Strychnos 1990 - 2004 - Crops for the Future

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Author Title Year Source title Reference Abstract Dutta, G. R. and A. K. Roy Mycobial deterioration in strychnine and brucine of Strychnos nux vomica seed 1992 Indian Phytopathology 45(1), 77 - Author Title Year Source title Reference Abstract Gasquet, M., J. Quetinleclercq, P. Timondavid, G. Balansard and L. Angenot Antiparasitic properties of diploceline, a quaternary alkaloid from Strychnos goss 1992 Planta Medica 58(3): 276-277 - Author Title Year Source title Reference Kopp, B., W. P. Bauer and A. Bernkopschnurch Analysis of some malaysian dart poisons 1992 Journal of Ethnopharmacology 36(1): 57-62 Abstract An investigation of nine Malaysian dart poisons has confirmed that their main active components are cardenolides from Antiaris toxicaria (Pers.) Lesch. and alkaloids probably from different forms of Strychnos ignatii P. Bergius. It is not possible to determine the ethnic origin of the poisons from the results of the analyses on their own. Two new cardiac glycosides have been isolated and their structures determined as 12-beta-hydroxycannogenin 3-beta-O-beta-D-deoxygulopyranoside and 3- b eta-O-alpha-L-rhamnopyranoside, respectively.
Author Title Year Source title Reference Kraus, G. A. and D. Bougie The preparation of a hexacyclic intermediate for the synthesis of Strychnos alkaloi 1992 Synlett (4): 279-280 Abstract The hexacyclic ring system, indolizino[7,8,8a,1-bcd]-pyrido[1,2,3-lm]carbazolone 10 has been synthesized in nine steps from the pyrido[3,2,1-jk]carbazolylethanal 3. Key steps include the selective reduction of aldehyde 3, the stereoselective introduction of an allyl unit via the Sakurai reaction and the ozonolysis/dehydrative cyclization to afford bridgehead enamine 10. Author Title Year Source title Reference Magnus, P., N. L. Sear, C. S. Kim and N. Vicker Studies on the synthesis of Strychnos alkaloids - a new entry into the azocino[4,3- 1992 Journal of Organic Chemistry 57(1): 70-78 Abstract Treatment of cyclohexanone-3-acetic acid with phenylhydrazine hydrochloride gave the tetrahydrocarbazole 7 (73%). The derived methyl ester 8 (99.6%) was oxidized to the 4-oxo compound 9 in 85% yield by treatment with DDQ/90% aqueous THF at 0-degrees-C. Treatment of 9 with NaH/DMF at 0-degrees-C followed by (p-methoxyphenyl)sulfonyl chloride gave 10 (81%). Hydrolysis of 10 using lithium hydroxide in aqueous THF gave the acid 11 (86%). The acid 11 was converted into the amide 12 by treatment with ethylchloroformate/NEt3/CH2Cl2 followed by aqueous NH4OH. The ketoamide 12 was exposed to NaBH4/MeOH/THF to give a single alcohol 13 (> 95%). Exposure of 13 to trifluoroacetic acid (cat)/CH2Cl2/0-20-degrees-C gave the azocino[4.3-b]indole core tetracyclic lactam 14 (90%). The amide 14 was reduced (BH3.THF) to give 21, which was directly acetylated (PhSCH2COCl) to give exocyclic amide 22. All attempts to close the C11-C12 bond only resulted in decomposition. Treatment of the acid 11 with EtO2CCl/Et3N followed by [2-(phenylthio)ethyl]amine gave the amide 24 (90%). Reduction of 24 using NaBH4 gave the alcohol 25 which upon exposure to CF3CO2H at room temperature cyclized to the tetracyclic amide 26 (96% overall). Oxidation of the sulfide 26 (m-CPBA) resulted in the diastereomeric sulfoxides 28. When the sulfoxides 28 were exposed to Pummerer conditions the only products that could be isolated were the (E)- and (Z)-vinyl sulfides 29 (72% and 25%, respectively). Similarly the dimethylthio acetal 33 was converted into the aldehyde 34 (100%). Treatment of 26 with POCl3/DMF gave 35 (90.8%) which was exposed to PhNHNH2/AcOH/AcONa to give the pyrazole 36 (85%). Attempts to close the E-ring via sulfoxides derived from either the pyrazole 36 or the oxazole 37 were unsuccessful. Treatment of the chloride 40 with KH/HN(SiMe3)2 in toluene resulted in a slow conversion into the 3-oxindole 4 4 .
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