Complex sentence: Alexander Shulgin in "TiHKAL" suggests that ergonovine is responsible instead, having verified psychoactive properties, though it is not unlikely that yet other undiscovered lysergamides are present in the seeds.
Split into simpler sentences: Alexander Shulgin in "TiHKAL" suggests ergonovine is responsible, instead. It has verified psychoactive properties, though as yet other undiscovered lysergamides possibly are present in the seeds.