[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.

Determination of Absolute Purities of Hygroscopic Substances by Quantitative NMR Analysis for the Standardization of Quantitative Reagents in the Japanese Pharmacopoeia (Part 2).

As a new absolute quantitation method for low-molecular compounds, quantitative NMR (qNMR) has emerged. In the Japanese Pharmacopoeia (JP), 15 compounds evaluated by qNMR are listed as reagents used as the HPLC reference standards in the assay of crude drug section of the JP. In a previous study, we revealed that humidity affects purity values of hygroscopic reagents and that (i) humidity control before and during weighing is important for a reproducible preparation and (ii) indication of the absolute amount (not purity value), which is not affected by water content, is important for hygroscopic products determined by qNMR. In this study, typical and optimal conditions that affect the determination of the purity of ginsenoside Rb1 (GRB1), saikosaponin a (SSA), and barbaloin (BB) (i.e., hygroscopic reagents) by qNMR were examined. First, the effect of humidity before and during weighing on the purity of commercial GRB1, with a purity value determined by qNMR, was examined. The results showed the importance afore-mentioned. The results of SSA, which is relatively unstable in the dissolved state, suggested that the standardization of humidity control before and during weighing for a specific time provides a practical approach for hygroscopic products. In regard to BB, its humidity control for a specific time, only before weighing, is enough for a reproducible purity determination.

[Determination of Absolute Purities of Hygroscopic Substances by Quantitative NMR Analysis for the Standardization of Quantitative Reagents in the Japanese Pharmacopoeia (Part 1)].

Quantitative NMR (qNMR) has been developed as an absolute quantitation method to determine the purity or content of organic compounds including marker compounds in crude drugs. The "qNMR test" has been introduced into the crude-drug section of the Japanese Pharmacopoeia (JP) for determining the purity of reagents used for the assay in the JP. In Supplement II to the JP 17th edition published in June 2019, fifteen compounds adopted qNMR test were listed as the reagents for the assay. To establish the "qNMR test" in the crude drug section of the JP, there were several problems to be solved. Previously, we reported that the handling impurity signals from reference substances and targeted marker compounds, chemical shifts of reference substances, and peak unity of signals of targeted marker compounds are important factors to conduct qNMR measurements with intended accuracy. In this study, we investigated that the hygroscopicity of reagents could cause the changes in the compounds' purity depending on increasing their water content. Twenty-one standard products used for the crude-drug test in JP were examined by water sorption-desorption analysis, and ginsenosides and saikosaponins were found to be hygroscopic. To prepare a sample solution of saikosaponin b2 for qNMR analysis, samples need to be maintained for 18 h at 25°C and 76% relative humidity; further, samples need to be weighed at the same humidity for the qNMR analysis.

Determination of perillaldehyde in perilla herbs using relative molar sensitivity to single-reference diphenyl sulfone.

Perillaldehyde (PRL) is one of the essential oil components derived from perilla plants (Perilla frutescens Britton) and is a characteristic compound of the traditional medicine "perilla herb ()" listed in the The Japanese Pharmacopoeia, 17th edition (JP17). HPLC using an analytical standard of PRL has been used to quantitatively determine the PRL content in perilla herb. However, PRL reagents have been reported to decompose easily. In this study, we utilized an alternative quantitative method using on a single reference with relative molar sensitivity (RMS) based on the results of experiments performed in two laboratories. It was possible to calculate the exact RMS using an offline combination of 1H-quantitative NMR spectroscopy (1H-qNMR) and an HPLC/photodiode array (PDA) detector (or an HPLC/variable-wavelength detector [VWD]). Using the RMS of PRL to the single-reference compound diphenyl sulfone (DFS), which is an inexpensive and stable compound, the PRL content in the perilla herb could be determined using HPLC/PDA or HPLC/VWD without the need for the analytical standard of PRL. There was no significant difference between the PRL contents of perilla herb determined using the method employing the single-reference DFS with RMS and using the JP17 assay, the calibration curve of which was generated using the analytical standard of PRL with adjusted purity measured by 1H-qNMR. These results demonstrate that our proposed method using a single reference with RMS is suitable for quantitative assays of perilla herb and can be an alternative method for the current assay method defined in the JP17.

