Two New Alkaloids from Bulbs of Lycoris squamigera

Asymmetric total synthesis of montanine-type amaryllidaceae alkaloids

“…They have been of great interest to many chemists and biologists since Wildman first isolated them from the plants of the Amaryllidaceae family in 1955. 1–16 According to biological studies, these natural products have demonstrated antimicrobial and anxiolytic properties, and promising potential for developing novel antidepressant and antiepileptic drugs. 5,16–19…”

Diastereoselective Construction of Fused Carbocyclic Pyrrolidines via a Copper-Catalyzed [3 + 2] Cycloaddition: Total Syntheses of Pancratinines B–C

“…Fused-[5, n ] carbocyclic pyrrolidines ( n = 5, 6, 7) are privileged structural motifs that are present in a broad spectrum of complex alkaloids, such as cephalocyclidin A ( 1 ), gracilamine ( 2 ), an amine-uptake inhibitor ( 3 ), and montanine-type alkaloids ( 4 – 6 ) (Figure ). , Biologically, these natural products not only display antimicrobial and anxiolytic activities but also show potential for the development of antidepressant and antiepileptic drugs. ,, As a result, these molecules have served as popular synthetic targets for decades . Overman accomplished the pioneering synthesis of pancracine ( 4 ) by the use of an aza-Cope rearrangement/Mannich cyclization strategy to build the fused-[5,6] carbocyclic pyrrolidines. , Other synthetic strategies − to access this skeleton include intramolecular [3 + 2] cycloaddition, chemoenzymatic approach/intramolecular radical cyclization, and intramolecular Michael addition .…”

Analysis of Bioactive Amaryllidaceae Alkaloid Profiles in Lycoris Species by GC-MS

“…Reported in L. radiata bulbs, lycosinine A and lycosinine B were classified as a new structural group (galanthindole-type), in addition to the unusual lycorine-type alkaloids, lycoranine A and lycoranine B, all of them completely characterized by spectroscopic methods [30,31]. Moreover, a new montanine-type alkaloid named squamigine, together with 2Rhydroxy-N,O-dimethylnorbelladine and 3-O-ethyltazettinol, were isolated from the bulbs of L. squamigera and L. aurea [32,33]. Recent studies with bulbs of L. radiata resulted in the isolation of 5,6-dehydrodihydrolycorine, 6β-acetoxycrinamine, 8-O-acetylhomolycorine-N-oxide, 5,6-dehydrolycorine, 3α,6β-diacetylbulbispermine, 3α-hydroxy-6β-acetylbulbispermine, 8,9-methylene-dioxylhomolycorine-N-oxide, 5,6-dihydro-5-methyl-2-hydroxyphenanthridine, and 2α-methoxy-6-O-ethyloduline [34][35][36].…”