Synthesis of 2-amino-6-oxocyclohexenylsulfonamides and their activity against Botrytis cinerea.

BACKGROUND: With the objective of exploring the fungicidal activity of 2-oxocyclohexylsulfonamides (2), a series of novel 2-amino-6-oxocyclohexenylsulfonamides (6 to 23) were synthesised, and their fungicidal activities against Botrytis cinerea Pers. were evaluated in vitro and in vivo. RESULTS: The compounds were characterised by IR, 1H NMR and elemental analysis. Bioassay results of mycelial growth showed that compounds 6 to 23 had a moderate antifungal activity against B. cinerea. N-(2-methylphenyl)-2-(2-methylphenylamino)-4,4-dimethyl-6-oxocyclohexenylsulfonamide (13) and N-(2-chlorophenyl)-2-(2-chlorophenylamino)-6-oxocyclohexenylsulfonamide (21) showed best antifungal activities, with EC50 values of 8.05 and 10.56 µg mL(-1) respectively. Commercial fungicide procymidone provided an EC50 value of 0.63 µg mL(-1) . The conidial germination assay showed that most of compounds 6 to 23 possessed excellent inhibition of spore germination and germ-tube elongation of conidia of B. cinerea. For in vivo control of B. cinerea colonising cucumber leaves, the compound N-cyclohexyl-2-(cyclohexylamino)-4,4-dimethyl-6-oxocyclohexenylsulfonamide (19) showed a better control effect than the commercial fungicide procymidone. CONCLUSION: The present work demonstrated that 2-amino-6-oxocyclohexenylsulfonamides can be used as possible new lead compounds for further developing novel fungicides against B. cinerea.

A new chromone derivative from Berchemia lineata.

To study the chemical constituents from the root of Berchemia lineata (L.) DC., nine compounds were isolated from the EtOAc extract by using silica gel, RP-C18 silica gel column chromatography and preparative HPLC. Based on the spectroscopic analysis, their structures were identified as 5-hydroxy-7-(2'-hydroxypropyl)-2-methyl-chromone (1), (-)-(1'R, 2'S)-erythro-5-hydroxy-7-(1', 2'-dihydroxypropyl)-2-methyl-chromone (2), naringenin (3), eriodictyol (4), (+)-aromadendrin (5), (+)-taxifolin (6), (+)-catechin (7), (+)-epigallocatechin (8) and quercetin (9). Among them, compound 2 is a new chromone derivative. Compound 1 is a known chromone derivative and isolated from this genus for the first time. Compounds 3-9 are known flavonoids and isolated from this plant for the first time.