Aktivitas Antibakteri Ekstrak Etanol Biji Ketumbar (Coriandrum sativum L.) terhadap Escherichia coli dan Shigella spp. serta Profil Senyawa Aktifnya = Antibacterial Activity of Ethanol Extract of Coriander Seeds (Coriandrum sativum L.) against Escherichia coli and Shigella spp. and Active Compound Profile

ABSTRAK KHAIRUNNISA. Aktivitas Antibakteri Ekstrak Etanol Biji Ketumbar (Coriandrum sativum L.) terhadap Escherichia coli dan Shigella spp. serta Profil Senyawa Aktifnya (dibimbing oleh Anna Khuzaimah dan Yanti Leman). Latar Belakang: Diare masih merupakan masalah kesehatan masyarakat yang utama, terutama apabila disebabkan oleh patogen bakteri seperti Escherichia coli dan Shigella spp. Peningkatan resistensi antimikroba mendorong perlunya eksplorasi agen antibakteri berbasis bahan alam. Biji ketumbar (Coriandrum sativum L.) mengandung berbagai senyawa bioaktif yang berpotensi memiliki aktivitas antibakteri. Tujuan: Penelitian ini bertujuan untuk mengevaluasi aktivitas antibakteri secara in vitro dari ekstrak etanol biji ketumbar terhadap Escherichia coli dan Shigella spp., serta mengarakterisasi profil kimianya menggunakan LC–MS. Metode: Ekstrak disiapkan melalui metode maserasi menggunakan etanol dengan rendemen ekstraksi sebesar 19%. Aktivitas antibakteri diuji menggunakan metode difusi cakram pada konsentrasi 10%, 20%, dan 40%, dengan kotrimoksazol dan natrium karboksimetil selulosa (Na-CMC) masing-masing sebagai kontrol positif dan kontrol negatif. Zona hambat diukur dan dianalisis menggunakan uji Kruskal–Wallis. Senyawa bioaktif dalam ekstrak dianalisis menggunakan LC–MS. Hasil: Ekstrak etanol menunjukkan aktivitas antibakteri yang signifikan dan bergantung pada konsentrasi (p < 0,05). Pada konsentrasi 40%, diameter zona hambat terhadap Escherichia coli dan Shigella spp. masing-masing sebesar 15,16 ± 0,57 mm dan 16,17 ± 0,29 mm, yang menunjukkan aktivitas antibakteri kuat. Analisis LC–MS mengidentifikasi 11 senyawa bioaktif, dengan senyawa utama berupa monoterpena dan ester terpenoid (linalool, α-terpineol, linalil asetat, dan geranil asetat), serta asam lemak tidak jenuh rantai panjang seperti asam petroselinat dan asam oleat. Asam petroselinat (C18:1) merupakan senyawa yang terdeteksi paling banyak, dengan persentase area sebesar 18,9 %. Kesimpulan: Ekstrak etanol biji ketumbar (Coriandrum sativum L.) memiliki aktivitas antibakteri in vitro terhadap Escherichia coli dan Shigella spp. tertinggi pada konsentrasi 40%. Sejumlah senyawa bioaktif ekstrak etanol biji ketumbar diidentifikasi melalui LC–MS dengan senyawa tertinggi yaitu asam petroselinat (C18:1), yang merupakan marker khas biji ketumbar. Hasil ini menunjukkan potensi ekstrak sebagai sumber senyawa antibakteri alami terhadap bakteri enteropatogen, meskipun diperlukan penelitian lanjutan untuk mengonfirmasi efektivitas dan mekanisme kerjanya secara lebih mendalam. Kata Kunci : aktivitas antibakteri; bakteri enteropatogen; Coriandrum sativum L.; LC–MS; senyawa bioaktif ABSTRACT KHAIRUNNISA. Antibacterial Activity of Ethanol Extract of Coriander Seeds (Coriandrum sativum L.) against Escherichia coli and Shigella spp. and Active Compound Profile (supervised by Anna Khuzaimah and Yanti Leman). Background: Diarrhea remains a major public health problem, particularly when caused by bacterial pathogens such as Escherichia coli and Shigella spp. Increasing antimicrobial resistance has encouraged the exploration of natural-based antibacterial agents. Coriander seeds (Coriandrum sativum L.) contain various bioactive compounds with potential antibacterial activity. Objective: This study aimed to evaluate the in vitro antibacterial activity of ethanolic extract of coriander seeds against Escherichia coli and Shigella spp. and to characterize its chemical profile using LC–MS. Methods: The extract was prepared by maceration using ethanol, yielding an extraction efficiency of 19%. Antibacterial activity was assessed using the disk diffusion method at concentrations of 10%, 20%, and 40%, with cotrimoxazole and sodium carboxymethyl cellulose (Na-CMC) as positive and negative controls, respectively. Inhibition zones were measured and analyzed using the Kruskal–Wallis test. Results: The ethanolic extract exhibited significant concentration-dependent antibacterial activity (p < 0.05). At 40% concentration, inhibition zones against Escherichia coli and Shigella spp. were 15.16 ± 0.57 mm and 16.17 ± 0.29 mm, respectively, indicating strong antibacterial activity. LC–MS analysis identified 11 bioactive compounds, including major constituents such as monoterpenes and terpenoid esters (linalool, α-terpineol, linalyl acetate, and geranyl acetate), as well as long-chain unsaturated fatty acids, including petroselinic acid and oleic acid. Petroselinic acid (C18:1) was the compound most frequently detected with an area percentage of 18,9%. Conclusion: Ethanol extract of coriander seeds (Coriandrum sativum L.) has the highest in vitro antibacterial activity against Escherichia coli and Shigella spp. at a concentration of 40%. Several bioactive compounds in the ethanol extract of coriander seeds were identified through LC–MS, with the highest content of Petroselinic acid (C18:1), which is a typical marker of coriander seeds. These results indicate the potential of the extract as a source of natural antibacterial compounds against enteropathogenic bacteria, although further research is needed to confirm its effectiveness and mechanism of action in more depth. Keywords: antibacterial activity; bioactive compound; enteropathogenic bacteria; Coriandrum sativum L.; LC–MS