Methoxycoumarin Research Articles

Control of thermoresponsivity of biocompatible poly(trimethylene carbonate) with direct introduction of oligo(ethylene glycol) under various circumstances

ABSTRACTPoly(trimethylene carbonate) (PTMC) is a well‐known biodegradable polymer with good biocompatible properties which make it suitable for biomedical applications. Poly(5‐[2‐{2‐(2‐methoxyethoxy)ethyoxy}‐ethoxymethyl]‐5‐methyl‐1,3‐dioxa‐2‐one) (PTMC‐MOE3OM) and copolymers, bearing oligo ethylene glycol (OEG) at the side chain of PTMC backbone, were selected to investigate the cloud point behavior by solvents such as PBS, water, 10% ethanol solution and various ionic strengths. A pH‐responsive copolymer, poly(TMCM‐MOE3OM‐co‐(5‐methyl‐5‐carboxylic‐1,3‐dioxane‐2‐one)) as carboxylic acid carbonate showed a decreased critical temperature at pH 2. Photo‐responsive copolymer, poly(TMCM‐MOE3OM‐co‐coumarin derivatives) bearing 1% and 10% of photo‐induced molecules (7‐[(5‐(5‐methyl‐1,3‐dioxa‐2‐one)methoxy)]‐methoxy coumarin (TMCM‐coumarin)) exhibited a low cloud point because of the hydrophobic moieties. Meanwhile, alternative coumarin polymer including 2% of 4‐methyl‐7‐[(5‐(5‐methyl‐1,3‐dioxa‐2‐one)methoxy)butoxy)]‐methoxy coumarin (TMCM‐4‐methyl‐coumarin) has been successfully synthesized and copolymerized as a novel molecule. The various combinations of monomers were studied and the significant properties were determined via external triggers after copolymerization. This study showed basically synthetic progress toward designs and trivial rationalization of thermoresponsive copolymers close to body temperature. At present, various pendant groups as side part affect to the lower critical solution temperature (LCST) and biodegradable polymer in order to utilize the actual external stimuli application. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3466–3474

Anti-nociceptive Effect of 7-methoxy Coumarin from Eupatorium Triplinerve vahl (Asteraceae).

Aim:To evaluate the anti-nociceptive activity of 7-methoxy coumarin isolated from ethyl acetate fraction of the alcoholic extract of Eupatorium triplinerve Vahl.Materials and Methods:The shade dried leaves of E. triplinerve were extracted with ethyl alcohol and the extract was condensed. This extract was fractionated with n-hexane, ethyl acetate, and n-butanol. The ethyl acetate fraction was subjected to column chromatography which yielded a crystalline compound-A, which was investigated for spectral characteristics.Pharmacological studies:The isolated compound-A was subjected to behavioral studies and anti-nociceptive evaluation in mice by acetic acid induced writhing and formalin induced nociception.Results:The spectral studies indicated that the structure of compound-A complies with 7- methoxy coumarin. Pre-treatment with 7-methoxy coumarin reduced the number of abdominal constrictions in mice and decreased the time spent in paw licking and biting response in formalin assay. There were no significant behavioral changes.Conclusion:A dose dependent anti-nociceptive action of 7- methoxy coumarin was revealed by the present experiments which support the traditional use of E. triplinerve in pain and inflammatory disorders.SUMMARY Bio-guided fractionation of alcoholic extract of E. triplinerve yielded 7-methoxy coumarin.7-methoxy coumarin was evaluated for its anti-nociceptive potential by acetic acid induced writhing and formalin induced nociception assays.7-methoxy coumarin exhibited significant inhibition of acetic acid induced writhing response and the second phase of formalin nociception.The anti-nociceptive action of 7-methoxy coumarin revealed by the present experiments supports the traditional use of E. triplinerve in pain and inflammatory disorders. Abbreviation used: TLC-Thin layer chromatography, Kg-kilogram, g-gram, TXB2-Thromboxane B2, UV-Ultraviolet, IgE-Immunoglobulin E, s.c-subcutaneous, p.o-oral route

Insect feeding deterrent and growth inhibitory activities of scopoletin isolated from Artemisia annua against Spilarctia obliqua (Lepidoptera: Noctuidae)

Artemisia annua (Asteraceae) is well known for its antimalarial activities due to presence of the compound artemisinin. We isolated a methoxy coumarin from the stem part of A. annua and confirmed its identity as scopoletin through mass spectral data. The structure was established from 1H-nuclear magnetic resonance (NMR), 13C-NMR. The compound scopoletin was evaluated for its feeding deterrence and growth inhibitory potential against a noxious lepidopteran insect, Spilartctia obliqua Walker. Scopoletin gave FD50 (feeding deterrence of 50%) value of 96.7 μg/g diet when mixed into artificial diet. S. obliqua larvae (12-day-old) exposed to the highest concentration (250 μg/g diet) of scopoletin showed 77.1% feeding-deterrence. In a growth inhibitory assay, scopoletin provided 116.9% growth inhibition at the highest dose of 250 μg/g diet with a GI50 (growth inhibition of 50%) value of 20.9 μg/g diet. Statistical analysis showed a concentration-dependent dose response relationship toward both feeding deterrent and growth inhibitory activities. Artemisinin is found mainly in the leaves of A. annua and not in the stems, which are typically discarded as waste. Therefore identification of scopoletin in stems of A. annua may be important as a source of this material for pest control.

