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D Hadjipavlou-Litina

Publications and source records attributed to D Hadjipavlou-Litina.

14 recordsLinked to original sources
PubMed2006

Analysis of the essential oil of Origanum dubium growing wild in Cyprus. Investigation of its antioxidant capacity and antimicrobial activity.

The volatile composition of Origanum dubium in two different maturation stages has been studied. The essential oils were obtained by hydrodistillation in a modified Clevenger-type apparatus, and their analyses were performed by GC and GC-MS. Identification of the components was made by comparison of mass spectra and retention indices with literature records and by co-chromatography with authentic compounds. Carvacrol was shown to be the main constituent. The essential oils were evaluated for antimicrobial activity and proved to be active against all tested microorganisms. Furthermore, their potential antioxidant activity was investigated and found to be significant in scavenging O2-. The samples were further evaluated for inhibition of soybean lipoxygenase LOX and showed high inhibitory activity.

Anti-Bacterial Agents↗
PubMed2006

Evaluation of anti-inflammatory and antioxidant activities of mixed-ligand Cu(II) complexes of dien and its Schiff dibases with heterocyclic aldehydes and 2-amino-2-thiazoline.

A new series of complexes of the type [Cu(dien)(2a-2tzn)Y2] and [Cu(dienXX)(2a-2tzn)Y2] has been tested for anti-inflammatory and antioxidant activity. The tested compounds inhibit significantly the carrageenin induced paw edema (36.4-55.8%) and present important scavenging activities. Although their interaction with the free stable radical DPPH is not high they peroxide anions. Compound 7 is the most potent (55.8%) in the in vivo experiment. Lipophilicity--as RM values and theoretically calculated logP values--has been determined. An attempt to correlate the biological results with their structural characteristics and physicochemical parameters has been done.

Aldehydes↗
PubMed2006

Antioxidant and anti-inflammatory activity of aryl-acetic and hydroxamic acids as novel lipoxygenase inhibitors.

Lipoxygenase plays an essential role in the biosynthesis of the leukotrienes. Leukotrienes, as LO metabolites of arachidonic acid (AA), have been implicated as mediators in the pathophysiology of inflammatory diseases, host defense reactions and to play important role in the propagation of the diseases states, exacerbating the local events and ultimately leading to tissue damage. Simple stable molecules containing the hydroxamic acid functionality have been shown to inhibit 5-lipoxygenase. In fact, several hydroxamates are orally active inhibitors of the enzyme as determined by their ability to block the biosynthesis of leukotriene in vivo. In order to establish the inhibitory utility of simple hydroxamates several omega-phenylalkyl and omega-naphthylalkyl hydroxamic acids were synthesized. In an attempt to expand and delineate these results we tried to synthesize some more for a further pharmacochemical study. Since lipophilicity is a significant physicochemical property determining distribution, bioavailability, metabolic activity and elimination, we tried to determine experimentally their lipophilicity from RPTLC method. The compounds are tested in vitro on: a) soybean lipoxygenase inhibition, b) interaction with 1,1-diphenyl-2-picryl-hydrazyl (DPPH) stable free radical, c) the HO* radical mediated oxidation of DMSO, d) inhibition of lipid peroxidation, e) scavenging of superoxide anion radicals f) interaction with glutathione and g) in vivo for the inhibition of carrageenin induced rat paw edema. The compounds have shown important antioxidant activity, medium anti-inflammatory activity and potent inhibition of soybean lipoxygenase as a result of their physichochemical features.

Acetates↗
PubMed2005

A review on quantitative structure-activity relationships (QSARs) of natural and synthetic antioxidants compounds.

During the last decade an increasing number of reports describe the roles of active oxygen species in the development or exacerbation of various kinds of diseases. Antioxidants are of great interest because of their involvement in important biological and industrial processes. They have been found to possess anticancer, anti-cardiovascular, anti-inflammatory and many other activities. Many attempts have been made to elucidate the QSAR of antioxidants by using different physicochemical parameters. Unfortunately the limited number of antioxidants and the unavailable sigma Hammett values of complex substituents did not lead to significant results in regression analysis. The redox potentials are well correlated to the antioxidant activities. In this report we will attempt to collect and discuss all the published results concerning the QSAR research on natural and synthetic antioxidants compounds.

Antioxidants↗
PubMed2000

Quantitative structure--activity relationship (QSAR) studies on non steroidal anti-inflammatory drugs (NSAIDs).

