Resultant compound from sublimation test for Gentianae Radix in Japanese Pharmacopoeia was 5-(hydroxymethyl)furfural

Gentianae Radix, an herbal medicine, has been used as a gastrointestinal drug in Japan. In the Japanese Pharmacopoeia 18th Revision, the sublimation test is specified as an identification test for Gentianae Radix. The compound obtained in this sublimation test was believed to be gentisin, a xanthone family compound. However, the compound we identified using liquid chromatography-high-resolution mass spectrometry (LC-HRMS) and 1H- and 13C-NMR was 5-(hydroxymethyl)furfural (5-HMF). The same compound was found to be a sublimate of Gentianae Scabrae Radix and Gentianae Macrophyllae Radix, belonging to the same genus as Gentianae Radix. These results indicate the necessity to revise the identification test for Gentianae Radix to a more unique method.

In Silico Prediction of N-Nitrosamine Formation Pathways of Pharmaceutical Products

The recent discovery of N-nitrosodimethylamine (NDMA), a mutagenic N-nitrosamine, in pharmaceuticals has adversely impacted the global supply of relevant pharmaceutical products. Contamination by N-nitrosamines diverts resources and time from research and development or pharmaceutical production, representing a bottleneck in drug development. Therefore, predicting the risk of N-nitrosamine contamination is an important step in preventing pharmaceutical contamination by DNA-reactive impurities for the production of high-quality pharmaceuticals. In this study, we first predicted the degradation pathways and impurities of model pharmaceuticals, namely gliclazide and indapamide, in silico using an expert-knowledge software. Second, we verified the prediction results with a demonstration test, which confirmed that N-nitrosamines formed from the degradation of gliclazide and indapamide in the presence of hydrogen peroxide, especially under alkaline conditions. Furthermore, the pathways by which degradation products formed were determined using ranitidine, a compound previously demonstrated to generate NDMA. The prediction indicated that a ranitidine-related compound served as a potential source of nitroso groups for NDMA formation. In silico software is expected to be useful for developing methods to assess the risk of N-nitrosamine formation from pharmaceuticals.

N-Nitrosodimethylamine (NDMA) Formation from Ranitidine Impurities: Possible Root Causes of the Presence of NDMA in Ranitidine Hydrochloride

N-Nitrosodimethylamine (NDMA) is a probable human carcinogen. This study investigated the root cause of the presence of NDMA in ranitidine hydrochloride. Forced thermal degradation studies of ranitidine hydrochloride and its inherent impurities (Imps. A, B, C, D, E, F, G, H, I, J, and K) listed in the European and United States Pharmacopeias revealed that in addition to ranitidine, Imps. A, C, D, E, H, and I produce NDMA at different rates in a solid or an oily liquid state. The rate of NDMA formation from amorphous Imps. A, C, and E was 100 times higher than that from crystalline ranitidine hydrochloride under forced degradation at 110 °C for 1 h. Surprisingly, crystalline Imp. H, bearing neither the N,N-dialkyl-2-nitroethene-1,1-diamine moiety nor a dimethylamino group, also generated NDMA in the solid state, while Imp. I, as an oily liquid, favorably produced NDMA at moderate temperatures (e.g., 50 °C). Therefore, strict control of the aforementioned specific impurities in ranitidine hydrochloride during manufacturing and storage allows appropriate control of NDMA in ranitidine and its pharmaceutical products. Understanding the pathways of the stability related NDMA formation enables improved control of the pharmaceuticals to mitigate this risk.

A simple and rapid method to simultaneously analyze ciclesonide and its impurities in a ciclesonide metered-dose inhaler using on-line supercritical fluid extraction/supercritical fluid chromatography/quadrupole time-of-flight mass spectrometry

A simple and rapid on-line SFE/SFC/quadrupole TOF-MS method to simultaneously analyze active pharmaceutical ingredients and impurities from metered-dose inhalers (MDIs) was developed using ciclesonide MDI (CIC-MDI) as an example. CIC-MDI, as drug Alvesco®, has been approved for the treatment of bronchial asthma, and its major impurities are listed in the European Pharmacopoeia and in the supplementary package inserts of Alvesco® (called as "Pharmaceutical interview form" in Japan). In the developed method, CIC-MDI was manually sprayed only once on a glass disc prior to the SFE/SFC/quadrupole TOF-MS. In the SFE, CIC and its impurities and other impurities having various polarities and hydrophobicity, were extracted in 3.5 min and subsequently separated on a CHIRALPAK IE-3 column to be detected by quadrupole TOF-MS in 6.5 min. This method would be applicable to the analysis of other inhalable pharmaceutical products whose sample preparation requires complicated procedures, as well as to the analysis of general pharmaceutical products for profiling impurities.

