Hordenin aus Pancratium maritimum L.

Construction of the 5,10b‐Phenanthridine Skeleton Using [3+2]‐Cycloaddition of a Non‐Stabilized Azomethine Ylide: Total Synthesis of (±)‐Maritidine and (±)‐Crinine Alkaloids

“…The family has produced over 500 structurally diverse alkaloids with a wide range of interesting physiological effects, including antitumor, antiviral, acetylcholinesterase inhibitory, immunostimulatory and antimalarial activities. [5,6] Maritidine (1a) and its structural analogues, isolated from Pancratium maritimum, Pancratium tortuosum, and Zephyranthes genera, [7][8][9][10][11] is the first alkaloid with the 5,10b-ethanophenanthridine nucleus containing dimethoxy rather than methylenedioxy substituents at the C-8 and C-9 positions of the crinine skeleton ( Figure 1). These alkaloids possess fused tetracyclic skeletons displaying adjacent quaternary and tertiary carbon stereocenters with fused pyrrolidine ring systems for which stereochemical incorporation is the critical element in their synthesis.…”

Alkaloidal constituents of Hymenocallis rotata Herb. (Amaryllidaceae).

“…(Amaryllidaceae) together with eleven known bases, vittatine (6), alkaloid-13 (7), 3-epimacronine (8), ismine (9), pretazettine (10), lycoramine (11), lycorine (12), tazettine (13), haemanthamine (14), galanthamine (15), and N-demethylgalanthamine (16). Keywords (6), alkaloid-13 (7 ) , 3-epimacronine (8), ismine (9), pretazettine (10), lycoramine (11), lycorine (12), tazettine (13), haemanthamine (14), galanthamine (15), and N-demethylgalanthamine (16) All melting points are given as uncorrected values. The spectrophotometers used were a Hitachi IR-215 for IR spectra, a JEOL JMS-D 300 for MS, a Shimadzu UV-200 for UV spectra, a Union PM-201 for optical rotation, a JASCO ORD/UV-5 spectrometer for ORD, and a JEOL JNM-PS-100 or a Hitachi R-22 for 1H-NMR spectra with tetramethylsilane (TMS) as an internal standard.…”

Hemi acetal aldehyde ammonia-interconversions and structures in Amaryllidaceae alkaloids

“…The incorporation of The synthesis of montanine had Indicated its relationship to the 11-hydroxylated crinane nucleus. Since 11-hydroxyvittatine (17) was known to be a minor alkaloid in Rhodophiala bifida (18), Peinstein (19) investigated the biosynthesis of haemanthamine (15) and montanine (18) by feeding vittatine (19). The conversion of vittatine into montanine and haemanthamine from tracer studies supported the biosynthesis of montanine via 11-hydroxyvittatine ( Figure 7).…”