Matrine derivatives

Okuda has suggested that some degradation products of matrine (gross structure 160) are derivatives of l,2,3,4-tetrahydro-5-methyl-8-propyl- 1,6-naphthyridine.242... 

Matrine Group.—A new member of this group, sophorbenzamine, has been isolated from Goebelia pachycarpa and shown to be the benzyl derivative (17) on the basis of spectroscopic studies.7 Sophora moorcroftiana contains the known alkaloids a-matrine, oxymatrine, and sophocarpine.13... 

The structures of sophocarpine (CXLIX) and sophoramine (CL) follow from their syntheses from matrine (113), which was first converted to a dichloro derivative by the action of thionyl chloride and sulfur dichloride. One of the halogens was removed by catalytic reduction. The second halogen was then eliminated as hydrogen chloride to... 

The hydrogenated pyndo[3,2-//]-1,6-naphthyridin-6-one 305 was synthesized from l,6-naphthyridin-5(6i/)-one 306 in six steps (1986CPB2018). The key stage of the scheme consists in the Heck reaction of 8-iodo-l,6-naphthyridine 307 with ethyl acrylate. Reduction of the double bond in the resulting derivative 308 and cyclization of 309 under the action of sodium methoxide complete the synthesis. The structural fragment in 305 is present in the alkaloid matrine (sophocarpidine) found in dried roots of several plants belonging to the genus Sophora. 

Acyl-substituted octa(deca)hydro-l,8-naphthyridines were synthesized as derivatives of matrine- and allomatryne-type alkaloids, and the structure-activity relations were examined by the acotic acid-induced abdominal contraction test (2003MI10, 2003MI11). 

Quinolizidine derivatives formed by hydrogenation of the dicyano ketone 4 to catalyst loading affects the stereochemistry of cyclization, probably by isomerization. 

Quinolizidine Alkaloids.—Previous results demonstrate that the quinolizidine skeleton in its entirety derives from lysine.Further research has indicated that lysine is a precursor of all the alkaloids of this type in five species of Leguminosae. From the levels of activity observed in the individual alkaloids it was concluded that saturated alkaloids are precursors for those with a pyridone ring. This was supported by the observation that label from radioactive sparteine (24) and lupanine (25) appeared in more highly oxidized alkaloids. (This compares with a similar situation in the biosynthesis of matrine-type alkaloids. ) A metabolic grid for the biosynthesis of quinolizidine alkaloids from lysine was proposed, based on these results,... 

Matrine was obtained as the main alkaloidal component of this plant. In addition, oxymatrine, anagyrine, methylcytisine, and sophocarpine were also isolated, together with other alkaloids. The name matrine is derived from one of the Japanese plant names of S. Jlauescens, where this plant is known as Matori-gusa in some areas [1,2]. 

Regarding the biosynthesis of matrine, from an incorporation experiment using [l,5- " C2]-cadaverine, it was concluded that three cadaverine moieties were introduced into a molecule of matrine [6]. Because it was known that cadaverine was derived from lysine, it was implied that the nitrogen atoms of the quinolizidine units of matrine were derived from lysine. 

Thus, the tetrahydroanabasine derived from two molecules of A -piperideine was cleaved and was closed to form a ring resulting in a lupi-nane skeleton. To this lupinane moiety was attached another A -piperideine moiety to form matrine. Actually, when [6- CJ-A -piperideine was administered, an unequal result was obtained, namely that (black circle) was introduced to the extent of 90% at the C-3 and C-5 positions of matrine, whereas only 10% of was introduced at the C-10 position. This observation suggests that the pool size of tetrahydroanabasine is larger than that of A -piper ideine. 

Sparteine is considered to be construaed from three molecules of cadav-erine derived from lysine decarboxylation, as in the case of matrine [1]. Thus, when a A -piperideine moiety is attached to the lupinane skeleton, if route (a) is taken a matrine type alkaloid is formed, and a sparteine type alkaloid is formed by taking route (b). 

An alternative tetracyclic skeleton to the one found in sparteine 6.53) is seen in matrine 6.58) and a similar derivation from three molecules of lysine via cadaverine has been demonstrated ( = labels, as in Scheme 6.12) [36, 37]. 

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