Instructions: Given a title, a list of keywords and main findings, create an abstract for a scientific article.
Title: Synthesis and activity in enhancing long-term potentiation (LTP) of clausenamide stereoisomers.\nKeywords: structure-activity relationship, stereoisomers, synthesis, nootropic activity, ltp.
Main findings: (+)-Epi-Cis-Clausenamide (1), (-)-Cis-Neoclausenamide (2), (-)-Cis-Clausenamide (3), (-)-Epi-Neoclausenamide (4), (+)cis-Clausenamide (5), Neoclausenamide (6), L-Clausenamide (7), (-)-Neoclausenamide (8), Clausenamide (9), (+)-Epi-Neoclausenamide (10), (+)-Cis-Neoclausenamide (11), (-)-Epi-Clausenamide (12), (+)-Epi-Cis-Neoclausenamide (13), (+)-Epi-Clausenamide (14) were isolated from Clausena lansium.
Abstract: