The structures of the condensed tannins isolated from leaf, fruit and stem bark of Delonix regia have been investigated with 13C nuclear magnetic resonance (13C-NMR), high performance liquid chromatography electrospray ionization mass spectrometry (HPLC-ESI-MS) coupled with thiolysis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analyses. The results showed that these condensed tannins from Delonix regia possessed structural heterogeneity in monomer units and degree of polymerization. Propelargonidin (PP) and procyanidin (PC) were found in the leaf, fruit and stem bark of Delonix regia, while prodelphinidin (PD) was just found in the leaf organs. The polymer chain lengths of condensed tannins from leaf and fruit organs were detected to be trimers to hexadecamers but from trimers to tridecamers for stem bark. B-type linkages were present in all these compounds. Condensed tannins from different parts of Delonix regia can be explored as beneficial tyrosinase inhibitor and food antioxidants because of their potent antityrosinase and antioxidant activities. Keywords: Delonix regia; Condensed tannins; NMR; HPLC-ESI-MS; MALDI-TOF MS; Antityrosinase activity; antioxidant activities.

Peroxiredoxins (Prxs) are potential therapeutic targets for major diseases such as cancers. However, isotype-specific inhibitors remain to be developed. We report that adenanthin, a diterpenoid isolated from the leaves of Rabdosia adenantha, induces differentiation of acute promyelocytic leukemia (APL) cells. We show that adenanthin directly targets the conserved resolving cysteines of Prx I and Prx II and inhibits their peroxidase activities. Consequently, cellular H(2)O(2) is elevated, leading to the activation of extracellular signal-regulated kinases and increased transcription of CCAAT/enhancer-binding protein β, which contributes to adenanthin-induced differentiation. Adenanthin induces APL-like cell differentiation, represses tumor growth in vivo and prolongs the survival of mouse APL models that are sensitive and resistant to retinoic acid. Thus, adenanthin can serve as what is to our knowledge the first lead natural compound for the development of Prx I- and Prx II-targeted therapeutic agents, which may represent a promising approach to inducing differentiation of APL cells.

Stepwise adsorption in a metal-organic framework with both micro- and meso-pores is caused by adsorbates first filling the micropores, then adsorbing along the mesopore walls, and finally filling the mesopores.

Picky cage: A dicopper(II)-paddle-wheel-based metal-organic framework (PCN-80, see picture) with a rare (3,3,4)-connected topology has been synthesized by using a unique octatopic ligand featuring 90°-bridging-angle-dicarboxylate moieties. PCN-80 has Brunauer-Emmett-Teller (BET) and Langmuir surface areas of 3850 and 4150 m(2)  g(-1), respectively. It exhibits high gas-uptake capacity for H(2) and large adsorption selectivity of CO(2) over N(2).

Reaction of copper(ii) tetrazolate-5-carboxylate with different neutral N-donor spacer ligands under hydrothermal conditions leads to the formation of five new coordination polymers,[Cu(tzc)(pyz)(0.5)(H(2)O)(2)](n)·H(2)O (1),[Cu(tzc)(pyz)](n)(2),[Cu(tzc)(pym)(H(2)O)](n)(3),[Cu(tzc)(dpe)(0.5)(H(2)O)](n)(4) and [Cu(tzc)(azpy)(0.5)(H(2)O)](n)(5)(tzc = tetrazolate-5-carboxylate, pyz = pyrazine, pym = pyrimidine, dpe = 1,2-di(4-pyridyl)ethylene and azpy = 4,4'-azopyridine). All five structures were characterized by X-ray single-crystal measurements and bulk material can be prepared phase pure in high yields. The crystal structures of the hydrates 1, 3, 4 and 5 show dimeric [Cu(2)(N(tzc)-N(tzc))(2)] building units formed by μ(2)-N1,O1:N2 bridging tzc ligands as the characteristic structural motif. These six-membered entities in 1, 4 and 5 are connected by μ(2)-N,N' bridging N-donor ligands into 1D chains and in 3 into 2D layers. In the crystal structure of compound 2 adjacent Cu(ii) cations are connected by μ(2)-N1,O1:N4,O2 bridging tzc ligands into chains, which are further connected by μ(2)-N,N' bridging pyz ligands forming 2D layers. Extensive hydrogen bonds in all compounds play an important role in the construction of their supramolecular networks. Investigations of their thermal properties reveal water release upon heating according to the formation of anhydrates before starting decomposing above 220 °C. Furthermore, the magnetic properties have been studied leading to consistent global antiferromagnetic exchange interactions with coupling constants of J = 3 ± 1 cm(-1) and long-range antiferromagnetic ordering states at lower temperatures.

Despite great efforts, the development of a reliable way to assemble mesoporous metal-organic frameworks (mesoMOFs) remains a challenge. In this work, we have designed a cooperative template system, comprising a surfactant (cetyltrimethylammonium bromide) and a chelating agent (citric acid), for the generation of a mesoMOF containing a hierarchical system of mesopores interconnected with microspores. The surfactant molecules form micelles and the chelating agent bridges the MOF and the micelles, making self-assembly and crystal growth proceed under the direction of the cooperative template. However, when the surfactant or the chelating agent was applied individually, no mesoMOF was obtained.

A metal-organic framework (MOF) for reversible alteration of guest molecule adsorption, here carbon dioxide, upon photochemical or thermal treatment has been discovered. An azobenzene functional group, which can switch its conformation upon light irradiation or heat treatment, has been introduced to the organic linker of a MOF. The resulting MOF adsorbs different amount of CO2 after UV or heat treatment. This remarkable stimuli-responsive adsorption effect has been demonstrated through experiments.

A metal-organic framework (MOF) with helical channels has been constructed by bridging helical chain secondary building units with 2,6-di-p-carboxyphenyl-4,4'-bipyridine ligands. The activated MOF shows permanent porosity and gas adsorption selectivity. Remarkably, the MOF exhibits a facile transition from micro- to meso-porosity.

A stable MOF, assigned PCN-105, with two types of mesoporous cages, has been prepared by using a new multidentate flexible ligand with amine functional groups, and PCN-105 exhibits a marked N(2), O(2), Ar and H(2) hysteretic behaviour.