Chemical Constituents from a Soil‐Derived Actinomycete,Actinomadura miaoliensis BCRC 16873, and Their Inhibitory Activities on Lipopolysaccharide‐Induced Tumor Necrosis Factor Production

An investigation on the secondary metabolites from the BuOH extract of the fermentation broth of the thermotolerant polyester‐degrading actinomycete Actinomadura miaoliensis BCRC 16873 was carried out. One previously undescribed α‐pyrone (=pyran‐2‐one) derivative, designated as miaolienone ( 1 ), and a new butanolide, miaolinolide ( 2 ), together with 13 known compounds, 3 – 15 , were obtained. Their structures were established on the basis of extensive 1D‐ and 2D‐NMR analyses in combination with HR‐MS experiments. In addition, the isolated compounds 1 – 15 were evaluated for the inhibitory effects of the isolates on the production of tumor necrosis factor (TNF‐α) induced by lipopolysaccharide (LPS). Among the isolates, 1 and 2 significantly inhibited TNF‐α production in U937 cells in vitro, and the IC₅₀ values were 0.59 and 0.76 μM , respectively. Compounds 3 – 5 displayed moderate inhibitory activities on LPS‐induced TNF‐α production.     

Selective binding of imatinib to the genetic variants of human α1-acid glycoprotein

Imatinib is a selective tyrosine kinase inhibitor, successfully used for the treatment of chronic myelogenous leukaemia. Its strong plasma protein binding referred to α₁-acid glycoprotein (AGP) component was found to inhibit the pharmacological activity. AGP shows genetic polymorphism and the two main genetic variants have different drug binding properties. The binding characteristics of imatinib to AGP genetic variants and the possibility of its binding interactions were investigated by various methods. The results proved that binding of imatinib to the two main genetic variants is very different, the high affinity binding belongs dominantly to the F1-S variant. This interaction is accompanied with specific spectral changes (induced circular dichroism, UV change, intrinsic fluorescence quenching), suggesting that the bound ligand has chiral conformation that would largely overlap with other ligands inside the protein cavity. Binding parameters of K_a = 1.7(± 0.2) × 10⁶ M^− 1 and n = 0.94 could be determined for the binding on the F1-S variant at 37°. Imatinib binding on the A variant is weaker and less specific. The binding affinity of imatinib to human serum albumin (nK_a ≈ 3 × 10⁴ M^− 1) is low. Pharmacologically relevant binding interactions with other drugs can be expected on the F1-S variant of AGP.     

Hydrolysis by phospholipase D of phospholipids in solution state or adsorbed on a silica matrix

Phospholipases D (PLD) catalyse hydrolysis and transphosphatidylation reactions in phospholipids. In the present study, the hydrolytic activity for cabbage PLD was investigated with five different substrates (dipalmitoylphosphatidylethanolamine (DPPE), dipalmitoylphosphatidylcholine (DPPC), didecanoylphosphatidylcholine (DDPC), 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine and lyso-phosphatidylcholine (lyso-PC)) in solution or adsorbed on a silica matrix. In the specific buffer solutions, where the substrates were proved to form large multilamellar polydisperse aggregates, PLD showed preference for DPPC > DPPE > DDPC > 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine > lyso-PC. When the substrates were adsorbed on the silica matrix, PLD hydrolysed 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine and lyso-PC, DDPC, but not DPPC or DPPE. Theoretical studies of the simplest possible adducts between the phospholipids and the silica matrix were performed. Examination of local geometries of DPPC showed a significant blocking of the P-O-X bond-prone to hydrolysis, which could possibly block the access of PLD. Immobilization of phospholipids could be applied for improving the yield of reactions catalysed by PLD as well as for performing a targeted production of short-chain length phosphatidic acid analogs.     

Introducing Templates for Sustainable Product Development

We have previously developed a method for sustainable product development (MSPD) based on backcasting from basic sustainability principles. The MSPD informs investigations of product‐related social and ecological sustainability aspects throughout a concurrent engineering product development process. We here introduce “templates” for sustainable product development (TSPDs) as a complement. The idea is to help product development teams to arrive faster and more easily at an overview of the major sustainability challenges and opportunities of a product category in the early development phases. The idea is also to inform creative communication between top management, stakeholders, and product developers. We present this approach through an evaluation case study, in which the TSPDs were used for a sustainability assessment of televisions (TVs) at the Matsushita Electric Group. We study whether the TSPD approach has the ability to (1) help shift focus from gradual improvements of a selection of aspects in relation to past environmental performance of a product category to a focus on the remaining gap to a sustainable situation, (2) facilitate consensus among organizational levels about major sustainability challenges and potential solutions for a product category, and (3) facilitate continued dialogue with external sustainability experts, identifying improvements that are relevant for strategic sustainable development. Our findings indicate that the TSPD approach captures overall sustainability aspects of the life cycle of product categories and that it has the above abilities.     

