Electronic Theses and Dissertation

Alstonia scholaris merupakan salah satu tumbuhan yang memiliki banyak manfaat sebagai obat. Tumbuhan ini mengandung berbagai senyawa aktif yang berpotensi sebagai antioksidan, antiinflamasi, analgesik, antimalaria, antimikroba, antiasma, dan antikanker. Penelitian ini bertujuan untuk mengetahui aktivitas antioksidan menggunakan metode 1,1-diphenyl-2-picrylhydrazyl (DPPH) dan antiinflamasi menggunakan metode aktivitas antiproteinase pada ekstrak diklorometana (DCM) kulit batang A. scholaris. Kulit batang A. scholaris memiliki senyawa metabolit sekunder berupa alkaloid, flavonoid, tanin, fenol, steroid, dan terpenoid. Kulit batang A. scholaris diekstraksi dengan pelarut DCM sehingga diperoleh ekstrak DCM A. scholaris sebanyak 35,42 g (1,91%). Ekstrak DCM kulit batang A. scholaris dilakukan partisi asam basa sehingga didapatkan crude alkaloid sebanyak 1,11 g (3,34%). Crude alkaloid dipisahkan komponen-komponen kimianya menggunakan kromatografi kolom menghasilkan 5 subfraksi, yaitu subfraksi A-E diuji aktivitas antioksidan dan antiinflamasi. Hasil aktivitas antioksidan sampel yang paling bagus terdapat pada subfraksi B dengan nilai IC50 139,7 ppm. Sementara aktivitas antiinflamasi sampel yang paling kuat terdapat pada ekstrak DCM kulit batang A. scholaris dengan nilai IC50 99,1 ppm. Analisis LC-HRMS terhadap ekstrak DCM kulit batang A. scholaris mengidentifikasi sebanyak, 319 senyawa yang didominasi oleh golongan alkaloid. Rhynchophylline merupakan senyawa dengan kelimpahan relatif tertinggi yaitu 72,28%.

Kata kunci: Alstonia scholaris, diklorometana, alkaloid, antioksidan, antiinflamasi,

Alstonia scholaris is one of the medicinal plants that possesses numerous therapeutic properties. This plant contains various bioactive compounds with potential antioxidant, anti-inflammatory, analgesic, antimalarial, antimicrobial, anti-asthmatic, and anticancer activities. This study aimed to evaluate the antioxidant activity using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and the anti-inflammatory activity using the antiproteinase activity assay of the dichloromethane (DCM) extract of A. scholaris stem bark. The stem bark of A. scholaris contains secondary metabolites, including alkaloids, flavonoids, tannins, phenolic compounds, steroids, and terpenoids. The stem bark of A. scholaris was extracted using DCM, yielding 35.42 g of DCM extract (1.91%). The DCM extract of A. scholaris stem bark was subjected to an acid–base extraction, resulting in 1.11 g of crude alkaloids (3.34%). The crude alkaloids were separated into their chemical components by column chromatography, producing five subfractions, designated A–E, which were subsequently evaluated for their antioxidant and anti-inflammatory activities. The strongest antioxidant activity was observed in B subfractions, with an IC₅₀ value of 139,7 ppm. Meanwhile, the strongest anti-inflammatory activity was exhibited by the DCM extract of A. scholaris stem bark, with an IC₅₀ value of 99,1 ppm. LC-HRMS analysis of the DCM extract of A. scholaris stem bark identified a total of 319 compounds, predominantly belonging to the alkaloid class. Rhynchophylline was the most abundant compound, with a relative abundance of 72.28%. LC-HRMS analysis of the DCM extract of A. scholaris stem bark identified a total of 319 compounds, predominantly belonging to the alkaloid class. Rhynchophylline was the most abundant compound, with a relative abundance of 72.28%. Keywords: Alstonia scholaris, dichloromethane, alkaloids, antioxidant, anti-inflammatory