Utility of triphenylphosphine dihalides in organic reactions: esterification using triphenylphosphine dibromide as the dehydrating agent

A new esterification method was investigated using triphenylphosphine dibromide as a dehydrating agent. This investigation has established that the method is useful when the acid is aromatic or arylallylic. That primary and secondary alcohols esteTZfy acid satisfactorily whereas tertiary alcohols fail to react was also established in this experiment

Fine chemical from biological resources: the wealth from nature

Man has exploited plants, animals and other microorganisms since the beginning of civilization for a great variety of purposes. In addition to providing food, clothing, fuel and timber, these bio resources also produce fine chemicals which have found widespread use as medicines, insecticides, fragrances, pigments etc. With the advent of biotechnology particularly in the field of genetic engineering and cell culture the interest to search for high value fine chemicals resurges due to the possibility of producing the desired products in more efficient, economical and environmental friendly manner

Dicentrine: The Major Alkaloid of Cyclea laxiflara Miers

The major alkaloid of Cyclea laxiflora Miers. was isolated and identified as dicentrine from its spectral and physical data

Characterization antibacterial constituent from Ficus deltoideusJack leaves

An antibacterial constituent, has been isolated from Ficus deltoideus Jack leaves. Based on spectroscopic data (IR, 1H-NMR, 13 C NMR 1D and 2D and MS), the structure of this compound was identified as Olean-12en-3β-ol, (β-amyrin), C30H50O. This compound showed antibacterial activities against E. coli, B. subtilis and S.  aureus.  The minimum inhibition concentration (MIC) agains  E.  coli,  B. subtilisand  S. aureusare 230, 380 and 460 (µg/mL) respectively.Key words: Antibacterial activity,Ficus deltoideusJack, β-amyri

Characterization antibacterial constituent from Ficus deltoideus Jack leaves Karakterisasi konstituen antibakteri dari daun Ficus deltoideus Jack

An antibacterial constituent, has been isolated from Ficus deltoideus Jack leaves. Based on spectroscopic data (IR, lH-NMR, 13CNMRlD and 2D and MS), the structure of this compound was identified as Olean-12en-3&#946-ol, (&#946-amyrln), C&#8323&#8320H&#8325&#8320O. This compound showed antibacterial activities against E. coli, B. subtilis and S. aureus. The minimum inhibition concentration (MIC) agains E. coli, B. subtilis and S. aureus are 230, 380 and 460 (µ/mL) respectively. Suatu konstituen antibakteri, telah diisolasi dari daun Ficus deltoideus Jack. Karakterisasi struktur menggunakan data spektroskopi IR, lH-NMR, 13C_ NMR, lD dan 2D serta data MS, menunjukkan bahwa konstituen hasll isolasi adalah Olean-12en-3&#946-0I, (&#946-amyrin), C&#8323&#8320H&#8325&#8320O. Uji aktivitas antibakteri terhadap E. coli, B.subtilis dan S. aureus menunjukkan bahwa &#946-amyrin dapat menghambat pertumbuhan bakteri, dengan nllai MIC 230 µ/mL untuk E. coli, 380 µ/mLuntuk B. subtilis, dan 460 µ/mL untuk bakteri S. aureus

Ichthyotoxic properties and essential oils of Syzygium malaccense (Myrtaceae)

The preliminary ichthyotoxic test on all parts of Syzygium malaccense (Myrtaceae) revealed that the leaves fraction was the most ichthyotoxic against tilapia-fish (Tilapia oreochromis). Three compounds, namely ursolic acid (1), β-sitosterol (2) and sitost-4-en-3-one (3), were isolated and their structures were elucidated with the aid of spectroscopic data and comparison with previously reported investigations. However none of these compounds gave any significant ichthyotoxicity. The volatile constituents of the leaves and fruit were determined by Gas Chromatography-Mass Spectrometer (GC-MS), with 180 and 203 compounds being identified in the aroma concentrates, respectively

Pemprosesan Kimia ke atas Buangan Pertanian Padi

The production process of 2-furaldehyde (furfural) from agricultural wastes including the husk, leaf and straw was investigated chemically. Three types of pro tic acid were tested with respect to its cataly tic activity. The effect of hydrochloric acid concentration on the yield percentage was also investigated

Extraction and identification of the main compound present in Elaeis guineensis flower volatiles

The main compound contained in the volatile oils of the oil palm flowers was identified as l-methoxy-4 (2-propenyl) benzene or estragole. The same compound was extracted from the anthesizing male and female flowers of the oil palm (Elaeis guineensis). The newly identified compound is believed to be responsible for attracting the adults of the oil palm pollinating weevil, Elaeidobius kemerunicus (Coleoptera: Curculionidae). Steam distillation of1 kg of fresh male and female flowers yielded O.7g and O.2g of volatile oils. The chemical structure and characteristics were confirmed by mass spectromeric analysis, nuclear magnetic resonance (NMR) analysis, and the infrared spectra analysis. The possible usage of the compound in ecological research on the weevil and in the industry' are discussed

Effects of ionic and non-ionic micelles on rate of hydroxide ion-catalyzed hydrolysis of securinine

The effects of micelles of cetyltrimethylammonium bromide (CTABr), tetradecyltrimethylammonium bromide (TTABr), sodium dodecyl sulfate (SDS) and polyoxyethylene 10 lauryl ether (C12E10) on the rates of alkaline hydrolysis of securinine were studied at a constant [−OH] (0.05 M). An increase in the total concentrations of CTABr, TTABr, SDS and C12E10 from 0.0 to 0.2 M causes a decrease in the observed pseudo-first-order rate constants (kobs) by factors of ca 2.5, 3, 7 and 4, respectively. The observed data are explained in terms of pseudophase and pseudophase ion-exchange (PIE) models of micelle. The binding constants, KS, of securinine with SDS, C12E10, CTABr and TTABr micelles are 32.4, 14.8, 22.1, and 9.1 M−1, respectively. The magnitudes of the second-order rate constants, kM, for the reactions in the micellar pseudophase are negligible compared with the corresponding rate constant, kW, for the reaction occurring in the aqueous pseudophase for CTABr, TTABr, SDS and C12E10