This study investigated the role of furfuryl alcohol (FFA) in the formation of furfurylthiol (FFT), the most important odorant in roasted coffee, using in-bean and spiking experiments. Green beans were spiked with FFA, and after roasting FFT was quantified by stable isotope dilution analysis. The FFT level in the roasted beans increased dose-dependently with addition of FFA.
View Article and Find Full Text PDFThere is an important medical need for effective therapies to redress the general bone loss associated with advanced osteoporosis. Prostaglandin E(2) and related EP4 receptor agonists have been shown to stimulate bone regrowth but their use has been limited by systemic side effects. Herein is described the design and synthesis of novel dual-action bone-targeting conjugate pro-drugs where two classes of active agents, a bone growth stimulating prostaglandin E(2) EP4 receptor subtype agonist (5 or 6) and a bone resorption inhibitor bisphosphonate, alendronic acid (1), are coupled using metabolically labile carbamate or 4-hydroxyphenylacetic acid based linkers.
View Article and Find Full Text PDFAs the largest secondary metabolite to be discovered as of yet, the polyether marine neurotoxin maitotoxin constitutes a major structural and synthetic challenge. After its originally proposed structure ( 1) had been questioned on the basis of biosynthetic considerations, we provided computational and experimental support for structure 1. In an effort to provide stronger experimental evidence of the molecular architecture of maitotoxin, its GHIJKLMNO ring system 3 was synthesized.
View Article and Find Full Text PDF[reaction: see text] Indole N-substituted diyne tetracobalt complexes (4) undergo a Lewis acid mediated dimerization-cyclization reaction through the indole 3-position to afford indolophanetetrayne cobalt complexes (7). Substitution of the indole fragment of (4) with a 3-methyl function allows analogous formation of indolophanetetrayne complex (9), linked through the indole 2-position.
View Article and Find Full Text PDFChem Commun (Camb)
July 2002
Nicholas reactions of the p-phenyl linked bis(propargyl acetate) complex (3a) with electron rich arenes give cyclophanetetrayne complexes (5). The use of bis(propargyl ether) complex (8) with (3a) allows formation of a mixed cyclophanetetrayne complex (9), and in addition gives retro-Nicholas/intramolecular Nicholas reaction product (2).
View Article and Find Full Text PDFIndoles, when treated with methyldiazomalonate under catalysis by rhodium(II)acetate, undergo C-H and N-H insertion reactions regioselectively depending on the substitution pattern on the indole moiety. In indoles where the 3-position is unsubstituted, high yields of the C3-H insertion product were observed. In 3-alkylindoles, 2-substitution predominated, while N-methyltetrahydrocarbazole yielded the product resulting from insertion into the C6-H bond.
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