The structure of corgoine

153

Classical type phthalideisoquinolines are derived biogenetically from tetrahydroprotoberberines, and the former in turn lead to the secophthalideisoquinolines. The secophthalideisoquinolines may come in different forms including enol lactones, keto lactones, keto acids and diketo acids. The most logical biogenetic sequence appears to be classical type phthalideisoquinoline-^classical type phthalideisoquinoline .Y-metho salt->secophthalide enol lactone->secophthalide keto acid->secophthalide diketo acid. Thus if one were to start with (-)-bicuculline (1), the sequence would be 1-»( -)-bicuculline .Y-metho salt (la)->the Z enol lactone aobamidine (32)->the keto acid adlumidiceine (36)->the diketo acid bicucullinine (42) (100). A seco diketo acid may then undergo oxidative cleavage to yield the alkaloid fumariflorine (51), or one of its analogs. Alkaloids of the fumariflorine type may thus represent a final stage in the catabolism of the phthalideisoquinolines (101). It is worth noting here that the presence of classical type phthalideisoquinoline .Y-metho salts has been detected in Fumaria parviflora Lam. ( 70).An enol lactone such as aobamidine (32) may undergo photoisomerization to a mixture of Z and E isomers, and in fact the E analog of aobamidine is known as a natural product under the name adlumidiceine enol lactone (33).It has recently been shown that secophthalideisoquinoline enol lactones readily react with ammonia to form hydroxy lactams (e.g. fumschleicherine (50) ). A secophthalide hydroxy lactam can then undergo facile dehydration to an enelactam. Four enelactams have been apparently isolated from natural sources, namely, fumaramine (45), fumaridine (46), fumaramidine (48), and narceine imide (49). Since ammonium hydroxide is usually used in the course of the isolation, it seems likely that these four compounds, together with fumschleicherine (50), are artifacts of isolation. Until and unless the presence of secophthalideisoquinoline hydroxy lactams and enelactams is conclusively demonstrated in the plant extracts prior to treatment with ammonia, it can be concluded that they are artifacts and not true alkaloids (100). Nevertheless, and for the sake of completeness, the hydroxy lactam fumschleicherine (50) and the four enelactams 45, 46, 48, and 49, have been included in the present listing.The secophthalideisoquinoline keto acid nornarceine (40) may also be another artifact. It is the only known seco base which does not incorporate a complete ,. -dimethylaminoethyl side chain. It was isolated only once, and that time from opium, and it may very well have arisen from the known in vitro N-demethylation of narceine (39) in acid solution (100).All uv data are in nm with log < values between parentheses. Ir frequencies are in cm-1.The nmr chemical shift values quoted are from the first reference cited. However, in case we have found it necessary to modify the original assignment, this has been indicated by a double asterisk (**) as a superscript immediately after the reference. Whenever possible, we have ...

mentioning

confidence: 99%

The Phthalideisoquinoline Alkaloids

Bogáts¹,

Gula²,

Shamma³

1982

153

“…Typically, in TFA-J, C-5 appears at 25 ppm, C-6 at 56 ppm, C-8 at 59 ppm, 013 at 41 ppm and C-14 at 95 ppm, while the N-methyl carbon is near 46 ppm (131). (15) SOURCES: BERBERIDACEAE: Berberís (16) FUMARIACEAE: Corydalis (30,33,34,38,40,42,43,44,49,50,51,54,55,58,59,60,64,65,66,67,76,86,88,91,118,119,120,121) Dactylicapnos (61) Dicentra (38,52,56) Fumaria (1,29,47,57,68,69) P APA VE RACE AE: Argemone (2,25,26,114,115,116) Bocconia (103,122) Chelidonium (36,…”

mentioning

confidence: 99%

The Protopine Alkaloids

Guinaudeau¹,

Shamma²

1982

Sixteen naturally occurring protopines are known. The prototype for these bases is the widely distributed alkaloid protopine (1) wrhose numbering system is indicated in expression 1. The listing for the occurrence of this alkaloid as well as of allocryptopine (2) emphasizes the more recent findings. For an older listing of the occurrence of protopine (1) and allocryptopine (2) in plants, the reader should refer to H.-G. Boit's Ergebnisse der Alkaloid-Chemie Bis 1960, Akademie Verlag, Berlin (1961), pp. 349-351. Protopines are optically inactive, except in the case of C-13 substitution. The absolute configuration of the 13-methylated base corycavine (13) has been recently determined by correlation with a 13-methylated berbine of established absolute configuration (37).The alkaloid oreophiline is not a protopine base as long believed, but is instead a berbine (81).Among the Rutaceae, the genera Fagara and Zanthoxylum are generally considered to be identical. Neverthless, in the present listing, they have been kept apart to reflect the botanical names cited in the literature. It will be noted also that pseudoprotopine (9) and fagarine II (10) are the only two protopines substituted at C-10,11 rather than at the more common C-9,10 sites. Significantly, both of these alkaloids are found only among the Rutaceae.Uv wave lengths are in nm, and ir frequencies in cm-1. The solvent is always given whenever it has been indicated in the original literature. nmr chemical shifts are in CDCh solution unless indicated otherwise. In instances where chemical shift assignments were changed from those made in the original literature, this has been indicated with a double asterisk (**) as a superscript immediately after the appropriate reference. The H-l absorption in the protopines is found further downfield than that due to H-4 because of deshielding by the carbonyl function (5). The C-5 methylene protons are found near 52.6 4 5

“…Coreximine was first isolated from Dicentra eximia (Papaveraceae) (11) in 1938 and later from Corydalispseudoadunca (Papaveraceae) (12), Corydalis incisa (13), Erythrina orientalis (Leguminosae) (14), and Asimina triloba (Annonaceae) (15). To our knowledge, this is the first reported isolation of any protoberberine-type alkaloid from the genus P achy gone.…”

mentioning

confidence: 85%

Additional Alkaloids of Pachygone ovata

Slatkin¹,

Schiff²,

Dasgupta³

et al. 1984

Pachygone ovata (Menispermaceae), indigenous to the sandy seashores of southern India, is a woody climber whose fruits have been used as a rodenticide and fish poison. Chromatography of the extract of the roots resulted in the reisolation of the alkaloids liriodenine, coclaurine, trilobine (1), and magnoflorine and the isolation of stepholidine, coreximine, isoboldine, norjuziphine, and nortrilobine (2). Nortrilobine (2) is a new dibenzo-p-dioxin bisbenzylisoquinoline alkaloid whose structure was established by a consideration of spectral data and conversion to isotrilobine (3).