Racemic andransinine (1), an indole alkaloid derivative obtained during isolation of alkaloids from Alstonia angustiloba and Kopsia pauciflora, was found to undergo spontaneous resolution when crystallized in EtOAc, forming racemic conglomerates (an equimolar mechanical mixture of enantiomerically pure individual crystals). X-ray analyses of the enantiomers (obtained from crystals from EtOAc so...

The pyridazino[4,5-b]indole (3), which is conveniently available from 3-methylthioindole and the tetrazine (2), undergoes thermally induced inverseelectron-demand Diels-Alder reactions with enamines to afford the cycloalkeneannelated carbazoles (7,8) or the 2-substituted carbazole (9), respectively. We have previously shown that 1,2-diazines annelated to a second π-electron-deficient aromatic r...

Microwave-assisted synthesis of some novel compounds, namely, 3-(2-methyl-1H-indol-3-yl)-6-aryl-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazoles 5a,b was accomplished via bromination of 2-methyl-3-[4-(arylideneamino)-5-mercapto-4H-[1,2,4]triazol-3-yl]-1H-indoles 3a,b. Also, new [1,3,4]thiadiazoles 12a,b, [1,2,4]triazoles 15a,b and [1,3,4]oxadiazoles 19a,b, with indole moieties, were prepared by cycliz...

The first enantioselective total synthesis of a member of the okaramine family of bis-indole alkaloids, okaramine N (1), has been accomplished via intermediates 2-7, as outlined. The N-prenylated derivative of (S)-tryptophan methyl ester (2) was coupled with Fmoc-protected N-tert-prenylated tryptophan (3) to form the amide 4 in 70% yield. Pd(II)-mediated cyclization/rearrangement, a key step in...

A potential antitumoral fluorescent indole derivative, methyl 6-methoxy-3-(4-methoxyphenyl)-1H-indole-2-carboxylate, was evaluated for the in vitro cell growth inhibition on three human tumor cell lines, MCF-7 (breast adenocarcinoma), A375-C5 (melanoma), and NCI-H460 (non-small cell lung cancer), after a continuous exposure of 48 h, exhibiting very low GI50 values for all the cell lines tested ...

A Fischer indole synthesis with a cis-configurated octahydroisobenzofuran-6-one yielded exclusively a furo[3,4-c]carbazole derivative as the product of a regioselective angular annulation reaction. A Friedländer quinoline synthesis from the same substrate gave a mixture of angular and linear annulation products, i. e. furo[3,4-a]acridine and furo[3,4-b]acridine derivatives. When submitting a mi...

A new one-pot synthesis of 2-(hetero)aryl indoles via sequential C-C coupling followed by C-Si bond cleavage and a subsequent tandem C-C/C-N bond forming reaction is described. A variety of functionalized indole derivatives were prepared by conducting this four step reaction under Pd/C-Cu catalysis. The methodology involved coupling of (trimethylsilyl)acetylene with iodoarenes in the presence o...

Sch 20569 is a semisynthetic derivative of gentamicin with activity against many gentamicin-resistant gram-negative bacilli. We compared its bactericidal action with that of gentamicin and amikacin against 171 clinical isolates of Enterobacteriaceae, Staphylococcus aureus, and Pseudomonas aeruginosa. Sch 20569 and amikacin showed markedly greater activity than gentamicin against Escherichia col...

A series of indole-based aryl(aroyl)hydrazone analogs of antiplatelet indole-3-carboxaldehyde phenylhydrazone were synthesized by the Schiff base formation reaction and their antiplatelet activity was assessed using human platelet rich plasma. The platelet concentrate was obtained using a two-step centrifugation protocol and ADP, arachidonic acid and collagen were used as inducers of platelet a...