Quantification of Protocatechuic Acid in Hibiscus sabdariffa Collected in Vietnam by HPLC-PDA . Tropical Journal of Natural Product Research , [S. l.], v. 9, n. 9, p. 4428 – 4435, 2025. DOI: 10.26538/tjnpr/v9i9.43. Disponível em: https://tjnpr.org/index.php/home/article/view/7377. Acesso em: 29 dec. 2025.