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Journals and Conferences
As a part of the work conducted in our laboratory, we encountered a case in which new chemical compound was contained in a certain product. This compound was found to have a molecular weight of 310 Da by liquid chromatography–mass spectrometry and gas chromatography–mass spectrometry. Accurate mass spectrometry measurements showed that the compound had an… (More)
Salvileucalin B (2), having an unprecedented rearranged neoclerodane skeleton, was isolated from the aerial parts of Salvia leucantha Cav. (Labiatae) along with salvileucalin A (1). The absolute structures were elucidated by spectroscopic analysis, X-ray crystallographic analysis, and vibrational circular dichroism. Compound 2 represents a novel… (More)
Two bicyclic hexapeptides, allo-RA-V (4) and neo-RA-V (5), and one cyclic hexapeptide, O-seco-RA-V (6), were isolated from the roots of Rubia cordifolia L. Their gross structures were elucidated on the basis of spectroscopic analysis and X-ray crystallography of compound 5. The absolute stereochemistry of compounds 4 and 5 were established by their total… (More)
Five limonoids were isolated from the leaves of Cedrela sinensis (Meliaceae) and their structures were determined to be 11beta-hydroxy-7alpha-obacunyl acetate, 11-oxo-7alpha-obacunyl acetate, 11-oxo-7alpha-obacunol, 11beta-hydroxycneorin G, and 11-oxocneorin G, by 2D NMR spectroscopic experiments, X-ray crystallographic analysis, and chemical methods.
A novel cis amide bond surrogate incorporating 1,2,4-triazole was designed and synthesized by the reaction of a thionotripeptide, formic hydrazide, and mercury(II) acetate. This method of surrogate formation was also applicable to a cyclic thionopeptide.
The reaction of triptolide and its analogues with a fluorinating agent, that is, bis(2-methoxyethyl)aminosulfur trifluoride (Deoxo-Fluor) or (diethylamino)sulfur trifluoride (DAST), was studied. One of the fluorinated products, 14beta-dehydroxy-14beta-fluoro triptolide, was found to be more cytotoxic than the parent natural triptolide.
During our careful survey of unregulated psychotropic drugs in June 2013 in the Tokyo metropolitan area, we found a new compound in a herbal product. It was identified as an analog of NNEI (MN-24) and differed in that its molecule possessed another N-pentyl indole-carbonyl group: N, N-bis(1-pentylindol-3-yl-carboxy)naphtylamine (BiPICANA, compound 2).… (More)
BACKGROUND In mammals, adrenaline and ATP are life-essential vicinal diol and cis-diol functional groups. Here, we show that interactions between a safe organogermanium compound and these cis-diol compounds have the potential to regulate physiological functions. In addition, we represent a possible new druggable target for controlling the action of cis-diol… (More)
Triptolide γ-lactone and C-14 analogues were prepared and evaluated cytotoxity against human lung adenocarcinoma epithelial A549 cells and human colon adenocarcinoma HT-29 cells. γ-Lactone substructure and C-14 substituents affected the biological activities significantly.
Three quassinoids, eurycolactone D (1), eurycolactone E (2) and eurycolactone F (3) were isolated from the roots of Eurycoma longifolia Jack. The structures of 1-3 were elucidated by spectroscopic methods, and that of 3 was further confirmed by X-ray crystallography. The known quassinoids, laurycolactone B (4) and eurycomalactone (5) were also identified.