Four new nitroasterric acid derivatives, pseudogymnoascins A-C (1-3) and 3-nitroasterric acid (4), along with the two known compounds questin and pyriculamide, were obtained from the cultures of a Pseudogymnoascus sp. fungus isolated from an Antarctic marine sponge belonging to the genus Hymeniacidon. The structures of the new compounds were determined by extensive NMR and MS analyses. These co...

In this manuscript, we describe the synthesis of the carbohydrazide 2. Acid-catalyzed condensation with several carbonyl compounds to afford the corresponding carbohydrazide derivatives 3-12. Their acetylation afforded the corresponding acetyl derivatives 13-22. Oxidative cyclization of O-acetyl derivatives 19-22 afforded the corresponding 1,3,4-oxadiazole derivatives 23-2...

Tranexamic acid derivatives modified by amino acids, i.e. tranexamic acid-His, tranexamic acid-Leu-His, tranexamic acid-Glu-Phe, tranexamic acid-Glu-Lys, tranexamic acid-Ser-Tyrand, tranexamic acid-Ser-Phe, were synthesized by Fmoc solid-phase peptide synthesis, purified by reversed-phase high performance liquid chromatography and characterized by 1H and electrospray ionisation mass spectrometr...

Dihydro [2,3D] pyridine substituted enaminosulfonamide compounds have been synthesized and their effects on carbonic anhydrase II (hCAII) evaluated. Pyrido [2,3 d] pyrimidines were from barbituric acid derivatives, malonanitrile, aldehyde derivatives in basic condition then hydrolyzed with hydrochloric acid. The targeted syn-thesized amino sulfanilamide, dihydro compounds, triethylorthoformate....

a simple and efficient method for synthesis of tetrahydropyrimido[4,5-b]quinoline derivatives via three component reaction of aromatic aldehydes, dimedone and 6-amino uracil derivatives using a catalytic amount of sulfonic acid functionalized nanoporous silica (sba-15-pr-so3h) is described. the advantages of this method are easy and clean work-up, high yield, mild reaction condition, reusable c...

nano sulfated titania was tested as solid acid heterogeneous catalyst for the synthesis of 4-(trifluoromethyl) coumarin and coumarin derivatives under solvent-free condition. factorial design evidenced a positive effect of reaction temperature, amount of catalyst, and solvents.  this nano-sized sulfated titania has been prepared by a sol-gel hydrothermal process. the prepared sulfated titania s...

Various antibacterial fluoroquinolone compounds were prepared by the direct amination of 7-halo-6- fluoroquinolone-3-carboxylic acids with a variety of piperazine derivatives and (4aR,7aR)-octahydro-1H-pyrrolo[3,4-b] pyridine using Zirconia Sulfuric Acid (ZrSA) nanoparticle, as a catalyst in the presence of ordinary or magnetized water upon reflux condition. The results showed that ZrSA exh...

3Alpha, 7alpha, 12alpha-trihydroxy-5beta-cholestan-26-oic acid (C27-5beta-cholestanoic acid) derivatives with different carbon-number side chains were incubated with rat liver 800 g supernatant to study the effect of the side-chain length on the beta-oxidation system in bile acid biosynthesis. The intermediate alpha, beta-unsaturated and beta-hydroxylated bile acids, and the corresponding degra...