Shinjulactone

Only nine quassinoids possessing the C19 basic skeleton were isolated until 1985 samaderins B (11), C (12), D (13), an 3,4-dihydrosamaderin B (14) from the stem and leaves of Samadera indica, cedronin (15) and cedronolin (16) isolated from the fruits of Simaba cedron, eurycomalactone (17) and 5,6-dehydroeurycomalactone (18) from Eurycoma longifolia Jack, and shinjulactone B (19) isolated from Ailanthus altissima Swingle [1],... 

The eight new quassinoids C19 type shinjulactone B (19) with a presence of a l,2-seco-l-nor-(5->10)-a >eo-picrasan-2,5-olide skeleton have been isolated from Simaroubaceae species. 

Likewise, quassinoid shinjulactone A (232) had a good EC50 value of ca. 5 pM but was cytotoxic at this concentration. Shinjulactone B (19) and ailantinol A (43) showed no cytotoxicity and were marginally active with EC50 values of 28 and 30 pM, respectively. 

The most promising compound was shinjulactone C (233) this compound had a TI of >25 and showed significant anti-HIV activity with an EC50 value of 10.6 pM. Further studies on analogs and related compounds to increase the pharmacological profiles of (233) are in progress [103],... 

Examination of the bitter principles of Simaroubaceous plants, in particular Ailanthus altissima Swingle led to the discovery in 1983 of an intriguing quassinoid, Shinjulactone C (341), possessing a modified picrasane skeleton [139]. 

The total synthesis of the quassinoid shinjulactone C (341) is detailed above, which proceeds via pentacyclic lactone [140] and... 

Eighteen quassinoid glycosides and nine known quassinoids were tested for inhibitoiy activity against HIV replication in H9 lymphocytic cells, as shown in Table 14. Of the compoimds tested, shinjulactone-C (123) demonstrated the highest anti-HIV activity (EC5o=10.6 p,M) in the absence of cytotoxicity with a therapeutic index of >25 [37]. 

In vitro evaluation of anti-tuberculosis activity was conducted for fifty-six quassinoids isolated in our laboratory from the Simaroubaceous plants A. altissima (10 compounds), B. antidysenterica (16 compounds), P. ailanthoides (14 compounds), and B.javanica (16 compounds), as shown in Table 15. Of the compounds tested, shinjulactone-K (119)... 

Rabdokaurin D, R-lOOOl Shinjulactone L, in C-10066 4,6,8,9-Tetrahydroxy-7-daucanone 6-(4-Hydroxybenzoyl), in T-10041... 

Ailanthone (19) has been converted into shinjulactone C (18a) in the following manner (35) The monosilyl derivative (20) was acetylated to give the monosilyl diacetate (21) which isomerised to a monosilyl enolacetate (22) on heating in pyridine. Desilylation of (22) afforded (23) which was oxidised to the a-diketone (24). The latter was transformed by refluxing in pyridine, into di-O-acetylshinjulactone C (25) and then hydrolysed to shinjulactone C (18a). 

Dihydroailanthone (26) has been found as a minor quassinoid in the bark of Ailanthus glandulosa (=A. altissima) (8). The same structure was assigned to shinjulactone A isolated from the Japanese A, altissima (65). 

Furuno, T., H. Naora, T. Murae, H. Hirota, T. Tsuyuki, T. Takahashi, A. Itai, Y. IiTAKA, and K. Matsushita Structure of Shinjulactone B, A New Bitter Principle from Ailanthus altissima. Chemistry Lett. 1797 (1981). 

ISHIBASHI, M., T. Tsuyuki, and T. Takahashi Conversion of Ailanthone into Shinjulactone C through an Ionic (4-1-2) Cycloaddition Reaction. Tetrahedron Lett. 4843 (1983). 

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