Influence of pyrrolizidine alkaloids depletion upon the biological activity of Symphytum officinale L. extracts.

Ethnopharmacological Relevance: Comfrey (Symphytum officinale L., Boraginaceae) root preparations are used as both traditional remedies and therapeutic agents in treating pain and inflammation associated with joint, bone, and muscle ailments. Even though numerous phytochemicals contribute to the beneficial effects of comfrey, the presence of toxic pyrrolizidine alkaloids (PAs) overshadows its uses.

Influence of the Post-Harvest Storage Time on the Multi-Biological Potential, Phenolic and Pyrrolizidine Alkaloid Content of Comfrey ( L.) Roots Collected from Different European Regions.

Comfrey ( L.) roots are well-known bioactive ingredients included in various cosmeceutical and pharmaceutical preparations. In this study, the influence of the post-harvest storage on the chemico-biological potential of roots collected from different European regions and stored for up to six months was investigated.

Globoidnan A, rabdosiin and globoidnan B as new phenolic markers in European-sourced comfrey (Symphytum officinale L.) root samples.

Introduction: Symphytum officinale L. (comfrey, Boraginaceae) is a cultivated or spontaneously growing medicinal plant that is traditionally used for the treatment of bone fractures, hematomas, muscle pains and joint pains. A wide range of topical preparations and dried roots for ex tempore applications are marketed in European drug stores or pharmacies.

Symphytum officinale L.: Liquid-liquid chromatography isolation of caffeic acid oligomers and evaluation of their influence on pro-inflammatory cytokine release in LPS-stimulated neutrophils.

Ethnopharmacological Relevance: Symphytum officinale L. (comfrey, Boraginaceae) has been traditionally used for millennia in joint distortions, myalgia, bone fractures and hematomas. However, key activity-determining constituents and molecular mechanisms underlying its use have not been completely elucidated.

Is comfrey root more than toxic pyrrolizidine alkaloids? Salvianolic acids among antioxidant polyphenols in comfrey (Symphytum officinale L.) roots.

Comfrey root preparations are used for the external treatment of joint distortions and myalgia, due to its analgesic and anti-inflammatory properties. Up to date, key activity-determining constituents of comfrey root extracts have not been completely elucidated. Therefore, we applied different approaches to further characterize a comfrey root extract (65% ethanol).

Biotransformation of hexabromocyclododecanes with hexachlorocyclohexane-transforming Sphingobium chinhatense strain IP26.

Bacterial evolution has resulted in the appearance of several Sphingomonadacea strains that gained the ability to metabolize hexachlorocyclohexanes (HCHs). HCHs have been widely used as pesticides but were banned under the Stockholm Convention on persistent organic pollutants (POPs) in 2009. Here we present evidence for bacterial transformation reactions of hexabromocyclododecanes (HBCDs), which are structurally related to HCHs.

A simple HPLC-MS method for the quantitative determination of the composition of bacterial medium chain-length polyhydroxyalkanoates.

Bacterial poly(hydroxyalkanoates) (PHAs) vary in the composition of their monomeric units. Besides saturated side-chains, unsaturated ones can also be found. The latter leads to unwanted by-products (THF ester, secondary alcohols) during acidic cleavage of the polymer backbone in the conventional analytical assays.

Autoxidation of medium chain length polyhydroxyalkanoate.

Polyhydroxyalkanoates (PHAs) are a class of biopolymers that are currently the subject of intensive research for various applications (packaging, consumer products, medical applications, etc.). It is known from synthetic polymers that all plastic materials show more or less pronounced autoxidation (aging induced by UV radiation, temperature, heavy metal ions, etc.

Quantitative analysis of bacterial medium-chain-length poly([R]-3-hydroxyalkanoates) by gas chromatography.

Standard chromatographic methods for the quantification of bacterial poly(3-hydroxyalkanoate) (PHA) proved to be inappropriate for the analysis of medium-chain-length PHA (mcl-PHA). Transesterification catalyzed by protic acids is not quantitative for mcl-PHA under common conditions due to slow reaction kinetics and formation of side-products in case of functionalized side-chains. To circumvent these limitations, an improved method for the quantification of mcl-PHA by GC-FID was developed.

Efficient production of (R)-3-hydroxycarboxylic acids by biotechnological conversion of polyhydroxyalkanoates and their purification.

An efficient method to prepare enantiomerically pure (R)-3-hydroxycarboxylic acids from bacterial polyhydroxyalkanoates (PHAs) accumulated by Pseudomonas putida GPo1 is reported in this study. (R)-3-Hydroxycarboxylic acids from whole cells were obtained when conditions were provided to promote in vivo depolymerization of intracellular PHA. The monomers were secreted into the extracellular environment.

Bacterial poly(hydroxyalkanoates) as a source of chiral hydroxyalkanoic acids.

Polyhydroxyalkanoates (PHA) are polyesters of various hydroxyalkanoates accumulated in numerous bacteria. All of the monomeric units of PHA are enantiomerically pure and in R-configuration. R-Hydroxyalkanoic acids can be widely used as chiral starting materials in fine chemical, pharmaceutical and medical industries.

Molecular assembly of redox-conductive ferrocene-streptavidin conjugates--towards bio-electrochemical devices.

Peptidic spacers, 0.4 and 2 nm in length, were used to couple ferrocene moieties to streptavidin. The resulting conjugates were immobilised on electrode surfaces using biotin binding.

Redox labelled avidin for enzyme sensor architectures.

Conjugates of avidin with ferrocene and with microperoxidase 8 have been used as electrochemically active molecular building blocks. Assemblies of the conjugates with biotinylated glucose oxidase or lactate oxidase on gold electrodes were tested as enzyme sensors for glucose and lactate. The electrochemical detection is based either on ferrocene-mediated oxidation of the substrate in oxygen-free solution, or on microperoxidase-catalysed reduction of H2O2 which is enzymatically produced from the substrate and molecular oxygen.