Editing Ergot (section)

==Evolution==
Regarding the evolution of plant parasitism in the [[Clavicipitaceae]], an [[Amber#Paleontological significance|amber fossil]] discovered in 2020 preserves a [[Poaceae|grass spikelet]] and an ergot-like parasitic fungus. The fossil shows that the original hosts of the Clavicipitaceae could have been grasses. The discovery also establishes a minimum time for the conceivable presence of [[psychotropic]] compounds in fungi.<ref>{{cite journal |last1=Poinar |first1=George Jr. |last2=Alderman |first2=Stephen |last3=Wunderlich |first3=Joerg |name-list-style=amp |year=2015 |title=One hundred million year old ergot: psychotropic compounds in the Cretaceous? |url=http://www.palaeodiversity.org/pdf/08/02Palaeodiversity_8-15_Poinar-et-al_1.pdf |journal=Palaeodiversity |volume=8}}</ref><ref>{{cite web |url= http://www.sci-news.com/paleontology/science-burmese-amber-fungus-infected-grass-02482.html |title= 100-Million-Year-Old Burmese Amber Preserves Fungus-Infected Grass |website=sci-news.com |date=10 February 2020|access-date=7 September 2020}}</ref>
Several evolutionary processes have acted to diversify the array of ergot alkaloids produced by fungi; these differences in enzyme activities are evident at the levels of substrate specificity (LpsA), product specification (EasA, CloA) or both (EasG and possibly CloA).<ref name="Schardl">{{cite journal|last=Schardl|first=Christopher L.|title=Introduction to the Toxins Special Issue on Ergot Alkaloids|journal=Toxins|date=7 October 2015|volume=10|issue=7|pages=4232–4237|doi=10.3390/toxins7104232|pmid=26665699|pmc=4626731|doi-access=free}}</ref> The "old yellow enzyme", EasA, presents an outstanding example. This enzyme catalyzes reduction of the C8=C9 double-bond in chanoclavine I, but EasA isoforms differ in whether they subsequently catalyze reoxidation of C8–C9 after rotation.<ref name="Schardl"/> This difference distinguishes most Clavicipitaceae from Trichocomaceae, but in Clavicipitaceae it is also the key difference dividing the branch of classical ergot alkaloids from dihydroergot alkaloids, the latter often being preferred for pharmaceuticals due to their relatively few side effects.<ref name="Schardl"/>