The Soluble Adenylyl Cyclase Inhibitor LRE1 Prevents Hepatic Ischemia/Reperfusion Damage Through Improvement of Mitochondrial Function

Hepatic ischemia/reperfusion (I/R) injury is a leading cause of organ dysfunction and failure in numerous pathological and surgical settings. At the core of this issue lies mitochondrial dysfunction. Hence, strategies that prime mitochondria towards damage resilience might prove applicable in a clinical setting. A promising approach has been to induce a mitohormetic response, removing less capable organelles, and replacing them with more competent ones, in preparation for an insult. Recently, a soluble form of adenylyl cyclase (sAC) has been shown to exist within mitochondria, the activation of which improved mitochondrial function. Here, we sought to understand if inhibiting mitochondrial sAC would elicit mitohormesis and protect the liver from I/R injury. Wistar male rats were pretreated with LRE1, a specific sAC inhibitor, prior to the induction of hepatic I/R injury, after which mitochondria were collected and their metabolic function was assessed. We find LRE1 to be an effective inducer of a mitohormetic response based on all parameters tested, a phenomenon that appears to require the activity of the NAD+-dependent sirtuin deacylase (SirT3) and the subsequent deacetylation of mitochondrial proteins. We conclude that LRE1 pretreatment leads to a mitohormetic response that protects mitochondrial function during I/R injury.

Synthesis, antibacterial activities, and sustained perfume release properties of optically active5-hydroxy- and 5-acetoxyalkanethioamide analogues

Abstract5-Acetoxy- and 5-hydroxyalkanethioamide analogues showed high antibacterial activity against Staphylococcus aureus. Antibacterial thioamides were prepared from 5-alkyl-δ-lactones by amidation, thionation, and subsequent deacetylation. Optically active thioamides with 99% diastereomeric excesses were prepared by diastereomeric resolution using Cbz-L-proline as the resolving agent. Antibacterial thioamides were slowly lactonized by a lipase catalyst. Therefore, these thioamides are potential sustained-release perfume compounds having antibacterial properties.

A Novel and Facile Synthesis of Thiopyrimidines and O-Glucosides

Reaction of 3-methyl-5-(3'-aryl prop-2'-enoyl)-1,2-benzisoxazole (1a-j) with thiourea and alcoholic solution of KOH afforded 3-methyl-5-(4'-aryl-2'-thiopyrimidin-6'-yl)-1,2-benzisoxazoles (2a-j). Oxidation of products 2a-j using alkaline KMnO4 solution produces 5-(4'-aryl-2'-thiopyrimidin-6'-yl)-1,2-benzisoxazole-3-carboxylic acids (3a-j). Condensation of products 3a-j with 2,3,4,6-tetra-Oacetyl-α-D-glucopyranosyl bromide (TAGBr), the glucosylating agent synthesized 3-(2,3,4,6-tetra-O-acetyl-3-acetyl-β-D-glucopyranosyl)-5-(4'-aryl-2'-thiopyrimidin-6'-yl)-1,2-benzisoxazoles (4a-j). Subsequent deacetylation of compounds 4a-j were carried out with CH3ONa furnishes β-Dglucopyranosyl-5-(4'-aryl-2'-thiopyrimidin-6'-yl)-1,2-benzisoxazole-3-carboxylates (5a-j). All the synthesized compounds were analyzed by elemental analysis (C, H and N), FT-IR, 1H NMR and mass spectral data. Most of the prepared compounds were analyzed their antibacterial and antifungal activities by cup-plate method. The present approach offers several advantages such as shorter reaction times, cleaner reactions, good yields, low-cost reagent and mild reaction conditions.

CNT-anchored cellulose fluorescent nanofiber membranes as a fluorescence sensor for Cu2+ and Cr3+

1,4-Dihydroxyanthraquinone (1,4-DHAQ, a fluorophore) doped carbon nanotubes@cellulose (1,4-DHAQ-doped CNTs@CL) nanofibrous membranes have been prepared via electrospinning and subsequent deacetylation in this work.

