Judul: Senyawa Kimia Penciri Jernang untuk Pembaruan Parameter Standar Nasional Indonesia
Abstrak: Dragon’s blood, a resin exudated from rattan (Daemonorops draco) fruits has many benefits so that prices and demand are always high. The National Standardization Agency has issued Indonesia National Standard (SNI) for dragon’s blood based on physical characteristics and visual parameters. Three qualities of this commodity from the highest to the low quality are “super” , A , and B. However, these parameters are prone to be manipulated by traders to add weight and purity of the resin. In this study, it was discovered that all SNI parameters are not always correlated in determining the classification of dragon’s blood. Analysis by ultraviolet-visible spectrophotometer at a wavelength of 473.5 nm showed that the classification according to SNI was positively correlated with the resin content and the absorbance. A quantitative analytical method proposed for SNI revision is extraction through maceration using acetone. Compound identification using gas chromatography-mass spectrometer showed the presence of dracorhodin compounds in all resins samples was. Therefore, dracorhodin can be used as a marker in dragon’s blood commodity.
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Judul: Upaya Isolasi Drakorodin dari Resin Daemonorops draco
Abstrak: Dragon’s blood is a secretion of rattan fruits. The commonly used rattan species is Daemonorops draco that contain the highest dracorhodin, but the content has not been determined quantitatively. Dracorhodin is a natural flavylium compound, anthocyanin derivative, and provides the natural color of dragon’s blood. This compound is potential as drug materials and natural dye. Dracorhodin isolated from dragon’s blood crude extract were analyzed using ultraviolet-visible (UV-Vis) spectrophotometric and high performance liquid chromatography (HPLC) with C18 column (5 μm, 250 × 4.6 mm id, Dikma). The samples were treated in acidic (60% HClO4) and non-acidic medium. UV-Vis spectra showed that dracorhodin was also detected at 400—490 nm. Dracorhodin was detected in HPLC chromatogram at retention time of 5 minutes, using ethyl acetate 1% in methanol as eluent, 0.5 mL/min flow rate, and detection wavelength at 475 nm. Dracorhodin content obtained from non-acidic medium crude methanol extract was 55.6%, which was higher than that in the acidic medium, namely 37.4% from the starting materials that was refluxed for about 1 hour. The isolates can be used as standard for quantifying dracorhodin in commercial dragon’s blood.
Keyword: high performance liquid chromatography, flavylium, dragon’s blood, dracorhodin, Daemonorops draco

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology