Two highly sensitive methods for the determination of genotoxic alkyl methane sulfonates (AMSs) and alkyl paratoluene sulfonates (APTSs) in lamivudine using hyphenated techniques have been presented. AMSs were determi...Two highly sensitive methods for the determination of genotoxic alkyl methane sulfonates (AMSs) and alkyl paratoluene sulfonates (APTSs) in lamivudine using hyphenated techniques have been presented. AMSs were determined by GC-MS method using GSBPINOWAX (30 m 0.25 mm 0.25 mm) column. Temperature program was set by maintaining at 100 1C initially for 3 min, then rised to 220 1C at the rate of 15 1C/min and maintained at 220 1C for 16 min. N,N-dimethyl formamide was used as diluent. APTSs were determined by LC-MS using Zorbax, Rx C8, 250 mm 4.6 mm, 5 mm column as stationary phase. 0.01 M ammonium acetate is used as buffer. The mixture of buffer and methanol in 75:25 (v/v) ratio was used as mobile phase A and mixture of buffer and methanol in 5:95 (v/v) ratio was used as mobile phase B. The gradient program (T/%B) was set as 0/28, 16/50, 17/100, 23/100, 27/28 and 40/28. Both the methods were validated as per International Conference on Harmonization guidelines. Limit of quantitation was found 1.5 mg/mL for AMSs and was in the range of 1.0-1.5 mg/mL for APTSs.展开更多
The degradation mechanism of photocrosslinking products formed by cyclized polyisoprene-diazide system under the influence of the different alkyl benzene sulfonic acids was studied. The effects of alkyl chain length a...The degradation mechanism of photocrosslinking products formed by cyclized polyisoprene-diazide system under the influence of the different alkyl benzene sulfonic acids was studied. The effects of alkyl chain length and the concentration of alkyl benzene sulfonic acids on the rate of degradation reaction were discussed. It was found that in the initial stage of degradation, the cyclicity ratio and the average fused ring number did not change considerably, but the percentage of uncyclized parts content varied significantly. The suitable mechanism was supposed.展开更多
A multicomponent reductive cross-coupling of unactivated alkyl halides and alkyl tosylates connected via sodium metabisulfite was established for the general construction of alkyl-alkyl sulfones.Neither a metal cataly...A multicomponent reductive cross-coupling of unactivated alkyl halides and alkyl tosylates connected via sodium metabisulfite was established for the general construction of alkyl-alkyl sulfones.Neither a metal catalyst nor a metal reductant is required in this“green”reductive cross-coupling.Inorganic sodium metabisulfite served as both the sulfur dioxide source and the robust connector.展开更多
Synthetic studies towards the C(3)-C(13) and C(14)-C(24) segments (3,4) of the potent antiviral and antitumor compound macrolactin A (1) are presented. Compound 3 was constructed via a convergent and facile approach, ...Synthetic studies towards the C(3)-C(13) and C(14)-C(24) segments (3,4) of the potent antiviral and antitumor compound macrolactin A (1) are presented. Compound 3 was constructed via a convergent and facile approach, exploiting Wittig olefination to generate the sensitive E, Z-diene moiety. Compound 4 was synthesized from the chiral-pool derived sulfone 39a via an α-alkylation-desulfonation reaction sequence. Cu(II)-catalyzed coupling of a Grignard reagent with an allylic bromide and Julia olefination were also investigated for the preparation of compound 4.展开更多
文摘Two highly sensitive methods for the determination of genotoxic alkyl methane sulfonates (AMSs) and alkyl paratoluene sulfonates (APTSs) in lamivudine using hyphenated techniques have been presented. AMSs were determined by GC-MS method using GSBPINOWAX (30 m 0.25 mm 0.25 mm) column. Temperature program was set by maintaining at 100 1C initially for 3 min, then rised to 220 1C at the rate of 15 1C/min and maintained at 220 1C for 16 min. N,N-dimethyl formamide was used as diluent. APTSs were determined by LC-MS using Zorbax, Rx C8, 250 mm 4.6 mm, 5 mm column as stationary phase. 0.01 M ammonium acetate is used as buffer. The mixture of buffer and methanol in 75:25 (v/v) ratio was used as mobile phase A and mixture of buffer and methanol in 5:95 (v/v) ratio was used as mobile phase B. The gradient program (T/%B) was set as 0/28, 16/50, 17/100, 23/100, 27/28 and 40/28. Both the methods were validated as per International Conference on Harmonization guidelines. Limit of quantitation was found 1.5 mg/mL for AMSs and was in the range of 1.0-1.5 mg/mL for APTSs.
文摘The degradation mechanism of photocrosslinking products formed by cyclized polyisoprene-diazide system under the influence of the different alkyl benzene sulfonic acids was studied. The effects of alkyl chain length and the concentration of alkyl benzene sulfonic acids on the rate of degradation reaction were discussed. It was found that in the initial stage of degradation, the cyclicity ratio and the average fused ring number did not change considerably, but the percentage of uncyclized parts content varied significantly. The suitable mechanism was supposed.
基金support provided by NSFC(nos.22071057,21971065,and 21871089)STCSM(nos.20XD1421500,20JC1416800,and 18JC1415600)+1 种基金Innovative Research Team of High-Level Local Universities in Shanghai(no.SSMU-ZLCX20180501)Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning.
文摘A multicomponent reductive cross-coupling of unactivated alkyl halides and alkyl tosylates connected via sodium metabisulfite was established for the general construction of alkyl-alkyl sulfones.Neither a metal catalyst nor a metal reductant is required in this“green”reductive cross-coupling.Inorganic sodium metabisulfite served as both the sulfur dioxide source and the robust connector.
基金Project supported by the National Natural Science Foundation of Chinathe State Key Laboratory of Bio-organicNatural Products Chemistry
文摘Synthetic studies towards the C(3)-C(13) and C(14)-C(24) segments (3,4) of the potent antiviral and antitumor compound macrolactin A (1) are presented. Compound 3 was constructed via a convergent and facile approach, exploiting Wittig olefination to generate the sensitive E, Z-diene moiety. Compound 4 was synthesized from the chiral-pool derived sulfone 39a via an α-alkylation-desulfonation reaction sequence. Cu(II)-catalyzed coupling of a Grignard reagent with an allylic bromide and Julia olefination were also investigated for the preparation of compound 4.
