3-(Diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one(DEPBT) condensation developed by our group is an effective organophosphorus condensation reagent for the synthesis of protected peptides containing Tyr,Ser and Th...3-(Diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one(DEPBT) condensation developed by our group is an effective organophosphorus condensation reagent for the synthesis of protected peptides containing Tyr,Ser and Thr with unprotected hydroxyl group on their side chain.Thus,DEPBT is useful for the synthesis of peptide alcohols,which have attracted much attention not only as the ligands but also as the enzyme inhibitors.A side reaction of DEPBT was found in the synthesis of Boc-β-Ala-HisOMe with unprotected imidazolyl group.In this paper,the discovery of this side reaction and the confirmation of the structure of this side product were reported.In addition,the influence of different reaction conditions on the side reaction were studied.Imidazolyl group was a key factor to cause the side reaction,excess DEPBT and high reaction temperature promoted the side reaction.展开更多
Nimbya alternantherae is a leaf spot fungus isolated from Alternanthera philoxeroides.It could produce phytotoxin to Alternanthera philoxeroides in several kinds of liquid media,especially in modified Fries.The filtra...Nimbya alternantherae is a leaf spot fungus isolated from Alternanthera philoxeroides.It could produce phytotoxin to Alternanthera philoxeroides in several kinds of liquid media,especially in modified Fries.The filtrate of the pathogen was chromatographed on a DM-130 colophony column eluting with methanol,and evaporation of the solvent gave a brown mush.The crude product was then extracted with ethyl acetate.The toxin could be purified as white needles by re-crystallizing from benzene and acetone（volume ratio is 1∶1） and silica gel chromatograph.The results of elemental analysis,MS,IR and NMR indicate that molecular weight of the toxin was 240,formula was C11H12O6,and its chemical name was 2-acetyl-3,4-dihydroxy-5-methoxyphenyl-acetic acid（Vulculic acid）.展开更多
文摘3-(Diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one(DEPBT) condensation developed by our group is an effective organophosphorus condensation reagent for the synthesis of protected peptides containing Tyr,Ser and Thr with unprotected hydroxyl group on their side chain.Thus,DEPBT is useful for the synthesis of peptide alcohols,which have attracted much attention not only as the ligands but also as the enzyme inhibitors.A side reaction of DEPBT was found in the synthesis of Boc-β-Ala-HisOMe with unprotected imidazolyl group.In this paper,the discovery of this side reaction and the confirmation of the structure of this side product were reported.In addition,the influence of different reaction conditions on the side reaction were studied.Imidazolyl group was a key factor to cause the side reaction,excess DEPBT and high reaction temperature promoted the side reaction.
文摘Nimbya alternantherae is a leaf spot fungus isolated from Alternanthera philoxeroides.It could produce phytotoxin to Alternanthera philoxeroides in several kinds of liquid media,especially in modified Fries.The filtrate of the pathogen was chromatographed on a DM-130 colophony column eluting with methanol,and evaporation of the solvent gave a brown mush.The crude product was then extracted with ethyl acetate.The toxin could be purified as white needles by re-crystallizing from benzene and acetone（volume ratio is 1∶1） and silica gel chromatograph.The results of elemental analysis,MS,IR and NMR indicate that molecular weight of the toxin was 240,formula was C11H12O6,and its chemical name was 2-acetyl-3,4-dihydroxy-5-methoxyphenyl-acetic acid（Vulculic acid）.
