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Abstract: Cynomorium coccineum L. is a non-photosynthetic plant, spread over Mediterranean countries, amply used in traditional medicine. We investigated the composition and effect on intestinal Caco-2 cell viability and lipid profile of fixed oil obtained from dried stems of the plant. Oil isolation has been performed by supercritical fractioned extraction with CO2. 13C NMR spectroscopy has been used to study the molecular composition of oil lipids; fatty acid composition was identified using GC and HPLC techniques. The fixed oil was composed mainly by triacylglycerols and derivates. The main fatty acids were 18:1 n−9 (38%), 18:2 n−6 (20%), 16:0 (15%), and 18:3 n−3 (10.8%). The oil showed a significant in vitro inhibitory effect on the growth of colon cancer undifferentiated Caco-2 cells. Moreover, cell viability, lipid composition, and lipid peroxidation were measured in intestinal epithelial cells (differentiated Caco-2 cells) after 24h incubation with fixed oil. The oil did not show a toxic effect on colon epithelial cell viability but induced a significant change in fatty acid composition, with a significant accumulation of the essential fatty acids 18:3 n−3 and 18:2 n−6. The results showed remarkable biological activity of Maltese mushroom oil, and qualify it as a potential resource for food/pharmaceutical applications. [Copyright &y& Elsevier]

Abstract: Tyrosinase is a copper-enzyme involved in important biological processes. Many studies investigating these topics have relied on commercial preparations of mushroom tyrosinase as a tool or use as a model system. In this study, several commercial preparations of tyrosinase have been examined with regard to their composition and purity. Enzyme activities different from tyrosinase were found. Laccase, β-glucosidase, β-xylosidase, and xylanase activities were found in almost all samples examined. In particular, laccase and β-glucosidase were investigated for their ability to affect tyrosinase activity under certain experimental conditions. Laccase activity was variable in different commercial preparations and its presence could lead to misinterpretation of results ascribed to tyrosinase activity. In fact, it could hide the inhibitory effect of tropolone and kojic acid in relation to tyrosinase activity. β-Glucosidase released the aglycon moiety from the glucoside esculin which in turn could become a tyrosinase inhibitor or substrate. SDS–PAGE of commercial mushroom tyrosinase showed a complex pattern of unidentified proteins with at least four major and many minor protein staining bands. Taken together, these findings confirm that investigators should use caution in interpreting data relying on commercial sources of mushroom tyrosinase. [Copyright &y& Elsevier]

Abstract: Phenosafranine is a toxic, polluting dye, belonging to the N-phenylphenazinium class, whose inexpensive and environmentally friendly elimination from industrial effluents could be of interest. In this study we report phenosafranine degradation and concomitant decolorization of the corresponding wastewaters by H2O2 oxidation in the presence of 5,10,15,20-tetrakis(4-sulfonatophenyl)-porphine-Mn(III) catalyst immobilized on a modified silica support bearing imidazolyl functionality. Some operational features of the catalytic process are described and a chemical mechanism for the bleaching process is hypothesized. The proposed method was compared to others, based on the use of the oxidizing enzymes such as laccase, horseradish peroxidase, and lignin peroxidase. [Copyright &y& Elsevier]

Kojic acid is a natural antifungal and antibacterial agent that has been extensively studied for its tyrosinase inhibitory and metal coordination properties. Tyrosinase is a metalloenzyme with two copper ions in the active site. It is widely accepted that the tyrosinase inhibitory activity of kojic acid is related to its ability to coordinate metals. Over the past five years, we have used kojic acid to synthesize new and efficient bis-kojic acid chelators of iron and aluminium. In parallel, we investigated whether the de novo designed ligands could interfere with proper tyrosinase functioning. The present study combines our experience with inhibition and coordination studies of the new ligand: Kojic-βAla-Kojic. Research aimed at the assembly of a new potent tyrosinase inhibitor was based on the well-known crystal structure of the enzyme. Two questions were whether two kojic acids could act better than one and to what extent the length and kind of linker could ameliorate metal coordination, and inhibitory activity. Our results show that Kojic-βAla-Kojic has high affinity for Fe(III), Al(III), Zn(II), and Cu(II) and strong tyrosinase inhibitory effect and it can be proposed for use in industrial and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Abstract: Ferula communis (L.), a plant belonging to Apiaceae, is widely present in Sardinia, Italy. Currently, interest in F. communis focuses on the presence of two chemotypes in the wild. One chemotype is poisonous to animals, whereas the other chemotype is non-poisonous. Polyphenol oxidase (PPO) has been extracted and partially purified from the two chemotypes of F. communis. The biochemical characterization of the enzymes showed significant differences. In particular, while the two PPOs were not able to use 6- and 7-hydroxycoumarin as substrates, they showed distinct specificity for 6,7- and 7,8-dihydroxycoumarin. Significant differences in the enzyme behavior towards common PPO inhibitors were also observed. In addition, activation energy and activation energy for denaturation were determined, showing significant differences between FP-PPO and FNP-PPO, particularly for denaturation kinetics. The possible roles of the two PPOs in determining differences in composition and toxicity of the two F. communis chemotypes are also discussed. [Copyright &y& Elsevier]

