Solid-phase synthesis of polyglutamates of folic acid

Abstract

New techniques suggest that inorganic iron absorption in the elderly is not normally reduced. The chief abnormal finding in a group of elderly healthy people was an increase in absorbed iron, possibly due to ineffective erythropoiesis.

Jejunal perfusion of simple and conjugated folates in celiac sprue.

“…In each experiment, column chromatography ofthe luminal aspirates revealed similar spectra ofhydrolytic products of [ ["4C]PG-1 was found impaired in both celiac sprue groups, with significant improvement on treatment. In mucosal biopsies from the sprue patients, the in vitro activity of folate conjugase in whole homogenates was higher and the activity of disaccharidase lower than in a group of 12 normal mucosal biopsies. These in vitro data suggest that the predominant cellular location of mucosal folate conjugase is different from that of disaccharidase, whereas comparison with the re-…”

“…The materials included 3',5',9' [3H]pteroylmonoglutamate (Amersham/Searle Corp., Arlington Heights, Ill.) and pteroyl-,u['4C]glutamyl-y-hexaglutamate.2 The latter compound was synthesized by the solid-phase method so that the 14C label was on the first glutamyl unit (12), and was provided by The Nutrition Program, University of Alabama. As described (4), these folates were purified on DEAEcellulose columns and were quantitated spectrophotometrically using peak absorbance at 256, 285, and 365 nm.…”

Jejunal Perfusion of Simple and Conjugated Folates in Tropical Sprue

“…2) The pre-and post-treatment recoveries of each label paralleled the luminal disappearances. Initially, recovery of 3H was 35.7+4.5% and that of 14C was 16 (Fig. 4).…”

“…The development of methods for the synthesis of labeled pteroylpolyglutamates has permitted a greater definition of the process involved in the intestinal absorption of conjugated folates (16,22). In several patients this process has been approached by measuring levels of serum radioactivty and(or) excretion of the radioactive label in the urine or expired air (4-6, 23, 24).…”

The Identification of Hexa-, Hepta- and Octoglutamates as the Polyglutamyl Forms of Folate Found throughout the Growth Cycle of Yeast

“…Folate or p-arninobenzoylpolyglutamates are difficult to synthesize chemically (Krumdieck & Baugh, 1969). Their general lack of availability as markers for the co-chromatography used in the identification of folate polyglutamates from different sources, has limited research in this area to a small number of laboratories.…”