• Archives of Pharmacal Research
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• v.19 no.3
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• pp.240-242
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• 1996

We have reported the convenient biomimetic methodology for the synthesis of all kinds of substituent pattern benzo[c]phenanthridine alkaloids (Hanaoka et al., 1990; Hanaoka et al., 1991). Regioselective demethylation of C-8 position on oxyfagaridine (5), an intermediate for the synthesis of Fagaridine (4), would afford the precursor for the synthesis of Isofagaridine because the strong hydrogen bonding between amide and hydroxyl group of C-7 position probably resists to be reacted with week base and electrophiles. Thus, a selective alkylation of dihydroxy compound supposed to be possible and be lead to the target compound, Isofagaridine.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.2 no.1
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• pp.56-60
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• 2016

Benzyltrimethylammonium dichloroiodate in the presence of $ZnCl_2$ has been used for aromatic iodination of electron rich aromatic compounds. However, Baylis-Hillman type regioselective ${\alpha}$-iodination was carried out electronically rich coumarin compound under mild reaction condition with excellent chemical yield. Finally, $BBr_3$ demethylation gave ${\alpha}$-iododaphnetin.

• Bulletin of the Korean Chemical Society
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• v.12 no.1
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• pp.26-31
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• 1991

Facile and efficient syntheses of terpenic perfumeries cis-jasmone, dihydrojasmone, and tetrahydrojasmone have been investigated. Cis-jasmone was synthesized by successive metallation followed by alkylation of acetone N,N-dimethylhydrazone with (Z)-2-penten-1-yl tosylate (or 2-pentyn-1-yl tosylate) and propylene oxide in one flask to give a ketonic alcohol, which was oxidized to the corresponding diketone, followed by base-catalyzed intramolecular aldol condensation to give a regioselective cyclization product. Dihydrojasmone and tetrahydrojasmone could be conveniently obtained from 2-octanone. The dimethylhydrazone of the ketone was lithiated with butyllithium and reacted with propylene oxide to give a ketonic alcohol, which was oxidized to a diketone, followed by base-catalyzed intramolecular cyclization to afford dihydrojasmone. Tetrahydrojasmone was prepared by converting the ketonic alcohol into corresponding iodoketone, followed by base-catalyzed intramolecular cycloalkylation to furnish an odoriferous product.

• Mass Spectrometry Letters
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• v.11 no.4
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• pp.103-107
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• 2020

We report the application of 2,4,6-trichlorobenzoyl chloride (often referred to as Yamaguchi esterification reagent) for the selective derivatization of the carboxylic group for GC-MS with the sample preparation method optimized for GC-MS analysis. The reagent was shown to be capable of selectively turning the carboxylic group into a reaction center, i.e., anhydride, of which the further reaction was directed to a near complete formation of required esters by unique steric and electronic effects of the reagent. Using the developed method, the chiral separation of hydroxycarboxylic acids by GC-MS using non-chiral columns was successfully demonstrated.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.353.2-353.2
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• 2002

5-Arylamino-6-chloro-4.7-dioxoindazoles (DZs) were newly synthesized for the evaluation of antifungal activities. The compounds DZs were prepared by regioselective nucleophilic substitution of 5.6-dichloro-4.7-dioxoindazoles with appropriate arylamines in high yield. DZs were tested for their growth inhibitory activities against Candida species and Aspergillus niger. The MIC values were determined by the two-fold dilution method. In general. DZs showed in vitro antifungal activities. Among the tested compounds, DZ1, 3, 6, 7 and 12 showed potent antifungal activities against Candida species and Aspergillus niger. DZ7 was the most effective in preventing the growth of Candida species.

• Archives of Pharmacal Research
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• v.16 no.1
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• pp.75-77
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• 1993

The cycloaddition reaction of N-phenyl-C-cinnamonitrilimine 4 to coumarin leads to the for-mation of 3-styrylbenzopyrano[4,3-c]pyrazole derivative 6, whereas 3-phenylsulfonylcoumarin 9 or 3-bromocoumain 10 or 3-cyanocoumarin 11 gives 1-styrylbenzopyrano[3,4]pyrazole derivative 7. Also, the cycloaddition of 4 to 3-acetylocoumarin 15 and 3-benzoylocumain 16 gives the corresponding dihydropyrano[3,4-c]pyrazole adducts 17 and 18 respectively. Oxidation of 17 and 18 gives 7.

