Study on the transfer of dosage values of Bu Zha Ye decoction pieces and standard decoctions based on UPLC fingerprint spectrum and multi-component quantification
Bu Zha Ye is a characteristic medicinal herb in Lingnan, mainly composed of flavonoids, alkaloids, terpenes, organic acids, etc. It has the effects of promoting gastrointestinal peristalsis and gastric juice secretion, lowering blood lipids, reducing yellowing, anti-inflammatory, analgesic, cardiovascular protection, anti-aging, etc. It is a dual-purpose Chinese medicine for both medicine and food. In recent years, the attention to Bu Zha Ye has increased, and research on it has also become more and more extensive.
Traditional Chinese medicine mainly uses decoctions as the main form of medication, which are the material basis for the efficacy of Chinese medicine. After thousands of years of clinical practice, establishing quality standards for standard decoctions of Chinese medicine can provide important references for the establishment of quality standards for modern Chinese medicine preparations such as formula granules. At present, there are no research reports on the standard decoction of Bu Zha Ye. In our company’s research on the national standard of Bu Zha Ye formula granules, we have studied the key quality indicators of the standard decoction according to the “Technical Requirements for Quality Control and Standard Development of Traditional Chinese Medicine Formula Granules” (hereinafter referred to as the technical requirements), including paste yield, extract, content and transfer rate of indicator components, fingerprint spectrum, to investigate the transfer law of the quantity value from Bu Zha Ye decoction pieces to the standard decoction, providing reference for the development of quality standards for Bu Zha Ye formula granules and related preparations.

The quality of Bu Zha Ye is relatively light, but its chemical composition is complex. During the decoction process, a large amount of components overflow, resulting in more impurities in the standard decoction, which affects the chromatographic separation and analysis of effective ingredients. When using solvents with high polarity such as methanol and ethanol to treat the standard decoction, the fingerprint spectrum baseline is unstable, the chromatographic peak separation is poor, the chromatographic peaks are disorderly, and there are many small peaks. Therefore, in the pre-treatment method of standard decoction test samples, the separation, purification and enrichment method of ethyl acetate extraction was investigated to reduce the interference of impurities, and compared with conventional treatment methods. The results showed that using ethyl acetate as the extraction solvent could significantly improve the influence of impurity peaks, ensure the purity and separation of the main chromatographic peaks, and solve the problems of unstable chromatographic baseline and small absorption of some chromatographic peaks. In the investigation of chromatographic conditions, different mobile phase elution systems were examined, such as acetonitrile-0.1% phosphoric acid solution, acetonitrile-0.1% acetic acid solution, methanol-0.1% formic acid solution, methanol-0.1% acetic acid solution, etc. The results showed that using methanol-0.1% acetic acid solution as the elution system resulted in a higher number of chromatographic peaks and better overall separation. Considering the establishment of ultra-high performance liquid chromatography fingerprint spectra, the selection of chromatographic columns is crucial. Therefore, this experiment investigated chromatographic columns of different particle sizes and brands, and ultimately chose the Agilent ZORBAX SB C18 chromatographic column (2.1mm × 150mm, 1.8 μ m), with the best peak shape and resolution of each shared fingerprint peak.
Research has shown that the leaves of Bu Zha contain numerous flavonoids. Xiao et al. successfully identified 31 compounds from Bu Zha Ye using UPLC-Q-TOF-MS/MS technology, including 28 flavonoids and 3 phenolic acids. Pharmacological studies have shown that flavonoids are an important material basis for the digestion, digestion, heat clearing, and dampness relieving effects of Bu Zha Ye. Representative components such as vitexin, isovitexin, and narcissin have high content in Bu Zha Ye and certain solubility in water. Therefore, Bu Zha Ye standard decoction uses vitexin, isovitexin, and narcissin as content determination indicators, and establishes a content determination method for Bu Zha Ye decoction pieces based on the decoction, in order to guide the study of the transfer of standard decoction values.
Bu Zha Ye medicinal herbs are mainly distributed in Guangdong, Guangxi, and Hainan, and belong to the authentic medicinal herbs produced in Guangdong. 15 batches of Bu Zha Ye medicinal herbs were collected from the three aforementioned production areas, demonstrating sufficient representativeness. From the determination results of 15 batches of standard decoction extract, extract, and 15 batches of Bu Zha Ye decoction pieces for three flavonoids, it can be seen that there are certain differences among the samples from different batches, with the maximum and minimum values differing by about two times. This difference is related to the quality of the medicinal materials themselves and meets the requirements of the Technical Requirements. There are no obvious abnormal values.
From the results of the transfer rate determination, the average transfer rate of the three flavonoids ranged from 40% to 60%, with vitexin having the highest transfer rate, followed by narcissin and isovitexin, and the overall transfer rate was relatively stable. The fingerprint spectrum research results showed that there was a certain change in the proportion of peaks from Bu Zha Ye decoction pieces to standard decoction. OPLS-DA analysis identified five significantly different chromatographic peaks, namely peaks 1, 2, 3, 4, and 6. Except for peak 3, which was not identified, all other chromatographic peaks were known. Among them, peaks 1, 2, and 4 were phenolic acid components. Therefore, peak 3 is speculated to be a phenolic acid. Phenolic acid components are a special presence in plants, which can serve as precursors for the synthesis of other compounds and can also be hydrolyzed from various compounds. Therefore, the significant increase in the relative peak area of phenolic acid components in the standard decoction of Bu Zha Ye is considered to be due to the hydrolysis of other components during the decoction process. The structure of peak 6 isovitexin is similar to that of peak S isovitexin, with little difference in polarity, but there is a significant difference in transfer rate. It is considered that there is a certain degree of interconversion between isovitexin and isovitexin during the decoction process of standard decoction, and further research is needed.
This study is based on the key quality indicators of the standard decoction of Bu Zha Ye, and conducts in-depth research and analysis on the value transfer of the standard decoction of Bu Zha Ye decoction pieces, providing important references for the formulation of quality standards for Bu Zha Ye formula granules and related preparations.