Judul: Profil Metabolit Volatil Rimpang Jahe Merah (Zingiber officianale var. Rubrum) yang Dipanen pada Waktu Berbeda
Abstrak: The effect of sunlight intensity to red ginger secondary metabolite has not been known properly. Metabolic profiling can be used to study the correlation between sunlight intensity and secondary metabolite. The profile of volatile metabolite substances from different harvesting time had been examined. Samples of red ginger were harvested in the morning and afternoon. Around 47 volatile substances has been detected using GCMS instrument. Major component that were identified from both harvesting time are camphene, cineol, z-citral, 2,6- octadienol, benzene and α-zingiberene. Antioxidant activity was carried out using DPPH assay. Ascorbic acid was employed as positive control. Essential oil of red ginger was tested using DPPH assay and showed inhibition activities against DPPH radical, nevertheless the inhibition percentage was low and there is not enough prove to show red ginger essential oil have potential as a source of antioxidant. There was no significant difference in radical inhibition activities between both essential oil samples. There was however, a difference in the composition of the volatile component from red ginger essential oil. α-zingiberene compound had showed a significant difference in quantity at different harvesting time under the confirmation of t-test with α=0,05. The quantity of α-zingiberene was higher in afternoon harvesting time.
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Judul: Total Flavonoids, Antioxidant Capacity, and Compound Identification of Red Ginger (Zingiber officinale var. rubrum) Extract from Sukabumi
Abstrak: Jahe Merah (Zingiber officinale var. rubrum) dikenal sebagai tanaman tradisional yang dimanfaatkan sebagai obat. Salah satu potensi dari jahe merah sebagai antioksidan karena adanya kandungan metabolit sekunder berupa senyawa flavonoid. Metode ekstraksi dan pelarut yang digunakan perlu diperhatikan untuk memperoleh hasil senyawa antioksidan dari ekstrak jahe merah asal Sukabumi. Penelitian ini bertujuan menentukan total flavonoid, kapasitas antioksidan, dan identifikasi senyawa dari ekstrak etanol serta ekstrak air jahe merah asal Sukabumi. Ekstraksi dilakukan dengan metode maserasi. Ekstrak dari kedua pelarut masing-masing diukur kadar total flavonoid serta kapasitas antioksidan dengan metode FRAP. Hasil penelitian menunjukkan ekstrak etanol memiliki nilai total flavonoid dan kapasitas antioksidan lebih tinggi sebesar 5,99 mg QE/g dan 473,93 µmol TE/g dibanding ekstrak air 3,73 mg QE/g dan 206,75 µmol TE/g. Uji lanjutan ekstrak etanol kemudian dianalisis menggunakan LC-MS/MS yang menghasilkan 22 senyawa aktif seperti golongan fenolik dan terpenoid. Kedua golongan tersebut memberikan kapasitas antioksidan yang tinggi di jahe merah asal Sukabumi., Red ginger (Zingiber officinale var. rubrum) is known as a traditional plant that is used as medicine. One of the potentials of red ginger as an antioxidant is that it contains secondary metabolites in the form of flavonoid compounds. The extraction method and solvent used need to be considered to obtain antioxidant compounds from red ginger extract from Sukabumi. This research aimed to determine total flavonoids, antioxidant capacity, and identify compounds from the ethanol extract and water extract of red ginger from Sukabumi. Extraction is carried out using the maceration method. Extracts from both solvents were each measured for total flavonoid content and antioxidant capacity using the FRAP method. The results showed that the ethanol extract had a higher total flavonoid and antioxidant capacity value of 5.99 mg QE/g and 473.93 µmol TE/g compared to the water extract of 3.73 mg QE/g and 206.75 µmol TE/g. Further tests of the ethanol extract were then analyzed using LC-MS/MS, which produced 22 active compounds such as phenolics and terpenoids. These two groups provide high antioxidant capacity in red ginger from Sukabumi.
Keyword: antioxidant, flavonoids, red ginger, solvent, LC-MS/MS

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