Living heritage bridge is a part of living heritage,which not only plays a traffic function in today's society,but also has historical,cultural and artistic value of heritage bridge,and has gradually become an imp...Living heritage bridge is a part of living heritage,which not only plays a traffic function in today's society,but also has historical,cultural and artistic value of heritage bridge,and has gradually become an important part of world heritage protection.In this paper,the living heritage bridges in Hangzhou are taken as samples,which are divided into four categories:“use value”,“landscape value”,“social and cultural value”and“historical value”.Different protection schemes are put forward for different types of bridges,aiming at classifying and protecting the living heritage bridges in Hangzhou and providing reference for the protection of living heritage bridges in China.展开更多
It has previously been shown that tryptophan, the biosynthesis precursor ofPeganum harmala alkaloids, and its derivatives have anti-TMV activity bothin vitro and in vivo. Further exploration of this led to the identif...It has previously been shown that tryptophan, the biosynthesis precursor ofPeganum harmala alkaloids, and its derivatives have anti-TMV activity bothin vitro and in vivo. Further exploration of this led to the identification of NK0238as a highly effective agent for the prevention and control of diseases caused byplant viruses, but the existing routes are unsuitable for its large-scale synthesis.This study optimized a route for two-step synthesis of this virucide candidate viareaction of L-tryptophan with triphosgene to produce L-tryptophan-N-carboxylicanhydride, which then reacts with n-octylamine to give NK0238 at up to 94%yield and nearly 97% HPLC purity. In addition, the route was used for thepreparation of NK0238 on a > 40 g scale permitting further assessment of itsantivirus activity in the greenhouse and field experiments, and toxicity tests.NK0238 exhibited useful antiviral activities against a variety of viruses both ingreenhouse and field experiments. The toxicity tests showed that NK0238 wasnot acutely toxic to birds, fish, honey bees and silkworms. The optimized routeprovides a solid foundation for its large-scale synthesis and subsequent efficacyand toxicity studies, its excellent activity and safety make NK0238 a promisingdrug candidate for further development.展开更多
基金Sponsored by Youth Fund for Humanities and Social Sciences Research of the Ministry of Education(20YJC850017)。
文摘Living heritage bridge is a part of living heritage,which not only plays a traffic function in today's society,but also has historical,cultural and artistic value of heritage bridge,and has gradually become an important part of world heritage protection.In this paper,the living heritage bridges in Hangzhou are taken as samples,which are divided into four categories:“use value”,“landscape value”,“social and cultural value”and“historical value”.Different protection schemes are put forward for different types of bridges,aiming at classifying and protecting the living heritage bridges in Hangzhou and providing reference for the protection of living heritage bridges in China.
基金The authors are grateful to the National Natural Science Foundation of China(21977056,21732002)the Fundamental Research Funds for the Central Universities,Nankai University(63201043)for generous financial support for their programs.
文摘It has previously been shown that tryptophan, the biosynthesis precursor ofPeganum harmala alkaloids, and its derivatives have anti-TMV activity bothin vitro and in vivo. Further exploration of this led to the identification of NK0238as a highly effective agent for the prevention and control of diseases caused byplant viruses, but the existing routes are unsuitable for its large-scale synthesis.This study optimized a route for two-step synthesis of this virucide candidate viareaction of L-tryptophan with triphosgene to produce L-tryptophan-N-carboxylicanhydride, which then reacts with n-octylamine to give NK0238 at up to 94%yield and nearly 97% HPLC purity. In addition, the route was used for thepreparation of NK0238 on a > 40 g scale permitting further assessment of itsantivirus activity in the greenhouse and field experiments, and toxicity tests.NK0238 exhibited useful antiviral activities against a variety of viruses both ingreenhouse and field experiments. The toxicity tests showed that NK0238 wasnot acutely toxic to birds, fish, honey bees and silkworms. The optimized routeprovides a solid foundation for its large-scale synthesis and subsequent efficacyand toxicity studies, its excellent activity and safety make NK0238 a promisingdrug candidate for further development.