Pharmacokinetics of Active Components of Yokukansan, a Traditional Japanese Herbal Medicine after a Single Oral Administration to Healthy Japanese Volunteers: A Cross-Over, Randomized Study.

CONTEXT: Yokukansan (YKS) is a traditional Japanese herbal medicine called kampo medicine in Japan. Its extract comprises seven crude drugs: Atractylodis lanceae rhizoma, Poria, Cnidii rhizoma, Uncariae uncis cum ramulus, Angelicae radix, Bupleuri radix, and Glycyrrhizae radix. YKS is used to treat neurosis, insomnia, as well as behavioral and psychological symptoms of dementia. OBJECTIVE: To confirm the exposure and pharmacokinetics of the active components of YKS in healthy volunteers. DESIGN, SETTING, AND PARTICIPANTS: A randomized, open-label, 3-arm, 3-period, crossover trial was conducted on 21 healthy Japanese volunteers at the Kochi Medical University between May 2012 and November 2012. INTERVENTIONS: Single oral administration of YKS (2.5 g, 5.0 g, or 7.5 g/day) during each period. MAIN OUTCOME MEASURE: Plasma concentrations of three active compounds in YKS, namely 18ß-glycyrrhetinic acid (GA), geissoschizine methyl ether (GM), and hirsuteine (HTE). RESULTS: The mean maximum plasma concentrations (Cmax) of GM and HTE increased dose-dependently (ranges: 0.650-1.98 ng/mL and 0.138-0.450 ng/mL, respectively). The times to maximum plasma concentration after drug administration (tmax) were 0.500 h for GM and 0.975-1.00 h for HTE. The apparent elimination half-lives (t1/2) were 1.72-1.95 h for GM and 2.47-3.03 h for HTE. These data indicate the rapid absorption and elimination of GM and HTE. On the other hand, the Cmax, tmax, and t1/2 of GA were 57.7-108 ng/mL, 8.00-8.01 h, and 9.39-12.3 h, respectively. CONCLUSION: We demonstrated that pharmacologically active components of YKS are detected in humans. Further, we determined the pharmacokinetics of GM, HTE, and GA. This information will be useful to elucidate the pharmacological effects of YKS. TRIAL REGISTRATION: Japan Pharmaceutical Information Center JAPIC CTI-121811.

Metabolic profiling of the Uncaria hook alkaloid geissoschizine methyl ether in rat and human liver microsomes using high-performance liquid chromatography with tandem mass spectrometry.

Geissoschizine methyl ether (GM) is an indole alkaloid found in Uncaria hook, which is a galenical constituent of yokukansan, a traditional Japanese medicine. GM has been identified as the active component responsible for anti-aggressive effects. In this study, the metabolic profiling of GM in rat and human liver microsomes was investigated. Thirteen metabolites of GM were elucidated and identified using a high-performance liquid chromatography with tandem mass spectrometry method, and their molecular structures were proposed on the basis of the characteristics of their precursor ions, product ions, and chromatographic retention times. There were no differences in the metabolites between the rat and human liver microsomes. Among the 13 identified metabolites, there were two demethylation metabolites, one dehydrogenation metabolite, three methylation metabolites, three oxidation metabolites, two water-adduct metabolites, one di-demethylation metabolite, and one water-adduct metabolite followed by oxidation. The metabolic pathways of GM were proposed on the basis of this study. This study will be helpful in understanding the metabolic routes of GM and related Uncaria hook alkaloids, and provide useful information on the pharmacokinetics and pharmacodynamics. This is the first report that describes the separation and identification of GM metabolites in rat and human liver microsomes.

Specific binding and characteristics of geissoschizine methyl ether, an indole alkaloid of Uncaria Hook, in the rat brain.

