg/g dan aktivitas antioksidan tertinggi sebesar 844.050 μmol Tr/g. Kandungan kuersetin ekstrak etanol sebesar 1.473 mg/g dan fraksi air sebesar 1.055 mg/g. Aktivitas antioksidan ekstrak etanol sebesar 433.940 μmol Tr/g, fraksi n-heksan sebesar 8.975 μmol Tr/g dan fraksi air sebesar 743.597 μmol Tr/g.
Keyword: antioksidan, FRAP, kuersetin, sirih merah

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