heptaphylline and carbazole

Total syntheses of yatakemycin, PDE-II, dictyodendrins, and heptaphylline are described. This article focuses on the formation of aryl carbon-nitrogen bonds by two methods: first by an aromatic amination reaction using a combination of CuI and CsOAc, and then by a benzyne-mediated one-pot cyclization-functionalization sequence. The aryl amination reaction shows a high functional group compatibility and applicability for highly hindered substrates. The utility of this reaction has been fully demonstrated through a total synthesis of yatakemycin, which features the regioselective ring opening of (S)-epichlorohydrin with 2,6-dibromophenyllithium species and the efficient deprotection of benzyl groups of aryl benzyl ether with BCl3 in the presence of pentamethylbenzene. The copper-mediated aryl amination reaction was applied to a one-pot double aryl amination for facile access to the highly substituted pyrroloindole skeleton, which led to a concise total synthesis of PDE-II. A highly efficient total synthesis of dictyodendrins A-E was accomplished by the development of a novel benzyne-mediated one-pot indoline formation/cross-coupling sequence for the construction of a highly substituted key indoline intermediate. Peripheral substituents were introduced onto this intermediate in a modular fashion to complete the total synthesis of dictyodendrins A-E. The utility of the one-pot benzyne-mediated cyclization-functionalization reaction was demonstrated by the total synthesis of carbazole alkaloid, heptaphylline.

Topics: Alkaloids; Amination; Benzene Derivatives; Biological Products; Carbazoles; Carbon; Chemistry, Organic; Copper; Cyclic Nucleotide Phosphodiesterases, Type 2; Cyclization; Duocarmycins; Indoles; Nitrogen; Organic Chemistry Phenomena; Pyrroles

The tumor suppressor p53 is inactivated by mutation in approximately 50% of human cancers. Small molecules that bind and stabilize those mutants may represent effective anticancer drugs. Herein, we report the tumor cell growth inhibitory activity of carbazole alkaloids and amino derivatives, as well as their potential activation of p53. Twelve aminocarbazole alkaloids were semi-synthesized from heptaphylline (

Topics: Alkaloids; Antineoplastic Agents; Carbazoles; Cell Line; Cell Line, Tumor; Clausena; HCT116 Cells; HT29 Cells; Humans; Mutation; Neoplasms; Small Molecule Libraries; Tumor Suppressor Protein p53

New tacrine-carbazole hybrids were developed as potential multifunctional anti-Alzheimer agents for their cholinesterase inhibitory and radical scavenging activities. The developed compounds showed high inhibitory activity on acetylcholinesterase (AChE) with IC50 values ranging from 0.48 to 1.03 μM and exhibited good inhibition selectivity against AChE over butyrylcholinesterase (BuChE). Molecular modeling studies revealed that these tacrine-carbazole hybrids interacted simultaneously with the catalytic active site (CAS) and the peripheral anionic site (PAS) of AChE. The derivatives containing methoxy group showed potent ABTS radical scavenging activity. Considering their neuroprotection, our results indicate that these derivatives can reduce neuronal death induced by oxidative stress and β-amyloid (Aβ). Moreover, S1, the highest potency for both radical scavenging and AChE inhibitory activity, exhibited an ability to improve both short-term and long-term memory deficit in mice induced by scopolamine. Overall, tacrine-carbazole derivatives can be considered as a candidate with potential impact for further pharmacological development in Alzheimer's therapy.

Topics: Acetylcholinesterase; Alzheimer Disease; Amyloid beta-Peptides; Animals; Antioxidants; Butyrylcholinesterase; Carbazoles; Cell Line; Cholinesterase Inhibitors; Electrophorus; Humans; Male; Memory Disorders; Mice; Molecular Docking Simulation; Oxidative Stress; Tacrine