PROFIL KLT DAN UJI AKTIVITAS ANTITIROSINASE EKSTRAK ETANOL DAUN JENGKOL (Pithecellobium lobatum) MENGGUNAKAN MICROPLATE READER(Oleh Laode Muhammad Indra Kesuma; Pembimbing: Normaidah, Fadlilaturrahmah; 2025; 39 halaman)

Paparan sinar UV yang intens di daerah tropis dapat memicu hiperpigmentasi melalui peningkatan aktivitas enzim tirosinase dalam proses melanogenesis. Kondisi ini mendorong kebutuhan akan inhibitor alami yang lebih aman sebagai alternatif bahan pencerah kulit dibandingkan inhibitor sintetis yang berpotensi menimbulkan efek samping. Tanaman jengkol (Pithecellobium lobatum) diketahui mengandung metabolit sekunder seperti fenolik dan flavonoid yang berpotensi sebagai inhibitor tirosinase. Penelitian ini bertujuan menganalisis profil kromatografi lapis tipis (KLT) dan aktivitas antitirosinase ekstrak etanol daun jengkol secara in vitro menggunakan microplate reader. Ekstrak diperoleh melalui metode maserasi dari simplisia daun yang telah dideterminasi. Profil KLT menggunakan eluen etil asetat: n-heksan (1:9) menunjukkan keberadaan senyawa fenolik dengan nilai Rf 0,07–0,8. Uji aktivitas antitirosinase menggunakan substrat L-DOPA dan enzim tirosinase menghasilkan nilai IC?? sebesar 4.218 µg/mL , yang menunjukkan aktivitas penghambatan lemah jika dibandingkan dengan kontrol positif asam kojat yang memiliki nilai IC?? 65,22 µg/mL . Hasil penelitian ini menunjukkan bahwa meskipun ekstrak etanol daun jengkol mengandung senyawa fenolik, aktivitas antitirosinase yang dihasilkan tergolong rendah.

Kata Kunci: Pithecellobium lobatum, antitirosinase, kromatografi lapis tipis, ekstrak etanol, IC₅₀.

KLT PROFILE AND ANTI-TYROSINASE ACTIVITY ASSAY OF ETHANOL EXTRACT OF JENGKOL LEAVES (Pithecellobium lobatum) USING MICROPLATE READER (By Laode Muhammad Indra Kesuma; Supervisors: Normaidah, Fadlilaturrahmah; 2025; 39 pages)

Intense UV exposure in tropical regions can trigger hyperpigmentation through increased tyrosinase enzyme activity in the melanogenesis process. This condition drives the need for safer natural inhibitors as alternatives to synthetic skin-lightening agents that may cause adverse effects. Jengkol leaves (Pithecellobium lobatum) are known to contain secondary metabolites such as phenolics and flavonoids that potentially act as tyrosinase inhibitors. This study aimed to analyze the thin-layer chromatography (TLC) profile and the anti-tyrosinase activity of the ethanol extract of jengkol leaves in vitro using a microplate reader. The extract was obtained through maceration of authenticated leaf simplicia. The TLC profile using ethyl acetate: n-hexane (1:9) as the eluent indicated the presence of phenolic compounds with Rf values ranging from 0.07 to 0.8. The anti-tyrosinase assay using L-DOPA substrate and tyrosinase enzyme yielded an IC?? value of 4,218 µg/mL , demonstrating weak inhibitory activity compared with the positive control kojic acid, which showed an IC?? value of 65.22 µg/mL . These findings indicate that although the ethanol extract of jengkol leaves contains phenolic compounds, its anti-tyrosinase activity is relatively low.

Keywords: Pithecellobium lobatum, anti-tyrosinase, thin-layer chromatography, ethanol extract, IC??.