Xinchao Chen

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A series of 13 new (S,Z)-2-aminopurine methylenecyclopropane analogues was synthesized, and their antiviral activity was investigated. The nucleophilic displacement of chlorine of 2-amino-6-chloropurine derivative 5 with allyl-, propargyl-, cyclopropylmethyl-, isopropyl-, benzyl-, cyclohexyl-, and 2-hydroxyethylamine gave N(6)-alkyl compounds 2a, 2b, 2c,(More)
We have reported previously that purine methylenecyclopropane analogs are potent agents against cytomegaloviruses. In an attempt to extend the activity of these compounds, the 2-amino-6-cyclopropylaminopurine analog, QYL-1064, was selected for further study by modifying the purine 6 substituent. A total of 22 analogs were tested against herpes simplex virus(More)
Versatile intermediates 12'-iodovinblastine, 12'-iodovincristine and 11'-iodovinorelbine were utilized as substrates for transition metal based chemistry which led to the preparation of novel analogues of the vinca alkaloids. The synthesis of key iodo intermediates, their transformation into final products, and the SAR based upon HeLa and MCF-7 cell(More)
The Z- and E-2-fluoro- and 2-chloropurine methylenecyclopropanes 9a,b and 10a,b as well as enantiomeric Z-isoguanine methylenecyclopropanes 11a,b and their phenyl phosphoralaninate pronucleotides 11c,d were synthesized and their antiviral activity against several viruses was evaluated. Fluoro analogues 9a and 10a were active against human cytomegalovirus(More)
Absolute configurations of enantiomeric methylenecyclopropanecarbinols obtained by reaction of (R)- and (S)-epichlorohydrin 5 with methylenetriphenylphosphorane or resolution of the corresponding oxaphospholane 6 via a salt with L-(+)-tartaric acid and subsequent Wittig transformation with formaldehyde were revised. The (-)-oxaphospholane 6 has the S,S and(More)
Enzymatic generation of nitric oxide (NO) by nitric oxide synthase (NOS) consists of two oxidation steps. The first step converts L-arginine to N(G)-hydroxy-L-arginine (NOHA), a key intermediate, and the second step converts NOHA to NO and L-citrulline. To fully probe the substrate specificity of the second enzymatic step, an extensive structural screening(More)
Synthesis of (Z)-(2,3-bis-hydroxymethyl)methylenecyclopropane analogues of nucleosides adenosine 10a, 10b, 10c and 17 is described. Epimerization of Feist's acid (11) using acetic anhydride gave cyclic anhydride 12 which was reduced in situ to give diol 13. Acetylation (compound 14) followed by addition of bromine led to dibromo derivative 15.(More)
Synthesis and biological activity of racemic 2-aminopurine methylenecyclopropane analogues of nucleosides 4, 5, 10 and 11 is described. One-pot alkylation-elimination of 2-aminopurine (6) with dibromide 7 gave a mixture of four isomeric methylenecyclopropanes. The (E, Z)-N9 and (E, Z)-N7 isomers 8 and 9 were resolved by chromatography on silica gel.(More)
Hearing loss is a major public health concern with no pharmaceutical intervention for hearing protection or restoration. Using zebrafish neuromast hair cells-a robust model for mammalian auditory and vestibular hair cells- we identified a urea-thiophene carboxamide, 1 (ORC-001) as protective against aminoglycoside antibiotic (AGA)-induced hair cell death.(More)
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