Hartini, Y.S. , Utaminingsih, Julianus, J. , Patramurti, C. and Nugroho, L.H. 2024. Secondary Metabolite Profile in Mature and Old Leaves of Four Piper Species: Forest Betel (Piper aduncum L.), Red Betel (Piper crocatum Ruiz & Pav.), Javanese Chili Betel (Piper retrofractum Vahl.), and Green Betel (Piper betle L.). Plant Science Today. 11, 2 (May 2024). DOI:https://doi.org/10.14719/pst.3070.