Marunduri, Tri Putra Reformasi2021-10-192021-10-192021-03wahyu sari yenihttps://repository.unri.ac.id/handle/123456789/10283Rhizophora mucronata is a type of mangrove that has a variety of secondary metabolite compounds. Secondary metabolites in Rhizophora mucronata include alkaloids, flavanoids, tannins, and other phenol compounds. This research have been isolated secondary metabolites of Rhizophora mucronata mangrove leaves as well as toxicity tests by BSLT method. Dried mangrove leaves are then extracted using maceration method with ethanol solvent for 24 hours and filtered, the maceration process is repeated 5 times. Ethanol crude extract as much as 97.36 g is separated by gravitational column chromatography and obtained in the form of dirty crystals on vials 50-70, to get pure crystals done recrystallized and obtained compounds coded Rm-FE yellow crystals with melting point 172-174 ºC. Phytochemical tests conducted on Rm-FE compounds showed a discoloration from yellow solution to pink solution, discoloration showed positive compounds of flavonoid group. Rm-FE UV spectrum indicates the presence of absorption at λmax 274 nm, while the FT-IR spectrum shows peaks at waves of 1053-1141 cm-1 (C-O), 1606-1635 cm-1 (C=C), 2912–2936 cm-1 (C-H aliphatic), and 3309 cm-1 (O-H). Toxicity test results with BSLT (Brine Shrimps Lethality Test) method against ethanol coarse extract from Rhizophora mucronata leaves are non-toxic.enR. mucronatasecondary metabolitestoxicityArticle