Synthesis and reactivity of nitrogen nucleophiles-induced cage-rearrangement silsesquioxanes.

Novel phthalimide and o-sulfobenzimide-functionalized silsesquioxanes were successfully synthesized via nucleophilic substitution reactions from octakis(3-chloropropyl)octasilsesquioxane. Surprisingly, the formation of deca- and dodecasilsesquioxanes cages was discovered during substitution with phthalimide, but only octasilsesquioxane maintained a cage in the o-sulfobenzimide substitution reaction. Moreover, we report the electronic effect of nitrogen nucleophiles to promote cage-rearrangement of inorganic silsesquioxane core for the first time. Structures of products were confirmed by (1)H, (13)C, and (29)Si NMR spectroscopy, ESI-MS analysis, and single-crystal X-ray diffraction.

2-[(4-Chlorobenzyl)iminomethyl]phenol.

The title Schiff base compound, C(14)H(12)ClNO, was prepared from 4-chloro-benzyl-amine and salicyl-aldehyde. The mol-ecule is V-shaped: the dihedral angle between the aromatic rings is 67.51 (5)°. The rings are located on the opposite side of the C=N bond, giving an E configuration. An intra-molecular N-H⋯O hydrogen bond generates a S(6) ring. In the crystal structure, only weak non-classical C-H⋯O contacts are observed.

Salicyl-aldehyde-4-(dimethyl-amino)-pyridine (1/1).

In the title compound, C(7)H(10)N(2)·C(7)H(6)O(2), the components are linked by an O-H⋯N hydrogen bond. The mean planes of two mol-ecules form a dihedral angle of 78.68 (5)°. The crystal packing exhibits weak non-classical C-H⋯O contacts.

2-[(4-Meth-oxy-benz-yl)imino-meth-yl]phenol.

In the title Schiff base compound, C(15)H(15)NO(2), prepared from 4-meth-oxy-benzyl-amine and salicyl-aldehyde, an intra-molecular O-H⋯N hydrogen bonds influences the mol-ecular conformation; the two aromatic rings form a dihedral angle of 73.5 (1)°. In the crystal, weak inter-molecular C-H⋯O inter-actions link the mol-ecules into chains propagating in [010].

Acanthoic Acid.

THE TITLE COMPOUND [SYSTEMATIC NAME: (1R,4aR,7S,8aS,10aS)-1,4a,7-trimethyl-7-vinyl-1,2,3,4,4a,6,7,8,8a,9,10,10a-dodeca-hydro-phenanthrene-1-carb-oxy-lic acid], C(20)H(30)O(2), is a pimarane-type diterpene extracted from Croton oblongifolius. There are two independent mol-ecules in the asymmetric unit. In both of these, the six-membered rings A, B and C adopt chair, boat and half-chair conformations, respectively. Rings A and B are trans-fused. The two mol-ecules in the asymmetric unit form O-H⋯O hydrogen-bonded R(2) (2)(8) dimers. The absolute configuration was assigned on the basis of the published literature on analogous structures.

Enhanced anti-topoisomerase II activity by mucoadhesive 4-CBS-chitosan/poly (lactic acid) nanoparticles.

In this study, the biodegradable mucoadhesive 4-carboxybenzensulfonamide chitosan (4-CBS-chitosan)/poly (lactic acid) (PLA) nanoparticles were fabricated by the electrospray ionization technique for enhancing anti-topoisomerase II (Topo II) activity. The obtained (4-CBS-chitosan/PLA)-DOX nanoparticles were characterized using SEM, particle size analyzer. We emphasis on encapsulation efficiency, in vitro drug release behavior and also performed in vitro studies of Topo II inhibitory activity using gel electrophoresis. In addition, the cytotoxicity of the 4-CBS-chitosan/PLA nanoparticles using MTT assay was also studied. The mean particle size of spherical shaped (4-CBS-chitosan/PLA)-DOX is less than 300 nm. The DOX loaded 4-CBS-chitosan/PLA composite nanoparticles produced high entrapment efficiency of 85.8% and provided the prolonged release of DOX extended to 26 days and also still had strong Topo II inhibitory activity up to 77.4%. Overall, it was shown that 4-CBS-chitosan/PLA nanoparticles could be promising carriers for controlled delivery of anticancer drugs.

One-pot synthesis of halogen exchanged silsesquioxanes: octakis(3-bromopropyl)octasilsesquioxane and octakis(3-iodopropyl)octasilsesquioxane.

Metal halides, solvent effects, phase transfer catalysts, alkylating agent and reaction times were found to have important roles to complete halogen exchange reactions in "one pot" synthesis, starting from octakis(3-chloropropyl)octasilsesquioxane to obtain more reactive halide compounds: octakis(3-bromopropyl)octasilsesquioxane and octakis(3-iodopropyl)octasilsesquioxane. To confirm the complete halogen exchange, the desired products were characterized by (1)H, (13)C and (29)Si NMR spectroscopy, ESI-MS, elemental analysis and single-crystal X-ray diffraction analysis.