Miroestrol Quantification in Pueraria mirifica Crude Drugs and Products by Single-Reference UPLC/PDA/MS Using Relative Molar Sensitivities to Kwakhurin

Owing to occasional health damages caused by health food products derived from Pueraria mirifica (PM), the Japanese government has designated PM as an "ingredient calling for special attention." Miroestrol is a specific isoflavone isolated from PM and possesses very strong estrogenic activity enough to induce side effects in small amount. Therefore, routine analyses for miroestrol quantification is recommended to control the safety and quality of PM products. However, miroestrol content in PM is quite low, and commercial reagent for its detection is rarely available. In this study, we developed a quantitative analysis method for miroestrol in PM without using its analytical standard by using the relative molar sensitivity (RMS) of miroestrol to kwakhurin, another PM-specific isoflavone, as a reference standard. The RMS value was obtained by an offline combination of ¹H-quantitative NMR spectroscopy and a LC/photo diode array (PDA) and miroestrol content was determined by single-reference LC/PDA using RMS. Furthermore, we investigated miroestrol content in commercially available PM crude drugs and products, and the RMS method was compared with the conventional calibration curve method in terms of performance. The rate of concordance of miroestrol contents determined by two method was 89-101%. The results revealed that our developed LC/PDA/MS method with RMS using kwakhurin as a reference standard was accurate for routine monitoring of miroestrol content in PM crude drugs and products to control their quality.

Facile Synthesis of Kwakhurin, a Marker Compound of Pueraria mirifica and Its Quantitative NMR Analysis for Standardization as a Reagent

The side effects of kwao keur dietary supplements (obtained from the tuberous root of Pueraria mirifica) have recently been reported by the Ministry of Health, Labour and Welfare, Japan. To control the quality of kwao keur products, its ingredients need to be maintained by characteristic marker compounds, such as miroestrol, deoxymiroestrol, and kwakhurin (KWA). In this study, we described the facile synthesis of KWA, a marker compound of P. mirifica. Our revised synthetic method produced KWA with shorter steps and higher yield than the reported method. Furthermore, the absolute purity of KWA was determined by quantitative NMR analysis for standardization as a reagent, and its purity was 92.62 ± 0.12%.

Quality Assessment of Medicinal Product and Dietary Supplements Containing Vitex agnus-castus by HPLC Fingerprint and Quantitative Analyses

In this study, we aimed to evaluate the quality of 11 products sold in Japan (one medicinal product and 10 dietary supplements) containing/claiming to contain chasteberry extract (fruit of Vitex agnus-castus L.) using HPLC fingerprint (15 characteristic peaks), quantitative determination of chemical marker compounds, and a disintegration test. The HPLC profile of the medicinal product was similar to that of the reference standard of V. agnus-castus fruit dry extract obtained from European Directive for the Quality of Medicines (EDQM), whereas the profiles of some dietary supplements showed great variability, such as different proportions of peaks or lack of peaks. Results of the principal component analysis of the fingerprint data were consistent with those of the HPLC profile analysis. The contents of two markers, agnuside and casticin, in dietary supplements showed wide variability; this result was similar to that achieved with the HPLC fingerprint. In particular, agnuside and/or casticin was not detected in two dietary supplements. Furthermore, one dietary supplement was suspected to be contaminated with V. negundo, as evidenced from the results of agnuside to casticin ratio and assay of negundoside, a characteristic marker of V. negundo. Results of the disintegration test showed poor formulation quality of two dietary supplements. These results call attention to the quality problems of many dietary supplements, such as incorrect or poor-quality origin, different contents of the active ingredient, and/or unauthorized manufacturing procedures.