Abstract: With the aim to design new chelators for the clinical treatment of different diseases involving the trivalent metal ions Fe(III) and Al(III), we present the equilibria of kojic acid and its derivative 6-[5-hydroxy-2-hydroxymethyl-pyran-4-one]-5-hydroxy-2-hydroxymethyl-pyran-4-one with these two metal ions. Potentiometric and spectrophotometric techniques for iron, and potentiometry and 1H NMR for aluminum were used, supported by X-ray, electrospray ionization-mass spectrometry (ESI-MS), calorimetry and quantum chemical calculations. In this work, evidence is given on the formation of MeL, MeL2, and MeL3 complexes of both metal ions with kojic acid, confirmed by the X-ray structure of the FeL3 complex, and of variously protonated Me2L2 and MeL2 complexes of 6-[5-hydroxy-2-hydroxymethyl-pyran-4-one]-5-hydroxy-2-hydroxymethyl-pyran-4-one. The extremely good pFe value for this second ligand gives confidence to, and opens perspectives for, the search of new kojic acid derivatives. [Copyright &y& Elsevier]

A fractionation of wheat straw components in a two-step chemical pretreatment is proposed. Hemicelluloses were hydrolysed by dilute sulphuric acid, allowing a substantial recovery of crystalline xylose. Lignin was removed by means of a mild alkaline/oxidative solubilisation procedure, involving no sulphite or chlorine and its derivatives. The use of diluted reagents and relatively low temperatures, was both cheap and environmentally friendly. The pretreated material was nearly pure cellulose, whose enzymic hydrolysis proceeded fast and with high yields, leading to high glucose syrups of remarkable purity. [Copyright &y& Elsevier]

The botanical identity of the ancient vernacular cynomorium does not correspond to the modern scientific genus while it is not clear how many species of hipocistis (Cytinus sp.) were differentiated by the ancient physicians and whether Cynomorium coccineum was subsumed. The early history of therapeutic uses related to the herbal drugs derived from these parasitic taxa is therefore not easily accessible. Cynomorium coccineum became an important pharmaceutical commodity after the Siege of Malta but its importance decreased in the 18th century and now is considered obsolete. We compare the morphological, ecological and therapeutic information of Cynomorium and other parasitizing plant taxa across the past 2000 years and contextualize their uses with the pharmacological properties of their principal metabolites focusing on the raise and fall of C. coccineum as a medicine. The therapeutic uses of C. coccineum , the Maltese mushroom, seem to become clearly traceable since the Canon of Medicine by Avicenna. Styptic and astringent drugs such as Cynomorium , Cytinus but also gall apples and many others have been selected for their protein-linking capacity leading to the formation of a protective layer on the mucous membranes, which can be used to reduce the secretion of water and electrolytes in case of diarrhoea, dysentery and external bleedings. Whether C. coccineum is effective as a systemically applied anti-haemorrhagic drug is questionable. It appears that the vernacular cynomorium of the ancients corresponds to an edible Orobanche sp. while it remains doubtful whether the vernacular hipocistis was next to Cytinus sp. also applied to C. coccineum as evidence of C. coccineum parasitizing Cistus sp. is scarce. The isolation of gallic acid used as a styptic and the increasing availability of chemical styptics in the 18th century together with the availability of effective alternative anti-diarrhoeic drugs with a more reliable supply very probably led to the decline of the importance of the Maltese mushroom in pharmacy during the 18th century. The effectiveness of gallic acid as a systemic anti-haemorrhagic remains uncertain. Image 1 [ABSTRACT FROM AUTHOR]