Original sentence: Another phytoestrogen, in the human diet, with some estrogen activity is coumestans but much less well studied which are found in beans, split-peas, with the best sources being alfalfa, clover, and soybean sprouts.Plant lignans associated with high fiber foods such as cereal brans and beans are the principal precursor to mammalian lignans which have an ability to bind to human estrogen sites.Soybeans are a significant source of mammalian lignan precursor secoisolariciresinol  containing 13-273 µg/100 g dry weight.The best source of lignans is flax seed
Edited sentence: A third  phytoestrogen, in the human diet, with stronger  estrogen activity than either isoflavones or lignan but much less well studied  is coumestans which are found in beans, split-peas, with the best sources being alfalfa, clover, and soybean sprouts.Plant lignans associated with high fiber foods such as cereal brans and beans are the principal precursor to mammalian lignans which have an ability to bind to human estrogen sites, thus mimicking the hormone estrogen.The best source of lignans is flax seed but soybeans are a significant source of mammalian lignan precursor secoisolariciresinol  containing 13-273 µg/100 g dry weight