Amaryllidaceae Alkaloids

About: Amaryllidaceae Alkaloids is a research topic. Over the lifetime, 483 publications have been published within this topic receiving 12824 citations.

Alkaloids : chemical and biological perspectives

Abstract: Chapter headings. Carbon-13 and proton NMR shift assignments and physical constants of diterpenoid alkaloids. Supercritical fluid extraction of alkaloids. Recent advances in the total synthesis of amaryllidaceae alkaloids. Applications of radical cyclization reactions in total syntheses of naturally occurring indole alkaloids.

Chemistry, biology, and medicinal potential of narciclasine and its congeners.

Abstract: Ornamental flower growers know that placing a cut daffodil (a.k.a. narcissus) in a vase with other flowers has a negative effect on the quality of those flowers and significantly shortens their vase life. Furthermore, a common horticultural practice for the cultivation of narcissus flowers involves the introduction of cuts on the bulbs before immersing them into water. The mucilage that leaches out from the cuts is constantly removed by frequent changing of water and this leads to sprouting. These observations raise speculation that specific components in the mucilage of the narcissus bulbs may have powerful growth-inhibitory effects. Historical use of narcissus flowers, as well as at least thirty other plants of the Amaryllidaceae family, in folk medicine for the management of cancer1 speaks volumes to validate this conjecture. Indeed, powerful anticancer properties of Narcissus poeticus L. were already known to the Father of Medicine, Hippokrates of Kos (ca. B.C. 460–370), who recommended a pessary prepared from narcissus oil for the treatment of uterine tumors.2 His successors, the ancient Greek physicians Pedanius Dioscorides (ca. A.D. 40–90) and Soranus of Ephesus (A.D. 98–138) continued using this therapy in the first and second centuries A.D.3,4 In addition, the topical anticancer uses of extracts from this plant5,6 as well as from N. pseudonarcissus7–9 were recorded in the first century A.D. by the Roman natural philosopher Gaius Plinius Secundus, (A.D. 23–79), better known as Pliny the Elder.10 Even the Bible provides multiple references to the Mediterranean N. tazetta L., which has a long history of use against cancer.11 The applications of narcissus oil in cancer management continued in the middle ages in Chinese, North African, Central American and Arabian medicine.1,12 The uses of other genera of the Amaryllidaceae family were also common, e. g. Hymenocallis caribaea (L. emend Gawler) Herbert, utilized by early European medical practitioners for inflammatory tumors.13 More recently, the plants of the Amaryllidaceae have been under intense scrutiny for the presence of the specific metabolites responsible for the medicinal properties associated with this plant family. The study began in 1877 with the isolation of alkaloid lycorine from Narcissus pseudonarcissus14 and since then more than 100 alkaloids, exhibiting diverse biological activities, have been isolated from the Amaryllidaceae plants. Based on the present scientific evidence, it is likely that isocarbostyril constituents of the Amaryllidaceae, such as narciclasine, pancratistatin and their congeners, are the most important metabolites responsible for the therapeutic benefits of these plants in the folk medical treatment of cancer. Notably, N. poeticus L. used by the ancient Greek physicians, as was eluded before, is now known to contain some 0.12 g of narciclasine per kg of fresh bulbs.15 Continuing along this intriguing path, the focus of the present review is a comprehensive literature survey and discussion of the chemistry and biology of these compounds as specifically relevant to their potential use in medicine. The examination of the synthetic organic chemistry, more specifically the total synthesis efforts inspired by the challenging chemical structures of narciclasine, pancratistatin and their congeners, will be reduced to a minimum in view of the two very recent excellent reviews published on this subject.16,17

