摘要:
A method of preparing (.+-.)-calanolide A, 1, a potent HIV reverse transcriptase inhibitor, from chromene 4 is provided. Useful intermediates for preparing (.+-.)-calanolide A and its derivatives are also provided. According to the disclosed method, chromene 4 intermediate was reacted with acetaldehyde diethyl acetal or paraldehyde in the presence of an acid catalyst with heating, or a two-step reaction including an aldol reaction with acetaldehyde and cyclization either under acidic conditions or neutral Mitsunobu conditions, to produce chromanone 7. Reduction of chromanone 7 with sodium borohydride, in the presence of cerium trichloride, produced (.+-.)-calanolide A. A method for resolving (.+-.)-calanolide A into its optically active forms by a chiral HPLC system or by enzymatic acylation and hydrolysis is also disclosed. Finally, a method for treating or preventing a viral infections using (.+-.)-calanolide or (-)-calanolide is provided.
摘要:
A method of preparing (+)-calanolide A, 1, a potent HIV reverse transcriptase inhibitor, from chromene 4 is provided. According to the disclosed method, chromene 4 intermediate was subjected to a chlorotitanium-mediated aldol reaction with acetaldehyde to selectively produce (.+-.)-8a. Separation and enzyme-mediated resolution of (.+-.)-8a produced (+)-8a. Cyclization of (+)-8a under neutral Mitsunobu conditions followed by Luche reduction of (+)-7 produced (+)-calanolide A in high yield and enantiomeric purity. The method of the invention has been extended to produce potent antiviral calanolide A analogues.
摘要:
A method of preparing (.+-.)-calanolide A, 1, a potent HIV reverse transcriptase inhibitor, from chromene 4 is provided. Useful intermediates for preparing (.+-.)-calanolide A and its derivatives are also provided. According to the disclosed method, chromene 4 intermediate was reacted with acetaldehyde diethyl acetal or paraldehyde in the presence of an acid catalyst with heating, or a two-step reaction including an aldol reaction with acetaldehyde and cyclization either under acidic conditions or neutral Mitsunobu conditions, to produce chromanone 7. Reduction of chromanone 7 with sodium borohydride, in the presence of cerium trichloride, produced (.+-.)-calanolide A. A method for resolving (.+-.)-calanolide A into its optically active forms by a chiral HPLC system or by enzymatic acylation and hydrolysis is also disclosed. Finally, a method for treating or preventing viral infections using (.+-.)-calanolide A or (-)-calanolide A is provided.
摘要:
A method of preparing (+)-calanolide A, 1, a potent HIV reverse transcriptase inhibitor, from chromene 4 is provided. According to the disclosed method, chromene 4 intermediate was subjected to a chlorotitanium-mediated aldol reaction with acetaldehyde to selectively produce (.+-.)-8a. Separation and enzyme-mediated resolution of (.+-.)-8a produced (+)-8a. Cyclization of (+)-8a under neutral Mitsunobu conditions followed by Luche reduction of (.+-.)-7 produced (+)-calanolide A in high yield and enantiomeric purity. The method of the invention has been extended to produce potent antiviral calanolide A analogues.
摘要:
A connector comprising a first outer housing defining at least one cavity, the cavity being cylindrical, a first insert disposed in the cavity, the first insert comprising at least a first housing, the housing being cylindrical, a first ferrule in the first housing, the first ferrule configured with arcuate sides to be received in the cavity, the first ferule comprising an end face, at least one alignment hole for receiving an alignment pin defined in the end face, and at least one fiber-receiving channel for receiving an optical fiber, an optical fiber disposed in the fiber-receiving channel of the first ferrule.
摘要:
An apparatus and method for providing social network content in an online game is disclosed herein. Content is obtained from a social network site and is displayed within the game. The game also provides a mechanism for the user of the game to generate content to the posted within the social network from within the game. Such generated content is automatically posted in the social network for a recipient specified by the user.
摘要:
A method, system and voice browser execute voice applications to perform a voice-based function. A document is retrieved and parsed to create a parse tree. Script code is created from the parse tree, thereby consuming part of the parse tree to create a reduced parse tree. The reduced parse tree is stored in a cache for subsequent execution to perform the voice-based function.
摘要:
The present invention describes a system and method for surveillance cameras that maintain proper mapping of a mapped region of interest with an imaged region of interest based on feedback received regarding the current orientation of a surveillance camera. The system or method first determines the location of the imaged region of interest within the surveillance camera's imaged current field of view based on mechanical or imaged feedback, or a combination of both. The system or method then remaps the mapped region of interest within the surveillance camera's imaged current field of view such that the mapped region of interest is coextensive with the imaged region of interest.
摘要:
A connector comprising a first outer housing defining at least one cavity, the cavity being cylindrical, a first insert disposed in the cavity, the first insert comprising at least a first housing, the housing being cylindrical, a first ferrule in the first housing, the first ferrule configured with arcuate sides to be received in the cavity, the first ferule comprising an end face, at least one alignment hole for receiving an alignment pin defined in the end face, and at least one fiber-receiving channel for receiving an optical fiber, an optical fiber disposed in the fiber-receiving channel of the first ferrule.
摘要:
The present invention provides vaccine and pharmaceutical compositions for treating or preventing bacterial inventions. The vaccine compositions of the invention include a carbapenemase such as a serine carbapenemase, a metallo-β-lactamase or an immunogenic fragment thereof. The pharmaceutical compositions include an anti-carbapenemase antibody or fragment thereof. Also provided are methods for treating and preventing a bacterial infection using the vaccine and pharmaceutical compositions of the invention. The invention further provides antibody conjugates that include an antibody or fragment thereof conjugated to a siderophore or an analog thereof.