3d image of ergostane skeletal formula

ergostane tetracyclic triterpene terpene 24s-methylcholestane plant animal withanolides biomarker early eukaryotes stigmastane 3d biological activity bioactive herbal phytochemical herb natural herbalism pharmacognosy pharmacopoeia parasympathomimetic alkaloid flavonoid phytoalexin phytohormones growth regulator hormone auxin growth rooting cytokinesis cell biochemistry biology biomolecule atom molecule molecular structural structure formula skeletal geometry ball stick