Time resolved studies of dual emission and photoinduced energy transfer in a Tris methoxy coumarin derivative of a cryptand and its complex with Tb(NO3)3

The paper reports time resolved emission studies in different solvents of the dual emission observed in the macrotricyclic cryptand (L) where the three secondary amino nitrogen have been derivatized with methoxy coumarin at room temperature and at 77K. The emission from the ‘locally excited monomer state’ has a lifetime less than 1ns while the other emitting state is an exciplex state with a lifetime of 4–5ns depending on the solvent. The lifetime is found to increase significantly in the presence of protons and at 77K exhibiting photoinduced electron transfer (PET) in the system L. The system exhibits photoinduced energy transfer (ET) in its Tb(III) complex using NO3- ion as counteranion at room temperature as well as at 77K. The rate constants for energy transfer from coumarin moiety to Tb(III) have been evaluated at room temperature and at 77K following the decay of 5D4→7F5 emission of Tb(III). The results indicate that energy transfer takes place from the lowest triplet state of coumarin moiety to Tb(III) by exchange mechanism. The energy transfer (ET) rate constants at room temperature and at 77K have been evaluated and interpreted using the geometry of L obtained by theoretical calculation.

Photophysical properties of tris-methoxycoumarin derivative of a cryptand

The paper reports the photophysical studies of a macrobicyclic cryptand where the three secondary amino nitrogen have been derivatized with methoxy coumarin in various solvents at room temperature and at 77 K. The system having (F–S) 3–R configuration (where F is fluorophore, S is CH 2 spacer and R is receptor unit) shows intramolecular PET from the receptor nitrogen atoms of the cryptand moiety to the coumarin units reducing the fluorescence quantum yield and lifetime of coumarin in the ligand. However, the fluorescence intensity is enhanced in presence of protons and Zn +2 ion in dry THF medium. Metal ions like Cu(II) and Co(II) quench the fluorescence. Presence of protons induces a greater enhancement of emission intensity implying all the nitrogen lone pairs responsible for PET are protonated. Another interesting feature of this ligand is that it exhibits room temperature phosphorescence (RTP) apart from exhibiting PET. The observation of RTP has not been reported earlier for any other coumarin derivative.

Separation of biotin and its analogs by high-performance liquid chromatography: Convenient labeling for ultraviolet or fluorimetric detection

d-Biotin, dethiobiotin, d-biotin sulfoxides, and d-biotin sulfone are converted to uv-absorbing or fluorescent derivatives by reaction with ω-4-dibromoacetophenone or 4-bromomethyl methoxy coumarin. High-performance liquid chromatographic separation conditions of these esters are described using C 18 bonded phase.

Effects of 8-monochloro-3-beta-diethylaminoethyl-4-methyl-7-ethoxy carboxyl methoxy coumarin (AD 6) on aggregation, arachidonic acid metabolism and thromboxane B 2 formation in human platelets

Preincubation of human platelet rich plasma (PRP) with AD 6 (8-monochloro-3-beta-diethylaminoethyl-4-methyl-7-ethoxy carboxyl methoxy coumarin), inhibits the aggregations induced by threshold concentrations of arachidonic acid sodium salt, collagen and ADP at concentrations of 25,50 and 100 γ/ml respectively. When preincubated at the concentrations of 100γ/ml, AD 6 decreases the conversion of exogenous labelled arachidonic acid to thromboxane B 2 by washed platelets. At the same concentration, AD 6 decreases of more than 70% the production of TXB 2 from endogenous substrate, following the stimulation of PRP with collagen. The compound appears to act more on the utilization of arachidonic acid for thromboxane production than on the arachidonic acid cyclooxygenase.

Experiments on the synthesis of coumaryl styrenes

A number of hydroxy and methoxy coumarin acetic acids have been prepared by the method of Dey and Row with a view to convert them into the corresponding coumaryl styrenes. Except the simplest of them,i.e., 7-hydroxy coumarin-4-acetic acid, the others do not undergo the condensation with aromatic aldehydes, but suffer only decarboxylation. A study of the γ-acetates obtained by the high temperature acetylation of simpler chalkones and flavanones indicates that they are not coumaryl styrene derivatives, though their compositions agree with such.