▁at ▁discover ing ▁novel ▁marine ▁natural ▁products ▁possess ing ▁ant iv iral ▁activity . ▁E ight ▁analog ues ▁possess ing ▁similar ▁structure , ▁as ▁well ▁as ▁c yt ot ox icity ▁were ▁reported ▁in ▁ 1 9 9 2 . ▁ ▁Str ucture ▁On nam ide ▁A ▁is ▁a ▁complex ▁bi om ole c ule ▁with ▁a ▁ 3 9 ▁unique ▁carbon ▁atoms ▁and ▁ 1 1 ▁degrees ▁of ▁uns atur ation . ▁Its ▁core ▁contains ▁three ▁rings , ▁two ▁of ▁which ▁compr ise ▁a ▁dim er ic ▁la ct one ▁structure . ▁It ▁contains ▁a ▁long ▁side ▁chain ▁that ▁has ▁a ▁three ▁conjug ated ▁trans - ▁o lef ins ▁that ▁connect s ▁to ▁an ▁am ide ▁bond , ▁termin ating ▁in ▁an ▁arg in ine ▁resid ue . ▁The ▁s tere och em ical ▁assign ments ▁of ▁on nam ide ▁A ▁have ▁been ▁extens ively ▁character ized ▁by ▁experimental ▁and ▁advanced ▁N MR ▁studies . ▁ ▁B ios yn thesis ▁ ▁Gen omic ▁studies ▁suggest ▁strong ▁hom ology ▁with ▁Ped ▁gen es , ▁which ▁encode ▁the ▁production ▁of ▁p eder ins , ▁struct ur ally ▁similar ▁comp ounds ▁synth es ized ▁by ▁b acter ial ▁end os ym b ion ts ▁of ▁Pa eder us ▁be et les . ▁This ▁suggests ▁that ▁on nam ide ▁A ▁is ▁actually ▁the ▁product ▁of ▁b acter ial ▁end os ym b ion ts ▁of ▁the ▁marine ▁sp ong es ▁from ▁which ▁the ▁comp ound ▁was ▁first ▁isolated . ▁ ▁Thus , ▁the ▁b ios yn