The hapalindole-type alkaloids naturally show striking late stage diversification of what was believed to be a conserved intermediate, cis-indolyl vinyl isonitrile (1a). Here we demonstrate enzymatically, as well as through applying a synthetic biology approach, that the pathway generating 1a (itself, a potent natural broad-spectrum antibiotic) is also dramatically flexible. We harness this to ...

The effect of enantiomeric trifluoromethyl-indolyl-acetic acid ethyl esters on the fibrillogenesis of Alzheimer's amyloid beta (Abeta) peptide is described. These compounds have been previously identified as effective inhibitors of the Abeta self-assembly in their racemic form. Thioflavin-T Fluorescence Spectroscopy and Atomic Force Microscopy were applied to assess the potency of the chiral ta...

Significance: The authors developed a gold-catalyzed hydroamination followed by an asymmetric nucleophilic allylic substitution cascade to access oxazino[4,3-a]indoles in good yields and enantioselectivities. Owing to pharmacologically active indole alkaloids, this rapid synthesis and asymmetric decoration of the polycyclic indolyl core is highly important. Comment: Amazingly, the stereodiffere...

The mol-ecule of accanthomine A, C(15)H(13)N(5), is approximately planar, with the indolyl fused-ring and the pyrimidyl ring being twisted by 31.7 (1)° The amino group of the five-membered ring is an intramolecular hydrogen-bond donor to a nitro-gen acceptor of the pyrimide ring. The amino group of the pyrimide ring is a hydrogen-bond donor to the N atoms of adjacent mol-ecules. These hydrogen-...

A series of novel 3-benzisoxazolyl-4-indolyl-maleimides were synthesized and evaluated for their GSK-3β inhibitory activity. Most compounds exhibited high inhibitory potency towards GSK-3β. Among them, compound 7j with an IC₅₀ value of 0.73 nM was the most promising GSK-3β inhibitor. Preliminary structure-activity relationships were examined and showed that different substituents on the indole ...

This investigation concerns identification of alkaline phosphatase production by bacterial organisms, as detected by a blue color resulting from conversion of indolyl phosphate to indigo. Coagulase-positive Staphylococcus produced alkaline phosphatase; coagulase-negative Staphylococcus did not. Serratia did not produce alkaline phosphatase; those Enterobacteriaceae we tested did. Thus, this tes...

Tryptophol [2-(3-indolyl)-ethanol], a well-known constituent of terrestrial plants and microorganisms, has so far been isolated from tryptophan fermentations, plant seedlings, Aspergillus niger, Agrobacterium tumefaciens, Ceratocystis spp., and Rhizobium spp. (Buckingham, 1994). We have now isolated tryptophol from the marine sponge Ircinia spinulosa collected from the Aegean Sea. In addition t...

A simple and efficient method for the synthesis of 1,1-diarylalkanes via the Friedel-Crafts-type alkylation reaction of electron-rich arenes with cinnamic acid ester derivatives or chalcones is reported. Iron triflate has been found to be the best catalyst for the Friedel-Crafts-type alkylation reaction with α,β-unsaturated carbonyl compounds. This reaction afforded β,β-diaryl carbonyl compound...