[Research progress in quality control of Bufonis Venenum in preparations].

Bufonis Venenum, an animal medicinal material, is widely used for treating cardiovascular diseases and pain induced by rheumatics or malignant tumors. In view of the high activity and high toxicity, it is of great significance to pay attention to the quality control of Bufonis Venenum to ensure the safety and effectiveness of its preparations. China's drug standards involve 102 preparations(474 batch numbers) containing Bufonis Venenum approved for sale, including 14 preparations in the Chinese Pharmacopoeia(2020 edition) and 68 preparations in the standards issued by the Ministry of Health Drug Standard of the People's Republic of China. Bufonis Venenum is mostly used in pill and powder preparations in the form of raw powder, with the main functions of clearing heat, removing toxin, relieving swelling and pain, replenishing qi, activating blood, opening orifice, and awakening brain. Except the high level of quality control for Bufonis Venenum in the preparations in the Chinese Pharmacopoeia(2020 edition), the quality control standards of Bufonis Venenum in other preparations are low or even absent. Therefore, it is urgent to conduct research on the improvement of quality standards for the preparations containing Bufonis Venenum. This study retrieved the reports focusing on the quality evaluation and quality control of the preparations containing Bufonis Venenum from CNKI, PubMed, and Web of Science. Qualitative and quantitative analysis methods for 64 preparations containing Bufonis Venenum have been reported, mainly including thin-layer chromatography, HPLC fingerprint, and multi-component content determination. The index components mainly involved bufadienolides, such as gamabufalin, arenobufagin, bufotalin, bufalin, cinobufagin, and resibufogenin. According to the literature information, this paper suggests that attention should be paid to the correlations between the analysis methods and detection indexes of medicinal materials, decoction pieces and preparations, the monitoring of indole alkaloids, and the content uniformity inspection for further improving the quality standards for the preparations containing Bufonis Venenum.

[Application of QAMS for quality evaluation and control of Chinese patent medicines:taking Bufonis Venenum-contained preparations as examples].

As a new strategy capable of uncovering the characteristics of traditional Chinese medicines, the quantitative analysis of multi-components by single-marker(QAMS) has been widely employed for the quality evaluation of Chinese medicinal materials, slices, and extracts. However, its application in the assessment of Chinese patent medicines is yet to be explored. By referring to the determination of three bufogenins in Bufonis Venenum by QAMS described in Chinese Pharmacopoeia(2020 Edition), this paper selected seven representative preparations containing Bufonis Venenum and explored whether the relative correction factors(RCFs) of cinobufagin(CB) to bufalin(BF) and resibufogenin(RB) could be directly used for the quality control of Bufonis Venenum-contained preparations. Based on the qualitative analyses under the same chromatographic conditions as used for toad venom, combing specificity test, five preparations such as Yatong Yili Pills, Houzheng Pills, Xiongdan Jiuxin Pills, Liushen Pills and Niuhuang Xiaoyan Pills, were expected to use validated RCFs for the direct determination of three components. Taking Houzheng Pills as an example, the methodological validation of bufalin, cinobufagin and resibufogenin was carried out, and the recoveries of bufalin, cinobufagin and resibufogenin were 90.64%-106.1%. The obvious difference was not observed between the contents of bufalin and resibufogenin in 24 batches of preparation samples by QAMS and external reference method. In the tested samples, the content of bufalin, cinobufagin and resibufogenin were 1.27-2.61, 2.44-5.66 and 0.988-3.16 mg·g~(-1) in 10 batches of Liushen Pills samples. The contents of bufalin, cinobufagin and resibufogenin were 0.760-1.32, 1.35-2.39 and 0.600-1.55 mg·g~(-1) in 10 batches of Houzheng Pills samples from three manufacturers. The obtained data contribute to improving the quality standard of Bufonis Venenum-contained preparations, and they also provide some ideas for the application of QAMS in the quality evaluation and control of Chinese patent medicines.

[Rapid discovery of tyrosinase inhibitors from Sophora flavescens:significance for comprehensive utilization of its non-medicinal resources].

Sophorae Flavescentis Radix,derived from the root of Sophora flavescens in the Leguminosae family,has been widely used in the medicine,agriculture,animal husbandry,and daily chemical industry. A pharmacophore model-based method for rapid discovery of tyrosinase inhibitors( TIs) from S. flavescens was established by molecular docking under Lipinski rules,and verified by enzyme assays. Briefly,the chemical constituent database of S. flavescens( CDSF) was established based on the previous papers. Theoptimal pharmacophore model( OPM) was constructed by DS 2019 on the basis of known active TIs. Eighty-three hits predominated by flavonoids having higher fitting scores with OPM than the positive control were screened out,and subjected to molecular docking based on the three-dimensional structure of tyrosinase crystal protein. The potential TIs such as kurarinone and nor-kurarinone were rapidly discovered from the compounds with higher docking scores than the positive control under the Lipinski rules. The results were verified by the in vitro enzyme assays. The inhibition activities of tyrosinase from non-medicinal parts of S. flavescens were also tested to explore the relationship between the inhibition activity and chemical compositions. This study is expected to provide data support for the comprehensive application and development of S. flavescens and also a new method for the rapid discovery of active substances or functional constituents in the complex systems.

