Judul: Inhibitor Tirosinase Ekstrak Metanol Berbagai Bagian Pohon Jabon dan Mangium
Abstrak: Jabon and mangium are currently planted in community forest. The wastes resulted from the utilization of forest products can reach 75%, including leaves barks, and woods. One of the ways to increase value of those wastes can be done by utilizing the extractive compounds contained in wood waste as tyrosinase inhibitor. Parts of tree which were extracted consist of leaves, barks, sapwood, and heartwood. The extraction method used in this research was soxhletation using methanol for 12 hours. The yield of extracts was 0.89-13.02%, with the lowest yield from sapwood of mangium and the highest was resulted by jabon’s leaves. Mangium bark extract had the highest activity as inhibitors of tyrosinase, with the value of IC50 was 129.81 ppm for the monophenolase reaction or three times higher than kojic acid (38.45 ppm) and 240.88 ppm for the diphenolase reaction or two times higher than kojic acid (102.11 ppm). The compounds contained within mangium bark extracts were expected to be inhibitor of tyrosinase, which was classified to flavonoids.
Keyword: tyrosinase inhibitor, monophenolase, mangium, jabon, Diphenolase

Judul: Identification of Merbau Wood (Intsia palembanica) Active Compounds and Their Potential as In Silico Tyrosinase Enzyme Inhibitors
Abstrak: Tirosinase merupakan enzim pembatas laju yang terkait dengan sintesis melanin dalam melanosit. Peningkatan produksi melanin (melanogenesis) di melanosit menyebabkan terjadinya hiperpigmentasi atau penggelapan kulit. Senyawa aktif kayu merbau dapat digunakan sebagai inhibitor tirosinase. Penelitian ini bertujuan mengidentifikasi senyawa aktif kayu merbau dengan LC-MS serta menguji potensi senyawa aktif tersebut sebagai inhibitor tirosinase melalui parameter Energi Bebas Ikatan (∆G), Konstanta Disosiasi (Kd), dan jenis interaksi yang terbentuk antara ligan dan reseptor. Metode yang digunakan dalam penelitian ini adalah ekstraksi, LC-MS, dan penambatan molekuler menggunakan perangkat lunak YASARA Structure dengan reseptor 5M8M yang berasal dari homo sapiens. Hasil penelitian menunjukkan bahwa terdapat 25 senyawa aktif ekstrak etanol kayu merbau hasil LC-MS. Sebanyak 1 dari 25 senyawa yang berpotensi sebagai inhibitor tirosinase yaitu senyawa artemidiol. Senyawa artemidiol menunjukkan aktivitas inhibitor tirosinase terbaik dengan nilai ∆G sebesar -7.231 kkal/mol dan Kd 5.007 µM. Senyawa artemidiol memiliki 5 ikatan hidrogen. Simpulan dari penelitian adalah ligan uji artemidiol sangat berpotensi sebagai inhibitor tirosinase daripada ligan alami asam kojat., Tyrosinase is a rate limiting enzyme associated with melanin synthesis in melanocytes. Increased melanin production (melanogenesis) in melanocytes causes hyperpigmentation or darkening of the skin. The active compound of merbau wood can be used as a tyrosinase inhibitor. This study aimed to identify the active compound merbau wood with LC-MS and to test the potential of the active compound as a tyrosinase inhibitor through the parameters of bond free energy (∆G), dissociation constant (Kd), and the type of interaction formed between the ligand and the receptor. The methods used in this study were extraction, LC-MS, and molecular anchoring using YASARA Structure software with 5M8M receptors derived from homo sapiens. The results showed that there were 25 active compounds in the ethanol extract of merbau wood from LC-MS. As many as 1 of 25 compounds that had the potential as tyrosinase inhibitors were artemidiol compounds. Artemidiol compounds showed the best tyrosinase inhibitor activity with G values of -7.231 kcal/mol and Kd of 5.007 µM. Artemidiol compounds had 5 hydrogen bonds. The conclusion of the research was that the artemidiol test ligand had the potential as a tyrosinase inhibitor rather than the natural ligand of kojic acid.
Keyword: Hyperpigmentation, Melanogenesis, Merbau Wood, Molecular Docking, Tyrosinase

Judul: Implementation of Spatio-Temporal Change Query in Relational Database.
Abstrak: Geographic object changes in various views. Object changes are recorded using a model of static storage. No historical connection between old version data and new version data has been built. For that, a storage model of spatio-temporal queries that can analyze spatio-temporal changes has been developed. The object changes the geometry are grouped according to the taxonomy of Spatio-Temporal Pattern Change. This research has been able to apply the query patterns change including born, expand, merge, contract, split, normal and die. This query based on geometric (area) changes. The implementation of spatio-temporal change queries represents an object changes continuously with easy, change detection is done by comparing two versions of data. Keyword: spatio-temporal change query, spatio-temporal change pattern.
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