Different chemical structures have been found to possess different anti-inflammatory activities. Inflammation is a normal and essential response to any noxious stimulus which threatens the host and may vary from a localized response to a more generalized one. In view of the complexity and multitude of biochemical factors involved in inflammatory events, few general correlations of chemical structures and physicochemical properties with biological activities would be expected. Nevertheless some general features seem to be commonly associated with a large number of active drugs. However, these main features are not sufficient, but they could reflect certain physicochemical requirements for in vivo efficacy. QSAR is a useful means for maximizing the potency of a new lead compound. In the lead optimization phase of the synthetic project various QSAR procedures with the aid of computer-technology have been proposed. Among them, the classical Hansch approach has been widely used leading to quite a few successful examples. In the QSAR approaches, the prescription to optimise the lead structure is inferred from mathematical equations correlating variations in the potency of a certain biological activity with physicochemical and structural descriptors among congeneric molecules. The QSAR procedures are based on physical organic concepts and involve calculational operations. In the last years, quantum-chemical descriptors have been used in QSAR studies, because of the large physical information content encoded in many of the descriptors. Several anti-inflammatory receptor site models have been proposed. Since inflammation is a complex phenomenon involving interrelationships between humoral and cellular reactions through a number of inflammatory mediators, there is not much evidence on QSAR studies. Several QSAR studies have been reported obtaining only partial results. It was found that substituents which contribute to the high lipophilicity, were favourable to the activity. Substituents of short length (H, CH3) have also a favourable effect. Satisfactory relationships between the in vivo activities and deprotonation energies, the HOMO energies and lipophilicities were found.

Animals↗
PubMed1999

Synthesis, in vitro cytotoxicity and in vivo anti-inflammatory activity of long chain 3-amino-1,2-diols.

The synthesis of long chain 3-amino-1,2-diols was carried out based on Sharpless asymmetric epoxidation of long chain allylic alcohols and regioselective nucleophilic ring opening by azido group. The in vitro cytotoxicity of the compounds prepared was evaluated against six solid tumor cell lines (A2780, H322, LL, WiDr, C26-10, UMSCC-22B). Free 3-amino-1,2-diols exhibited IC50 values between 1.45 microM and 32 microM. These compounds also presented interesting inhibition of carrageenin-induced paw edema in rats (85.3% - 79.6% at a concentration of 0.15 mmol/kg).

Amino Alcohols↗
PubMed1999

Synthetic routes to lipidic diamines and amino alcohols: a class of potential antiinflammatory agents.

Simple and efficient methods for the synthesis of lipidic amino alcohols and diamines are described in this paper. Lipidic 2-amino alcohols and 1,3-diamines can be synthesized starting from synthetic lipidic alpha-amino acids. Alternatively, commercially available lipidic 1,2-diols may be used as starting material for the synthesis of 2-amino alcohols. Initial experiments on the in vivo antiinflammatory activity of the compounds synthesized gave promising results.

Alkanes↗
PubMed1998

Review, reevaluation, and new results in quantitative structure-activity studies of anticonvulsants.

This paper reviews and reevaluates all of the published QSAR treatments of anticonvulsants and extends them to a new relationship. This reveals that in almost all cases, the Clog P relationship plays a significant part in the QSAR relationship whether the data stems from receptor to whole animal studies. In some cases the steric factors (B5, B1, and L) are important and, in one case, the log VW relationship is of marginal importance. Electronic effects, except for the Hammett's constant sigma, are comparatively unimportant. This suggests that the receptors involved possess a special stereochemical and electronic feature: The aromatic ring and the nitrogen moieties (e.g., an amide group) are the primary binding groups. The study shows that log P, as calculated by the Clog P program, is suitable for this form of QSAR study. Log Po of 2 was found to be ideal for passive penetration of these agents into the CNS.

Animals↗
PubMed1997

1-[3-(Aryloxy) propyl]-diamines: a new class of non-steroidal basic antiinflammatory agents. Structure-activity studies: Part II.

Six substituted aryloxy diamines, synthesized as potential new antiinflammatory agents, were tested in vivo and in vitro in order to evaluate their biological activities. These derivatives reduced significant carrageenin rat paw edema and showed antiproteolytic activity. The in vitro inhibition of soybean lipoxygenase ranged from 41-77%. The results are discussed from the view of structural modifications.

Animals↗
PubMed1996

QSAR of thiosemicarbazones derived from formyl- and acyl-diazines designed as antiviral agents.

This study is an approach to the QSAR of certain Thiosemicarbazones (TSCs) with antiherpesvirus activity, shown to be based on inhibition of ribonucleotide reductases (RR). With regard to the inhibition of RR by TSCs no clear mechanism of interaction could emerge. A good correlation was shown to exist between the inhibitory effect and steric properties of substituents. The presence of a 1,2-N ring was also shown to be significant.

Antiviral Agents↗
PubMedDate not supplied

Computer aided prediction of biological activity spectra: evaluating versus known and predicting of new activities for thiazole derivatives.

Computer aided prediction of biological activity spectra by the computer program PASS was applied to a set of 89 new thiazole derivatives. Experimentally tested activities (NSAID, local anaesthetic and antioxidant) coincide with the experiment in 70.8% cases, that exceeds significantly the random guess-work (approximately 0.1%). Therefore, computer aided prediction using the Prediction of Activity Spectra for Substances (PASS) system (http://www.ibmh.msk.su/PASS) provides a reliable basis for planning of synthesis and experimental study for new compounds. New psychotropic activities are predicted for some compounds from the series under study. In particular, 7, 44 and 55 compounds likely have anxiolytic, anticonvulsant and cognition enhancer effects, respectively. Most of these compounds have the estimated values of probability to be active (Pa) less than 60%. Therefore, if their activity will be confirmed by the experiment, they might occur to be New Chemical Entities.

Anesthetics, Local↗