Search results for "Biological activity"
showing 10 items of 465 documents
Diaryl-dithiolanes and -isothiazoles: COX-1/COX-2 and 5-LOX-inhibitory, OH scavenging and anti-adhesive activities
2008
Three series of non-steroidal anti-inflammatory drugs (NSAIDs) inhibiting the cyclooxygenase/5-lipoxygenase (COX/5-LOX) pathways as such as formation of hydroxyl radicals and adhesion were prepared: 4,5-diaryl isothiazoles, 4,5-diaryl 3H-1,2-dithiole-3-thiones and 4,5-diaryl 3H-1,2-dithiole-3-ones. The aim of the present study was to develop substances which can intervene into the inflammatory processes via different mechanisms of action as multiple target non-steroidal anti-inflammatory drugs (MTNSAIDs) with increased anti-inflammatory potential. The current lead 11a was evaluated in COX-1/2, 5-LOX and (*)OH scavenging in vitro assays and in a static adhesion assay where it proved to inhib…
Generation and release of eosinophil chemotactic factor from human polymorphonuclear neutrophils by arachidonic acid
1978
This study describes the generation and release of an eosinophil chemotactic factor from human polymorphonuclear neutrophils, rat basophilic leukemia cells, and from a lymphocyte monocyte basophil suspension by arachidonic acid (AA). The eosinophil chemotactic factor (ECF) is highly specific for eosinophils and resembles the ECF activity obtained from human polymorpho-nuclear neutrophils after stimulation with the Ca ionophore or during phagocytosis. In this regard, AA-induced ECF represents a biological activity distinct from oxidized AA and its conversion products. AA may therefore have a dual function: it represents an important mechanism of cell activation; as AA is converted into prost…
Diterpenoids from Tetraclinis articulata that Inhibit Various Human Leukocyte Functions
2003
Ten new compounds, eight of them pimarane derivatives (1-8), together with a menthane dimer (9) and a totarane diterpenoid (10), were isolated from the leaves and wood of Tetraclinis articulata. The structures of 1-10 were established by using spectroscopic techniques, including 2D NMR spectra. Pimaranes 1-5 were found to possess an unusual cis interannular union of the B and C rings, which, from a biogenetic perspective, could be derived from the hydration of a carbocation at C-8. Compounds 4-6 and a mixture of 7 and 11 modulated different human leukocyte functions at a concentration of 10 microM, mainly the degranulation process measured as myeloperoxidase release and, to a lesser extent,…
Synthesis of the new ring system pyrrolizino[2,3-b]indol-4(5H)-one
2011
Derivatives of the new ring system pyrrolizino[2,3-b]indol-4(5H)-one were prepared in four steps starting from substituted benzonitriles bearing a functionalized amino group in the adjacent position. The unsubstituted- and the dimethoxy-pyrrolizinoindolones 5a and 5b exhibited modest activity against the HL-60(TB) human leukemia cell line, whereas the N-methylated dimethoxy-pyrrolizinoindolone 6b showed to be selective against MOLT-4 leukemia, A549/ATCC, HOP-92, and NCI-H460 non-small cell lung cancer, and CAKI-1 renal cancer cell lines.
Facile synthesis of 5-benzamido-4-diazopyrazole derivatives, a class of biologically active agents and key intermediates
1995
Abstract By reacting l-R1-3-R2-5-(R3-substituted)benzamidopyrazoles with a great ex-cess of nitrous acid in acetic acid media, the related 4-diazoderivatives in 65–80% yields were obtained.
ChemInform Abstract: Facile Synthesis of 5-Benzamido-4-diazopyrazole Derivatives, a Class of Biologically Active Agents and Key Intermediates.
2010
Abstract By reacting l-R1-3-R2-5-(R3-substituted)benzamidopyrazoles with a great ex-cess of nitrous acid in acetic acid media, the related 4-diazoderivatives in 65–80% yields were obtained.
New heteronuclear gold(I)-platinum(II) complexes with cytotoxic properties: are two metals better than one?
2014
A series of mono- and heterodinuclear gold(I) and platinum(II) complexes with a new bipyridylamine-phosphine ligand have been synthesized and characterized. The X-ray structures of the ligand precursor 4-iodo-N,N-di(pyridin-2-yl)benzamide, and of one gold derivative are reported. All the complexes display antiproliferative properties in vitro in human cancer cells in the range of cisplatin or higher, which appear to correlate with compounds' uptake. Interestingly, studies of the interactions of the compounds with models of DNA indicate different mechanisms of actions with respect to cisplatin. The biological activity study of these complexes provides useful information about the interest of…
SYNTHESIS OF PYRROLO[3,2-H]QUINOLINONES WITH GOOD PHOTOCHEMOTHERAPEUTIC ACTIVITY AND NO DNA DAMAGE
2010
In the search for new photochemotherapeutic agents, a series of derivatives of the ring system pyrrolo[3,2-h]quinoline--bioisosters of the angular furocoumarin angelicin--were synthesized through a four-step synthetic approach, in reasonable overall yields. Eight of the synthesized derivatives showed a remarkable phototoxicity against a panel of four human tumor cell lines and a great dose UV-A dependence, reaching IC₅₀ values at submicromolar level. The mode of cellular death photoinduced by pyrrolo[3,2-h]quinolines was evaluated through a series of flow cytometric analysis and other tests were performed to clarify their mechanism of action.
Pharmacological properties of the methanol extract from Mentha suaveolens Ehrh.
2002
The present study analyses the pharmacological activity in in vivo and in vitro models of the methanol extract obtained from the leaves and steams of Menta suaveolens Ehrh. This extract lacked toxicity, but exhibited a central nervous system depressant action; an analgesic effect in models of chemical and mechanical stimulation suggesting the induction of a peripheral analgesic response. The extract also exhibited an antiinflammatory action inhibiting the rat paw oedema induced by carrageenin. Moreover, the in vitro studies showed a significant diminution in the contractile effects induced by histamine, serotonin and acetylcholine.
Biological effects of high molecular weight lignin derivatives
2010
Abstract A number of high molecular weight (HMW) lignin derivatives possessing varied chemical properties were screened for their biological effects in order to obtain more information on the possible structural features of HMW lignin-related effects. The studied compounds were both commercial and in-house extracted lignin derivatives. Bioassays used include reverse electron transport (RET), Vibrio fischeri, Daphnia magna , and juvenile rainbow trout ( Oncorhynchus mykiss) hepatocytes. The studied lignin derivatives inhibited the in vitro systems and luminescence of V. fischeri bacteria to some extent–daphnids were not affected. It seems that, at least in the RET assay, certain pH-dependent…