Zinc ion binding to human brain calcium binding proteins. Calmodulin and S100b protein

Comparative studies have been performed on the binding properties of zinc ions to human brain calmodulin and S100b protein. Calmodulin is characterized by two sets of Zn²⁺ binding sites, with K_D ranging from 8.10^?5M to 3.10^?4M. The S100b protein also exhibited two sets of zinc binding sites, with a much higher affinity. K_D = 10^?7 ? 10^?6M. We suggest that S100b protein should no longer be considered only as a “calcium binding protein” but also as a “zinc binding protein”, and that Zn²⁺ ions are involved in the functions of the S100 proteins.     

The interaction of an amphipathic fluorescence probe, 2-p-toluidinonaphthalene-6-sulphonate,with isolated chloroplasts

The amphipathic fluorescence probe, 2-p-toluidinonaphthalene-6-sulphonate has been used to investigate the surface electrical properties of chloroplast thylakoid membranes. The fluorescence yield of 2-p-toluidinonaphthalene-6-sulphonate in aqueous solution increases on addition of hypotonically shocked chloroplast, and the emission maximum shifts towards the blue to 440 nm, although the emission spectrum is somewhat distorted by chloroplast pigment absorption.The intensity of 2-p-toluidinonaphthalene-6-sulphonate fluorescence is further increased on adding salts to the membrane suspension, and changes of >100% are routinely observed. Similar observations have also been made with soya bean phospholipid (azolectin) liposomes. The magnitude of the fluorescence increase is dependent on membrane concentration, being more pronounced at high surface area/suspending volume ratios. The effect of salt addition appears to be that of shielding the fixed negative charges on the membrane surface, thus increasing the fraction of 2-p-toluidinonaphthalene-6-sulphonate molecules at the surface, where the 2-p-toluidinonaphthalene-6-sulphonate has a higher fluorescence yield than in free aqueous solution. This concept is supported by the fact that the effectiveness of salts in increasing 2-p-toluidinonaphthalene-6-sulphonate fluorescence is as predicted by classical electrical double layer theory: governed mainly by the charge carried by the cation with an order of effectiveness C³⁺ > C²⁺ > C⁺, and not by the chemical nature of the cation or by the nature of its co-ion.It has been argued that the chlorophyll fluorescence yield, controlled by the cation composition of the suspending medium follows the total diffusible positive charge density at the thylakoid membrane surface (Barber, J., Mills, J. and Love, A. (1977) Febs. Lett. 74, 174–181). Although the cation induced 2-p-toluidinonaphthalene-6-sulphonate and chlorophyll fluorescence yield changes show similar characteristics, there are also distinct differences between the two phenomena particularly when cations are added to chloroplasts initially suspended in a virtually cation-free medium. Therefore it is concluded that although both 2-p-toluidinonaphthalene-6-sulphonate and chlorophyll fluorescence yields are governed by the electrical properties of the thylakoid membrane surface, the mechanism controlling their cation sensitivity is not the same.     

A fluorimetric study of substrate and effector binding of D-ribulose-1,5-biphosphate carboxylase/oxygenase from spinach

2-p-toluidino-naphthalene-6-sulfonate (TNS) is a sensitive fluorescent reporter group for the detection of the events at the reaction centres of the ribulose biphosphate carboxylase/oxygenase from spinach. The formation of binary complexes of the carboxylase with substrates and effectors is associated with significant changes (ΔF) of the fluorescence emission of the enzyme-TNS-complex. This indicates substrate and effector induced conformational changes of the enzyme. From the concentration dependence of ΔF the following dissociation constants for ribulose biphosphate (RuBP) and Mg²⁺ were determined: K(RuBP) = 0,5 μM and K(Mg²⁺) = 1 mM. Sugar phosphates, e.g. 6-phosphogluconate, which show regulatory effects in the carboxylation and oxygenation of RuBP, function antagonistically to RuBP, presumably by competition with RuBP for its allosteric binding site.     

Sustainability Constraints as System Boundaries: An Approach to Making Life-Cycle Management Strategic

Sustainable management of materials and products requires continuous evaluation of numerous complex social, ecological, and economic factors. A number of tools and methods are emerging to support this. One of the most rigorous is life-cycle assessment (LCA). But LCAs often lack a sustainability perspective and bring about difficult trade-offs between specificity and depth, on the one hand, and comprehension and applicability, on the other. This article applies a framework for strategic sustainable development (often referred to as The Natural Step (TNS) framework) based on backcasting from basic principles for sustainability. The aim is to foster a new general approach to the management of materials and products, here termed "strategic life-cycle management". This includes informing the overall analysis with aspects that are relevant to a basic perspective on (1) sustainability, and (2) strategy to arrive at sustainability. The resulting overview is expected to help avoid costly assessments of flows and practices that are not critical from a sustainability and/or strategic perspective and to help identify strategic gaps in knowledge or potential problems that need further assessment. Early experience indicates that the approach can complement some existing tools and concepts by informing them from a sustainability perspective-for example, current product development and LCA tools.