betulin molecular structure, 3d model molecule c30h50o2, structural chemical formula view from a microscope

betulin molecule microscope molecular structure bubble air chemical formula transparent glass model c30h50o2 atom chemistry bark birch tree oncology cancer composition silver drawing skeletal compound protein icon line alder flat science element antitumoral betuline bullosa elementbinding epidermolysis triterpene conceptual reaction scientific ball substance nature elemental grey herbal plastic structural view from microscope