Effect of Schisandrae Fructus on glycyrrhizin content in Kampo extracts containing Glycyrrhizae Radix used clinically in Japan

Glycyrrhizae Radix is an important crude drug in Japan and is the most frequently prescribed drug in Kampo medicines for the treatment of a wide range of diseases. Glycyrrhizin (GL), the major active ingredient of Glycyrrhizae Radix, has various pharmacological actions but causes adverse effects such as pseudoaldosteronism. In a previous study, the GL content of shoseiryuto was found to be unexpectedly low, and Schisandrae Fructus in shoseiryuto reduced the pH value of the decoction and drastically decreased the extraction efficiency of GL from Glycyrrhizae Radix. In the present study, we investigated the extraction efficiency of GL from Glycyrrhizae Radix in decoctions comprising Glycyrrhizae Radix and five different fruit-derived crude drugs. Among the five fruit-derived crude drugs tested, Schisandrae Fructus markedly decreased both the pH value of the decoction and the extraction efficiency of GL. A comparison of the pH value of the decoction and the GL content of 12 Kampo prescriptions (containing at least Glycyrrhizae Radix and Schisandrae Fructus) showed that the GL content per daily dose was proportional to the compounding amount of Glycyrrhizae Radix, and that the extraction efficiency of GL from Glycyrrhizae Radix was strongly correlated with the pH value of the decoction. In addition, the pH value of the decoction was similar to the pH value documented in interview forms provided by pharmaceutical companies. These results suggested that the GL content in Glycyrrhizae Radix-containing Kampo products can be estimated from both the compounding amounts of Glycyrrhizae Radix and the pH value documented in their interview forms. Knowledge of GL content will help avoid adverse reactions due to Glycyrrhizae Radix.

Geissoschizine synthase controls flux in the formation of monoterpenoid indole alkaloids in a Catharanthus roseus mutant

A Catharanthus roseus mutant accumulates high levels of ajmalicine at the expense of catharanthine and vindoline. The altered chemistry depends on increased expression and biochemical activities of strictosidine β-glucosidase and ajmalicine synthase activities and reduced expression and biochemical activity of geissoschizine synthase. The Madagascar periwinkle [Catharanthus roseus (L.) G. Don] is a commercially important horticultural flower species and is a valuable source for several monoterpenoid indole alkaloids (MIAs), such as the powerful antihypertensive drug ajmalicine and the antineoplastic agents, vinblastine and vincristine. While biosynthesis of the common MIA precursor strictosidine and its reactive aglycones has been elucidated, the branch point steps leading to the formation of different classes of MIAs remain poorly characterized. Screening of 3600 ethyl methyl sulfonate mutagenized C. roseus plants using a simple thin-layer chromatography screen yielded a mutant (M2-0754) accumulating high levels of ajmalicine together with significantly lower levels of catharanthine and vindoline. Comparative bioinformatic analyses, virus-induced gene silencing, and biochemical characterization identified geissoschizine synthase, the gateway enzyme that controls flux for the formation of iboga and aspidosperma MIAs. The reduction of geissoschizine synthase transcripts in this high ajmalicine mutant, together with increased transcripts and enzyme activities of strictosidine β-glucosidase and of heteroyohimbine synthase, explains the preferential formation of ajmalicine in the mutant instead of catharanthine and vindoline that accumulates in the wild-type parent. Reciprocal crosses established that that the high ajmalicine phenotype is inherited as a Mendelian recessive trait.

