Photoactivation of Ligands for Extrinsically and Intrinsically Triggered Disassembly of Amphiphilic Nanoassemblies.

Specific response to the concurrent presence of two different inputs is one of the hallmarks of incorporating specificities in nature. Artificial nanoassemblies that concurrently respond to two very different inputs are of great interest in a variety of applications, especially in biomedicine. Here, we present a design strategy for amphiphilic nanoassemblies with such capabilities, enabled by photocaging a ligand moiety that is capable of binding to a specific protein. New molecular designs that offer nanoassemblies that respond to either of two inputs or only to the concurrent presence of two inputs are outlined. Such biomimetic nanoassemblies could find use in many applications, including drug delivery and diagnostics.

Propagation of Enzyme-Induced Surface Events inside Polymer Nanoassemblies for a Fast and Tunable Response.

We report a new molecular design strategy that allows for the propagation of surface enzymatic events inside a supramolecular assembly for accelerated molecular release. The approach addresses a key shortcoming encountered with many of the currently available enzyme-induced disassembly strategies, which rely on the unimer-aggregate equilibria of amphiphilic assemblies. The enzymatic response of the host to predictably tune the kinetics of guest-molecule release can be programmed by controlling substrate accessibility through electrostatic complexation with a complementary polymer. Accelerated guest release in response to the enzyme is shown to be accomplished by a cooperative mechanism of enzyme-triggered supramolecular host disassembly and host reorganization.

Syntheses and evaluation of multicaulin and miltirone-like compounds as antituberculosis agents.

Four multicaulin and miltirone-like phenanthrene derivatives were synthesised and evaluated as antituberculosis agents. The crucial step of the synthesis was Pschorr coupling of 4-(3-isopropyl-4-methoxyphenyl)-2-(2-aminophenyl)ethane (13) to give 2-isopropyl-3-methoxy-9,10-dihydrophenanthrene (9) and 4-isopropyl-3-methoxy-9,10-dihydrophenanthrene (9a). Compound 9 was converted to multicaulin and miltirone-like phenanthrene derivatives by further reactions. The best antituberculosis activity was exhibited by 2-isopropylphenanthrene-3-ol (11).

Total syntheses of multicaulins via oxidative photocyclization of stilbenes.

The Wittig reaction of 3-isopropyl-4-methoxybenzaldehyde and 2,3-dimethylbenzylphosphonium bromide afforded the corresponding stilbene mixture 16. Oxidative photocyclization of stilbene 16 with iodine facilitated the first total synthesis of 7-isopropyl-6-methoxy-1,2-dimethylphenanthrene, multicaulin (1). The O-demethylation of 1 with BBr3 afforded the 7-isopropyl-1,2-dimethylphenanthren-6-ol, O-demethylmulticaulin (2).

Disassembly of polymeric nanoparticles with enzyme-triggered polymer unzipping: polyelectrolyte complexes vs. amphiphilic nanoassemblies.

Alkaline phosphatase (ALP) responsive polymers, which can unzip from head to tail are reported. Hydrophilic and hydrophobic modification of the polymer was carried out for the formation of a polyelectrolyte complex and an amphiphilic nanoassembly, respectively, which offered distinct enzyme-triggered disassembly kinetics.

Syntheses and antibacterial activities of 4 linear nonphenolic diarylheptanoids.

Four linear nonphenolic diarylheptanoids were synthesized and their antibacterial activities were studied. ( S )-2-Me-CBS-catalysed reduction of alnustone with BH3SMe2 gave ( R )(-)(4 E ,6 E )-1,7-diphenylhepta-4,6-dien-3-ol, a natural product. Reduction of alnustone with Na in t -BuOH at -15 °C under N3 atm gave (E)-1,7-diphenylhept-5- en-3-one as a Birch-type reduction product. t-BuOK catalysed condensation of benzalacetone with propionyl chloride gave (4 Z ,6 E )-5-hydroxy-1,7-diphenylhepta-4,6-dien-3-one, a natural product. (1 E ,4 Z ,6 E )-5-Hydroxy-4-phenethyl-1,7-diphenylhepta-1,4,6-trien-3-one, a curcuminoid, was synthesized starting from pentan-2,4-dione in 3 steps. The synthesized chemical compounds were applied against 2 gram-positive bacteria ( Bacillus cereus and Arthrobacter agilis ), 4 gram-negative bacteria ( Pseudomonas aeruginosa , Xanthomonas campestris , Klebsiella oxytoca , and Helicobacter pylori ), and 1 yeast (Candida albicans) by the disc diffusion method. All of the synthesized compound exhibited different degrees of antimicrobial activity at concentrations between 20-100 µg/disc against the test organisms.