This review covers the literature on simple indole alkaloids and those with a nonrearranged monoterpenoid unit from the beginning up to the end of 2004. Newly isolated alkaloids, structure determinations, total synthesis and biological activities are included.
This review covers the literature on simple indole alkaloids and those with a nonrearranged monoterpenoid unit. Newly isolated alkaloids, structure determinations, total syntheses and biological activities are included.
-Teriparatide, a therapeutic agent for osteoporosis, has been reported to increase the incidences of bone neoplasms such as osteosarcoma when administered subcutaneously to Fischer 344 (F344) rats for a long term, but its non-carcinogenic dose level following 2-year daily administration has not been established. Here we report detailed studies on the carcinogenicity of teriparatide following longterm administration. When teriparatide was administered subcutaneously to male and female SpragueDawley (SD) rats daily for 2 years, the incidence of osteosarcoma was increased at 13.6 μg/kg/day. The non-carcinogenic dose level was 4.5 μg/kg/day for both males and females. The development of osteosarcoma in SD rats depends on the dose level of, and treatment duration with, teriparatide. Responses of the bones to teriparatide were similar between F344 and SD rats in many aspects. These results suggested that the carcinogenic potential of teriparatide in SD rats is essentially the same as in F344 rats.
We have accomplished the first total synthesis of (+/-)-hinckdentine A (1). The key steps are m-CPBA oxidation of 2-arylindole followed by acid-mediated Mannich-type C-C bond formation of 2-hydroxyindolin-3-one, seven-membered ring closure, and regioselective tribromination.
The asymmetric total synthesis of both enantiomers of the potent antitumor antibiotic fredericamycin A (1) is detailed based on the protocol for the construction of its peri-hydroxy polyaromatic skeleton bearing the chirality at the spiro carbon via a strong base-induced cycloaddition of suitably substituted homophthalic anhydrides (AB-ring unit) with an optically active CDEF-ring unit. Particular attention has been given to the novel synthesis of the optically active spiro carbon center by a stereospecific rearrangement of optically active benzofuzed-trans-epoxy acylates leading to spirocyclopentane-1,1'-indane systems. This method is quite useful for the construction of an optically active spiro compound and was applied to the synthesis of the optically pure CDEF-ring unit of 1. Cycloaddition of the optically pure CDEF-ring unit to AB-ring units prepared via benzyne afforded two natural and unnatural-type hexacyclic compounds, which were converted to natural and unnatural enantiomers of synthetic 1, and the absolute configuration of natural 1 was determined as S.
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