Chemical Analysis of Counterfeit Hepatitis C Drug Found in Japan

In January 2017, counterfeits of the hepatitis C drug 'HARVONI^® Combination Tablets' (HARVONI^®) were found at a pharmacy chain through unlicensed suppliers in Japan. A total of five lots of counterfeit HARVONI^® (samples 1-5) bottles were found, and the ingredients of the bottles were all in tablet form. Among them, two differently shaped tablets were present in two of the bottles (categorized as samples 2A, 2B, 4A, and 4B). We analyzed the total of seven samples by high-resolution LC-MS, GC-MS and NMR. In samples 2A, 3 and 4B, sofosbuvir, the active component of another hepatitis C drug, SOVALDI^® Tablets 400 mg (SOVALDI^®), was detected. In sample 4A, sofosbuvir and ledipasvir, the active components of HARVONI^®, were found. A direct comparison of the four samples and genuine products showed that three samples (2A, 3, 4B) are apparently SOVALDI^® and that sample 2A is HARVONI^®. In samples 1 and 5, several vitamins but none of the active compounds usually found in HARVONI^® (i.e., sofosbuvir and ledipasvir) were detected. Our additional investigation indicates that these two samples are likely to be a commercial vitamin supplement distributed in Japan. Sample 2B, looked entirely different from HARVONI^® and contained several herbal constitutents (such as ephedrine and glycyrrhizin) that are used in Japanese Kampo formulations. A further analysis indicated that sample 2B is likely to be a Kampo extract tablet of Shoseiryuto which is distributed in Japan. Considering this case, it is important to be vigilant to prevent a recurrence of distribution of counterfeit drugs.

Qualitative and Quantitative Evaluation of Drug and Health Food Products Containing Red Vine Leaf Extracts on the Japanese Market

Red vine leaf extracts (RVLEs) have traditionally been used for leg wellness and are now standardized to be used as OTC drugs in Europe. In Japan, one brand of RVLE products was recently approved as a direct OTC drug, and RVLEs are still used as ingredients in health food products. Since there is no mandated criterion for the quality of health food products in Japan, the consistent quality and composition of these products are not assured. Here we analyzed OTC drug and health food products containing RVLEs with different lot numbers by LC/MS. Subsequent multivariate analyses clearly indicated that the quality of the health food products was highly variable compared to that of the drug products. Surprisingly, the component contents in the health foods were different even within a same lot in a same brand. The quantitative analyses of flavonols and stilbene derivatives in the drugs and health foods indicated that the concentration of each substance was kept constant in the drugs but not in the health foods. These results strongly indicated that the quality of RVLEs as a whole was not properly controlled in the manufacturing process of health foods. Since RVLE is an active ingredient with pharmaceutical evidences and is used for drugs, the proper regulation for ensuring the consistent quality of RVLEs from product to product would be recommended even in the health foods.

Authentication of the botanical origin of Western herbal products using Cimicifuga and Vitex products as examples

Various herbal medicines have been developed and used in various parts of the world for thousands of years. Although locally grown indigenous plants were originally used for traditional herbal preparations, Western herbal products are now becoming popular in Japan with the increasing interest in health. At the same time, there are growing concerns about the substitution of ingredients and adulteration of herbal products, highlighting the need for the authentication of the origin of plants used in herbal products. This review describes studies on Cimicifuga and Vitex products developed in Europe and Japan, focusing on establishing analytical methods to evaluate the origins of material plants and finished products. These methods include a polymerase chain reaction-restriction fragment length polymorphism method and a multiplex amplification refractory mutation system method. A genome-based authentication method and liquid chromatography-mass spectrometry-based authentication for black cohosh products, and the identification of two characteristic diterpenes of agnus castus fruit and a shrub chaste tree fruit-specific triterpene derivative are also described.

Identification of New Diterpenes as Putative Marker Compounds Distinguishing Agnus Castus Fruit (Chaste Tree) from Shrub Chaste Tree Fruit (Viticis Fructus)

Agnus Castus Fruit is defined in the European Pharmacopoeia as the dried ripe fruit of Vitex agnus-castus. In Europe it is used as a medicine targeting premenstrual syndrome and climacteric disorder. In Japan, Agnus Castus Fruit is becoming popular as a raw material for over-the-counter drugs and health food products, though its congenic species, Vitex rotundifolia and Vitex trifolia, have been used as Shrub Chaste Tree Fruit in traditional medicines. Therefore, it is important to discriminate these Vitex plants from the viewpoint of regulatory science. Here we tried to identify putative marker compounds that distinguish between Agnus Castus Fruit and Shrub Chaste Tree Fruit. We analyzed extracts of each crude drug by liquid chromatography-mass spectrometry, and performed differential analysis by comparison of each chromatogram to find one or more peaks characteristic of Agnus Castus Fruit. A peak was isolated and identified as an equilibrium mixture of new compounds named chastol (1) and epichastol (1a). The planar structures of 1 and 1a were determined spectroscopically. Their relative configurations were revealed by nuclear Overhauser effect spectroscopy and differential nuclear Overhauser effect-NMR data. Since avoiding contamination from closely related species is needed for the quality control of natural pharmaceuticals, this information will be valuable to establish a method for the quality control of both, Agnus Castus Fruit and Shrub Chaste Tree Fruit products.

