Analysis of Four Solvatomorphs of Betulin by TG–DTA–EI/PI–MS System Equipped with the Skimmer-Type Interface

Abstract

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 H 2 O, 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.

Microcrystalline solid–solid transformations of conformationally-responsive solvates, desolvates and a salt of N,N′-(1,4-phenylene)dioxalamic acid: the energetics of hydrogen bonding and n/π → π* interactions

“…The loss of DMF in two steps, in the range of 80–200 °C, has also been observed in the TG of the 1 : 1 betulin–DMF solvate 53 without DMF decomposition. 54 All these DMF-solvates, including the herein reported H 2 pOx·2DMF, have very weak or null DMF–DMF interactions, as a common structural feature. Besides, their calculated packing fraction (PF) values are small, in the 0.659–0.687 range, with no void space.…”

On-Line Thermally Induced Evolved Gas Analysis: An Update—Part 1: EGA-MS

“…The MS was equipped with the skimmer-type interface as a real-time and onsite analysis technique. Four solvatomorphs of Betulin were analyzed for the first time and five main volatile gaseous species were clearly identified [ 332 ].…”

Insights Into the Properties of Amygdalin Solvatomorphs: X-ray Structures, Intermolecular Interactions, and Transformations

“…Compared with the SXRD method, TG–MS analysis provides more flexible requirements for the samples, particularly those solvatomorphs that hardly form as single crystals, which are suited for SXRD experiments. Previous researchers have also reported the use of the TG–MS method to analyze and characterize solvatomorphs. − The six crystal forms were characterized by thermal analysis, including TG, DSC, and TG–MS.…”