Seminar Nasional Penelitian, Pendidikan, dan Penerapan MIPA 2009

Antihistamin merupakan salah satu jenis obat yang pemanfaatannya dalam bidang medis dan farmasi sangat luas. Selain dipakai untuk mengobati bermacam gangguan alergi juga dipakai sebagai antikolinergis, antiemetis, antiphlogistis, sedativum, antiserotonin dan memiliki aktivitas anastetik lokal. Beragamnya penggunaan dan prevalensi penyakit yang terus meningkat mendorong perlunya pengawasan dan kontrol kualitas obat. Deksklorfeniramin maleat adalah antihistamin derivat propilamin dan merupakan salah satu antihistamin yang banyak direkomendasikan. Penelitian ini bertujuan mempelajari perilaku antihistamin deksklorfeniramin maleat di permukaan elektroda pasta karbon pada pengukuran secara voltametri. Studi voltametri terhadap deksklorfeniramin maleat telah dilakukan dengan menggunakan teknik voltametri siklik dan voltametri pulsa diferensial. Rentang potensial pengukuran yang dapat dipakai untuk studi antihistamin deksklorfeniramin maleat adalah -200 sampai dengan 600 mV terhadap potensial Ag/AgCl. Studi voltametri dilakukan dengan menggunakan elektroda kerja pasta karbon dengan perbandingan komposisi grafit : parafin adalah 70 % : 30 %. Berdasarkan data arus puncak yang diperoleh dari voltamogram siklik dan kajian awal voltametri pulsa diferensial, dapat disimpulkan bahwa penentuan deksklorfeniramin maleat dapat dilakukan dengan menggunakan metode voltametri

The Synthesis of Imidazoline Derivative Compounds as Corrosion Inhibitor towards Carbon Steel in 1% NaCl Solution

Oleic imidazoline is one of the nitrogen containing heterocyclic compounds that has been widely used as commercial corrosion inhibitor, especially in minimizing the carbon dioxide induced corrosion process in oilfield mining. In this present work, some imidazoline derivative compounds have been synthesized utilizing both conventional and microwave assisted organic synthesis (MAOS) methods, in order to determine their corrosion inhibition properties on carbon steel surface. The MAOS method is more effective in synthesizing these compounds than the conventional method regarding to the higher chemical yields of products (91% to 94%) and the shorter reaction times (7 to 10 minutes). The characterization of corrosion inhibition activities of the synthesized products towards carbon steel in 1% NaCl solution was determined by the Tafel plot method. The corrosion inhibition activities of compound 1b ((Z)-2-(2-(heptadec-8-enyl)-4,5-dihydroimidazol-1-yl)ethanamine), 2b ((Z)-2-(2-(heptadec-8-enyl)-4,5-dihydroimidazol-1-yl)ethanol) and 3b (2-(2-heptadecyl-4,5-dihydroimidazol-1-yl)ethanamine) at 8 ppm concentration in 1% NaCl solution are, respectively, 32.18%, 39.59% and 12.73%. The heptadec-8-enyl and hydroxyethyl substituents at C(2) and N(1) position of imidazoline ring, respectively, gave the most effective corrosion inhibition activity towards carbon steel compared to the presence of other substituents. The increase in concentrations of compound 1b, 2b and 3b in 1% NaCl solution tends to improve their corrosion inhibition activities. Based on the analysis of the free Gibbs adsorption energy (ÄG0ads) values of compound 1b, 2b and 3b (-32.97, -34.34 and -31.27 kJ/mol, respectively), these compounds have the potential to interact with carbon steel through semi-physiosorption or semi-chemisorption

Nouvelles strategies permettant l'acces aux petits cyclopeptides

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Fractionation and activity assay of the root extract of Piper sarmentosum Roxb. ex Hunter against Candida albicans

Piper sarmentosum Roxb. ex Hunter (“sirih duduk”) has long been used as a traditional medicine against fungoid diseases, especially at vagina and foot-sole. The investigation of the bioactive compounds of P. sarmentosum roots has not infections been carried yet. This research was then aimed to fractinate and to examine the antifungus activity of the extract of P. sarmentosum roots.The extraction was performed by using organic solvents such as methanol, ethyl acetate, chloroform, benzene, and n-hexane. The bioactivity tests were performed against C. albicans. The active extracts were then fractionated by coloumn chromatography.The result showed that the ethyl acetate fraction of methanol extract of P. sarmentosum roots have an antifungus activity against C. albicans. Phytochemical study showed that the active fractions of the methanol extracts of P. sarmentosum roots contained alkaloid.Key words : Piper sarmentosum, activity test, Candida albicans

Pengantar pratikum kimia organik

xxii, 510 p. : il.; 33 cm

Synthesis of dipeptide benzoylalanylglycine methyl ester and corrosion inhibitor evaluation by Tafel equation

Corrosion is one of the major problems in petroleum mining and processing industry. The pipelines used to transport crude oil from reservoir to the processing installation were made from carbon steel that is susceptible towards corrosion. One of the best methods to prevent corrosion that occurred at the inner parts of carbon steel pipelines is to use organic corrosion inhibitor. One of the potent organic corrosion inhibitors is amino acids derivatives. In this study, dipeptide compound namely benzoylalanylglycine methyl ester and benzoylalanylglycine have been synthesized. The structure elucidation of the products was performed by IR, MS and NMR spectroscopy. The determination of corrosion inhibition activity utilized the Tafel method. The corrosion inhibition efficiency of glycine methyl ester, benzoylalanine, dipeptide benzoylalanylglycine methyl ester and dipeptide benzoylalanylglycine were 63.34%, 35.86%, 68.40% and 27.72%, respectively. These results showed that the formation of dipeptide benzoylalanylglycine methyl ester, derived from carboxylic protected glycine and amine protected alanine, increased the corrosion inhibition activity due to the loss of acidity center in the structure of glicine and L-alanine that would induce the corrosive environment towards carbon steel

Properties of immobilized candida antarctica lipase B on highly macroporous copolymer

In spite of their excellent catalytic properties, enzymes should be improved before their implementation both in industrial and laboratorium scales. Immobilization of enzyme is one of the ways to improve their properties. Candida antarctica lipase B (Cal-B) has been reported in numerous publications to be a particularly useful enzyme catalizing in many type of reaction including regio- and enantio- synthesis. For this case, cross-linking of immobilized Cal-B with 1,2,7,8 diepoxy octane is one of methods that proved significantly more stable from denaturation by heat, organic solvents, and proteolysis than lyophilized powder or soluble enzymes. More over, the aim of this procedure is to improve the activity and reusability of lipase. Enzyme kinetics test was carried out by transesterification reaction between 4-nitrophenyl acetate (pNPA) and methanol by varying substrate concentrations, and the result is immobilized enzymes follows the Michaelis-Menten models and their activity is match with previous experiment. Based on the Vmax values, the immobilized enzymes showed higher activity than the free enzyme. Cross-linking of immobilized lipase indicate that cross-linking by lower concentration of cross-linker, FIC (immobilized lipase that was incubated for 24 h) gave the highest activity and cross-linking by higher concentration of cross-linker, PIC (immobilized lipase that was incubated for 2 h) gives the highest activity. However, pore size and saturation level influenced their activity