One pot synthesis of the dinucleoside phosphonate GpCH2U

Summary The preparation of the dinucleoside phosphonate GpCH₂U, starting from the isosteric phosphonate analogue of uridine (3) and the guanosine derivative5 is described.

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Eintopfsynthese des Dinucleosidphosphonats GpCH₂U

Zusammenfassung Die Herstellung des Dinucleosidphosphonats GpCH₂U aus dem isosteren Phosphonatanalogen von Uridin (3) und dem Guanosinderivat5 wird beschrieben.

     

Synthesis,Antiviral, and Antimicrobial Activity of N‐ and S‐Alkylated Phthalazine Derivatives

A series of N‐alkylphthalazinone were synthesized by the reaction of phthalazin‐1(2H)‐one derivatives 1a , 1b , 1c with alkylating agents namely, propargyl, allyl bromide, epichlorohydrin, 1,3‐dichloro‐2‐propanol, 4‐bromobutylacetate, and 1‐(bromomethoxy)ethyl acetate to give the corresponding N‐alkylphthalazinone 2a , 2b , 2c , 3a , 3b , 3c , 5a , 5b , 5c , 6a , 6b , 6c , 7a , 7b , 7c , and 9a , 9b , 9c . Alkylation of phthalazin‐1(2H)‐thione to give a series from S‐alkylphthalazine 12 , 13 , 14 and thioglycosides 15 and 17 was performed. Deprotection of compounds 7a , 7b , 7c , 9a , 9b , 9c , 15 , and 17 resulted in the formation of the corresponding products 8a , 8b , 8c , 10a , 10b , 10c , 16 , and 18 . The structure of newly synthesized compounds was assigned by IR, ¹H, ¹³C NMR, and elemental analysis. Some of these compounds were screened for antiviral and antimicrobial activity.     

Mentha longifolia subsp. typhoides and subsp. schimperi: Antimicrobial and Antiquorum-Sensing Bioactivities

Chemistry of Natural Compounds -     

Synthesis,Antiviral, and Antimicrobial Activity of 1,2,4-Triazole Thioglycoside Derivatives

Abstract

The reaction of 5-(2-methylthio)phenyl-1,2,4-triazole-3-thiol with glucosyl, galactosyl, lactosyl bromide, and peracetylated ribose under the conventional and microwave irradiation methods afforded the corresponding S-glycosides. Deacetylation of S-glycosides gave the corresponding deacetylated derivatives. Reaction of 5-(2-methylthio)phenyl-1,2,4-triazole-3-thiol with 4-acetoxybutyl bromide, 2-acetoxyethoxymethyl bromide, 3-chloropropanol, 1,3-dichloroopropan-2-ol, epichlorohydrin, allyl bromide, and propargayl bromide gave the corresponding S-acyclonucleosides, which were deacetylated to give the corresponding deacetylated compounds. All the newly synthesized compounds were characterized by the IR, ¹H, ¹³C NMR, and elemental analyses. Some of these compounds were screened for their antiviral and antimicrobial activity.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the related elements to view the free supplemental file.     

Probing the Water Stability Limits and Degradation Pathways of Metal–Organic Frameworks

A comprehensive model to describe the water stability of prototypical metal–organic frameworks (MOFs) is derived by combining different types of theoretical and experimental approaches. The results provide an insight into the early stages of water-triggered destabilization of MOFs and allow detailed pathways to be proposed for the degradation of different MOFs under aqueous conditions. The essential elements of the approach are computing the pK_a values of coordinated water molecules and geometry relaxations. Variable-temperature and pH infrared spectroscopy techniques are used to corroborate the main findings. The model developed herein helps to explain stability limits observed for several prototypical MOFs, including MOF-5, HKUST-1, UiO-66, and MIL-101-Cr, in aqueous solutions, and thus, provides an insight into the possible degradation pathways in acidic and basic environments. The formation of a metal hydroxide through the autoprotolysis of metal-coordinated water molecules and the strength of carboxylate–metal interactions are suggested to be two key players that govern stability in basic and acidic media, respectively. The methodology presented herein can effectively guide future efforts, which are especially significant for in silico screening, for developing novel MOFs with enhanced aqueous stability.