Structure analysis of powder sample
MicroED has very low requirements for the size of the resolved crystals, so for some drugs that are difficult to cultivate large-size single crystals, we can directly select the appropriate microcrystalline particles from the powder. The minimum dimensional size of the crystal needs to be greater than 100nm for structural analysis using MicroED.
API powder C34H22O4 → Electron diffraction pattern → Suitable crystal under electron microscope → Crystal cell structure
Structure analysis of eutectic drug structure
The two ligands of the eutectic drug are bonded by hydrogen bond, which can be dissociated by conventional single crystal cultivation methods. The structure of the eutectic drug and the ratio of the two ligands were determined by in situ structure analysis of the powder drug using MicroED and the absolute configuration of the molecule.
Crystal screening under electron microscope → Electron diffraction data collection → （Coeus Dynamic refinement）→ Ibuprofen: Leucine = 2:3
Analysis of absolute configuration of small molecules
The electron beam emitted by MicroED interacts with the atoms in the drug molecule, and the obtained electron diffraction pattern has a strong dynamic effect, which is different with different chirality. Dynamic refinement can confirm the absolute configuration of chiral compounds and avoid different biological effects caused by incorrect chirality.
Oseltamivir phosphate powder → Suitable crystal under electron microscope → Electron diffraction pattern → Crystal cell structure