Judul: Identification of Metabolites and Grouping of Sidaguri (Sida rhombifolia L.) from Different Growing Locations Using LC-MS/MS
Abstrak: Tumbuhan obat telah banyak digunakan untuk berbagai macam tujuan, baik untuk mencegah maupun mengobati penyakit. Salah satu spesies tanaman yang digunakan sebagai ramuan obat tradisional di Indonesia ialah sidaguri (Sida rhombifolia). Penelitian ini bertujuan mengidentifikasi kandungan senyawa ekstrak metanol herba spesies tersebut dari lokasi tumbuh berbeda. Analisis ekstrak metanol herba sidaguri diklasifikasikan berdasarkan lokasi tumbuh di Malang, Solo, Sukabumi, Tawangmangu, dan Yogyakarta menggunakan kromatografi cair- spektrometri massa dan dikelompokan menggunakan principal component analysis. Sebanyak 17 senyawa berhasil teridentifikasi dalam ekstrak. Senyawa tersebut termasuk dalam golongan fenolik, alkaloid, steroid, flavonoid, monoterpena lakton, dan golongan asam amino dan asam lemak. Didapatkan pola fragmentasi untuk 17 senyawa dengan cara fragmentasi spektrum massa berdasarkan kelompok senyawa masing-masing. Senyawa yang terdapat pada sampel terkelompok sesuai dengan lokasi tumbuhnya masing-masing dengan total varians 66%., Medicinal plants have been widely used for various purposes, both to prevent and treat diseases. One of the plant species used as traditional medicinal ingredients in Indonesia is sidaguri (Sida rhombifolia). This study aims to identify the compound content of the herbal methanol extract of these species from different growing locations. Analysis of sidaguri herb methanol extracts were classified based on growing locations in Malang, Solo, Sukabumi, Tawangmangu, and Yogyakarta using liquid chromatography-mass spectrometry and grouped using principal component analysis. A total of 17 compounds were identified in the extract. These compounds are included in the phenolic group, alkaloids, steroids, flavonoids, monoterpene lactones, and amino acids and fatty acids. Fragmentation patterns were obtained for 17 compounds by means of mass spectrum fragmentation based on each compound group. The compounds contained in the samples were grouped according to their respective growth locations with a total variance of 66%.
Keyword: LC-MS, sidaguri, Sida rhombifolia, PCA, pola fragmentasi

Judul: Identifikasi Metabolit Akar Sidaguri (Sida rhombhifolia L.) Berdasarkan Waktu Tanam Berbeda Menggunakan LC-MS/MS
Abstrak: Sidaguri (Sida rhombifolia L.) merupakan salah satu jenis tanaman yang telah digunakan sebagai obat tradisional dengan berbagai khasiat untuk mengobati banyak penyakit karena adanya kandungan metabolit bioaktif di dalamnya. Kandungan metabolit di dalam akar tanaman sidaguri dipengaruhi oleh beberapa faktor, salah satunya adalah usia tanam. Penelitian ini bertujuan mengidentifikasi senyawa dan mengelompokkan ekstrak akar sidaguri berdasarkan waktu tanam berbeda menggunakan data hasil ekstraksi yang diperoleh dari LC-MS/MS yang dikombinasikan dengan kemometrik. Sebanyak 19 senyawa teridentifikasi dan terkonfirmasi pada ekstrak akar tanaman sidaguri dengan usia tanam 3, 4, dan 5 bulan. Senyawa-senyawa tersebut termasuk ke dalam golongan fenolik, alkaloid, steroid, flavonoid, kumarin, asam benzoat dan asam lemak. Berdasarkan hasil pengelompokkan dengan PCA menggunakan variabel luas puncak 19 senyawa metabolit yang teridentifikasi, ekstrak sidaguri mengelompok sesuai usia tanam masing-masing dengan total plot skor sebesar 68%., Sidaguri (Sida rhombifolia L.) is a type of plant that has been used as a traditional medicine with various properties for treating many diseases because of the bioactive metabolites it contains. The metabolites content in the roots of the sidaguri were affected by some factors, such as cultivation age. This research aims to identify compounds and classify sidaguri root extracts based on different planting times using extraction data obtained from LC-MS/MS combined with chemometrics.. A total of 19 compounds were identified and confirmed in the root extract of the sidaguri plant with a planting age of 3, 4 and 5 months. These compounds belong to the phenolic, alkaloids, steroids, flavonoids, coumarins, benzoic acid and fatty acids groups. Based on the results of grouping using PCA using the peak area variable of 19 identified metabolite compounds, sidaguri extracts were grouped according to their respective planting ages with a total score plot of 68%.
Keyword: metabolit, metabolit sekunder

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
Keyword: