Molekul, Vol. 17. No. 3, November 2022: 328 – 334 328 MOLEKUL eISSN: 2503-0310 Articles https://doi.org/10.20884/1.jm.2022.17.3.5808 Toxicity and Antimicrobial Activity of Zerumbon from Zingiber zerumbet Rhizome Hartiwi Diastuti*, Ari Asnani, Eva Vaulina Yulistia Delsy, Restu Pamukasari, Sri Indriani Department of Chemistry, Faculty of Mathematics and Natural Sciences Universitas Jenderal Soedirman Jl. Dr. Soeparno 61 Grendeng Purwokerto Central Java, Indonesia *Corresponding author email: hartiwi.diastuti@unsoed.ac.id Received May 13, 2022; Accepted July 19, 2022; Available online November 20, 2022 ABSTRACT. Zingiber zerumbet is a medicinal plant that has the potential as a source of bioactive compounds. Zerumbone is a major compound of the essential oil fraction of Z. zerumbet. Research on antimicrobial activity and toxicity of zerumbone is still limited. In this study, the zerumbone was isolated from Z. zerumbet rhizome and studied for its potential as antimicrobial agent and toxicity properties. The isolation of the zerumbone compound was carried out through extraction, fractionation and purification. The structure of zerumbone was determined by an NMR spectrophotometer (1D and 2D) and GCMS. The toxicity assay was carried out using the Brine Shrimp Lethality Test (BSLT) method, while the antimicrobial activity assay was carried out using the microdilution method against Escherichia coli FNCC-0195, Propionibacterium acnes ATCC-11827, Bacillus cereus ATCC-11778, Staphylococcus aureus FNCC-0047, Candida albicans, Malassezia furfur, and Aspergillus sp. The isolation of zerumbone from the n-hexane fraction of Z. zerumbet rhizome obtained a pure compound in the form of white crystals, with melting point 65.5 ºC. Toxicity assay of zerumbone was obtained LC50 values of 21.29 μg/mL. The activity assays on the seven test microbes were showed potential activities with a range of MIC values of 15.62–250 μg/mL. Zerumbone has the highest activity against Aspergillus sp with the MIC value of 15.62 μg/mL. Keyword: Antimicrobial, BSLT, GCMS, NMR, zerumbone, INTRODUCTION Traditional medicine based on biological natural resources, especially plants, has long been used in Indonesia. Therefore, it is not surprising that medicinal plants are one of the most important topics as an alternative to cure various diseases in Indonesia (Achmad et al., 2009) Indonesia as an area with a high diversity of plant species makes it possible to find compounds that have important biological activities and pharmacological effects. One of these plants is lempuyang (Zingiber zerumbet.) from the Zingiberaceae family. The rhizome of Z. zerumbet is widely used by the community as traditional medicine, among others, to treat swelling, cough, fever, stomach pain, diarrhea, toothache, skin disease, and diuretic (Rana et al., 2012). Several studies have reported that elephant lempuyang rhizome extract has various biological activities, including antioxidant and antibacterial (Thummajitsakul et al., 2016), antimicrobial (Golam, et al., 2011), larvicidal activities againts Aedes aegypti and Anopheles nuneztovari and its toxic to Artemia salina Leach larvae, anthelmitic (Sahu et al., 2018), immunomodulatory effect (Hardi et al., 2017), immunosuppressive effect (Ghazalee, et al., 2019), and therapeutic effect (Ahmadabadi et al., 2019). The secondary metabolites contained in the rhizome of Z. zerumbet include two main groups, namely terpenoids and flavonoids. The zerumbone compound is one of the main terpenoid compounds in Z. zerumbet rhizome, with the highest content ranging from 13 - 88% (Rana et al., 2012). The results showed that zerumbone has several pharmacological effects including antisecretory, gastroprotective, and antioxidant activities (Sidahmed et al., 2015), repellent (Wu et al., 2017), immunomodulatory effect (Keong et al., 2010), induce of apoptosis (Mukherjee et al., 2016), antibacterial and antiproliferative (Padalia et al., 2018), and anticancer (Abdul et al., 2008 and Koga et al., 2016). Murini et al (2018) reported that the zerumbone which isolated from the methanol extract of Z. zerumbet rhizome showed good larvicidal activity, with LC50 41.75 ± 0.05 ppm and LC90 57.66 ± 3.37 ppm. Zerumbone is the main terpenoid compound in the essential oil fraction of Z. zerumbet rhizome. Zerumbone exhibits several important biological activities, but research on the toxicity and antimicrobials of the zerumbone that isolated from the rhizome of Z. zerumbet is still limited. This reseach was studies the toxicity and antimicrobial activity of zerumbone that isolated from the rhizome of Z. zerumbet. Toxicity test was carried out on Artemia salina Leach larvae using the Brine Shrimp Lethality Test (BSLT) method, while antimicrobial testing was carried out on Escherichia coli FNCC-0195,