If you want the concentration to be really accurate, you can put the extract into a volumetric flask and make the solution up to volume with additional solvent.

The concentration of your extract will be the starting mass divided by the present volume of solvent.  So since your extract is now in 400 ml, you can either use it as is at a concentration of 50 g/400 ml, or you can dilute it to get it back to 50 mg/ml.  It may depend on what you are planning to do with it. 

As for the dried extract, I think usually people assume the volume of the extract is negligible compared to the solvent volume, and they just add the desired final volume of solvent.  But it would be more accurate to add just enough solvent to dissolve all the solid, then transfer the solution to a volumetric flask and make it up to volume.  If I understand correctly what you're asking.

Thank you Anita Brinker! I get it now. It's easier for me to do it after knowing the concentration would be based on my present volume of solvent. This helps me so much :)

I appreciate the way Anita madam has answered your question. I just want to add that if it were 100% ethanol it is ok. But you have taken 95% ethanol for extarction. Kindly adjust the 5% water content in your calculations. 

It is always better to dry the whole solvent and use the dried powder for your further work since the presence of even small amount of solvent can disturb the activity f the etahnolic extract.

Thank you and best of luck.

Rao

I am agree with Dr. Rao opinion. It always better to use completely dried extract for further uses.....

Thanks

good luck 

Hi

You can nothing do with 50mg/ml.

You have extracted, filtered, concentrated. Now, check the TS in your liquid extract.

that will be your starting point. From that you can get TE and TS.

Please say it, what is the end use are application, then only it is easy to explain you.

all the best