Synthesis of Silicon Sulfide by Using CS2 Gas

Silicon sulfide (SiS2) was synthesized from Si, SiC, Si3N4, and a eutectic Al-Si liquid. An Ar-CS2 gas mixture, after bubbling through liquid CS2, was passed over pulverized Si, SiC, Si3N4, or a eutectic Al-Si alloy liquid. White, needle-shaped SiS2 was precipitated as a single phase on the colder downstream surface when Si powder in a SiO2 liner was heated over 1273 K. This deposition mechanism involves a reaction between Si and CS2 to form SiS2, with the vaporization of SiS(g) and deposition as SiS2(s) from SiS(g) and S2(g). Quartz was unaffected by the reaction gases. Notably, Si, SiC, Si3N4, and the eutectic Al-Si liquid were found to be suitable sources for SiS2 synthesis, although this was suppressed owing to Al2S3 formation on the latter.

Isolation of Secondary Metabolite A. niger “In-Habiting” Queen M. gilvus Hagen.’s Nest

Aspergillus niger is pathogen fungi that can live in various locations and can live contiguous with many hosts, one of them is queen termite’s nest. The aims of the study were to isolated the secondary metabilite of A.niger. Extraction proccess of secondary metabolite compounds was carried out by maceration method using methanol solvent. Based on that proccess, methanol extract was be yield 4,32% sample weight. Fractination proccess was carried out in the separating funnel using ethyl acetate solvent, which ethyl acetate fraction was be yield 14.39% methanol extract. Separation of the compounds was carried out by column chromatography method using n-hexane and ethyl asetate eluents. Purification of the compounds were done by recrystallization method using n-hexane and ethyl asetate. Two secondary metabolite compounds were successfully isolated from ethyl acetate fraction of the methanolic extract of fungus A. niger “In-Habiting” queen termite’s nest M. gilvus Hagen. Based on organoleptic examination, the compound signed AM-12-22-01 is 35 mg, white needle crystals, melting point 151-153 oC. While, the AM-12-60-01* is 15 mg, white needle crystals, melting point 91-93 oC. Based on the chemical analysis, thin layer chromatography, ultraviolet and infrared spectra data it was identified that AM-12-22-01 and AM-12-60-01 were a phenolic compounds.Key words: isolation, A. niger, In-Habiting, M. gilvus Hagen.

ISOLASI KUMARIN DARI KULIT BUAH LIMAU SUNDAI (Citrus nobilis Lour)

Coumarin has been isolated and characteritated from rind of Citrus nobilis Lour by maseration methode with methanol. After fractionation by n-hexane and ethyl acetate, collected the phase ethyl acetate which positive of coumarin. From ethyl acetate extract coumarin have been isolated by column chromatography. The isolation results was obtain 2,159 g of pure white needle-shape crystalline with the melting point of 126,2-127,60C. Structure of the isolated coumarine was elucidated by spectroscopic methodes, UV-Vis,13C-NMR, 1H-NMR, 2D-NMR (DEPT/HSQC, COSY, NOESY, HMBC) and IR spectra. Based on the spectra data the isolated coumarine is marmin.