ETHNOPHARMACOLOGICAL RELEVANCE: Geissoschizine methyl ether (GM) is an indole alkaloid that is a component of Uncaria Hook, and has been identified as the active component responsible for the anti-aggressive effects of the Uncaria Hook-containing traditional Japanese medicine, yokukansan. Recently, GM was shown to reach the brain by crossing the blood-brain barrier in rats following the oral administration of yokukansan. This finding suggested that there may be specific binding sites for GM in the brain. Here we show evidence that tritium-labeled GM ([(3)H]GM) binds specifically to several brain areas of rats. MATERIALS AND METHODS: Male rats were used. [(3)H]GM was synthesized from a demethylated derivative of GM. Specific binding sites of [(3)H]GM on brain sections were determined by quantitative autoradiography, and maximum binding densities (Bmax) and dissociation constants (Kd) were calculated. Several chemical compounds were used to clarify the molecules that recognize [(3)H]GM in the completion-binding assay. Emulsion microautoradiography was also performed to identify the cells that bind [(3)H]GM. RESULTS: Specific binding of [(3)H]GM was observed in the frontal cortex, including the prefrontal cortical region (e.g., prelimbic cortex (PrL)), hippocampus, caudate putamen, amygdala, central medial thalamic nucleus, dorsal raphe nucleus (DR), and cerebellum. Bmax ranged between 0.65 and 8.79pmol/mg tissue, and Kd was between 35.0 and 232.6nM. Specific binding with relatively high affinity (Kd less than 62nM) was dense in the frontal cortical region, moderate in the DR, and sparse in the cerebellum. The specific binding of [(3)H]GM in the PrL was significantly replaced by the serotonin 1A (5-HT1A) receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (DPAT), 5-HT2A receptor antagonist ketanserin, 5-HT2B receptor agonist BW 723C86, 5-HT2C receptor agonist RO60-0175, adrenergic α2A receptor antagonist yohimbine, L-type Ca(2+) channel blocker verapamil, and µ-opioid receptor antagonist naloxone. Similar results were obtained in the frontal cortex and DR, but not in the cerebellum. Microautoradiography revealed that [(3)H]GM signals were distributed throughout the frontal cortex, which included neuron-like large cells. CONCLUSION: These results demonstrate that specific binding sites for GM exist in rat brain tissue, and suggest that the pharmacological actions of GM are mainly associated with 5-HT receptors in the frontal cortex and DR. These results provide an insight into the neuropharmacology of GM and GM-containing herbal medicines.

Ultra-compact 8 × 8 strictly-non-blocking Si-wire PILOSS switch.

We report on a path-independent insertion-loss (PILOSS) 8 × 8 matrix switch based on Si-wire waveguides, which has a record-small footprint of 3.5 × 2.4 mm2. The PILOSS switch consists of 64 thermooptic Mach-Zehnder (MZ) switches and 49 low-crosstalk intersections. Each of the MZ switches and intersections employs directional couplers, which enable the composition of a low loss PILOSS switch. We demonstrate successful switching of digital-coherent 43-Gbps QPSK signal.

Total synthesis of hydroxy-α- and hydroxy-ß-sanshool using Suzuki-Miyaura coupling.

Here, we describe the first total synthesis of hydroxyl-α- and hydroxyl-ß-sanshool, which involves Suzuki-Miyaura coupling (SMC). Hydroxy-α-sanshool (1) was synthesized by SMC of bromoalkyne 4 with boronate 3 followed by (Z)-selective reduction of the triple bond in the coupling product. Hydroxy-ß-sanshool (2) was synthesized by regio- and (E)-selective conversion of 4 to iodoalkene 11 followed by SMC with 3.

Urinary eosinophil-derived neurotoxin concentrations in patients with atopic dermatitis: a useful clinical marker for disease activity.

BACKGROUND: It has been reported that measurements of eosinophil-derived neurotoxin (EDN) may be useful for identifying eosinophil activities in allergic diseases including atopic dermatitis. METHODS: EDN concentrations in the urine were measured by enzyme-linked immunosorbent assay, and the number of eosinophils in the peripheral blood was counted in 30 patients with atopic dermatitis. The severity of atopic dermatitis was graded on the criteria proposed by Rajka and Langeland. The disease activity was assessed by each patient on a visual analogue scale (VAS). RESULTS: Urinary concentrations of EDN in patients with atopic dermatitis showed a significant positive correlation with disease severity. Urine EDN concentrations also correlated with VAS scores for itching, skin condition, overall skin symptoms and total VAS score, but not with the VAS score for skin dryness. Urinary EDN concentrations did not correlate with the number of eosinophils in the peripheral blood. CONCLUSIONS: The urinary EDN concentration in patients with atopic dermatitis is a useful clinical marker for monitoring disease activity.