Synthesis And Evaluation Antibacterial Activity Of Horsejradjsih Anajogs

Erucin(structure as shown in Scheme 1) was used as target compound, which was isolated and identified from the horseradish plant with lower content. Five series of 50 sulfur ethers isothiocyanates compounds were synthesized by changing the carbon chain length and different substituents in different sites. The biological activity of target compounds were tested against t bacterias, root-knot nematode and tumor cells.Scheme 1. erucin,The main contents of this thesis is researched as follows:1. Five series compounds were synthesized as follows:I)aliphatic isothiocyanates(12)II)unsaturated alkylisothiocyanates(6)III)aromatic isothiocyanates(26)IV)heterocyclic isothiocyanates(6)34 compounds have not been reported before among the synthesized。2. All the synthesized compounds were tested for their antimicrobial activity in vitro against Escherichia coli(DH5a), Staphylococcus aureus(ATCC25923), Staphylococcus albus(ATCC8799), Staphylococcus lutea(ACCC11001), Bacillus subtilis(ATCC6633), Bacillus cereus(ACCC11077) and Micrococcus tetragenus(ATCC35098) by turbidimetry.The preliminary bioassay results demonstrated that all of the tested compounds showed potent antimicrobial activity. Among these compounds, aromatic isothiocyanates with substituents 2-chlorobenzyl, 3-chlorobenzyl, 4-chlorobenzyl, 2-nitrobenzyl, 3-nitrobenzyl and 4-nitrobenzyl showed ecellent bacteria inhibition activity. All the MIC were 3.9μg/ml. Especially, the aromatic isothiocyanates with substituents 2-chlorobenzyl, 3-chlorobenzyl and 4-chlorobenzyl showed the best antibacterial activity(MIC 3.9μg/ml).3、Some synthesized compounds were subjected to an in vitro bioassay to kill root knot nematodes in vitro.The results indicated that compounds(3-Isothiocyanatopropyl)(ethyl)sulfane and(4-Isothiocyanatobutyl)(4-chlorobenzyl)sulfane showed the excellent growth inhibitory activity. But,(4-Isothiocyanatobutyl)(4-chlorobenzyl)sulfane had significant impact to the plant, withering most of the test plant.(3-Isothiocyanatopropyl)(ethyl)sulfane had a certain inhibition effect on the root knot nematodes, however, at the same time a certain instability has also been observed. The statistical results of inhibition rate showed that only two samples were over 90%, while other samples have no obvious inhibition effect.4、Some synthesized compounds were screened for their antitumor activities in vitro against breast cancer cells(MCF-7), cervical cancer cells(He La-229) and lung cancer cells(A549) by MTT assay.The preliminary bioassay results demonstrated that all of the tested compounds showed potent antitumor activities. Among these compounds, compound(4-Isothiocyanatobutyl)-(4-methylbenzyl)sulfane showed the best inhibitory effect against A549 with IC50 value of 0.44 μM. Compound(4-Isothiocyanatobutyl)(2-nitrobenzyl)sulfane displayed the best inhibitory effect against He La-229 with IC50 value of 0.32 μM.Structure-activity relationship shows that the length of carbon chain had little effect on inhibitory activity, while different substituents in different sites play the most important roles in determining the inhibitory activity;...