New linear bromopyrrole-imidazolidine alkaloids from the Formosan sponge .

Chemical investigation of the natural products from Formosan sponge led to the isolation of two undescribed bromopyrrole-imidazolidine alkaloids, nakamudines A and B. The structures of the compounds were determined by extensive spectroscopic analyses, including 2D NMR correlations, while their relative configurations were resolved NOESY correlation analysis. The alkaloids were assigned as rare linear bromopyrrole alkaloidal epimers possessing an 2,4-imidazolidinedione (hydantoin) moiety.

A Mechanistic Spectrum of O-H Bond Cleavage Observed for Reactions of Phenols with a Manganese Superoxo Complex.

Reaction of a rare and well-characterized Mn-superoxo species, Mn(BDPP)(O⋅) (1, HBDPP=2,6-bis((2-(S)-di(4-bromo)phenylhydroxylmethyl-1-pyrrolidinyl)methyl)pyridine), with 4-dimethylaminophenol at -80 °C proceeds via concerted proton electron transfer (CPET) to produce a Mn-hydroperoxo complex, Mn(BDPP)(OOH) (2), alongside 4-dimethylaminophenoxy radical; whereas, upon treatment with 4-nitrophenol, complex 1 undergoes a proton transfer process to afford a Mn-hydroperoxo complex, [Mn(BDPP)(OOH)] (3). Intriguingly, the reactions of 1 with 4-chlorophenol and 4-methoxyphenol follow two routes of CPET and sequential proton and electron transfer to furnish complex 2 in the end. UV-vis and EPR spectroscopic studies coupled with DFT calculations provided support for this wide mechanistic spectrum of activating various phenol O-H bonds by a single Mn-superoxo complex, 1.

The Cooperativity of Fe O and Metal-Organic Framework as Multifunctional Nanocomposites for Laser Desorption Ionization Process.

A novel and facile strategy in developing a water stable magnetic metal-organic framework nanocomposite (Fe O @MOF) is herein reported, in which a Keggin polyoxometalate, phosphotungstic acid (HPW), was encapsulated within the MOF framework via one-pot synthesis method. The combination of HPW-embedded MOF and Fe O endowed the composite with high surface area, strong UV absorption, good hydrophilicity, and enhanced water stability. With these unique properties, the Fe O @MOF embedded HPW served as adsorbent as well as matrix for SALDI-MS (surface-assisted laser desorption ionization mass spectrometry) analysis of polar and non-polar compounds.

Pore Environment Control and Enhanced Performance of Enzymes Infiltrated in Covalent Organic Frameworks.

In the drive toward green and sustainable methodologies for chemicals manufacturing, biocatalysts are predicted to have much to offer in the years to come. That being said, their practical applications are often hampered by a lack of long-term operational stability, limited operating range, and a low recyclability for the enzymes utilized. Herein, we show how covalent organic frameworks (COFs) possess all the necessary requirements needed to serve as ideal host materials for enzymes.

Investigation of the Mesoporous Metal-Organic Framework as a New Platform To Study the Transport Phenomena of Biomolecules.

Mesoporous materials, Tb-mesoMOF and MCM-41, were used to study the transport phenomena of biomolecules entering the interior pores from solution. Vitamins B and B were successfully encapsulated into these mesoporous materials, whereas Tb-mesoMOF (0.33 g of B/g, 0.

Solid-phase microextraction of phthalate esters in water sample using different activated carbon-polymer monoliths as adsorbents.

In this study, the application of different activated carbon-polymer (AC-polymer) monoliths as adsorbents for the solid-phase microextraction (SPME) of phthalate esters (PAEs) in water sample were investigated. The activated carbon (AC) was embedded in organic polymers, poly(butyl methacrylate-co-ethylene dimethacrylate) (poly(BMA-EDMA)) or poly(styrene-co-divinylbenzene) (poly(STY-DVB)), via a 5-min microwave-assisted or a 15-min water bath heating polymerization. Preliminary investigation on the performance of the native poly(BMA-EDMA) and poly(STY-DVB) demonstrated remarkable adsorption efficiencies for PAEs.