Fractionation and characterization of lignin carbohydrate complexes (LCCs) of Eucalyptus globulus in residues left after MWL isolation. Part I: Analyses of hemicellulose-lignin fraction (HC-L)

The residual wood meal left after milled wood lignin (MWL) isolation (MWR) was extracted with the cellulose solvent lithium chloride/N,N-dimethylacetamide (LiCl/DMAc) to obtain a soluble fraction (C-L) and an insoluble fraction (C-L-residue). The C-L-residue was further extracted with the hemicellulose solvent 3 M NaOH to give a soluble fraction named hemicellulose-lignin fraction (HC-L) with 21.3% yield based on MWR. It was found that HC-L was composed of xylan, cellulose and lignin with abundant S-type β-O-4 substructures. HC-L lignin was bonded to HC-L cellulose or HC-L hemicelluloses or both. The method, which comprised acetylation for hardwood xylan (by acetic anhydride/pyridine/formamide) and extraction with chloroform, was found to be effective for selective xylan acetate fractionation. HC-L was further fractionated by the same method and subsequent deacetylation to give a xylan-lignin fraction (X-L) in 11.3% yield based on HC-L. X-L was composed mainly of xylan and lignin with abundant S-type β-O-4 substructures, and bonded to X-L xylan. X-L is considered as a promising fraction for elucidation of the structure of lignin-carbohydrate linkages.

Glycosylation of Triterpene Alcohols and Acids of the Lupane and A-Secolupane Series

A series of 3- and 28-glucosides and glucosyl esters of betulinic acid (1a), 28-hydroxy-3,4-secolupa-4(23),20(29)-dien-3-oic acid (22a), dimethyl ester of 28-hydroxy-2,3-secolup-20(29)-en-2,3-dioic acid (43a), their 20(29)-dihydro derivatives (1b, 22b, 43b) and several other triterpenes of the lupane (12a, 12b) and 3,4-secolupane series (18a, 18b, 32a) has been prepared by reaction of tetra-O-acetyl-α-D-glucopyranosyl bromide in acetonitrile in the presence of mercury(II) cyanide and subsequent deacetylation of the obtained tetra-O-acetyl-β-D-glucopyranosyl derivatives. In several cases attempted glucosylation in the presence of silver silicate afforded predominantly the corresponding 1,2-orthoacetates of α-D-glucopyranose.

Synthesis of Deoxy, Dideoxy and Didehydrodideoxy Analogs of 9-(β-D-Hexofuranosyl)adenine

Condensation of 1,2-di-O-acetyl-3,5,6-tri-O-benzoyl-D-glucofuranose with N6-benzoyladenine, catalyzed with tin tetrachloride, afforded nucleoside I. Partial deacetylation of I, followed by mesylation, gave 9-(3,5,6-tri-O-benzoyl-2-O-methanesulfonyl-β-D-glucofuranosyl)adenine (III). 9-(2,5,6-Tri-O-acetyl-3-O-methanesulfonyl-β-D-glucofuranosyl)-N6-benzoyladenine (IV) was prepared by condensation of 1,2,5,6-tetra-O-acetyl-3-O-methanesulfonyl-D-glucofuranose with N6-benzoyladenine. Reaction of mesyl derivative III with methanolic sodium methoxide and of mesyl derivative IV with methanolic ammonia led to 2',3'-anhydronucleosides V and VI which were acetylated to give the respective 9-(5,6-di-O-acetyl-2,3-anhydro-β-D-mannofuranosyl)adenine (VII) and 9-(5,6-di-O-acetyl-2,3-anhydro-β-D-allofuranosyl)adenine (VIII). Epoxy derivative VII was cleaved with bromotrimethylsilane, affording a mixture of 9-(5,6-di-O-acetyl-2-bromo-2-deoxy-β-D-glucofuranosyl)adenine (Xa) and 9-(5,6-di-O-acetyl-3-bromo-3-deoxy-β-D-altrofuranosyl)adenine (XIa), epoxy derivative VIII was cleaved analogously to give 9-(5,6-di-O-acetyl-3-bromo-3-deoxy-β-D-glucofuranosyl)adenine (XIIa). Their dehalogenation with tributylstannane and subsequent deacetylation led to 9-(2-deoxy-β-D-arabino-hexofuranosyl)adenine (Xc), 9-(3-deoxy-β-D-arabino-hexofuranosyl)adenine (XIc) and 9-(3-deoxy-β-D-ribo-hexofuranosyl)adenine (XIIc). 9-(2,5,6-Tri-O-acetyl-3-bromo-3-deoxy-β-D-glucofuranosyl)adenine (XIId), which was prepared by acetylation of XIIa, on reductive elimination with Cu/Zn couple and subsequent deacetylation gave 9-(2,3-dideoxy-β-D-erythro-hex-2-enofuranosyl)adenine (XIV). 9-(2,3-Dideoxy-β-D-erythro-hexofuranosyl)adenine (XVI) was obtained either by catalytic hydrogenation of bromo derivative XIId followed by deacetylation, or by catalytic hydrogenation of didehydro derivative XIV. The synthesized nucleosides were tested for antiviral activity.

