Luteodienoside A is a novel glycosylated polyketide produced by the Australian fungus Aspergillus luteorubrus MST-FP2246, consisting of an unusual 1-O-β-d-glucopyranosyl-myo-inositol (glucinol) ester of 3-hydroxy-2,2,4-trimethylocta-4,6-dienoic acid. Mining the genome of A. luteorubrus identified a putative gene cluster for luteodienoside A biosynthesis (ltb), harbouring a highly reducing polyketide synthase (HR-PKS, LtbA) fused at its C-terminus to a carnitine O-acyltransferase (cAT) domain. Heterologous pathway reconstitution in Aspergillus nidulans, substrate feeding assays and gene truncation confirmed the identity of the ltb cluster and demonstrated that the cAT domain is essential for offloading luteodienoside A from the upstream HR-PKS. Unlike previously characterised cAT domains, the LtbA cAT domain uses glucinol as an offloading substrate to release the product from the HR-PKS. Furthermore, the PKS methyltransferase (MT) domain is capable of catalysing gem-dimethylation of the 3-hydroxy-2,2,4-trimethylocta-4,6-dienoic acid intermediate, without requiring reversible product release and recapture by the cAT domain. This study expands the repertoire of polyketide modifications known to be catalysed by cAT domains and highlights the potential of mining fungal genomes for this subclass of fungal PKSs to discover new structurally diverse secondary metabolites.

Due to similar coordination chemistry of palladium and platinum, a large number of palladium compounds as well have been investigated for their anticancer activity. In the present study, we describe synthesis, characterization, and anticancer activity of palladium complex [Bis(1,8-quinolato)palladium (II)], coded as NH3 against seven different cancer cell lines. NH3 is found to have higher antitumor activity than cisplatin against both parent ovarian A2780 cell line and cisplatin-resistant cell lines. Also, NH3 has the lower IC50 value in HT-29 colorectal cancer cell line. The higher antitumor activity of NH3 is due to the presence of bulky 8-Hydroxyquinoline ligand, thus reducing its reactivity. Proteomic study has identified significantly expressed proteins which have been validated through bioinformatics. NH3 has been found to be less toxic than cisplatin at 2.5 mg/kg and 5 mg/kg dosages on mice models. Binary combinations of NH3 with curcumin and epigallocatechin gallate (EGCG) have demonstrated dose and sequence-dependent synergism in ovarian and colorectal cancer models. All of the preclinical studies indicate promising therapeutic potential of NH3 [Bis(1,8-quinolato)palladium (II)] as an anticancer drug.

Herein we describe single crystalX-ray diffraction and spectroscopic investigations of the coordinationchemistry of copper(II) complexes of cyclam derivatives with between 1 and 4pendant alkynes. The crystal structures of these copper complexes unexpectedly reveala range of coordination modes, and the surprising occurrence of five uniquecomplexes within a single recrystallisation of the tetra-N-propargyl cyclam ligand. One of these species exhibits weakintramolecular copper-alkyne coordination, and another is formed by a surprisingintramolecular copper-mediated hydroalkoxylation reaction with the solventmethanol, transforming one of the pendant alkynes to an enol ether. Multiplefunctionalisation of the tetra-N-propargylligand is demonstrated via a ‘tetra-click’reaction with benzyl azide, and the copper-binding behaviour of the resultingtetra-triazole ligand is characterised spectroscopically.