[Separation and structural elucidation of C25 epimers of furostanol saponin from aerial parts of Paris polyphylla var. chinensis].

Paris polyphylla var. chinensis(PPC) is used as one of the origin plants of Paridis Rhizoma described in the Chinese Pharmacopoeia(2020 edition). Its resources shortage makes the planting scale gradually expand, and plenty of aerial parts are abandoned because of not being effectively used. On the basis of previous research, this study separated steroidal saponins to further clarify the chemical composition of the aerial parts of PPC. As a result, three pairs of 25R or 25S epimers of furostanol saponins were obtained by various column chromatography techniques. Their structures were identified as neosolanigroside Y6(1), solanigroside Y6(2), neoprotogracillin(3), protogracillin(4), neoprotodioscin(5) and protodioscin(6) by spectral data combining with chemical transformation. Compound 1 is a new compound, and compounds 2, 3 and 5 are isolated from Paris plants for the first time. Compounds 4 and 6 are isolated from this plant for the first time. Previously, only several spirostanol glycosides with 25S configuration were isolated from Paris plants. Guided by mass spectrometry, the present study isolated the furostanol saponins with 25S configuration from this genus for the first time, which further enriches the chemical information of Paris genus and provides a reference for the isolation of similar compounds.

[Study on quality standard of Bufonis Venenum and its processed slice, toad venom powder].

Bufonis Venenum(toad venom) is prepared from the dried secretion of Bufo bufo gargarizans or B. melanostictus. Toad venom powder is one of the processed slices of crude material toad venom. In the present study, the global quality control method and standard of toad venom and its processed slice, toad venom powder were established, including TLC identification, characteristic chromatogram and QAMS by HPLC. The relative correction factor(RCF) was re-calculated and validated. The average RCFs of cinobufagin to gamabufotalin, bufotalin, bufalin and resibufogenin were considered for the determination of five bufadienolides in the samples. The total amount in the different batches of the dried samples varied from 4.06% to 17.0%. Referring to the revised methods for crude materials, the quality standard of toad venom powder was drafted including appearance description, TLC examination, characteristic chromatogram, water content and the total amount of five bufadienolides. The present investigation provided scientific evidences for the quality standard improvement of toad venom to be described in the next edition of Chinese pharmacopoeia(2020 edition).

[Study on revision of quality standard of Sophorae Flavescentis Radix and its processed slices].

Sophorae Flavescentis Radix is prepared from the root of Sophora flavescens. The comprehensive knowledge of the effective components in S. flavescens makes its quality standard improvement more possible. TLC identification method for main flavonoids and alkaloids in one test was established using GF_(254) thin layer plate and the lower solution of chloroform-methanol-water-formic acid(4∶2∶1∶0.6) as developing solvent. The quantitative method of marker alkaloids was revised including the simplified sample preparation procedure and the chromatographic conditions. The determination of four alkaloids in the samples indicated that 32 batches of tested samples were qualified ones. The total oxymatrine and matrine, total oxysophocarpine and sophocarpine, as well as total amount of four tested components in the different samples were 1.08%-2.55%, 0.369%-0.860%, 1.67%-3.40%, respectively. There was a significantly positive correlation between oxymatrine and oxysophocarpine. Total oxymatrine and matrine had same correlation with total oxysophocarpine and sophocarpine. The moisture content and extractive in 32 batches of samples fulfilled the require of not more than 11.0% and not less than 20.0%, respectively. Thirteen tested pesticides were not detected in 12 batches of samples. The present study provided the evidence for the revision of quality standard of Sophora Flavescentis Radix.

[Study on quality control method of toad venom based on characteristic chromatogram and QAMS].

Toad venom (Chansu) is prepared from the dried secretion of parotid gland and skin gland from Bufo bufo gargarizans or B. melanostictus. Up to now, much attention shall be paid to the poor quality of commercial toad venom because of the adulteration. So, it is urgent to establish a scientific and perfect quality control method to improve the quality of toad venom and guarantee its safety and effectiveness in clinical application. The different batches of toad venom samples were assayed by high performance liquid chromatography (HPLC) and the quantitative analysis of multi-components by single marker (QAMS) was used to detect the contents of five bufagenins. As a result, the reference characteristic chromatogram was established, displaying serotonin, gamabufotalin, arenobufagin, hellebrigenin, telocinobufagin, bufotalin, cinobufotalin, bufalin, cinobufagin and resibufogenin as characteristic peaks. Taking cinobufagin as an internal reference substance, QAMS was verified for the determination of five bufagenins (gamabufotalin, bufotalin, bufalin, cinobufagin, resibufogenin) in toad venom samples. The durability and applicability of the relative correction factor (RCF) were also studied systematically. RCFs of cinobufagin to gamabufotalin, bufotalin, bufalin and resibufogenin were determined as 1.05, 0.895, 1.09 and 0.913, respectively. The characteristic chromatogram and QAMS established in this study could effectively control the quality of toad venom and provide scientific evidence for the improvement of the quality standard of the toad venom to be described in Chinese Pharmacopoeia (2020 edition).