Judul: Isolasi dan Pemurnian Xantorizol dari Temu Lawak (Curcuma xanthorrhiza Roxb.)
Abstrak: Xanthorrhizol is the main active component in the essential oil of temu lawak (Curcuma xanthorriza Roxb.). Xanthorrhizol has antifungal, antibacterial, antioxidant, and anti-inflammatory activities. Xanthorrhizol is isolated by Asriani (2010) using solvent extraction (ethanol 96%), acetylation, Preparative Thin Layer Chromatography (PTLC), and deacetylation, which produce xanthorrhizol with 99% purity. The xanthorrhizol obtained is not pure because there are still other compounds in the mixture. This research perfoms xanthorrhizol isolation using three different modifications based on Asriani’s method. The modified method I conducts two-times extraction: ethanol and hexane extractions. The modified method II conducts three-times extraction: ethanol, hexane, and diethyl ether extractions. The modified method III conducts two-times extraction using ethanol and hexane as solvents, and also conduct PTLC phase II in order to extract the deacetylated product. The modification method I and II produce xanthorrhizol with purity 78.1 and 80.1 % for ethanol extract, and 80.1 and 88.1 % for hexane extract, respectively. Modified method III is able to isolate xanthorrhizol with the highest purity, i.e. 94.3%. GC-MS analysis to the product shows that one of the two peaks appeared at the retention time of 11.44 minutes with an area of 94.3% and MW 218.0 is xanthorrhizol. The results from all of these modified methods were lower than Asriani’s method, which comes to the conclusion that Asriani’s method is better and more efficient.
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Judul: Isolasi Xantorizol dari Temulawak Terpilih Berdasarkan Nomor Harapan
Abstrak: Temulawak (Curcuma xanthorrhiza) termasuk ke dalam famili Zingiberaceae, yang secara empiris banyak digunakan sebagai obat untuk mengatasi batu empedu, batu ginjal, demam, kolesterol tinggi, nyeri haid, nyeri sendi, pelancar ASI, sembelit, dan eksim. Banyaknya ragam manfaat temulawak baik untuk obat tradisional maupun fitofarmaka adalah karena rimpangnya mengandung komponen aktif utama yang berkhasiat, yaitu kurkuminoid dan minyak atsiri. Beberapa penelitian menunjukkan bahwa komponen aktif utama dalam minyak atsiri temulawak yang juga merupakan senyawa khas dari rimpang temulawak adalah xantorizol. Kandungan dan komposisi senyawa aktif, termasuk xantorizol, pada temulawak yang merupakan hasil metabolisme sekunder dari tanaman sangat bergantung pada interaksi antara sifat genetik tanaman dan kondisi agrobiofisik tanaman yang meliputi iklim, media tanam (jenis tanah), dan ketinggian. Penelitian ini bertujuan menentukan nomor harapan temulawak A atau F koleksi Balittro yang terbaik berdasarkan kandungan xantorizol yang tinggi, menentukan kondisi lingkungan agrobiofisik yang menghasilkan tingkat bahan aktif tinggi, dan memperoleh metode pemisahan baru yang dapat mengisolasi xantorizol dengan hasil yang lebih tinggi dibandingkan dengan metode terdahulu (metode Hwang) yang berhasil mengisolasi xantorizol dari fraksi etil asetat ekstrak metanol sebanyak 0.2% (b/b) dari rimpang temulawak kering.
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Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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