Five phenolic compounds, 4-hydroxybenzoic acid methyl ester (1), vanillic acid methyl ester (2), 4-hydroxy benzaldehyde (3), 4-hydroxybenzoic acid (4) and ferulic acid (5), and four flavonoids, 5,5'-dihydroxy-4',6,7-trimethoxyflavanone (6), luteolin (7), vitexicarpin (8) and artemetin (9), were isolated from fruits and leaves of Vitex rotundifolia L. The biological activities of these nine comp...

Kinetic data on potassium release from and killing of Candida albicans by the four polyene antibiotics amphotericin B, amphotericin B methyl ester hydrochloride, nystatin, and nystatin methyl ester hydrochloride are presented. The nystatins were relatively more effective than the amphotericins in causing potassium release rather than killing. These data suggest that the aqueous channels or pore...

Low-temperature ozonation (-78 degrees C) of 2-methyl-1,3-dioxolane (1a) in acetone-d6, methyl acetate, and tert-butyl methyl ether produced both the corresponding acetal hydrotrioxide (3a, ROOOH) and the hemiortho ester (2a, ROH) in molar ratio 1:5. Both intermediates were fully characterized by 1H, 13C, and 17O NMR spectroscopy, and they both decomposed to the corresponding hydroxy ester at h...

Although the pimeloyl moiety was long known to be a biotin precursor, the mechanism of assembly of this C7 α,ω-dicarboxylic acid was only recently elucidated. In Escherichia coli, pimelate is made by bypassing the strict specificity of the fatty acid synthetic pathway. BioC methylates the free carboxyl of a malonyl thioester, which replaces the usual acetyl thioester primer. This atypical prime...

--This research is aimed to investigate experimentally the performance and exhaust emission characteristics of a direct injection (DI) diesel engine when fuelled with blends of conventional diesel fuel and ethanol, blends of rice bran methyl ester with ethanol, blends of diesel and rice bran methyl ester over the entire range of load on the engine. The experimental results showed that the highe...

Within EN 14214, method EN 14103 specifies the fatty acid methyl ester (FAME) and linolenic acid methyl ester content (Figure 1), which is used to profile the vegetable or animal oil feedstock used in biodiesel production. EN 14103 calls for calibration of all FAME components by relative response to a single compound, methyl heptadecanoate. This requires the measurement of accurate weights for ...

Background and Aims: Alysicarpus glumaceus is a plant used in Africa, Asia some parts of the Arabian Peninsula with folkloric claims having anti-tussive, anti-asthmatic, anti-diarrheal, abortifacient, anti-psychotic, anti-inflammatory, diuretic stimulatory activities. The aim this study was to determine phytoconstituents present methanol extract (ME) its fractions. Methods: Standard qualitative...

Malonic acid silylatesreadily to yield the expected bis-trimethylsilyl (TMS) ester; this ester reacts further in the silylating mixture to yield a tris-TMS derivative, apparently through enolization of one of the ester groups. Methylmalonic and hydroxymalonic acids behave similarly. The methyl and ethyl esters of malonic acid also silylate once with some facility. Mass spectra of these derivati...

The roots of Chrysopogon zizanioides (L.) Roberty, belonging to the Poaceae family, are main source volatile that has substantial value in perfume, cosmetics, pharmaceutical and food industries. study C. volatiles, obtained from plant cultivated Tunisia, using GC GC/MS revealed more than 50 compounds were detected which 14 constituents identified representing 33.87% total. Oleic acid (17.09%) (...

A cell free system prepared from etiolated cucumber (Cucumis sativus, L) in tris-sucrose buffer is able to incorporate delta-aminolevulinic acid-4- (14)C into the two components of protochlorophyll: protochlorophyllide and protochlorophyllide ester. The activity is associated with the etioplasts. Optimal incorporation is obtained at pH 7.7. For the formation of protochlorphyllide ester, oxygen,...