Synthesis of Deoxy, Dideoxy and Didehydrodideoxy Analogs of 9-(4-C-Hydroxymethyl-α-L-pentofuranosyl)adenine

Condensation of 1,2-di-O-acetyl-3,5-di-O-benzoyl-4-C-benzoyloxymethyl-L-arabinofuranose with N6-benzoyladenine, catalyzed with tin tetrachloride, afforded nucleoside I, which upon partial deacetylation and subsequent mesylation was converted into 9-(3,5-di-O-benzoyl-4-C-benzoyloxymethyl-2-O-methanesulfonyl-α-L-arabinofuranosyl)adenine (III). 9-(2,5,6-Tri-O-acetyl-4-C-acetoxymethyl-3-O-methanesulfonyl-α-L-arabinofuranosyl)-N6-benzoyladenine (V) was obtained by condensation of 1,2,5-tri-O-acetyl-4-C-acetoxymethyl-3-O-methanesulfonyl-L-arabinose with N6-benzoyladenine. Reaction of mesyl derivatives III and V with methanolic sodium methoxide afforded 2',3'-anhydro nucleosides VIa and VIIa, which were acetylated to give 9-(5-O-acetyl-4-C-acetoxymethyl-2,3-anhydro-α-L-ribofuranosyl)adenine (VIb) and 9-(5-O-acetyl-4-C-acetoxymethyl-2,3-anhydro-α-L-lyxofuranosyl)adenine (VIIb). Epoxy derivative VIb was cleaved with bromotrimethylsilane to 9-(5-O-acetyl-4-C-acetoxymethyl-2-bromo-2-deoxy-α-L-arabinofuranosyl)adenine (VIIIa); the same reaction with epoxy derivative VIIb afforded a mixture of 9-(5-O-acetyl-4-C-acetoxymethyl- 2-bromo-2-deoxy-α-L-xylofuranosyl)adenine (IXa) and 9-(5-O-acetyl-4-C-acetoxymethyl-3-bromo- 3-deoxy-α-L-arabinofuranosyl)adenine (Xa). Their dehalogenation with tributylstannane and subsequent deacetylation led to 9-(2-deoxy-4-C-hydroxymethyl-α-L-erythro-pentofuranosyl)adenine (VIIIc), 9-(2-deoxy-4-C-hydroxymethyl- α-L-threo-pentofuranosyl)adenine (IXc) and 9-(3-deoxy-4-C-hydroxymethyl-α-L-threo-pentofuranosyl)adenine (Xc). 9-(2,5-Di-O-acetyl-4-C-acetoxymethyl-2-bromo-2-deoxy-α-L-arabinofuranosyl)adenine (VIIId), prepared by acetylation of VIIIa, on reductive elimination with Cu/Zn couple and subsequent deacetylation afforded 9-(2,3-dideoxy-4-C-hydroxymethyl-α-L-glycero-pent-2-enofuranosyl)adenine (XIb). 9-(2,3-Dideoxy-4-C-hydroxymethyl-α-L-glycero-pentofuranosyl)adenine (XIIb) was obtained either by catalytic hydrogenation of bromo derivative VIIId, followed by deacetylation, or by catalytic hydrogenation of didehydro derivative XIb. The nucleosides synthesized were tested for antiviral activity.

Synthesis of methyl 3,4-di-O-(β-D-xylopyranosyl)-β-D-xylopyranoside, a methyl β-xylotrioside related to branched xylans

The condensation of 2,3,4-tri-O-acetyl-α-D-xylopyranosyl bromide (I) with methyl 2-O-benzyl-β-D-xylopyranoside (II) afforded methyl 2-O-benzyl-3,4-di-O-(2,3,4-tri-O-acetyl-β-D-xylopyranosyl)-β-D-xylopyranoside (III). Hydrogenolytic cleavage of the benzyl group from III and subsequent deacetylation led to the crystalline title methyl β-xylotrioside (V) related to branched xylans. Compound V was characterized by its crystalline per-O-acetate VI and per-O-methyl derivative VII.

Synthesis of some partially methylated sucrose derivatives

1',6,6'-Tri-O-methylsucrose, a new compound, has been synthesized by methylation of 2,3,3',4,4'-penta-O-acetylsucrose with diazomethane and boron trifluoride with subsequent deacetylation. 2,3,3',4,4'-Penta-O-methylsucrose has been obtained in improved yield from the tri-O-trityl derivative by reduction with lithium in liquid ammonia. A major product of the incomplete methylation of 11,6,6'-tri-O-tritylsucrose was the 2,3,3',4'-tetra-O-methyl derivative, and after reductive detritylation 2,3,3',4'-tetra-O-methylsucrose, a new compound, was isolated and identified by examination of its hydrolysis products.