Judul: Potential Endophytic Actinobacteria of Dayak Onion (Eleutherine palmifolia (L.) Merr) as Antioxidant Producers
Abstrak: Aktinobakteri endofit merupakan koloni aktinobakteri dalam jaringan suatu tanaman yang memiliki kemampuan untuk menghasilkan senyawa bioaktif. Persebaran koloni aktinobakteri endofit cukup tinggi karena mampu bertahan di berbagai kondisi lingkungan. Umumnya, aktinobakteri endofit menghasilkan senyawa bioaktif serupa dengan milik inangnya. Senyawa bioaktif banyak dimanfaatkan terkait bidang kesehatan, contohnya adalah aktivitas antioksidan flavonoid. Antioksidan dapat menghambat kelebihan radikal bebas dari polusi kendaraan bermotor hingga radiasi barang elektronik yang masuk ke dalam tubuh manusia. Selain itu, antioksidan juga mencegah munculnya penyakit akibat gangguan pada fungsi sel tubuh, seperti kanker payudara. Tanaman bawang dayak (Eleutherine palmifolia (L.) Merr) yang juga dikenal dengan nama bawang Tiwai menjadi salah satu contoh tanaman yang diketahui menghasilkan flavonoid. Bawang dayak biasanya diolah menjadi ramuan tradisional untuk konsumsi karena diyakini mampu menyembuhkan tumor dan kanker payudara. Informasi mengenai aktivitas antioksidan senyawa bioaktif dari bawang dayak telah banyak dikaji di masyarakat, namun penelitian tentang aktivitas antioksidan senyawa bioaktif dari aktinobakteri endofit asal bawang dayak masih terbatas. Oleh sebab itu, penelitian ini dilakukan dengan tujuan mengkaji aktivitas antioksidan senyawa bioaktif yang dihasilkan aktinobakteri endofit bawang dayak. Aktivitas antioksidan sampel dalam penelitian ini diukur menggunakan metode DPPH (1,1-diphenyl-2-picrylhydrazil) dan ABTS (2,2-azinobis-3-ethyl benzothiazoline-6-sulphonic acid). Hasil pengukuran aktivitas antioksidan dihitung dalam persen inhibisi lalu digambarkan melalui nilai IC50 (inhibitory capacity). Senyawa flavonoid dalam sampel penelitian ini diidentifikasi menggunakan metode kromatografi lapis tipis (KLT) dan bioautografi aktivitas antioksidan DPPH. Hasil KLT dideteksi menggunakan UV transilluminator. Selanjutnya kadar total flavonoid dihitung menggunakan metode kolorimetrik aluminium klorida (AlCl3). Terdapat enam isolat aktinobakteri endofit yang berhasil diisolasi dari bawang dayak. Enam isolat tersebut memiliki jumlah rendemen yang berbeda dan isolat EPB 6 menghasilkan rendemen terbanyak sebesar 0.013%. Jumlah rendemen bawang dayak lebih besar dibandingkan keenam isolat aktinobakteri endofit, yaitu sebesar 0.070%. Nilai rata-rata IC50 yang dihasilkan isolat EPB 3 menunjukkan hasil terbaik dengan metode DPPH dan ABTS masing-masing sebesar 53.85 mg/ml dan 42.43 mg/ml. Ekstrak bawang dayak memiliki nilai rata-rata IC50 sebesar 49.11 mg/ml dengan DPPH dan 36.11 mg/ml dengan ABTS. Hasil amatan dengan UV 366 nm menunjukkan ekstrak bawang dayak memiliki warna spot yang berbeda dibandingkan ekstrak aktinobakteri endofit. Ekstrak aktinobakteri endofit isolat EPB 3 diketahui memiliki 2 spot senyawa biru dan merah, sedangkan ekstrak bawang dayak memiliki 3 spot senyawa merah, biru, dan hijau. Ekstrak aktinobakteri endofit isolat EPB 3 memiliki 3 spot aktif dengan nilai Rf 0.09, 0.33, 0.62 pada uji bioautografi aktivitas antioksidan DPPH. Ekstrak bawang dayak memiliki 4 spot aktif dengan nilai Rf 0.07, 0.21, 0.38, 0.88. Kadar total flavonoid ekstrak aktinobakteri endofit isolat EPB 3 sebesar 25.30 EQ/g adalah yang tertinggi di antara ekstrak isolat aktinobakteri endofit lainnya, sedangkan kadar total flavonoid ekstrak bawang dayak sebesar 46.03 EQ/g. Hasil dari penelitian ini menunjukkan bahwa aktinobakteri endofit dari bawang dayak memiliki senyawa bioaktif yang tergolong flavonoid dan berpotensi sebagai penghasil antioksidan., Endophytic actinobacteria are actinobacterial colonies in plant tissues that have the ability to produce bioactive compounds. The distribution of endophytic actinobacteria colonies is quite high because they are able to survive in various environmental conditions. Generally, endophytic actinobacteria produce bioactive compounds similar to those of the host. Bioactive compounds are widely used in the
Keyword: ABTS, DPPH, ethyl acetate, flavonoid, IC50

Judul: Kapasitas Antioksidan Bawang Dayak (Eleutherine palmifolia) dalam Bentuk Segar,Simplisia dan Keripik, pada Pelarut Nonpolar, Semipolar dan Polar
Abstrak: Bawang dayak (Eleutherine palmifolia) is a red bulb plant from Central Kalimantan, which has bioactive compounds such as phenols, flavonoids, alkaloids, glycosides and tannins. The existence of bioactive compounds become parameter of antioxidant activity of this red bulb. The study showed antioxidant capacity of bawang dayak in fresh form, simplisia (dried) form and chips form, which were extracted by the solvent hexane, ethyl acetate, methanol, ethanol and water. Antioxidant capacity was measured by DPPH method and rancimat method. Phytochemical screening was conducted to determine the bioactive compounds of bawang dayak in each form for every solvent. Based on DPPH method, bawang dayak in fresh form was extracted with ethyl acetate had the highest antioxidant capacity value that is 227.0% equal to 1.02 mg AEAC/mg extract. Simplisia form which was extracted with ethanol had antioxidant capacity value 51.8% equal to 0.21 mg AEAC/mg extract. Chips form was extracted with ethylacetate and ethanol had the highest antioxidant capacity values 57.5% and 46.5% which were equal to 0.24 mg AEAC/ mg extract and 0.18 mg AEAC/ mg extract. The induction time of ethylacetate fresh extract, ethanol simplisia extract and ethylacetate chip extract based on measurement with rancimat method, were 3.7 hours, 2.8 hours and 2.6 hours. All of extract had higher induction time than tocoferol. Besides, the measurement of phenolic content resulted that methanol fresh extract, ethanol simplisia extract and methanol chip extract had 4.29 mg GAE/100 mg extract, 3.52 mg GAE/ 100 mg extract and 3.38 mg GAE/100 mg extract. Vitamin C (ascorbic acid) on fresh bawang dayak was quite high, reaching 61.5mg/100gram, whereas vitamin C on simplicia and chip were decreased, respectively 41.0 mg/100 gram and 22.0 mg/100gram due to the heating process. The Ethylacetate fresh extract contains of alkaloid , phenolic, flavonoids, triterpenoids, steroids and glycosides compounds, while the ethanol simplscia extract and ethylacetate chip extract contains of alkaloids, saponins, tannins, phenolics, flavonoids, triterpenoids, steroids and glycosides compounds.
Keyword: 

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