ABSTRACT
It is proposed that the biosynthesis of the sesquiterpene valerenadiene, a key intermediate in the biosynthesis of a sedative in valerian, involves cyclopropane and not cyclobutane intermediates and includes as a key step a cyclopropylcarbinylcation-cyclopropylcarbinylcation rearrangement analogous to the one observed in the conversion of presqualene to squalene in triterpene and steroid biosynthesis. Similar mechanisms are proposed for the biosynthesis of the related sesquiterpenes pacifigorgiol, tamariscene and (+)-pacifigorgia-1,10-diene.
Subject(s)
Sesquiterpenes/metabolism , Valerian/metabolismABSTRACT
Structure 2 assigned presently to nardin is revised to that of valerenic acid (4), and structure 1 assigned presently to nardal is revised to that of valerenal (3). The names valerenic acid and valerenal have priority so the names nardin and nardal should no longer be used.
Subject(s)
Indenes/chemistry , Sesquiterpenes/chemistry , Magnetic Resonance Spectroscopy , Sesquiterpenes, GuaianeABSTRACT
A biogenetic-type synthesis of 2-hydroxy-4,4,7-trimethyl-1(4H)-naphthalenone (1), a modified apocarotenoid isolated from Ipomoeapes-caprae (Linn.) R. Br. showing anti-inflammatory activity by inhibiting prostaglandin synthesis in vitro, is described. A biogenetic proposal for the natural occurrence of 1 is also presented.
Subject(s)
Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/chemical synthesis , Carotenoids/chemistry , Ipomoea/chemistry , Plant Extracts/chemistry , Magnetic Resonance Spectroscopy , Molecular StructureABSTRACT
A biogenetic-type synthesis of (+)-cymbodiacetal (1), a novel bismonoterpenoid dihemiacetal, is described.