The Biosynthesis of Secondary Metabolites

Abstract: 1 Introduction.- 1.1 Primary and secondary metabolism.- 1.1.1 Introduction.- 1.1.2 Fatty acid biosynthesis.- 1.1.3 The biosynthesis of polyacetylenes and prostaglandins.- 1.2 Stereochemistry and biosynthesis.- 1.2.1 Chirality and prochirality.- 1.2.2 Chiral methyl groups.- 1.2.3 Hydroxylation at saturated carbon atoms.- 1.3 Some reactions of general importance in secondary metabolism.- 1.3.1 Oxidative coupling of phenols.- 1.3.2 Hydroxylation of aromatic substrates.- 1.3.3 Methylation.- References.- 2 Techniques for biosynthesis.- 2.1 Introduction.- 2.2 Isotopic labelling.- 2.2.1 Radioactive isotopes.- 2.2.2 Stable isotopes.- 2.3 Enzymes and mutants.- References.- 3 Polyketides.- 3.1 Introduction.- 3.2 Formation of poly-?-keto-acyl-CoA's.- 3.2.1 Acetate and malonate.- 3.2.2 Assembly of poly-?-keto-acyl-CoA's.- 3.3 Tetraketides.- 3.4 Pentaketides.- 3.5 Hexaketides.- 3.6 Heptaketides.- 3.7 Octaketides.- 3.8 Nona-and deca-ketides.- 3.9 Polyketides with mixed origins and large ring polyketides.- References.- 4 Terpenes and steroids.- 4.1 Introduction.- 4.2 Steroids.- 4.3 Pentacyclic triterpenes.- 4.4 Squalene.- 4.5 Monoterpenes.- 4.6 Sesquiterpenes.- 4.7 Diterpenes.- 4.8 Sesterpenes.- 4.9 Carotenoids and vitamin A.- References.- 5 The shikimic acid pathway.- 5.1 Introduction.- 5.2 Quinones.- 5.3 Coumarins.- 5.4 Flavonoids.- References.- 6 Alkaloids.- 6.1 Introduction.- 6.2 Piperidine and pyrrolidine alkaloids.- 6.2.1 Piperidine alkaloids.- 6.2.2 Pyrrolidine alkaloids.- 6.3 Isoquinoline and related alkaloids.- 6.3.1 Phenethylamines and simple isoquinolines.- 6.3.2 Aporphines.- 6.3.3 Erythrina alkaloids.- 6.3.4 Morphine and related alkaloids.- 6.3.5 Hasubanonine and protostephanine.- 6.3.6 Protoberberine and related alkaloids.- 6.3.7 Phenethylisoquinoline alkaloids.- 6.4 Amaryllidaceae and mesembrine alkaloids.- 6.4.1 Amaryllidaceae alkaloids.- 6.4.2 Mesembrine alkaloids.- 6.5 Quinoline and related alkaloids.- 6.6 Indole alkaloids.- 6.6.1 Simple indole derivatives.- 6.6.2 Terpenoid indole and related alkaloids.- 6.7 Ipecac alkaloids.- 6.8 Miscellaneous alkaloids.- References.- 7 Microbial metabolites containing nitrogen.- 7.1 Introduction.- 7.2 Piperidine and pyridine metabolites.- 7.3 Diketopiperazines.- 7.4 Benzodiazepines.- 7.5 Metabolites derived from the tryptophan pathway.- 7.5.1 Ergot alkaloids.- 7.5.2 Cyclopiazonic acids and carbazomycin B.- 7.5.3 Indolmycin.- 7.5.4 Streptonigrin and pyrrolnitrin.- 7.6 Metabolites derived from the shikimate pathway.- 7.6.1 Pseudans, phenoxazinones, phenazines, and chloramphenicol.- 7.6.2 Ansamycins, mitomycins and antibiotic A23187.- 7.6.3 Cytochalasins and pseurotin A.- 7.6.4 Nybomycin.- 7.6.5 Naphthyridinomycin, saframycin A and CC-1065.- 7.6.6 Isocyanides and tuberin.- 7.6.7 Sarubicin A.- 7.6.8 Arphamenines.- 7.7 ?-Lactams.- 7.7.1 Penicillins and cephalosporins.- 7.7.2 Clavulanic acid.- 7.7.3 Nocardicins.- 7.7.4 Thienamycin and tabtoxin.- 7.8 Miscellaneous metabolites.- 7.8.1 Prodiginines.- 7.8.2 Elaiomycin and valinimycin.- 7.8.3 Streptothricin, acivicin, reductiomycin and asukamycin.- 7.8.4 Myxopyronin A, myxothiazol, angiolam A, rhizoxin and malonimycin.- 7.8.5 Virginiamycin antibiotics.- 7.8.6 Cyclizidine.- References.