The present invention relates to low-molar mass condensed derivatives of silicic acid of sub-nano particle size characterized by particular structure and specific biological activities. Preparation methods and applications are presented for the here disclosed sub-nano silicic acid (SNSA) which interact with bio-molecules and modify significantly their structure and biological function. Preferred field of application of the inventive silicic acid derivatives is to modulate the structure and biological function of proteins particularly of those involved in reversible phosphorylation within biological signal transduction or membrane transport processes. Structure of the substances, methods for the preparation and stabilization, as well as pharmaceutical compositions comprising the substances and methods of application in the prevention, diagnosis and therapy of diseases are disclosed.