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

STRUCTURE CHARACTERIZATION OF FLAVONOID Aglycone FROM ETHYL ACETATE EXTRACT OF Rhodomyrtus tomentosa (AIT) HASSK

 ABSTRACT A flavonoid aglycone, 5-hydroxy-3,3’,4’,5’,7 pentamethoxy - flavone (Combretol), an antibacterial compound of ethyl acetate extract from the leaves of Rhodomyrtus tomentosa. The structure of this compound was established based on spectroscopic analyses and comparison with the related compound. The structure characterization of this compound will be discussed.  Keywords: Rhodomyrtus tomentosa, flavonoid aglycone, structure characterization

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

Comparison of antioxidative properties of carbazole alkaloids from Murraya koenigii leaves

A new dimeric carbazole alkaloid, 8,10′-[3,3′,11,11′ -tetrahydro-9,9′-dihydroxy-3,3′,5,8′-tetramethyl-3, 3′-bis(4-methyl-3-pentenyl)]bipyrano[3,2-a]carbazole (12), was isolated from the CH2Cl2 extract of Murraya koenigii together with six known carbazole alkaloids, koenimbine (6), O-methylmurrayamine A (7), O-methylmahanine (8), isomahanine (9), bismahanine (10), and bispyrayafoline (11). Their structures were determined on the basis of 1H and 13C NMR spectroscopic and mass spectrometric (MS) data. The antioxidative properties of 12 carbazole alkaloids isolated from leaves of M. koenigii were evaluated on the basis of the oil stability index together with their radical scavenging ability against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. On the basis of the lag time to reach a steady state, the 12 carbazoles were classified into three groups. It is suggested that an aryl hydroxyl substituent on the carbazole rings plays a role in stabilizing the thermal oxidation and rate of reaction against DPPH radical

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