Judul: Sintesis Flav-3-ena sebagai Prekursor Flavan-3-ol
Abstrak: Flavan-3-ol merupakan salah satu kelompok flavonoid yang penting bagi kesehatan tubuh karena dapat membantu kelancaran sirkulasi darah dan melindungi kulit dari kerusakan yang diakibatkan oleh sinar ultraviolet. Flavan-3-ol dapat diperoleh dari hidroborasi-oksidasi flav-3-ena. Dalam penelitian ini, flav-3-ena disintesis secara langsung dan bertahap. Sintesis diawali dengan menyiapkan 2’-hidroksikalkon dari o-hidroksiasetofenon (o-HAP) dan benzaldehida dengan katalis KOH 60%. Siklisasi reduktif langsung 2’-hidroksikalkon dengan NaBH4 tidak berhasil mendapatkan flav-3-ena. Di sisi lain, cara bertahap dilakukan melalui isomerisasi 2’-hidroksikalkon menjadi flavanon dengan basa NaOAc, reduksi flavanon menjadi flavan-4-ol dengan NaBH4, dan dehidrasi flavan-4-ol dengan katalis asam p-toluenasulfonat menghasilkan flav-3-ena. Rendemen flav-3-ena secara keseluruhan dari 4 tahap adalah 11% dari bahan awal o-HAP. Rendemen tersebut masih lebih rendah daripada yang dilaporkan sebelumnya, yaitu 25%. Sintesis 1-tahap flav-3-ena dari flavanon pada kondisi sangat asam diharapkan dapat meningkatkan rendemen tersebut.
Keyword: flavan-3-ol, flavan-4-ol, flavanon, flav-3-ena

Judul: Sintesis 1-(2-hidroksifenil)-3-fenilpropana-1,3-dion dari o-hidroksiasetofenon dan benzoil klorida
Abstrak: Flavonoid is the most abundant naturaly-occuring polyphenolic compound which has C6-C3-C6 carbon skeleton. Flavone is a group of flavonoid with wide bioactivity spectrum. It is widely distributed in higher plants. Its bioactivities include antioxidant, HIV-1 proteinase inhibitor, strong and selective apoptotic inducer in human colon cell, and ligand for BDZ-R receptor. One of the important and widely applicable flavones synthesis route is through 1-(2-hydroxyphenyl)-3- phenylpropane-1,3-dione (1,3-diketone) acid-catalyzed oxidative cyclization. In this study, 1,3-diketone has been successfully synthesized via four-step route. In the first step, phenol was acetylated with 74–95% yields. Subsequently, phenyl acetate was converted to o-hydroxyacetophenone (o-HAP) with 34% yield via AlCl3-catalyzed Fries rearrangement. Benzoylation of o-HAP followed by Baker- Venkataraman rearrangement of the ester product using KOH in pyridine finally produced 1,3-diketone. The third and fourth steps yield were 27–44% and 82– 85%, respectively. All products in this study have been characterized spectroscopically. Melting point characterization were also conducted to the solid products.
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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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