Acetyl-lycopsamine

Pyrrohzidine alkaloids Pyrrohzidine Acetyl- lycopsamine Acetyl-intermedine Europine Homospermidine namine Indicine-A-oxide Meteloidine Retronecine... 

Boraginaceae Heliotropium indicum Cynoglossum spp. Symphytum officinale Indicine-A-oxide Indicine-A-oxide Acetyl-intermedine Acetyl-lycopsamine... 

Acetate derived alkaloids 12, 40 Acetyl-intennedine 7, 29, 34, 103 Acetyl-lycopsamine 7, 29, 34, 103 Acetylajmalan 175 Acetylcorydamine 22 Acetylerucifoline 17 Acetylfolifidine 24, 155 AcetyUcomavine 40, 53 Acetylleucovernine 52 Acobine 167... 

Russian comfrey (Symphytum x uplandicum Nyman) is widely recommended as a medicinal herb and an item of human diet. A previous investigation of this species led to the isolation of three alkaloids which were not fully characterized (cf. Vol. 7, p. 57). Culvenor and co-workers have separated eight pyrrolizidine alkaloids from the leaves of this perennial plant by counter-current distribution.21 The known alkaloids echimidine (51), symphytine (52), lycopsamine (53), and intermedine (54) were present. In addition, four new alkaloids, i.e. 7-acetyl-lycopsamine (55), 7-acetylintermedine (56), symlandine (57), and uplandicine (58), were characterized by spectroscopic methods, and by hydrolysis. The total alkaloidal extract caused chronic hepatotoxic effects in rats, and the authors... 

Echimidine Symphytine Lycopsamine Intermedine 7-Acetyl-lycopsamine 7 - Acetylintermedine Symlandine Uplandicine... 

Symphytum upiandicum Viridflorine, anadoline, heneicisane, tricosane, acetylintermedine, acetyl-lycopsamine, uplandicine... 

Column uBondapak NH (300x4 mm ID), mobile phase acetonitrile - water (92 8), flow rate gradient from 2 ml/min to 6 ml/min in 18 min, detection UV 200 nm. Peaks 1, allantoin 2, symphytine N-oxide 3, echimidine N-oxide 4, acetyl-lycopsamine N-oxide 5, lycopsamine N-oxide. (Reproduced with permission from ref. 23, by courtesy of Hippokrates Verlag)... 

Symphytum officinale Acetyl-intermedine Acetyl-lycopsamine... 

A number of recent studies of the pyrrolizidine alkaloids in various Symphytum species have succeeded in characterizing twelve mono- and di-ester alkaloids of retronecine and hellotridine (31, 95-104). We have examined twelve samples each of comfrey root and leaf sold as herbs in the U.S. As determined by nmr, the total alkaloid content of the leaf samples was < 0.005% the roots, on the other hand, contained from 0.14-0.42% (130). Examination of the root alkaloid mixture by capillary gc-ms after derivatization allowed identification of seven alkaloids (Figures 4 and 7) in all of the samples the first four peaks, lycopsamine, intermedlne, and their 7-acetyl derivatives, accounted for 75% or more of the total alkaloids. The same seven alkaloids have been found in Russian comfrey, a cross between Symphytum officinale and asperum, sometimes called Symphytum X uplandIcum (31,96,104). 

The first step is the formation of the 1,2-double bond followed by a stereoselective hydroxylation at the C-7 converting the necine base moiety into either retronecine (7R) and heliotridine (7S) (Fig. 8). These structures may be further modified by introduction of a second necic acid (i.e., esterification at C-7) and additional modification of the necic acid moieties (i. e., hydroxylations, acetylations, etc.). The majority of the PAs of the lycopsamine type are monoesters or diesters of retronecine and heliotridine [3]. 

Necines with only one OH group can only form PA monoesters like supinine. If there exists a second OH group both can be found mono as well as diesters as demonstrated for lycopsamine and its acetyl derivative or as in lasiocarpine. These examples demonstrate the variability of the stereochemistry (Fig. 13.2). 

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