• BMB Reports
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• v.42 no.7
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• pp.401-410
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• 2009

We have developed a targeted lipidomics approach that makes it possible to directly analyze chiral eicosanoid lipids generated in cellular systems. The eicosanoids, including prostaglandins (PGs), thromboxanes (TXs), leukotrienes (LTs) and alcohols (HETEs), have been implicated as potent lipid mediators of various biological processes. Enzymatic formations of eicosanoids are regioselective and enantioselective, whereas reactive oxygen species (ROS)-mediated formation proceeds with no stereo-selectivity. To distinguish between enzymatic and non-enzymatic pathways of eicosanoid formation, it is necessary to resolve enantiomeric forms as well as regioisomers. High sensitivity is also required to analyze the eicosanoid lipids that are usually present as trace amounts (pM level) in biological fluids. A discovery of liquid chromatography-electron capture atmospheric pressure chemical ionization/mass spectrometry (LC-ECAPCI/MS) allows us to couple normal phase chiral chromatography without loss of sensitivity. Analytical specificity was obtained by the use of collision-induced dissociation (CID) and tandem MS (MS/MS). With combination of stable isotope dilution methodology, complex mixtures of regioisomeric and enantiomeric eicosanoids have been resolved and quantified in biological samples with high sensitivity and specificity. Targeted chiral lipidomics profiles of bioactive eicosanoid lipids obtained from various cell systems and their biological implications have been discussed.

• Applied Biological Chemistry
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• v.48 no.3
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• pp.292-295
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• 2005

Synthesis of methyl 3-methyloctanoate, a perfume component isolated from African orchid Aerangis confusa (or Aerangis kirkii) was achieved starting from itaconic acid in 9 steps. Itaconic acid is one of the cheapest organic compounds which is the fermentation product of microorganism Asp. terreus. As the key intermediate, 2-methyl-1,4-butanediol 4-acetate was obtained through the enzymatic regioselective hydrolysis of 2-methyl-1,4-butanediol diacetate with lipase. After Grignard reaction and oxidation, 3-methyloctanoic acid was obtained and converted to the various corresponding scented esters with a variety of alkyl alcohols, and the resulting fragrancy esters are expected to be utilized as the aroma additive materials in cosmetics, drinks and foods.

• Journal of Microbiology and Biotechnology
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• v.26 no.3
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• pp.493-497
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• 2016

Glucosyl rubusosides were synthesized by two dextransucrases. LcDexT was obtained from Leuconosotoc citreum, that LlDexT was obtained from Leuconostoc lactis. LcDexT and LlDexT regioselectively transferred a glucosyl residue to the 13-O-glucosyl moiety of rubusoside with high yield of 59-66% as analyzed by TLC and HPLC. Evaluation of the sweetness of these glucosyl rubusosides showed that their quality of taste, in particular, was superior to that of rubusoside. These results indicate that transglucosylation at the 13-O-glucosyl moiety of rubusoside by different regioselective dextransucrases can be applicable for increasing its sweetness and quality of taste.

• Journal of the Korean Chemical Society
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• v.43 no.5
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• pp.535-539
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• 1999

1,3-Dimethyllumazine derivatives were synthesized by using Timmis reaction. The reaction of 4-amino-1,3-dimethyl-5-nitrosouracil(1) with 2,4-pentanedione, ethyl cyanoacetate, and ethyl acetoacetate provided 6-acetyl-1,3,7-trimethyllumazine (2), ethyl 7-amino-1,3-dimethyllumazine-6-carboxylate (4), and ethyl 1,3,7-trimethyllumazine-6-carboxylate (5) in good yieId, respectively. The various 1,3-dimethyllumazine derivatives were prepared from the side chain reactions of 6-acetyl and ester group in compound 2,4, and 5. The structure and physical properties of obtained compounds were characterized NMR, UV, IR spectrum, and elementary analysis.