ChemInform Abstract: CRYSTALLIZATION CURVE OF HEXADECANE IN MIXTURES WITH METHYL NONADECANOATE, METHYL OCTADECANOATE, ETHYL OCTADECANOATE, AND METHYL HEXADECANOATE. A COMPARISON OF THE EXPERIMENTAL AND CALCULATED CURVES

In this study, the changes caused by variation of altitude to the essential oils (EOs), fatty acid methyl esters (FAMEs), and antimicrobial activities of Primula vulgaris Huds. subsp. vulgaris ( Pvv) and P. vulgaris Huds. subsp. sibthorpii (Hoffmanns) W.W. Sm. & Forrest ( Pvs)) grown in Turkey were investigated. Major fluctuations in the composition of Pvv and Pvs oils included methyl-4-methoxy salicylate (4.5–35.3%; Pvv and 3.2–37.2%; Pvs), ( Z,Z,Z)-7,10,13-hexadecatrienal (5.1–21.8%; Pvv and 4.4–15.2%; Pvs) and flavone (5.5–14.9%; Pvv and 1.6–18.0%; Pvs). Fatty acid profile (C6:0–C26:0) changes were noted in Pvv and Pvs. Methyl hexadecanoate (2.4–9.3%) and methyl octadecanoate (1.0–4.7%) were present in all the FAME samples of the plants. The antimicrobial activity of the EOs of Pvv and Pvs were tested against nine bacterial species, which showed activity against Mycobacterium smegmatis with minimum inhibitory concentrations (MIC) varying from 8.5 to 59.2 μg/mL in all samples, respectively, depending on the altitude at which the oils were obtained.

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Sesquiterpene Lactones from Elephantopus scaber

Zeitschrift für Naturforschung B ◽

10.1515/znb-2005-0212 ◽

2005 ◽

Vol 60 (2) ◽

pp. 200-204 ◽

Cited By ~ 9

Author(s):

Ni Ni Than ◽

Serge Fotso ◽

Madhumati Sevvana ◽

George M. Sheldrick ◽

Heinz H. Fiebig ◽

...

Keyword(s):

Single Crystal ◽

Sesquiterpene Lactones ◽

Spectroscopic Methods ◽

X Ray ◽

Whole Plant ◽

Elephantopus Scaber ◽

Ethyl Hexadecanoate ◽

Reported Data ◽

Acetone Extracts ◽

Ethyl Octadecanoate

The ethanolic and acetone extracts of the whole plant of Elephantopus scaber were found to contain ethyl hexadecanoate, ethyl-9,12-octadecadienoate, ethyl-(Z)-9-octadecenoate, ethyl octadecanoate, lupeol, stigmasterol, stigmasterol glucoside, deoxyelephantopin (1) and two new germacranolide sesquiterpene lactones named 17,19-dihydrodeoxyelephantopin (2) and iso-17,19- dihydrodeoxyelephantopin (3) whose stereostructures were determined by spectroscopic methods, comparison with reported data and single-crystal X-ray analysis.

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Some Aliphatic Methyl Esters from Aralia elata Seemann (Araliaceae)

Zeitschrift für Naturforschung C ◽

10.1515/znc-1975-11-1224 ◽

1975 ◽

Vol 30 (11-12) ◽

pp. 825-825

Author(s):

S. Watanabe ◽

Y. Hayashi ◽

Y. Murayama

Keyword(s):

Mass Spectrometer ◽

Methyl Esters ◽

Methyl Pentadecanoate ◽

Aralia Elata ◽

Methyl Octadecanoate

Abstract The dried bark of Aralia elata Seemann was extracted with n-hexane. Methyl pentadecanoate, methyl hexadecanoate, methyl octadecanoate, methyl eicosanoate, methyl docosanoate, methyl tetracosanoate, methyl hexacosanoate, and 1-hexacosene were identified from the extract by means of GC-Mass spectrometer.

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Analysis of zeolite crystallization using the "crystallization curve"

Industrial & Engineering Chemistry Research ◽

10.1021/ie00001a050 ◽

1992 ◽

Vol 31 (1) ◽

pp. 369-373 ◽

Cited By ~ 17

Author(s):

C. J. J. Den Ouden ◽

R. W. Thompson

Keyword(s):

Crystallization Curve

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Influence of Cooling Rate on the Size of the Precipitates and Thermal Characteristic of Al-Si Cast Alloys

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.15-17.59 ◽

2006 ◽

Vol 15-17 ◽

pp. 59-64 ◽

Cited By ~ 1

Author(s):

Rafal Maniara ◽

Leszek Adam Dobrzański ◽

Jerry Sokolowski ◽

Wojciech Kasprzak ◽

Witold T. Kierkus

Keyword(s):

Cooling Rate ◽

Solidus Temperature ◽

Thermal Characteristic ◽

Solidification Process ◽

Crystallization Curve ◽

Dendrite Coherency Point ◽

Cast Alloys ◽

Main Observation ◽

Coherency Point ◽

Work Effect

In this work effect of cooling rate on the size of the grains, SDAS, β phases and thermal characteristic results of Al-Si cast alloys have been described. The solidification process was studied using the cooling and crystallization curve at cooling rate ranging from 0,1 °Cs-1 up to 1 °Cs-1. The main observation made from this work was that when cooling rate is increased the aluminum dendrites nucleation temperature and solid fraction at the dendrite coherency point increases, which implies that mass feeding is extended. In addition to that, it was observed that solidus temperature and size of the β phases decreases when cooling rate increases. Investigations were showed, that the thermal modification could be quantitatively assessed by analysis of the crystallization curve.

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Deuterium isotope effects and assignment of 13C chemical shifts in spectra of methyl octadecanoate and the sixteen isomeric oxooctadecanoates

Canadian Journal of Chemistry ◽

10.1139/v77-160 ◽

1977 ◽

Vol 55 (7) ◽

pp. 1135-1142 ◽

Cited By ~ 35

Author(s):

A. P. Tulloch

Keyword(s):

Chemical Shifts ◽

Isotope Effects ◽

Carbonyl Groups ◽

Average Value ◽

Fatty Acid Chain ◽

Methylene Groups ◽

Deuterium Isotope Effects ◽

Methyl Octadecanoate ◽

Atom Effect ◽

C Nmr

13C nmr spectra of the 16 isomeric gem-dideuterooctadecanoates were measured and second and third atom deuterium isotope effects calculated for most of the affected carbons of 12 of the isomers. The average value for the second atom effect was −0.20 ppm and for the third atom effect was −0.05 ppm. From these effects and the changes in spectra caused by introduction of two deuterons at positions along the fatty acid chain, chemical shifts were determined for all carbons of methyl octadecanoate. Spectra of seven dideuterooxooctadecanoates, with both deuterons attached to a carbon γ to the oxo group, were measured, and using isotope effects, unambiguous assignments of chemical shift were made. Chemical shifts were thus assigned to all carbons in the 16 isomeric oxooctadecanoates and these show the effect of the carbonyl group at different positions in the chain. The results indicate that, in addition to large effects on carbons α and β to the oxo group, the γ to θ carbons are all shielded with displacements: γ −0.46, δ −0.30, ε −0.27, ζ −0.13, η −0.09, and θ −0.06 ppm. The effects of the oxo and ester carbonyls extend over seven methylene groups, but shielding due to ester carbonyl is a little smaller. Spectra of 2- to 9-oxo esters showed that interaction between the two carbonyl groups causes relatively greater shielding of carbons situated between the groups.

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