Biomedical subjects

N Fotouhi

Publications and source records attributed to N Fotouhi.

21 records · Page 2Linked to original sources

PubMed1992

Resistance of fatty acyl amides to degradation and hydrogenation by ruminal microorganisms.

Two in vitro trials were conducted to determine whether fatty acyl amides are degraded and hydrogenated by ruminal microorganisms. The treatments consisted of ground hay supplemented with either no lipid, linoleoyl Met ethyl ester, or free linoleic acid plus Met ethyl ester. Incubations were carried out in Erlenmeyer flasks at 39 degrees C under CO2. Cultures were sampled at predetermined times and analyzed for long-chain fatty acids, Met, and VFA. In trial 1, the rate of disappearance of linoleic acid was lower for the amide than for the FFA (.004 and -.047/h, respectively). In trial 2, there were no differences in the rate of disappearance of linoleic acid from 0 to 6 h (-.237 and -.357/h for amide and FFA, respectively), but the rates from 6 to 48 h (-.003 and -.027/h for amide and FFA, respectively) were different. Linoleoyl Met cultures also had higher acetate to propionate ratio and lower loss of Met compared with free linoleic acid cultures. There was no loss of radioactivity from [14C]stearoyl Met after 24 h of incubation, indicating its resistance to bacterial breakdown. The results showed that fatty acyl amides resist bacterial breakdown and prevent loss of double bonds by microbial biohydrogenation.

Amides↗

PubMed1990

Effects of lecithin and corn oil on site of digestion, ruminal fermentation and microbial protein synthesis in sheep.

Six Hampshire wethers with ruminal and duodenal cannulas were fed three diets in a replicated 3 X 3 latin square to compare phospholipids with triglycerides for their effects on ruminal digestion. The diets (56% concentrate, 44% bermuda-grass hay, air-dried basis) contained either no added fat (control), 5.2% soybean lecithin or 2.4% corn oil on a DM basis. All diets were isonitrogenous and both fat-supplemented diets had similar fatty acid and energy contents. Fat added to the diet, regardless of source, reduced digestibilities of DM, energy, ADF and fatty acids in the rumen but had no effect on total tract digestibility coefficients. Lecithin slightly increased (P = .06) fatty acid digestion in the hindgut compared to corn oil (91.0 and 87.0%, respectively). Both fat sources decreased (P less than .01) ruminal ammonia concentration and increased (P less than .10) N flow to the duodenum. Added fat also reduced ruminal (P less than .01) and total tract (P less than .05) N digestibilities. Microbial N flow to the hindgut was not affected by diet, but adding fat increased (P less than .06) true efficiency of microbial protein synthesis. Overall, phospholipids from soybean lecithin inhibited ruminal fermentation similarly to triglycerides from corn oil. Despite ruminal degradation of lecithin by microbial phospholipases as shown in other studies, feeding lecithin tended to increase fatty acid digestion in the hindgut.

Animals↗

PubMed1988

Practical preparation and deblocking conditions for N-alpha-(2-(p-biphenylyl)-2-propyloxycarbonyl)-amino acid (N-a-Bpoc-Xxx-OH) derivatives.

Reproducible preparations are given for salts of the following L-amino acid derivatives: Bpoc-Ala-OH, Bpoc-Arg(Mtr)-OH, Bpoc-Asn-OH, Bpoc-Asp(OtBu)-OH, Bpoc-Cys(Acm)-OH, Bpoc-Cys(S-tBu)-OH, Bpoc-Gln-OH, Bpoc-Glu(OtBu)-OH, Bpoc-Gly-OH, Bpoc-Ile-OH, Bpoc-Leu-OH, N-alpha-Bpoc-Lys(epsilon-Boc)-OH, Bpoc-Met-OH, Bpoc-Phe-OH, Bpoc-Pro-OH, Bpoc-Ser(OtBu)-OH, Bpoc-Thr(OtBu)-OH, Bpoc-Tyr-OH, Bpoc-Val-OH. A study of the deblocking of N-alpha-Bpoc peptides in dichloromethane containing 0.5% trifluoroacetic acid revealed that a rapid equilbrium is established between the first-formed monomeric alkene 2-p-biphenylylpropene and the hindered dimer 2,4-bis(p-biphenylyl)-4-methyl-1-pentene. Thioethers were found to be inefficient carbocation scavengers for the deblocking reaction. The most efficient scavengers were found to be thiophenol and benzyl mercaptan, and the following approximate reactivity order was established: benzyl mercaptan approximately thiophenol greater than indole much greater than 1,3-dimethoxybenzene approximately resorcinol greater than 1,3,5-trimethoxybenzene approximately dimethyl sulfide approximately thioanisole.

Amino Acids↗