Lignans neolignans, and related compounds

Amaryllidaceae and Sceletium alkaloids

The distribution of the chemical compounds iridoids, anthraquinones, and verbascosides is demonstrated in Dahlgrenograms. An analysis of iridoid biosynthesis and structure allows distinction of two main groups of compounds. Thus, the biosynthetic route I gives rise to the seco-iridoids and their derivatives, and another (route II) to aucubin and similar decarboxylated iridoid glucosides. Seco-iridoids from route I are widely distributed in Cornanae, Loasanae, and Gentiananae but never in Lamianae. Aucubinlike compounds derived by route II are commonly found in Lamianae and in three small families in Cornanae, but are not found in Gentiananae (...)

Systematic implications of the distribution of iridoids and other chemical compounds in the Loganiaceae and the other families of the Asteridae

By extending our oxidative phenol-coupling reactions using a hypervalent iodine(III) reagent, a versatile synthetic procedure for the galanthamine-type Amaryllidaceae alkaloids was accomplished. The first total synthesis of (±)-sanguinine and the total syntheses of (±)-galanthamine, (±)-narwedine, (±)-lycoramine, and (±)-norgalanthamine were also successfully carried out.

Oxidative Intramolecular Phenolic Coupling Reaction Induced by a Hypervalent Iodine(III) Reagent: Leading to Galanthamine-Type Amaryllidaceae Alkaloids

Publisher Summary This chapter discusses the chemical and biological aspects of Narcissus alkaloids. Numerous alkaloids have been isolated from Narcissus speciesasaresult of the continuing search for novel alkaloids with pharmacological activity in the Amaryllidaceae family. The alkaloids isolated from this genus, classified in relation to the different skeleton types. The different Narcissus wild species and intersectional hybrids, grouped into subgenera and sections, with their corresponding alkaloids, arranged according to their ring system are listed. The biosynthetic pathways of Narcissus alkaloids includes: (1) enzymatic preparation of the precursors, (2) primary cyclization mechanisms, (3) enzymatic preparation of intermediates, (4) secondary cyclization, diversification, and restructuring. The chapter discusses proton nuclear magnetic resonance ( 1 H NMR), carbon nuclear magnetic resonance ( 13 C NMR), and mass spectrometry (MS) for Narcissus alkaloids. A list of the different Narcissus alkaloids, their spectroscopic properties, and literature with the most recent spectroscopic data is given. Several Narcissus extracts shows the following activities: antiviral, prophage induction, antibacterial, antifungal, antimalarial, insecticidal, cytotoxic, antitumor, antimitotic, antiplatelet, hypotensive, emetic, acetylcholine esterase inhibitory, antifertility, antinociceptive, chronotropic, pheromone, plant growth inhibitor, and allelopathic.

O.M. Abdallah

Papers

Phenylpropanoid glycosides ofPrunus ssiori

Anthraquinone derivatives from Gladiolus segetum

Narcisine, an alkaloid from Narcissus tazetta

Minor alkaloids from Lycoris sanguinea

2-O-acetyl chlidanthine; an alkaloid from Haemanthus multiflorus