• Bulletin of the Korean Chemical Society
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• v.32 no.spc8
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• pp.2921-2927
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• 2011

This paper describes efficient synthetic approaches for isolating biologically interesting natural pyranochalcones and their unnatural derivatives from Mallotus Philippensis. The key strategies involve ethylenediamine diacetate-catalyzed benzopyran formation reactions and base-catalyzed aldol reactions.

• Bulletin of the Korean Chemical Society
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• v.26 no.12
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• pp.1933-1936
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• 2005

Total synthesis of biologically interesting $({\pm})$-cannabichromene, $({\pm})$-cannabichromenic acid, and $({\pm})$-daurichromenic acid is described. The key step in the synthetic strategy involves the formation of benzopyrans by ethylenediamine diacetate-catalyzed reactions of resorcinols with $\alpha$,$\beta$-unsaturated aldehydes.

• Bulletin of the Korean Chemical Society
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• v.28 no.9
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• pp.1579-1584
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• 2007

The efficient and concise synthesis of natural and non-natural pyranochalcones was achieved from readily available 2,4,5-trihydroxyacetophenone. The key steps in the synthetic strategy were ethylenediamine diacetate-catalyzed benzopyran formation and aldol reactions.

• YAKHAK HOEJI
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• v.33 no.6
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• pp.377-379
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• 1989

The methylated compound of ellagic acid was isolated from Potentilla chinensis (Rosaceae). The isolated compound was 3, 3', 4-tri-O-methylellagic acid, [2, 3, 7-trimethoxy-8-hydroxy[1] benzopyrano-[5, 4, 3, cde][1] benzopyran-5, 10-dione], $C_{17}H_{12}O_8$, m.p. $293-295^{\circ}C$. The isolation of trimethylellagic acid was conducted by the column chromatography and the identification of the compound was carried out by the methods of IR, NMR and MS spectroscopy.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.421.2-421.2
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• 2002

Recent studies show that KR-31378 ［(2S.3SAR)-N"-cyano-N-(6-amino-3A-dihydro-3-hydroxy-2-methyl-2-dimethoxymethyl-2H-benzopyran-4-yl)-N${\cdots}$-benzylguanidine］ has the neuroprotective effect as evidenced by the limitation of the size of infarct of the ischemia-reperfusion injury after an administration of KR-31378. In the literature. however. kinetics of KR-31378 distribution into the brain has not been systematically studied. (omitted)

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.197.1-197.1
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• 2003

Neuronal hyperexcitability followed by high level of intracellular calcium and oxidative stress play critical roles in neuronal cell death in stroke and neurotrauma. Hence, KR-31378, a novel benzopyran derivative was designed as a new therapeutic strategy for neuroprotection possessing both anti-oxidant and potassium channel modulating activities. In the present study, we tested for its neuroprotective efficacy against oxidative stress-induced cell death in primary cortical cultures and further investigated its neuroprotective mechanism. (omitted)

• Korean Journal of Clinical Pharmacy
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• v.6 no.2
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• pp.32-40
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• 1996

The electrophysiological effects of benzopyran potassium channel openers (PCOs: lemakalim, KR-30450 and KR-30818) on the ischemia/reperfusion-induced arrythmias were investigated. In anesthetized rats, subjected to 45 min occlusion of the left anterior descending coronary artery (LAD) followed by 90 min reperfusion, ventricular arrythmias were identified according to the Lambeth Conventions by lead II ECG. Rats were intravenously given vehicle ($1\%$ DMSO), lemakalim, KR-30450, and KR-30818 alone or in combination with a selective $K_{ATP}$ blocker glibenclamide, 30 min prior to coronary occlusion. Compared to vehicle, lemakalim ($30{\mu}g/kg$ i.v.), the active enantiomer of cromakalim, had a tendancy to increase the duration of ventricular tachycardia (Vl) and ventricular fibrillation (VF), the number of premature ventricular complexes (PVC) and the incidence of VF, especially in the early post-occlusion peroid ($0\~15$ min), while increasing ST-segment elevation. Both KR-30450 ($30{\mu}g/kg$, i.v.) and KR-30818 (30, $100{\mu}g/kg$, i.v.) showed similar proarrhythmic effects to lemakalim (PVC, duration of VT, and incidence of VF) with a tendancy to decrease the duration of VF and ST-segment elevation. Unlike other PCOs, however, glibenclamide (0.3, 1.0 mg/kg) had opposite effects on the induction of arrhythmias (PVC, the duration of VF); it had a tendancy to increase the duration of VT with a slight elevation of ST-segment. It seems likely that glibenclamide (0.3 mg/kg, i.v.), reduced the effects of lemakalim or KR-30450 ($30{\mu}g/kg$, i.v.) on arrhythmias (PVC, VT, VF and ST-segment). These results indicate that, in the coronary occluded rat model of ischemia, lemikuiln and KR-30450 exert a proarrhythmic activity, the effect being considered related to the opening of KATP channel.

• Bulletin of the Korean Chemical Society
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• v.29 no.6
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• pp.1205-1210
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• 2008

A new and efficient synthetic approach is reported for biologically interesting prenylated chalcones, 4'-Omethylxanthohumol (3), xanthohumol E (4), and sericone (5) from 2,4,6-trihydroxyacetophenone. The strategies involve the introduction of a prenyl group onto an aryl ring, benzopyran formation, and basecatalyzed aldol reactions.

• Rapid Communication in Photoscience
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• v.3 no.4
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• pp.64-66
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• 2014

Synthesis of a deuterium-labeled derivative of nitrospirobenzopyran (NSP), one of representative photochromic compounds, has been described. Four deuteriums were successfully introduced on 1-methyl and ${\alpha}$-methyne relative to spiro-carbon in the title compound with more than 95atom%D purity. Main photodegraded products of NSP were two oxindoles in acetonitrile, and additional products were formed in poly(isobutyl-methacrylate) films possibly due to restricted molecular motion in polymer matrix. Quantitative HPLC analysis revealed that partial introduction of deuterium to NSP brought a noticeable isotope effect, recognizable enhancement in photo-resistivity of NSP, i.e.,8.3% in solutions and 29% in polymeric films.

• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3229-3232
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• 2011

A FRET-based high-throughput screening system was developed for the discovery of competitive smallmolecule Hsp90 inhibitors. The biarsenical fluorescein derivative FlAsH and dabcyl-conjugated Hsp90 inhibitor GM were employed as the FRET donor and quencher, respectively. The spatial proximity perturbation between FlAsH-labeled Hsp90N and GM-dabcyl upon treatment of a small molecule led to changes in the FRET-induced fluorescence, monitored in a high-throughput fashion.