scholarly journals Long-chain betulaprenol-type polyprenols from the leaves of Ginkgo biloba

1983 ◽  
Vol 213 (2) ◽  
pp. 305-311 ◽  
Author(s):  
K Ibata ◽  
M Mizuno ◽  
T Takigawa ◽  
Y Tanaka

A long-chain betulaprenol-type polyprenol mixture was isolated from the leaves of Ginkgo biloba mainly as acetate. The structure was determined by mass spectroscopy, 1H-n.m.r. spectroscopy and 13C-n.m.r. spectroscopy. The mixture contained polyprenols-14-22, predominantly polyprenols-17, -18 and -19, and consisted of the dimethylallyl terminal unit (omega-terminal), two trans-isoprene residues, a sequence of 11-19 cis-isoprene residues and a terminal hydroxylated isoprene unit (alpha-terminal) aligned in that order. The concentration of these polyprenols in leaves increased from 0.04 to 2.0% of dry wt. with maturing of the leaves, though the content of total lipids was constant. The distribution of chain length in these polyprenols showed little variation throughout the whole life of the leaves.

1996 ◽  
Vol 1996 ◽  
pp. 98-98
Author(s):  
B M L McLean ◽  
R W Mayes ◽  
F D DeB Hovell

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 However, recent work by Cuddeford and Mayes (unpublished) has found that in horses the faecal recovery rates are similar regardless of chain lengths.


2012 ◽  
Vol 108 (4) ◽  
pp. 755-758 ◽  
Author(s):  
Charlotte J. Harden ◽  
Adam N. Jones ◽  
Tannia Maya-Jimenez ◽  
Margo E. Barker ◽  
Natalie J. Hepburn ◽  
...  

Long-chain fatty acids have been shown to suppress appetite and reduce energy intake (EI) by stimulating the release of gastrointestinal hormones such as cholecystokinin (CCK). The effect of NEFA acyl chain length on these parameters is not comprehensively understood. Anin vitroscreen tested the capacity of individual NEFA (C12 to C22) to trigger CCK release. There was a gradient in CCK release with increasing chain length. DHA (C22) stimulated significantly (P < 0·01) more CCK release than all other NEFA tested. Subsequently, we conducted a randomised, controlled, crossover intervention study using healthy males (n18). The effects of no treatment (NT) and oral doses of emulsified DHA-rich (DHA) and oleic acid (OA)-rich oils were compared using 24 h EI as the primary endpoint. Participants reported significantly (P = 0·039) lower total daily EI (29 % reduction) with DHA compared to NT. There were no differences between DHA compared to OA and OA compared to NT. There was no between-treatment difference in the time to, or EI of, the first post-intervention eating occasion. It is concluded that NEFA stimulate CCK release in a chain length-dependent manner up to C22. These effects may be extended to thein vivosetting, as a DHA-based emulsion significantly reduced short-term EI.


2020 ◽  
Vol 15 (5) ◽  
pp. 1934578X2092607
Author(s):  
Biljana Nikolić ◽  
Marina Todosijević ◽  
Iris Đorđević ◽  
Jovana Stanković ◽  
Zorica S. Mitić ◽  
...  

In leaf cuticular wax of Pinus pinaster, content of nonacosan-10-ol is high (77.1% on average). n-Alkanes ranged from C18 to C35 with the most dominant C29 (24.8%). The carbon preference index (CPItotal) ranged from 3.1 to 5.6 (4.0 on average), while the average chain length (ACLtotal) ranged from 14.0 to 17.0 (14.8 on average). Long-chain n-alkanes ( n-C25-35) strongly dominated (80.1%) over middle-chain ( n-C21-24 = 18.9%) and short-chain ( n -C18-20 = 0.9%) n-alkanes.


Author(s):  
A P Day ◽  
M D Feher ◽  
R Chopra ◽  
P D Mayne

Intestinal alkaline phosphatase (IALP) activity rises following the ingestion of a fat-containing meal. Previous studies on intestinal fluid and lymph have shown that the magnitude of this response is dependent upon fatty acid chain length. To examine this relation in the serum of healthy humans, 10 subjects consumed two standardized fat meals. One meal contained predominantly long chain fatty acid triglycerides, the other contained predominantly medium chain fatty acid triglycerides. Serum IALP activity was measured in serial blood samples using a sensitive immunological assay. IALP activity was ABO blood group and secretor status dependent. The post-prandial rise in serum IALP activity was significantly greater following the long chain fatty acid meal than following the medium chain fatty acid meal. Previous observations of the fatty acid chain length dependency of the IALP response to fat ingestion, therefore, also apply in the serum of healthy humans under normal physiological conditions. Standardized fat meals provide the basis of a useful method for the investigation of the role of IALP in fat absorption.


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