Two styryl-pyrones, (+)-goniotriol (1) and (+)-8-acetylgoniotriol (2), which are cytotoxic to human turnout cells, were isolated from the ethanolic extracts of the stem bark of Goniothalamus giganteus Hook. F., Thomas...Two styryl-pyrones, (+)-goniotriol (1) and (+)-8-acetylgoniotriol (2), which are cytotoxic to human turnout cells, were isolated from the ethanolic extracts of the stem bark of Goniothalamus giganteus Hook. F., Thomas (Annonaceae), in addition (+)-goniotriol was also isolated from the leaves and twigs of Goniothalamus展开更多
The structures assigned to all four members,1-4,of the recently reported favolasin class of natural product have been prepared for the first time by chemical synthesis.Suzuki-Miyaura cross-coupling chemistry was used ...The structures assigned to all four members,1-4,of the recently reported favolasin class of natural product have been prepared for the first time by chemical synthesis.Suzuki-Miyaura cross-coupling chemistry was used to establish the associated biaryl substructures.The key step used in preparing the 1,5-benzodioxepin ring system associated with compounds 3 and 4 was the acid-catalyzed 7-exo-tet cyclization of an appropriately substituted 2-(oxiran-2-ylmethoxy)phenol while a base-promoted 6-exo-tet cyclization of the same substrate was used to construct the 2,3-dihydrobenzo[b][1,4]dioxine core of target 2.The spectral data derived from the four synthetically-produced favolasins matched those reported for the corresponding natural products.Preliminary biological screening of compounds 1-3 as well as a suite of fourteen precursors reveal that they display no notable anti-bacterial,anti-fungal or anti-tumor activities but congener K(4)is active,in the mM range,against Plasmodium falciparum.展开更多
Although the classical Ritter reaction has beenwidely applied to prepare sterically hindered amides since 1948,it has intrinsic problems,such as harsh reaction conditions,the multistep preparation of synthetic precurs...Although the classical Ritter reaction has beenwidely applied to prepare sterically hindered amides since 1948,it has intrinsic problems,such as harsh reaction conditions,the multistep preparation of synthetic precursors,and the use of solvent quantities of nitrile.In particular,only a few examples of the total synthesis of natural products using the Ritter reaction as a key step have been reported to date.展开更多
文摘Two styryl-pyrones, (+)-goniotriol (1) and (+)-8-acetylgoniotriol (2), which are cytotoxic to human turnout cells, were isolated from the ethanolic extracts of the stem bark of Goniothalamus giganteus Hook. F., Thomas (Annonaceae), in addition (+)-goniotriol was also isolated from the leaves and twigs of Goniothalamus
基金National Natural Science Foundation of China(Grant Nos.22250410258 and 22250410259)the Ministry of Science and Technology of the People's Republic of China for financial support.
文摘The structures assigned to all four members,1-4,of the recently reported favolasin class of natural product have been prepared for the first time by chemical synthesis.Suzuki-Miyaura cross-coupling chemistry was used to establish the associated biaryl substructures.The key step used in preparing the 1,5-benzodioxepin ring system associated with compounds 3 and 4 was the acid-catalyzed 7-exo-tet cyclization of an appropriately substituted 2-(oxiran-2-ylmethoxy)phenol while a base-promoted 6-exo-tet cyclization of the same substrate was used to construct the 2,3-dihydrobenzo[b][1,4]dioxine core of target 2.The spectral data derived from the four synthetically-produced favolasins matched those reported for the corresponding natural products.Preliminary biological screening of compounds 1-3 as well as a suite of fourteen precursors reveal that they display no notable anti-bacterial,anti-fungal or anti-tumor activities but congener K(4)is active,in the mM range,against Plasmodium falciparum.
基金the NSFC(grant nos.21971095,21772076,and 91956203.)for financially supporting this work.
文摘Although the classical Ritter reaction has beenwidely applied to prepare sterically hindered amides since 1948,it has intrinsic problems,such as harsh reaction conditions,the multistep preparation of synthetic precursors,and the use of solvent quantities of nitrile.In particular,only a few examples of the total synthesis of natural products using the Ritter reaction as a key step have been reported to date.
