Eurycomanone is a glycoside so before you isolate it, could be better if the glycon separate with alcohol : water in variuos concentration. After that you can use the fraction 100% alcohol to isolatre your sample.
The other method; just macerate dry root and evaporte it until you get the gummy extract then use coloum chromatography to isolate the eurycomanone with hex : EtOAc on various concentration.