Disintegration Test of Health Food Products Containing Ginkgo Biloba L. or Vitex Agnus-Castus L. in the Japanese Market

For many years now, a number of Western herbs have been widely used in health food products in Japan and as pharmaceuticals in Europe. There are few or no mandated criteria concerning the quality of these herbal health food products, thus clarification is warranted. Here, we performed disintegration tests of 26 pharmaceutical and health food products containing the Western herbs ginkgo leaf and chaste tree fruit, in accord with the Japanese Pharmacopoeia. All eight pharmaceutical herbal products found in the European market completely disintegrated within the defined test time, and 11 of the 18 tested herbal products distributed as health foods in Japan disintegrated. Among the incompatible products identified in the Pharmacopoeia test, some products remained intact after incubation in water for 60 min. To ensure the efficacy of Western herbal products sold as health food in Japan, quality control, including disintegration, is therefore recommended, even though these products are not regulated under the Pharmaceutical Affairs Law.

Functional and structural characterization of a flavonoid glucoside 1,6-glucosyltransferase from Catharanthus roseus

Sugar-sugar glycosyltransferases play an important role in structural diversity of small molecule glycosides in higher plants. We isolated a cDNA clone encoding a sugar-sugar glucosyltransferase (CaUGT3) catalyzing 1,6-glucosylation of flavonol and flavone glucosides for the first time from Catharanthus roseus. CaUGT3 exhibited a unique glucosyl chain elongation activity forming not only gentiobioside but also gentiotrioside and gentiotetroside in a sequential manner. We investigated the functional properties of CaUGT3 using homology modeling and site-directed mutagenesis, and identified amino acids positioned in the acceptor-binding pocket as crucial for providing enough space to accommodate flavonoid glucosides instead of flavonoid aglycones. These results provide basic information for understanding and engineering the catalytic functions of sugar-sugar glycosyltransferases involved in biosynthesis of plant glycosides.

Purification and characterization of UDP-glucose : curcumin glucoside 1,6-glucosyltransferase from Catharanthus roseus cell suspension cultures

Catharanthus roseus cell suspension cultures converted exogenously added curcumin to a series of curcumin glucosides that possessed drastically enhanced water solubility. A cDNA clone encoding a glucosyltransferase responsible for glucosylation of curcumin to form curcumin 4'-O-glucoside was previously isolated, and in the present study a novel sugar-sugar glycosyltransferase, UDP-glucose:curcumin glucoside glucosyltransferase (UCGGT), was purified approximately 900-fold to apparent homogeneity from cultured cells of C. roseus. The purified enzyme (0.2% activity yield) catalyzed 1,6-glucosylation of curcumin 4'-O-glucoside to yield curcumin 4'-O-gentiobioside. The molecular weight and isoelectric point were estimated to be about 50 kDa and 5.2, respectively. The enzyme showed a pH optimum between 7.5 and 7.8. Both flavonoid 3-O- and 7-O-glucosides were also preferred acceptor substrates of the enzyme, whereas little activity was shown toward simple phenolic glucosides such as arbutin and glucovanillin, cyanogenic glucoside (prunasin) or flavonoid galactoside. These results suggest that UCGGT may also function in the biosynthesis of flavonoid glycosides in planta.

A single amino acid in the PSPG-box plays an important role in the catalytic function of CaUGT2 (Curcumin glucosyltransferase), a Group D Family 1 glucosyltransferase fromCatharanthus roseus

Curcumin glucosyltransferase (CaUGT2) isolated from cell cultures of Catharanthus roseus exhibits unique substrate specificity. To identify amino acids involved in substrate recognition and catalytic activity of CaUGT2, a combination of domain swapping and site-directed mutagenesis was carried out. Exchange of the PSPG-box of CaUGT2 with that of NtGT1b (a phenolic glucosyltransferase from tobacco) led to complete loss of enzyme activity in the resulting recombinant protein. However, replacement of Arg378 of the NtGT1b PSPG-box with cysteine, the corresponding amino acid in CaUGT2, restored the catalytic activity of the chimeric enzyme. Further site-directed mutagenesis revealed that the size of the amino acid side-chain in that particular site is critical to the catalytic activity of CaUGT2.

