*From net what i have got sharing:*
All long text is stored in STXH and STXL.
Object is MATERIAL.
Text-Id for basic data text is GRUN
Text-Id for purchase order text is BEST
For sales order text it is text object MVKE with text-id 0001
Go to SE37 function builder. Enter READ_TEXT and do a single test ( F8 )
Enter your parameters and execute. Example below.
NAME is a comibation of materialnumber (00000000008000000)WITH leading zeros
if numeric and sales org (1000) plus distribution channel (10)
Import parameters - Value
CLIENT - 010
ID - 0001
LANGUAGE - E
NAME - 000000000008000000100010
OBJECT - MVKE
ARCHIVE_HANDLE - 0
LOCAL_CAT
Just for future reference with regards to getting text id's etc.
eg: PO texts.
--> Go into the material master PO text
--> Double click into the required text.
--> Click the "GO TO" menu option.
--> click Header.
and all the info you need is there.
Regards,
Indranil
Reference.... https://scn.sap.com/thread/1850772