Various compositions and methods for Quasi-Amadori products and derivatives thereof are contemplated in which a halogenated carbohydrate is reacted with a primary amino group of an affinity ligand. In especially preferred aspects, the Quasi-Amadori product is formed from 2-fluorodeoxyglucose and an affinity moiety that preferentially or selectively binds to a neural cell or neural structure. Where contemplated compounds include .sup.18F, PET imaging using compounds presented herein is especially preferred.

The invention comprises radiolabeled oligonucleotide of the formula I

##STR00001## wherein n, X.sup.1, X.sup.2, the linker 1, the linker 2, Q and the receptor targeting moiety are as defined I the description. The radiolabeled oligonucleotides of the formula I can be used for the determination of the biodistribution and pharmacokinetics of the oligonucleotide in the tissue or body fluid.

The present invention relates to an antiviral application of nucleoside analogs. Specifically, the present invention relates to uses of nucleoside analogs and a pharmaceutical composition thereof as: (a) inhibitors for inhibiting the replication of coronaviruses, influenza viruses, respiratory syncytial viruses, flaviviridae viruses, filoviridae viruses and/or porcine epidemic diarrhea virus (PEDV); and/or (b) medicines for treating and/or preventing and mitigating diseases caused by coronavirus, influenza virus, respiratory syncytial virus, flaviviridae virus, filoviridae virus and/or porcine epidemic diarrhea virus (PEDV) infections. The nucleoside analogs according to the invention may treat and/or prevent and mitigate respiratory infection, pneumonia (COVID-19) and other related diseases caused by 2019 novel coronavirus infection.

The present application provides compositions and methods for preparing and using heavy nucleotide derivatives of thymidine or uridine by replacing the oxygen atom attached to one or more of positions with non-radioactive oxygen-18 (.sup.18O), administering it to a subject to target a tumor including incorporation into tumor cell DNA, and then treating the tumor with proton beam therapy to transmutate the .sup.18O to .sup.18F, resulting in a break of the new fluorine-phosphorous bond. This chemical event destabilizes ribose-phosphate DNA back-bone and base pairing thus produce single- and double strand breaks, clusters lesions that can lead to irreparable DNA damage and enhanced tumor cell killing. The atomic, chemical, and physical aspects result in the use of lower radiation doses and significantly alter acute and late morbidity of radiotherapy. Heavy thymidine and heavy uridine derivatives labeled with .sup.18O have been made and tested.

The present invention falls within the technical field of medicinal chemistry, and specifically relates to an antiviral nucleoside analogue, and a pharmaceutical composition and the use thereof. The nucleoside analogue of the present invention has a structure as represented by formula (I), and has a good chemical stability, a high oral bioavailability, and a significant antiviral activity. The nucleoside analogue can be used in the preparation of an inhibitor for inhibiting viral replication and/or a drug for preventing, alleviating and/or treating diseases caused by viral infection.

##STR00001##

The invention relates to a method of preparing an [.sup.18F]radio-labelled compound, wherein the water content is controlled. Controlling the water content and the origin of the water within the reaction process has a significant effect on both the yield and the purity of the product of the radiolabelling process.

A self-contained kit and method for the on-demand synthesis of 2-deoxy-2-[.sup.18F]fluoro-D-sorbitol (.sup.18F-FDS) from commercially available 2-deoxy-2-[F.sup.18]fluoroglucose (.sup.18F-FDG) is disclosed.

Described are methods for preparing a deuterated aldehyde using N-heterocyclic carbene catalysts in a solvent comprising D.sub.2O. The methods may be used to convert a wide variety of aldehydes (e.g., aryl, alkyl, or alkenyl aldehydes) to C-1 deuterated aldehydes under mild reaction conditions without functionality manipulation.

Compounds and methods of using said compounds, singly or in combination with additional agents, and salts or pharmaceutical compositions of said compounds for the treatment of viral infections are disclosed.

The present disclosure relates to a cyclopentyl adenosine derivative and a pharmaceutical use thereof. Specifically, the present disclosure provides a compound represented by formula (I) or a pharmaceutically acceptable salt thereof, wherein R.sup.1-R.sup.8 are as defined in the description.

##STR00001##