N-(3,4-Dichlorobenzyl)azoles—Investigations Regarding Synthesis, NMR-Spectroscopy and Affinity Towards Sisma-1 and Sigma-2 Receptors

A series of azoles and aminoazoles with a 3,4-dichlorobenzyl moiety attached to a ring nitrogen atom was synthesized via reaction of the parent systems with 3,4-dichlorobenzyl chloride. Regioisomeric products were discriminated on the basis of 13C-NMR data or by NOE-difference spectroscopy. The affinities of some representatives towards sigma-1 and sigma-2 receptors were determined by receptor binding assays.

Two Xanthones from Polygala paniculata and Confirmation of the 1-Hydroxy- 2,3,5-trimethoxy-xanthone at Trace Level by HRGC-MS

Polygala paniculata L. yielded the xanthones 1-hydroxy-5-methoxy-2,3-methylenedioxyxanthone (1) and 1,5-dihydroxy-2,3-dimethoxyxanthone (2), together with coumarin murragatin and flavonol rutin. Their structures were established by chemical and spectroscopic methods (EIMS, IR, 1H and 13C NMR, NOE difference spectroscopy). By posterior analysis of an apolar crude extract using high resolution gas chromatography coupled to mass spectrometry (HRGC-MS) it was possible to characterize two sterol (spinasterol and Δ25-spinasterol) and the minor 1-hydroxy-2,3,5-trimethoxyxanthone (3). Thus, the xanthone 3 was confirmed through of co-injection HRGC-MS of the respective extract with a certified standard obtained by methylation of 2 with diazomethane.

Chemical Constituents and Mechanisms of Discoloration of Taiwania (Taiwania cryptomerioides Hayata) Heartwood. The Structure Reconfirmation and Conversion Mechanism of Taiwanin A

Summary One of the color substances, taiwanin A, was isolated from Taiwania (Taiwania cryptomerioides Hayata) heartwood. According to the 13C-NMR, 1H-NMR, HSQC, HMBC, and NOE difference spectroscopy analyses, the diene structure of taiwanin A was reconfirmed to be the trans-trans formulation. In addition, it was proven that deep orange crystalline taiwanin A changed to white and pale yellow compounds, taiwanin C and taiwanin E, after light irradiation. The conversion mechanism of taiwanin A into taiwanin C and taiwanin E is also proposed and discussed in this study.