ABSTRACT
A new neolignan, (-)-(7R,8S,7'E)-3',4-dihydroxy-3-methoxy-8,4'-oxyneoligna-7'-ene-7,9,9'-triol(1), and seven known compounds, 9-(tetrahydropyran-2-yl)-nona-trans,trans-2,8-diene-4,6-diyn-1-ol (2), 9-(tetrahydropyran-2-yl)-trans-non-8-ene-4,6-diyn-1-ol (3), lobetyol (4), lobetyolin (5),dehydrodieoniferyl alcohol (6), 5-hydroxymethylfurfural (7), and 4, 4'-dihydroxy-3, 3'-dimethoxy-trans-stilbene (8), were isolated from the H2O extract of Codonopsis pilosula. The structures of 1-8 were elucidated by spectroscopic methods including NMR, HR-ESI-MS, and CD. In addition, compounds 2 and 3 were isolated from the genus Codonopsis for the first time.
ABSTRACT
Objective To measure the transcription level of thermostable direct hemolysin gene (TDH)in 24 strains of Vibrio parahaemolyticus.Methods Total RNA was extracted from strains of Vibrio parahaemolyticus which were isolated from patients,seafood and environment.The RNA was proved TDH positive with routine PCR method;then the real -time fluorescent quantitative PCR was carried out to obtain the cycle of threshold (Ct)of THD and internal standard of 16s rRNA.Transcription level of THD compared with 16s rRNA was designated as ΔCt which was calculated as Ct value of THD minus Ct value of 16s rRNA.Results Ct values of THD,16s rRNA and the difference between them of the 24 strains was 18.04 ~25.95,8.30 ~10.93 and 8.28 ~15.34 respectively.The difference between the maximum and the minimum of ΔCt was 7.06;the highest transcription level was 133 (ΔΔCt =27.06 )times of the lowest one.Conclusion A great difference of transcription level of THD in Vibrio parahaemolyticus has been proved and further study is needed to clarify the possible molecular mechanisms and relationship between the transcription level of THD and pathogenic mechanism.