Securinega virosa

East Africa. Dried leaves of Nicotiana tabacum and Securinega virosa are mixed in a paste and used externally to destroy worms... 

Securinega virosa (Roxb.) Pax Hoffmann Bai Yin Shu (leaf, root) Virosine, norsecurinine, dihydrosecurinine, virosecurinin, viroallosecurinine, norsecurinine, fluggein.56 Leaves used as a maturative, a detergent, it has antibiotic activity. Root to treat teeth and gum disease. 

Dictamnus albus L. subsp. dasycarpus (Turcz.) Winter, Dictamnus dasycarpus, Fraxinella dictamnus Moench Securinega virosa (Roxb.) Pax Hoffmann Solanum lyratum Thunb., S. melongena L. 

Saito and co-workers isolated an alkaloid from the roots of Securinega virosa which they originally called virosine 53). It was later renamed dihydronorsecurinine to avoid confusion (see footnote e, in Table I) 61). Dihydronorsecurinine was shown to be identical with the sodium borohydride reduction product of norsecurinine (Section III, A). Since the absolute configuration of the latter has been established, the structure and absolute stereochemistry of dihydronorsecurinine is fully represented by formula 165a (Scheme 27) 62). 

Norsecurinine (27) was first isolated in 1963 from a Securinega virosa BaiU. (= Flueggea virosa (Roxb. ex WiUd.) Royle) species collected in... 

Nigeria.Its structure was deduced solely on the basis of spectral evidence and was elucidated as an analog of securinine with a pyrrolidine A ring instead of a piperidine. Therefore, the term norsecurinine was introduced. Later, the same compound was isolated from a Securinega virosa species native to Formosa. This compound corresponded to (—)-norsecurinine. However, as in the case of securinine, the enantiomeric (+)-form was found too and could be isolated from Phyllanthus niruri and also Phyl-lanthus discoideus Finally, the structure of norsecurinine was fuUy assigned by spectroscopic methods and further secured by the X-ray analysis of its hydrochloride salt crystals.However, the tendency of the free base to polymerize was early observed.These polymers are now well-known and characterized as norsecurinine-based oligomers. 

Compound 28 was isolated by Saito and coworkers from the roots of Securinega virosa The name virosine was first proposed and later replaced by the more appropriate 14,15-dihydronorsecurinine. This compound could easily be prepared from norsecurinine (27) in a one-step reduction. Its structure and absolute configuration was therefore confirmed. 

Virosecurinine and viroallosecurinine obtained from the leaves of Securinega virosa were found to be the enantiomers of securine and allosecurinine, respectively. Securinega alkaloids obtained from the roots of Phyllanthus discoides are securinine, allosecurinine, and phyllantine. These alkaloids are biogenetically produced from lysine and a C6-C3 unit derived from tyrosine (Fig. 5.2.6). 

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