Aulia, Merisa2022-01-192022-01-192021-07wahyu sari yenihttps://repository.unri.ac.id/handle/123456789/10414Mangroves are plants that thrive in coastal areas that have very high potential for bioactive compounds, one of the type of mangrove is Bruguiera gymnorrhiza L. The purpose of this study was the isolation of secondary metabolites and toxicity tests using the BSLT (Brine Shrimps Lethality Test) method. Mangrove leaves were extracted by maceration method using ethanol and fractionated with n-hexane as solvent. The results of the fractionation obtained crude extract as much as 18 g which was dark green. The crude extract of n-hexane was then separated using liquid vacuum chromatography and 6 fractions produced. In fraction 1, it was followed by gravity column chromatography which resulted in the pure compound in the form of white crystals with a melting point of 146-1480C. The crystals were characterized using UV spectrophotometer and FTIR. The UV spectrum showed absorption at λmax 208 nm. While the FTIR spectrum shows absorption at wave numbers 1036 cm-1 (C-O), 1386 cm-1 (CH3), 1465 cm-1 (CH2), 1635 cm-1 (C=C), 2944 cm-1 (C-H) aliphatic and 3042 cm-1 (O-H). The results of the toxicity test using the BSLT method on the crude extract of n-hexane are inactive with an LC50 value of >1000 ppm.enBrine Shrimp Lethality Test (BSLT)B.gymnorrizha LArticle