An efficient chemoenzymatic production of small molecule glucosides with in situ UDP-glucose recycling

A one-pot system for efficient enzymatic synthesis of curcumin glucosides is described. The method couples the activities of two recombinant enzymes, UDP-glucose: curcumin glucosyltransferase from Catharanthus roseus (CaUGT2) and sucrose synthase from Arabidopsis thaliana (AtSUS1). UDP, a product inhibitor of UDP-glucosyltransferase, was removed from the system and used for regeneration of UDP-glucose by the second enzyme, AtSUS1. The productivity was increased several-fold and UDP-glucose initially added to the reaction mixture could be reduced to one-tenth of the normal level. The concept of enhancing glucosylation efficiency by coupling a UDP-glucose regeneration system with glucosyltransferases should be applicable to enzymatic production of a wide range of glucosides.

The use of epoxy patch grafts for the repair of experimentally-created diaphragmatic defects in dogs

Canine pericardium which had been treated with polyepoxy compounds (Denacol EX-313) was used as a patch graft for the correction of experimentally-created diaphragmatic defects in five dogs belonging to the same litter. Clinical, macroscopic and histological examinations were conducted every month up to five months after suturing of the patch graft. Clinical examination of the patch graft showed no apparent abnormalities. Macroscopic examination conducted during autopsy showed that the patch graft maintained adequate elasticity for five months after suturing, the surface of the patch graft was covered with a thin membrane and neovascularization was observed. Histological examination showed that the surface of the patch graft was covered with a thin membrane. Inflammatory tissue reactions were observed at one month, but gradually decreased from the second month onwards. In addition, the patch graft had excellent tissue affinity.

A new cytotoxic compound from a water extract of corn

A new cytotoxic compound 2 was isolated from a water extract of corn germ. Structural elucidation by spectroscopic data and chemical evidence fully substantiated 2 to be 11 (E)-10-oxo-11-octadecen-13-olide. Compound 2 exhibited considerably strong cytotoxic activity against various cell lines with IC50 of 0.9-2.8 micrograms/ml.

Structure and distribution of the lymphatic vessels in the parietal pleura of the monkey as studied by enzyme-histochemistry and by light and electron microscopy

The entire distribution of lymphatics in whole mount preparations of the Japanese monkey was studied using the enzyme-histochemical technique reported by KATO et al. (1990, 1991). In this staining, the lymphatic endothelium was colored dark brown by its positive 5'-nucleotidase activity, while most blood vessels (especially arterioles) were colored blue due to their positive alkaline phosphatase reaction. The whole mount preparations of the pleura treated enzyme-histochemically clearly indicated the distribution, branching patterns and running courses of lymphatic vessels. They revealed numerous short blind-ending knobs which represented the initial portions of lymphatics. These knobs were seen near the surface of the parietal pleura along its entire extent. In the costal and diaphragmatic pleura, the lymphatics ran parallel to the intercostal muscle fibers, but perpendicular to the tendinous and muscular fibers of the diaphragm; they formed ladders, independent of the courses of blood vessels. In the mediastinal pleura, lymphatic vessels showed a tree-like branching accompanying blood vessels. Under the light microscope, toluidine-blue stained semithin sections revealed the initial part of lymphatics as a small irregularly outlined cavity (7-10 microns in diameter) surrounded by a dense connective tissue. This lymphatic dilation was sometimes located close to a thin mesothelial layer. Such a structure suggesting a "stoma" was seen near the attachment of the muscular diaphragm to the sternum and along the borders of the ribs. Transmission electron microscopy revealed an occasional interruption in the mesothelium. This stoma continued to a submesothelial cavity whose base comprised an attenuated endothelium of an extended lymphatic vessel.