Synthesis of α-phosphotidic acids

Abstract

of a-phosphotidic acids. Can. J. Biochem. 48,1010Biochem. 48, -1013Biochem. 48, (1910. A procedure permitting the synthesis of both optical isomers as well as the racemic forin of saturated or unsaturated phosphoridic rrcids is reported. The phosphotidic acids are obtainable by treating the pyridinium salts of L-, D-, or DL-dihydroxypropylphosphonic acid for 24 h at 80" with a mixture of the anhydride and the tetraethylammonium salt of the fatty acid to be introduced, and separating the reaction products by column chromatography on silicic acid. The preparation of the dipalmitoyl and distearoyl L-dihydroxypropylphosphonic acids is described. IntroductionChibnall and Channon (1, 2), investigating the cytoplasrna of cabbage and spinach leaves, isolated a mixture of compounds whose main constituents were identified as calcium, magnesium, and potassium salts of phosphoric acid esters of diglycerides. These compounds, representing a new class of phospholipids, were given the generic name of phosphatidic acids. Subsequently, they were found to be present in wheat germs (3) and tubercle bacilli (4-8). The discovery by Hanahan and Chalkoff (9) of an enzyme in fresh cabbage leaves which splits specifically the nitrogenous base -phosphoric acid ester bond s f lecithins added considerable weight to the contention of Channon and Chibnall that the phosphatidic acids are intermediates in the biosynthesis and metabolism of phospholipids. The preparation of phosphatidic acids by enzymatic hydrolysis of egg lecithin (lo), yeast lecithin (1 1), and synthetic L-a-(dipalrnitoy1)lecithin (1 I) has been described by Kates. The chemical synthesis of racemic phosphatidic acids has been reported by a number of research workers using a variety of methods (12-21). ln all instances either the method of synthesis or the starting materials were not wholly satisfactory and gave products of questionable structure and purity. The first generally applicable methods for the synthesis of both opticaI isomers of saturated or unsaturated or-phosphatidic acids with identical fatty acid substituents were reported by Baer (22) and Baer and Buchlrea (23), respectively. The dioleoyl L-a-glycerophosphoric acid (23) showed a moderate activity in the Kolmer fixation test for syphilis.As far as the authors are aware, the synthesis of phssphonic acid analogues of ester phosphatidic acids, for which we propose the generic

Χημεια Του Αρσενικου Και Συνθεση Αρσονολιπιδιων

“…Even excess (300%) of epoxidizing reagent did not completely react with allyl arsonic acid (30-40% was found intact). Epoxide (6) was not formed in >5-10% yields and rac-DPAF-L (5) could not be isolated via these routes.…”

“…(5) ή του αντίστοιχου εποξειδίου (6). Τα αποτελέσματα αυτών των πειραμάτων έδειξαν ότι η αρσονική ομάδα προκαλούσε, κάτω από τις δικές μας συνθήκες, διάσπαση του δεσμού -0-0-των υπεροξυοξέων που χρησιμοποιήθηκαν (MCPBA, ΜΜΡΑ και HCOOOH) με συνέπεια ακόμη και περίσσεια εποξειδωτικού αντιδραστηρίου, της τάξεως του 300%, να αφήνει ανέπαφο ένα σημαντικό μέρος του αλλυλοαρσονικού οξέος (30-40%), πράγμα που δεν επέτρεψε την απομόνωση του προϊόντος rac-DPAHp, ενώ σε καμμία περίπτωση δεν προσδιορίσθηκε εποξείδιο (6) σε ποσοστά μεγαλύτερα του 5-10%.…”

“…This acid reacted with the epoxidizing and hydroxylating reagents, such as MCPBA, MMPA, HCOOOH, with the aims at the preparation of (5) or (6). The experiments, however, showed that the arsonic group caused the decomposition of the oxidizing reagents.…”

Συνθεσις Του Φωσφονο-Παραγωγου Της Σφιγγομυελινης (Trans-D-Erythro- Κηραμιδυλο-Ννν-Τριμεθυλο-Αμινοαιθυλο-Φωσφονικου Οξεος)

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