Fluorescent indicator dyes for calcium ions

The present invention discloses a new class of highly fluorescent indicator dyes that are specific for calcium ions. The new fluorescent indicator dyes combine a stilbene-type fluorophore with a tetracarboxylate parent Ca.sup.2+ chelating compound having the octacoordinate pattern of liganding groups characteristic of EGTA and BAPTA. Preferred forms contain extra heterocyclic bridges to reinforce the ethylenic bond of the stilbene and to reduce hydrophobicity. Compared to their widely used predecessor, quin2, the new dyes offer up to thirty-fold brighter fluorescence, major changes in wavelength (not just intensity) upon Ca.sup.2+ binding, slightly lower affinities for Ca.sup.2+, slightly longer wavelengths of excitation, and considerably improved selectivity for Ca.sup.2+ over other divalent cations. These properties, particularly the wavelength sensitivity to Ca.sup.2+, make the dyes useful indicators for many intracellular applications, especially in single cells, adherent cell layers, or bulk tissues. The present invention also discloses an improved method for synthesizing alpha-acyloxyalkyl bromides wherein the bromides so synthesized are free of contaminating bis(1-bromoalkyl)ether. The improved method is exemplified herein in the synthesis of acetoxymethyl bromide, a compound useful in preparing the acetoxymethyl esters disclosed herein as novel Ca.sup.2+ specific fluorescent indicators

Chelators whose affinity for calcium is decreased by illumination

The present invention discloses a group of calcium chelating compounds which have a descreased affinity for calcium following illumination. These new compounds contain a photolabile nitrobenzyl derivative coupled to a tetracarboxylate Ca.sup.2+ chelating parent compound having the octacoordinate chelating groups characteristic of EGTA or BAPTA. In a first form, the new compounds are comprised of a BAPTA-like chelator coupled to a single 2-nitrobenzyl derivative, which in turn is a photochemical precursor of a 2-nitrosobenzophenone. In a second form, the new compounds are comprised of a BAPTA-like chelator coupled to two 2-nitrobenzyl derivatives, themselves photochemical prcursors of the related 2-nitrosobenzophenones. The present invention also discloses a novel method for preparing 1-hydroxy- or 1-alkoxy-1-(2-nitroaryl)-1-aryl methanes. Methanes of this type are critical to the preparation of, or actually constitute, the photolabile Ca.sup.2+ chelating compounds disclosed and claimed herein

Synthetic genistein derivatives as modulators of glycosaminoglycan synthesis

Background: Mucopolysaccharidoses (MPS) are severe metabolic disorders caused by 26 accumulation of undegraded glycosaminoglycans (GAGs) in lysosomes due to defects in certain 27 lysosomal hydrolases. Substrate reduction therapy (SRT) has been proposed as one of potential 28 treatment procedures of MPS. Importantly, small molecules used in such a therapy might 29 potentially cross the blood-brain barrier (BBB) and improve neurological status of patients, as 30 reported for a natural isoflavone, 5, 7-dihydroxy-3- (4-hydroxyphenyl)-4H-1-benzopyran-4-one, 31 also known as genistein. Although genistein is able to cross BBB to some extent, its delivery to 32 the central nervous system is still relatively poor (below 10% efficiency). Thus, we aimed to 33 develop a set of synthetically modified genistein molecules and characterize physicochemical as 34 well as biological properties of these compounds. Methods: Following parameters were 35 determined for the tested synthetic derivatives of genistein: cytotoxicity, effects on cell 36 proliferation, kinetics of GAG synthesis, effects on epidermal growth factor (EGF) receptor’s 37 tyrosine kinase activity, effects on lysosomal storage, potential ability to cross BBB. Results: We 38 observed that some synthetic derivatives inhibited GAG synthesis similarly to, or more 39 efficiently than, genistein and were able to reduce lysosomal storage in MPS III fibroblasts. The 40 tested compounds were generally of low cytotoxicity and had minor effects on cell proliferation. 41 Moreover, synthetic derivatives of genistein revealed higher lipophilicity (assessed in silico) than 42 the natural isoflavone. Conclusion: Some compounds tested in this study might be promising 43 candidates for further studies on therapeutic agents in MPS types with neurological symptoms

Beneficial Effects of Vitamins K and D3 on Redox Balance of Human Osteoblasts Cultured with Hydroxyapatite-Based Biomaterials

