Structure and absolute configuration of a secolignan from Peperomia blanda

► A secolignan was isolated from the aerial parts of Peperomia blanda (Piperaceae). ► A relative cis configuration at the γ-butyrolactone ring was established by 1D NOESY experiment. ► The absolute configuration of (−)-1 was estabilished as (2R,3S) by the comparison of experimental and TDDFT-calculated ECD spectra.