Betulin (BE) has exceedingly become a potential natural product, providing multiple pharmacological and biological activities, including anti-cancer, anti-viral, and anti-inflammatory benefits. Previous research indicated that the solvatomorphism of BE can easily occur through crystallization with different organic solvents. This property of BE can directly affect its extraction, isolation, and preparation process. In this study, a system of thermogravimetry (TG)–differential thermal analysis (DTA) coupled with mass spectrometry (MS) with electron ionization (EI) and photoionization (PI) capability, equipped with the skimmer-type interface (i.e., skimmer-type interfaced TG–DTA–EI/PI–MS system), as a real-time and onsite analysis technique, was employed. Then, four solvatomorphs of BE, namely, with pyridine and water (A), sec-butanol (B), n,n-dimethylformamide (DMF) (C), and isopropanol (V), were analyzed for the first time. Finally, five kinds of the main volatile gaseous species, including H₂O, pyridine, sec-butanol, DMF, and isopropanol, were identified clearly. Furthermore, the multi-step desolvation processes of the four solvatomorphs of BE were revealed by this system for the first time. This system showed great potential for the rapid and accurate analysis of various solvatomorphs of natural products.

Graphic Abstract

中文翻译：

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使用配备撇渣器型接口的 TG-DTA-EI/PI-MS 系统分析桦木醇的四种溶剂型。


桦木醇 (BE) 已成为一种极具潜力的天然产物，具有多种药理和生物活性，包括抗癌、抗病毒和抗炎功效。先前的研究表明，BE 很容易通过与不同有机溶剂的结晶而发生溶剂化作用。 BE的这一性质可直接影响其提取、分离和制备过程。在这项研究中，热重分析（TG）-差热分析（​​DTA）与质谱（MS）相结合，具有电子电离（EI）和光电离（PI）功能，配备撇渣器型接口（即撇渣器-采用类型接口的TG-DTA-EI/PI-MS系统）作为实时现场分析技术。然后，首次分析了BE的四种溶剂化物，即吡啶和水(A)、仲丁醇(B)、 n,n-二甲基甲酰胺(DMF)(C)和异丙醇(V)。最终明确了H ₂ O、吡啶、仲丁醇、DMF、异丙醇5种主要挥发性气体组分。此外，该系统首次揭示了BE的四种溶剂化物的多步去溶剂化过程。该系统在快速准确分析天然产物的各种溶剂化物方面显示出巨大的潜力。

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