Hydroxyapatite-based biomaterials are commonly used in surgery to repair bone damage. However, the introduction of biomaterials into the body can cause metabolic alterations, including redox imbalance. Because vitamins D3 and K (K1, MK-4, MK-7) have pronounced osteoinductive, anti-inflammatory, and antioxidant properties, it is suggested that they may reduce the adverse effects of biomaterials. The aim of this study was to investigate the effects of vitamins D3 and K, used alone and in combination, on the redox metabolism of human osteoblasts (hFOB 1.19 cell line) cultured in the presence of hydroxyapatite-based biomaterials (Maxgraft, Cerabone, Apatos, and Gen-Os). Culturing of the osteoblasts in the presence of hydroxyapatite-based biomaterials resulted in oxidative stress manifested by increased production of reactive oxygen species and decrease of glutathione level and glutathione peroxidase activity. Such redox imbalance leads to lipid peroxidation manifested by an increase of 4-hydroxynonenal level, which is known to influence the growth of bone cells. Vitamins D3 and K were shown to help maintain redox balance and prevent lipid peroxidation in osteoblasts cultured with hydroxyapatite-based biomaterials. The strongest effect was observed for the combination of vitamin D3 and MK-7. Moreover, vitamins promoted growth of the osteoblasts, manifested by increased DNA biosynthesis. Therefore, it is suggested that the use of vitamins D3 and K may protect redox balance and support the growth of osteoblasts affected by hydroxyapatite-based biomaterials

Genistein Improves Neuropathology and Corrects Behaviour in a Mouse Model of Neurodegenerative Metabolic Disease

BACKGROUND: Neurodegenerative metabolic disorders such as mucopolysaccharidosis IIIB (MPSIIIB or Sanfilippo disease) accumulate undegraded substrates in the brain and are often unresponsive to enzyme replacement treatments due to the impermeability of the blood brain barrier to enzyme. MPSIIIB is characterised by behavioural difficulties, cognitive and later motor decline, with death in the second decade of life. Most of these neurodegenerative lysosomal storage diseases lack effective treatments. We recently described significant reductions of accumulated heparan sulphate substrate in liver of a mouse model of MPSIIIB using the tyrosine kinase inhibitor genistein. METHODOLOGY/PRINCIPAL FINDINGS: We report here that high doses of genistein aglycone, given continuously over a 9 month period to MPSIIIB mice, significantly reduce lysosomal storage, heparan sulphate substrate and neuroinflammation in the cerebral cortex and hippocampus, resulting in correction of the behavioural defects observed. Improvements in synaptic vesicle protein expression and secondary storage in the cerebral cortex were also observed. CONCLUSIONS/SIGNIFICANCE: Genistein may prove useful as a substrate reduction agent to delay clinical onset of MPSIIIB and, due to its multimodal action, may provide a treatment adjunct for several other neurodegenerative metabolic diseases

Związki naturalne w farmacji i medycynie. Kwas salicylowy i fenolokwasy. Natural products in pharmacy and medicine. Salicylic acid and related phenolic acids.

Kwas salicylowy (KS) jest najprostszym przedstawicielem grupy metabolitów wtórnych roślin wyższych, zwanych fenolokwasami, które odgrywają ważne role biologiczne zarówno w fizjologii roślin, jak i w ochronie zdrowia ludzkiego. W artykule przedstawiono krótki rys historyczny badań i zastosowań KS, pozyskiwanego ze źródeł naturalnych i przemysłowych, oraz wiadomości dotyczące występowania jego analogów strukturalnych w roślinach. Opisano rolę KS jako fitohormonu i induktora odpowiedzi na stres u roślin oraz jako inhibitora wytwarzania mediatorów stanu zapalnego u ludzi. Salicylic acid (SA) is the simplest example of molecule belonging to the group of plant secondary metabolites, classified as phenolic acids. These compounds are of considerable importance not only for well being of the host organisms but also have advantageous influence on human physiology. Short account of natural and synthetic SA studies, as well as its structural analogs, is presented. The role of SA in plant local and systemic pathogen resistance phenomena is described, and its significance for anti-inflammatory therapies in humans are discussed

Isoflavone research towards healthcare applications

A survey of the current literature on natural isoflavones and their biological activity is presented. This subcategory of a large group of plant polyphenolics has particular characteristics, structural as well as pharmacological, which makes it suitable for discussion of pleiotropic activities of phytochemicals and their exploitation in healthcare, beyond the concept of selectively targeted new drugs for narrow therapeutic indication

Curcumin and curcuminoids in quest for medicinal status

Curcumin, known for thousands of years as an Ayurvedic medicine, and popular as a spice in Asian cuisine, has undergone in recent times remarkable transformation into a drug candidate with prospective multipotent therapeutic applications. Characterized by high chemical reactivity, resulting from an extended conjugated double bond system prone to nucleophilic attack, curcumin has been shown to interact with a plethora of molecular targets, in numerous experimental observations based on spectral, physicochemical or biological principles. The collected preclinical pharmacological data support traditional claims concerning the medicinal potential of curcumin and its congeners but at the same time point to their suboptimal properties in the ADME (absorption, distribution, metabolism and excretion) area

Triterpene sapogenins with oleanene skeleton: chemotypes and biological activities

Critical survey of a selected class of pentacyclic triterpenes - the oleanane family, is presented based on current literature in order to underline their value for medicinal chemistry and drug development potential. Oleanenes may be considered as a renewable resource of valuable research materials which are structurally diverse, inherently biocompatible and have built-in affinity for many categories of functional proteins. Although availability of particular compounds from natural sources may be very low, synthetic methods elaborated by generations of chemists, secure a way to obtaining desirable structures from commercial starting materials