Structure elucidation of naturally occurring long-chain mono- and dienes

1989 ◽  
Vol 54 (2) ◽  
pp. 494-496 ◽  
Author(s):  
John R. Barr ◽  
Ralph T. Scannell ◽  
Keiichi Yamaguchi
Keyword(s):  
Structure Elucidation ◽  
Naturally Occurring ◽  
Long Chain

The Use of N-alkanes for Estimating Intake and Passage Rate in Horses

1996 ◽  
Vol 1996 ◽  
pp. 98-98
Author(s):  
B M L McLean ◽  
R W Mayes ◽  
F D DeB Hovell
Keyword(s):  
Recent Work ◽  
Chain Length ◽  
Carbon Chain ◽  
Carbon Chain Length ◽  
Passage Rate ◽  
Forage Crops ◽  
Carbon Chains ◽  
Naturally Occurring ◽  
Chain Lengths ◽  
Long Chain

Alkanes occur naturally in all plants, although forage crops tend to have higher alkane contents than cereals. N-alkanes have odd-numbered carbon chains. They are ideal for use as markers in feed trials, because, they are inert, indigestible and naturally occurring, and can be recovered in animal faeces. Synthetic alkanes (even-numbered carbon chains) are available commercially and can also used as external markers. Dove and Mayes (1991) cite evidence indicating that faecal recovery of alkanes in ruminants increases with increasing carbon-chain length. Thus the alkane “pairs” (e.g. C35 & C36, and C32 & C33) are used in calculating intake and digestibility because they are long chain and adjacent to each other. However, recent work by Cuddeford and Mayes (unpublished) has found that in horses the faecal recovery rates are similar regardless of chain lengths.

Structure Elucidation of Lolitrem F, a Naturally Occurring Stereoisomer of the Tremorgenic Mycotoxin Lolitrem B, Isolated fromLolium perenneInfected withAcremonium lolii

1996 ◽  
Vol 44 (9) ◽  
pp. 2782-2788 ◽  
Author(s):  
Sarah C. Munday-Finch ◽  
Alistair L. Wilkins ◽  
Christopher O. Miles ◽  
Richard M. Ede ◽  
Ralph A. Thomson
Keyword(s):  
Structure Elucidation ◽  
Naturally Occurring ◽  
Lolitrem B ◽  
Tremorgenic Mycotoxin

scholarly journals Structural and Solubility Parameter Correlations of Gelation Abilities for Dihydroxylated Derivatives of Long-Chain, Naturally Occurring Fatty Acids

2015 ◽  
Vol 21 (23) ◽  
pp. 8530-8543 ◽  
Author(s):  
Mohan Zhang ◽  
Sermadurai Selvakumar ◽  
Xinran Zhang ◽  
Mukund P. Sibi ◽  
Richard G. Weiss
Keyword(s):  
Fatty Acids ◽  
Solubility Parameter ◽  
Naturally Occurring ◽  
Derivatives Of ◽  
Long Chain

The Absorption and Fluorescence of Isoflavones and the Effect of Shift Reagents

1984 ◽  
Vol 39 (2) ◽  
pp. 238-243 ◽  
Author(s):  
Otto S. Wolfbeis ◽  
Eva Fiirlinger ◽  
Hem Chandra Jha ◽  
Fritz Zilliken
Keyword(s):  
Sulfuric Acid ◽  
Absorption Band ◽  
Absorption Maximum ◽  
Structure Elucidation ◽  
Sodium Acetate ◽  
Methanol Solution ◽  
Aluminium Chloride ◽  
Sodium Borate ◽  
Naturally Occurring ◽  
Aluminium Trichloride

The absorption and fluorescence maxima of 20 isoflavones have been determined in methanol solution and the effect of addition of water, 50% sulfuric acid, aluminium trichloride, borax, sodium acetate, ammonia and sodium hydroxide has been studied. The following findings may be useful in the structure elucidation of naturally occurring isoflavones: (a) 5-Hydroxyisoflavones have band I absorption maxima around 335 nm. 6-hydroxyisoflavones between 310 and 330 nm, and others below 310 nm. (b) Addition of water produces practically no shift in the absorption spectra, but - unlike other hydroxyisoflavones - can give distinctly longwave shifted new fluorescence bands with 7-hydroxyisoflavones. (c) Addition of sodium acetate gives rise to anion absorption of 7-hydroxyisoflavones and to partial anion absorption of 6-hydroxyisoflavones; the spectral maxima of 5-hydroxyisoflavones remain practically unchanged, (d) Ammonia gives rise to anion absorption of both 6- and 7-hydroxyisoflavones, but not of the 5-hydroxy isomers, (e) Sodium borate is a useful reagent to identify 6,7-dihydroxyisoflavones by virtue of its ability to form a chelate complex with an absorption maximum that is different from the anion absorption, (f) Aluminium trichloride forms complexes with both 5-hydroxy- and 6,7-dihydroxyisoflavones with distinct absorption maxima, (g) 5,7-D ihydroxyisoflavones may be recognized by addition of ammonia, which does not result in a longwave shift, but rather in an intensification of the longwave absorption band, (h) 6-H ydroxyisoflavones can be differentiated from the 7-hydroxy isomers by their longwave shifts (4 0-60 nm) following addition of ammonia. The respective shifts of the 7-hydroxy isomers are smaller, (i) 5-H ydroxyisoflavones are practically non-fluorescent. while others have fairly strong fluorescences, (j) The absorption and fluorescence maxima of isoflavones give unique combinations which may be useful in their identification, (k) Addition of aluminium chloride makes the non-fluorescent 5-hydroxyisoflavones fluorescent. (1) As in the case of absorption, 6,7-dihydroxyisoflavones form complexes with borate possessing fluorescence bands with maxima different from those of the anion bands

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