The common occurrence of furan fatty acids in plants

Abstract

The observation that F-acids (1) occur in rat chow initiated a search for F-acids in human diet. We observed that the amount of F-acids with a pentyl side chain in alpha-position taken up with a one-day diet correlates well with the amount of excreted degradation products, the pentyl urofuran acids (2), (3) and (4). Therefore it can be concluded that F-acids with a pentyl side chain are not produced in the human body but are introduced through the diet. The origin of F-acids carrying an alpha-propyl side chain is less clear. The amount of propyl-urofuran acids (2) and (3) excreted in urine was found in one case out of three to be five times higher than the amount of F-acids carrying a propyl group in alpha-position taken up by the diet. Therefore, it can presently not be excluded that a portion of the propyl F-acids is produced by the body. F-acids found in human food are mainly introduced into the body by vegetables and fruits. F-acids were found also in birch leaves in considerable amounts, as well as in grasses, dandelion and clover leaves. Thus, we can conclude that F-acids are common constituents of plants.

Furan fatty acid as an anti-inflammatory component from the green-lipped mussel Perna canaliculus

“…Spiteller hypothesized that furan fatty acids (F-acids), which were first isolated from the northern pike in 1974 (22), are such naturally occurring antioxidative fatty acids that ameliorate the oxidative risk of the cellular membrane (23,24). Even though F-acid concentration is usually low, these fatty acids are widely distributed in plants and aquatic organisms (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36). The unique structural feature of Facids is the tetraalkyl-substituted furan ring, which is a rarely observed skeleton in natural products.…”

“…Additionally, to circumvent the autoxidation of the tetraalkyl-substituted furan ring on the surface of silica gel (30,39), careful manipulations are required, especially in the case of lower quantities from natural sources. Previous reports used the method of Folch et al (40) or Bligh and Dyer (41) to extract total lipids, which were further separated by silica gel into cholesteryl ester, triglycerides, and phospholipid fractions (25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35). These esters were transesterified with a methanolic sodium methoxide solution to form fatty acid methyl esters and then were investigated by GC-MS.…”

“…The lipid extract of the greenlipped mussel (Lyprinol; 2.98 g) was dissolved in CH 2 Cl 2 (80 mL). The resulting pale yellow solution was hydrogenated with Pd-C (80 mg) under an H 2 atmosphere (25). After 3 h of stirring, the catalyst was removed by filtration.…”

Efficient Removal of Albumin-Bound Furancarboxylic Acid by Protein-Leaking Hemodialysis

“…The urinary excretion of CMPF in healthy subjects was about 1.2 mg/day [7]. Its urinary excretion is likely to be due to active renal tubular secretion, because so little of the unbound CMPF is avail able for glomerular filtration due to its high affinity for albumin [11], The active tubular secretion of CMPF is similar to p-aminohippuric acid, because CMPF inhibit ed the uptake of p-aminohippuric acid by rat kidney slices, and likewise, p-aminohippuric acid inhibited the uptake of CMPF [12], The origin of CMPF has not yet been elucidated, although some furanoid acids, possible precursors of CMPF, are found rich in foods, such as fish [ 13], vegeta bles and fruits [14]. The furanoid acids with methyl groups in positions 3 and 4 and propyl group in position 5 may be carboxylated at position 3, and subjected to p-oxidation, producing CMPF.…”

“…The furanoid acids with methyl groups in positions 3 and 4 and propyl group in position 5 may be carboxylated at position 3, and subjected to p-oxidation, producing CMPF. However, it cannot be excluded that a portion of CMPF is produced de novo in the body [14], In uremic patients, CMPF accumulates in blood in its albumin-bound form due to impaired renal clearance. A defect in albumin binding of drugs was demonstrated in uremic patients [15], CMPF was identified as a major inhibitor of albumin binding of drugs, thus accounting for the drug-binding defect of uremic serum [1][2][3][4]16].…”