Anti-proliferative. Shows anti-melanoma activity. Sun-block ingredient for cosmetics. Prevents sun burning, premature aging and skin cancer. Antibacterial.Source:birch bark (Betula alba)Formula:C39H56O5Solubility:methanol, acetone or DMSOMolecular Weight:~604.9Storage and Stability:Lyophilized powder may be stored at -20°C. Stable for 12 months after receipt at -20°C. Reconstitute with sterile buffer or ddH2O. Aliquot to avoid repeated freezing and thawing. Store at -20°C. Reconstituted product is stable for 6 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.