First Experimental Quantitative Charge Density Studies of Vitamin D Intermediate
Vitamins D are a group of fat-soluble secosteroids which play a regulatory role in the functioning of most cells. Rational design of new vitamin D analogs of increased therapeutic potency and lowered calcemic side effects requires high-resolution initial structures and a deep understanding of interactions with the vitamin D receptor. In this paper, using quantum crystallography methods, we present the first determination of the experimental quantitative charge density of an advanced intermediate of vitamin D analogues as well as a reconstruction of the theoretical electron density of final vitamin D analogues. Application of these methods allows for topological and electrostatic interaction energy analysis which is important for understanding biological effects.