[Quantitative Determination Method of Aconitum Monoester Alkaloids Using Relative Molar Sensitivity (RMS) for the Assay in the Japanese Pharmacopoeia].

Recently, a novel quantitative method using relative molar sensitivity (RMS) was applied to quantify the ingredients of drugs and foods. An important development in this regard can be observed in the Japanese Pharmacopoeia (JP) 18, where the quantification of perillaldehyde, an unstable compound, in crude drug "Perilla Herb," was revised to incorporate the RMS method. In this study, the primary objective was to improve the tester safety and reduce the amount of reagents used in the JP test. To achieve this, the quantification of three toxic Aconitum monoester alkaloids (AMAs) was explored using the RMS method, employing a single reference compound for all three targets. These AMAs, namely benzoylmesaconine hydrochloride, benzoylhypaconine hydrochloride, and 14-anisoylaconine hydrochloride, which are the quantitative compounds of Kampo extracts containing Aconite Root (AR), were quantified using the reference compound benzoic acid (BA). Reliable RMS values were obtained using both 1H-quantitative NMR and HPLC/UV. Using the RMS of three AMAs relative to the BA, the AMA content (%) in commercial AMAs quantitative reagents were determined without analytical standards. Moreover, the quantitative values of AMAs using the RMS method and the calibration curve method using the three analytical standards were similar. Additionally, similar values were achieved for the three AMAs in the Kampo extracts containing AR using the RMS and the modified JP18 calibration curve methods. These results suggest that the RMS method is suitable for quantitative assays of the Kampo extracts containing AR and can serve as an alternative to the current method specified in the JP18.

Helvamide, a new inhibitor of sterol O-acyltransferase produced by the fungus Aspergillus nidulans BF-0142.

A new piperazine derivative designated helvamide was isolated as a pair of rotamers (1 and 2) from the culture broth of the fungus Aspergillus nidulans BF-0142 along with a known helvafuranone (3). The structures of 1 and 2 were elucidated based on spectroscopic analyses by the interpretation of one-dimensional and two-dimensional nuclear magnetic resonance data, ROESY (rotational Overhauser effect spectroscopy) correlations, and a chemical method. Helvamide existed as a rotameric mixture (1 and 2) in dimethyl sulfoxide. Helvamide inhibited sterol O-acyltransferases 1 and 2 (SOAT1 and SOAT2) in enzyme-based and cell-based assays using SOAT1-expressing and SOAT2-expressing Chinese hamster ovary (CHO) cells.

Helvafuranone Produced by the Fungus Aspergillus nidulans BF0142 Isolated from Hot Spring-derived Soil.

The fungus, Aspergillus nidulans BFO 142, was isolated from hot spring-derived soil collected at Hell Valley in Noboribetsu, Hokkaido, Japan. A new furanone compound designated helvafuranone (1) was isolated along with microperfuranone (2), 9-hydroxymicroperfuranone (3), diorcinol (4), emestrin (5), and sterigmatocystin (6), from a culture broth of A. nidulans BF0142. The structure of 1 was elucidated as 5-hydroxy-4-(4-hydroxybenzyl)-3-(4- hydroxybenzyl)furanone based on various NMR experiments and chemical modifications.