Oxides of the form ABO4 with A = K, Rb, Cs and B = Ru and Os have been synthesized and characterized by diffraction and magnetic techniques. For A = K the oxides adopted the tetragonal (I41/a) scheelite structure. RbOsO4, which crystallizes as a scheelite at room temperature, underwent a continuous phase transition to I41/amd near 550 K. RbRuO4 and CsOsO4 were found to crystallize in the orthorhombic (Pnma) pseudoscheelite structure, and both displayed discontinuous phase transitions to I41/a at high temperatures. CsOsO4 was determined to undergo a phase transition to a P21/c structure below 140 K. CsRuO4 crystallizes with a baryte-type structure at room temperature. Upon heating CsRuO4 a first order phase transition to the scheelite structure in I41/a is observed at 400 K. A continuous phase transition is observed to P212121 below 140 K. DC magnetic susceptibility data is consistent with long-range antiferromagnetic ordering at low temperatures for all compounds except for CsOsO4, which is paramagnetic to 2 K. The effective magnetic moments are in agreement with the spin only values for an S = 1/2 quantum magnet. Effective magnetic moments calculated for Os compounds were lower than their Ru counterparts, reflective of an enhanced spin orbit coupling effect. A magnetic structure is proposed for RbRuO4 consisting of predominately antiferromagnetic (AFM) ordering along the 001 direction, with canting of spins in the 100 plane. A small ordered magnetic moment of 0.77 μB was determined.

Due to similar coordination chemistry of palladium with platinum, a lot of palladium compounds investigated for their anticancer activity after the discovery of cisplatin. Imidazo[1, 2-alpha]pyridine is a drug precursor scaffold and has already been successfully utilized to come up with a number of clinical drugs against various diseases. In this present study anticancer and antimicrobial activity of three palladium complexes e. g. [PdL4]2Cl (coded as NH4), PdL2Cl2 (coded as NH5) and [PdL4]2Cl.(4H(2)O).L (coded as NH6) where L=imidazo[1,2-alpha]pyridine ligand has been described. All of the synthesized palladium complexes have been characterized by elemental microanalysis and spectral techniques. [PdL4]2Cl and [PdL4]2Cl.(4H(2)O).L were also characterized by single crystal X-ray diffraction method. MTT reduction assay was used to determine the anticancer activity against three human ovarian tumour models and three colorectal tumour models. PdL2Cl2 has shown moderate anticancer activity with lower resistance factor value against ovarian cancer model compared to clinical standard cisplatin. The same complex also exhibited significant antitumour activity in all colorectal tumour models. The rest of the complexes did not show significant anticancer activity but one of the complexes displayed promising antibacterial activity against Staphylococcus aureus. PdL2Cl2 could act at least as a lead to develop new anticancer agent.

Synthetic anion transporters that facilitate transmembrane H+/Cl-symport (cotransport)have anti-cancer potential due to their ability to neutralize pH gradients and inhibit autophagy in cells. However, compared to the natural product prodigiosin, synthetic anion transporters have low-to-modest H+/Cl-symportactivity and their mechanism of action remains less well understood. We here report a chloride-selective tetraurea macrocycle that has a record-high H+/Cl-symportactivity similar to prodigiosin and most importantly demonstrates unprecedented voltage-switchable transport properties that is linked to the lack of uniport activity. By studying anion binding affinity and transport mechanisms of four other anion transporters, we show that the lack of uniport and the voltage-dependent H+/Cl-symport originate from strong binding to lipid phosphate headgroup that hampers the diffusion of the free transporters through the membranes, leading to an unusual H+/Cl-symport mechanism that involves only charged species. Our work provides important mechanistic insights into different classes of anion transporters and a new approach to achieve voltage-switchability in artificial membrane transport systems.

Ein Tetraharnstoff-Makrocyclus und andere synthetische Anionentransporter erleichtern den H+/Cl−-Symport und zeigen abgeschwächte Transportraten in Gegenwart eines Membranpotentials, wie P. A Gale und Mitarbeiter in ihrem Forschungsartikel auf S. 15286 beschreiben. Diese spannungsabhängige Eigenschaft, die an spannungsgesteuerte Ionenkanäle erinnert, steht im Zusammenhang mit der Bindung von Anionentransportern an Lipidphosphat-Kopfgruppen, die die Transmembrandiffusion von Anionentransportern hemmen.

