Analysis of the Chemical Composition of Sikamonia Lipids Based on UHPLC-Q-Orbitrap-HRMS Technology
Skamoyane is a milk like exudate from the roots of Convovulus scanmoria L., a plant in the Convovulus family, which is dried and processed. Listed in the Uyghur Medicine Volume of the “Drug Standards Issued by the Ministry of Health of the People’s Republic of China”, it can generate dryness and heat, remove abnormal mucus and bile, dry dampness and reduce swelling, dispel cold and relieve pain, expel insects and strengthen the stomach. It is used for damp cold or mucous diseases, systemic edema, joint pain, intestinal worms, and gastric weakness. This medicinal herb has been widely used as a prescription herb for dozens of formulations such as Xingnaokukeya tablets and Tongzhi Surunjiang tablets. But its existing quality standards are relatively simple, and there are no thin-layer identification or content determination items for reference medicinal materials or reference standards. Pharmaceutical companies generally report that the quality of Camonitril in the market is uneven, and existing standards are no longer able to control its quality. Due to the lack of systematic and in-depth research on the chemical composition of this medicinal herb, the identification of indicator components and the establishment of quantitative methods have not been resolved to improve the standards of medicinal herbs.

Through literature search, it was found that there are few reports on the chemical composition of semania. Previous studies have shown that semania lipids contain resin glycosides with biological activities such as anti-inflammatory, antiviral, and inhibitory effects on cancer cells. In recent years, liquid chromatography tandem high-resolution mass spectrometry (LC-HRMS) has shown great application prospects in the field of traditional Chinese medicine analysis, such as identifying known and unknown compounds in natural products. Especially, high-resolution mass spectrometry detectors (Q-TOF, Q-Orbitrap, etc.) can provide accurate molecular weights and predicted molecular formulas, providing more information for the identification of unknown compounds and metabolites. Therefore, this study utilized ultra-high performance liquid chromatography quadrupole orbital trap high-resolution mass spectrometry (UHPLC-Q-Orbitrap-HRMS) technology to establish a rapid analysis method for the chemical composition of shikamolipids, providing scientific data for the quality standard research of medicinal materials and related products.

This study found that the methanol extract of Skamoyne mainly contains two categories of components: hydroxycinnamoyl quinic acid and resin glycosides. According to the retention time, hydroxycinnamoylquinic acid is concentrated in the first 30 minutes, and there are more dimers (diesters) among the three types. In the characteristic components of resin glycosides, ether soluble compounds are composed of different small molecule organic acids introduced into the structure of shikamoxic acid A. There are also resin acid components with the B structure of shikamonic acid. For ether insolubility, previous studies have shown that there are several types of C14 and C16 cycloalkanoic acids as aglycones. In this paper, a type with 3S, 11S dihydroxyhexadecanoic acid (C16H31O4-) as aglycone was detected, and the characteristic fragment ions m/z 741.3874, 595.3184, 433.2817, and 287.2232 are also significantly different from those of ether soluble compounds.

The structure of resin glycosides is unique, and researchers at home and abroad have a strong interest in the synthesis and pharmacological effects of resin glycosides. Currently, only studies related to separation and structural confirmation have been reported for resin glycosides identified in Skamoxa lipids, and no commercially available standard products have been found. This study will provide a scientific basis for the discovery of standard medicinal materials and the preparation of high-purity standards in the future, as well as for improving the quality standards of Skamoyamide medicinal materials and related pharmaceuticals.