Schoberidine

This ring system is also contained in Serpenticine (294), Schoberidine (295), and Ophiorine (296) (Scheme 93). Picrasidine F (297) was identified as a hydrochloride in Picrasma quassioides and its structure was elucidated by an X-ray structure analysis (86CPB3228). Bleekerine (298) is an additional example. 3. 4. 5. 6 - T e t r a d e h y d r o 1 o n g i c a u d a t i n e (299)was identified in 1998 in Strychnos usambarensis collected from the Ivory Coast. The roots are the main ingredients of African arrow poisons. The absorption maxima were found at Amax = 204, 255, 308, and 367 nm in acidic as well as neutral solutions, thus suggesting a /1-carbolinium chromophore. A bathochromic shift was observed on deprotonation, due to the formation of a zwitterionic species (98P1263). 

A group of alkaloids having a novel structure has been isolated from Nitraria schoberi. The structure of nitrarine (22) was determined by X-ray crystal structure analysis of its dihydrochloride.Nitramidine (23) is a didehydro-derivative, and can be obtained from nitrarine by mercuric acetate oxidation, and schoberidine (24) is... 

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