A tetraurea macrocycle and other synthetic anion transporters facilitate transmembrane H+/Cl− symport and show attenuated transport rates in the presence of a membrane potential, as described by P. A. Gale et al. in their Research Article on page 15142 ff. This voltage-dependent property, reminiscent of voltage-gated ion channels, is related to the binding of anion transporters to lipid phosphate headgroups that inhibits the transmembrane diffusion of anion transporters.

Chemical investigation of an undescribed Australian fungus, Aspergillus nanangensis, led to the identification of the nanangenines - a family of seven new and three previously reported drimane sesquiterpenoids. The structures of the nanangenines were elucidated by detailed spectroscopic analysis supported by single crystal X-ray diffraction studies. The compounds were assayed for in vitro activity against bacteria, fungi, mammalian cells and plants. Bioinformatics analysis, including comparative analysis with other acyl drimenol-producing Aspergilli, led to the identification of a putative nanangenine biosynthetic gene cluster that corresponds to the proposed biosynthetic pathway for nanangenines.

Artificial receptors that recognise anionic species vianoncovalent interactions have a wide range of biomedical, industrial and environmental applications. A major challenge in this area of research is to achieve high affinity and selective anion binding in aqueous media. So far, only a few examples of receptors capable of strong (> 105M-1) anion binding in solutions containing > 50% water are available and none show selectivity for chloride. We report here the discovery of a D4h-symmetric fluorinated tetraurea macrocycle that fulfils this function owing to its unique self-assembly properties. The macrocycle has a strong tendency to self-associate into columnar aggregates viaintermolecular hydrogen bonds and aromatic stacking. In aqueous solutions, macrocycle aggregation generates hydrophobic and size-selective binding pockets favourable for hydrogen bonding with chloride. As a result, micromolar affinity and highly selective chloride binding has been achieved with this simple small molecule (MW < 700) in 60 vol% water/acetonitrile.

Synthetic anion transporters that facilitate transmembrane H+/Cl- symport (cotransport) have anti-cancer potential due to their ability to neutralize pH gradients and inhibit autophagy in cells. However, compared to the natural product prodigiosin, synthetic anion transporters have low-to-modest H+/Cl- symport activity and their mechanism of action remains less well understood. We report a chloride-selective tetraurea macrocycle that has a record-high H+/Cl- symport activity similar to that of prodigiosin and most importantly demonstrates unprecedented voltage-switchable transport properties that are linked to the lack of uniport activity. By studying the anion binding affinity and transport mechanisms of four other anion transporters, we show that the lack of uniport and voltage-dependent H+/Cl- symport originate from strong binding to phospholipid headgroups that hampers the diffusion of the free transporters through the membrane, leading to an unusual H+/Cl- symport mechanism that involves only charged species. Our work provides important mechanistic insights into different classes of anion transporters and a new approach to achieve voltage-switchability in artificial membrane transport systems.

The single-crystal structures of calcium D-gluconate and calcium α-D-isosaccharinate have been determined using X-ray diffraction at 100 K. Surprisingly, given its significance in industrial and medical applications, the structure of calcium D-gluconate has not previously been reported. Unexpectedly, the gluconate crystal structure comprises coordination polymers. Unusually, the calcium coordination number is nine. Adjacent metal centres are linked by three μ-oxo bridges, with a metal–metal separation of 3.7312 (2) Å. One of the gluconate ligands contradicts a suggestion from 1974 that a straight chain conformation is associated with an intramolecular hydrogen bond. This ligand binds to three adjacent metal centres. The use of synchrotron radiation provided an improved crystal structure with respect to that previously reported for the isosaccharinate complex, allowing the location of the hydroxy hydrogen sites to be elucidated. In contrast to the gluconate structure, there are no μ-oxo bridges in the isosaccharinate coordination polymer and the isosaccharinate bridging coordination is such that the distance between adjacent metal centres, each of which is eight-coordinate, is 6.7573 (4) Å. Complementing the crystal structure determinations, modelling studies of the geometries and coordination modes for the aqueous [CaGluc] + and [CaIsa] + complexes are presented and discussed.

In the title Ga-III complex compound with pentetic acid, [Ga(C14H20N3O10)(H2O)]center dot 3H(2)O, the Ga-III centre is bound in a slightly distorted octahedral coordination sphere by two amine N atoms, three carboxylate O atoms and one water O atom. The complex molecule exists as a zwitterion. In the crystal, the complexes are linked to each other via O-H center dot center dot center dot O and C-H center dot center dot center dot O hydrogen bonds, forming layers parallel to (001). Three uncoordinating water molecules link the complex layers via O-H center dot center dot center dot O, N-H center dot center dot center dot O and C-H center dot center dot center dot O hydrogen bonds, forming a three-dimensional network.

Ionic liquids (ILs) have been widely promoted as functional replacements of volatile organic solvents; however restricting their use to conventional solvents constrains their potential. One means of enhancing their utility is through the development of dual purpose ILs, capable of acting as both solvent and catalyst. A series of bromozincate ILs was synthesised, and the Lewis acidities probed spectroscopically. Furthermore, the crystal and molecular structure of [C2Py]2[ZnBr4] was determined through single-crystal X-ray diffraction. The ILs were then used in a model reaction, aimed at probing effects of both IL Lewis acidity and structural organisation on the reaction outcome.

The unexplored electron donor molecule triselenathiafulvalene (TSTF) and its corresponding charge transfer complex with the well-known electron acceptor TCNQ exhibit rich electronic, optical and semiconducting properties.

In the title GaIII complex compound with pentetic acid, [Ga(C14H20N3O10)(H2O)]·3H2O, the GaIII centre is bound in a slightly distorted octahedral coordination sphere by two amine N atoms, three carboxylate O atoms and one water O atom. The complex molecule exists as a zwitterion. In the crystal, the complexes are linked to each other via O—H...O and C—H...O hydrogen bonds, forming layers parallel to (001). Three uncoordinating water molecules link the complex layers via O—H...O, N—H...O and C—H...O hydrogen bonds, forming a three-dimensional network.

Abstract We report a rotaxane based on a simple urea motif that binds Cl− selectively as a separated ion pair with H+ and reports the anion binding event through a fluorescence switch‐on response. The host selectively binds Cl− over more basic anions, which deprotonate the framework, and less basic anions, which bind more weakly. The mechanical bond also imparts size selectivity to the ditopic host.

Artificial receptors that recognise anionic species via noncovalent interactions have a wide range of biomedical, industrial and environmental applications. A major challenge in this area of research is to achieve high affinity and selective anion binding in aqueous media. So far, only a few rare examples of receptors capable of strong (>105 M-1) anion binding in solutions containing > 50% water are available and none show selectivity for the highly biologically relevant anion chloride. We report here the discovery of a D4-symmetric fluorinated tetraurea macrocycle that fulfils this function owing to its unique self-assembly properties. The macrocycle has a strong tendency to self-associate into columnar aggregates via intermolecular hydrogen bonds and aromatic stacking interactions. In aqueous solutions, macrocycle aggregation generates size-selective and hydrophobic binding pockets favourable for interactions with chloride via urea hydrogen bond donors. As a result, micromolar affinity and highly selective chloride binding has been achieved with this simple small molecule (MV < 700) in 60 vol% water/acetonitrile.

In the title GaIII complex compound with pentetic acid, [Ga(C14H20N3O10)(H2O)]·3H2O, the GaIII centre is bound in a slightly distorted octa-hedral coordination sphere by two amine N atoms, three carboxyl-ate O atoms and one water O atom. The complex mol-ecule exists as a zwitterion. In the crystal, the complexes are linked to each other via O-H⋯O and C-H⋯O hydrogen bonds, forming layers parallel to (001). Three uncoordinating water mol-ecules link the complex layers via O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds, forming a three-dimensional network.