Determination of total flavonoid content in yellow wood (Arcangelisia flava (L.) Merr.) ethanol extract and antibacterial activity test against Staphylococcus aureus / Penentuan kadar flavonoid total ekstrak etanol kayu kuning (Arcangelisia flava (L.) Merr. ) dan uji antibakteri Staphylococcus aureus .

Indonesia has a diversity of plant species used as traditional medicine, one of which is yellow wood (Arcangelisia flava (L.) Merr.), this yellow wood is antibacterial, anti-inflammatory, antiseptic and antipyretic. It is known that yellow wood contains saponins, flavonoids, alkaloids, tannins, and steroids that can treat malaria, fever, rheumatism and itching. This study aims to determine the value of total flavonoid content contained in yellow wood extract in various ethanol concentrations (50%, 70% and 96%) and to determine the antibacterial inhibition zone in yellow wood extract. The stages of this study include processing plant materials, making ethanol extracts of yellow wood with ethanol concentrations of 50%, 70% and 96% using the maceration method then the extract obtained is concentrated with a rotary evaporator, examining characteristics, phytochemical screening, determining the total flavonoid content of yellow wood extract concentrations (50%, 70% and 96%) by UV-Vis spectrophotometric method and antibacterial test of Staphylococcus aureus  by diffusion method. The results showed that ethanol extract of yellow wood contains alkaloid, flavonoid, tannin, saponin, and steroid/terpenoid compounds. The results of the determination of total flavonoid content in yellow wood extract at 50% concentration amounted to 0.815200888 ± 0.02445546 mg QE/g, 70% concentration amounted to 1.0660462967 ± 0.03265799 mg QE/g and at 96% concentration amounted to 1.6781149 ± 0.0085 mg QE/g. Antibacterial test on 96% yellow wood extract obtained an inhibition zone of 18.05 mm with a strong category.

Indonesia memiliki keberagaman jenis tanaman yang digunakan sebagai obat tradisional, salah satunya yaitu kayu kuning ( Arcangelisia flava (L.) Merr. ), kayu kuning ini bersifat antibakteri, antiinflamasi, antiseptic dan antipiretik. Diketahui kayu kuning mengandung saponin, flavonoid, alkaloid, tanin, dan steroid yang dapat mengobati malaria, demam, rematik dan gatal – gatal. Penelitian ini bertujuan untuk mengetahui nilai kadar flavonoid total yang terdapat pada ekstrak kayu kuning dalam berbagai kosentrasi etanol (50%, 70% dan 96%) serta untuk mengetahui zona hambat antibakteri pada ekstrak kayu kuning.Tahapan penelitian ini meliputi pengolahan bahan tumbuhan, pembuatan ekstrak etanol kayu kuning dengan kosentrasi etanol 50%, 70% dan 96% dengan menggunakan metode maserasi kemudian ekstrak yang di peroleh dipekatkan dengan rotary evaporator, pemeriksaan karakteristik, skrining fitokimia, penetapan kadar flavonoid total ekstrak  kayu kuning kosentrasi ( 50%, 70% dan 96%) dengan metode spektrofotometri UV-Vis dan uji antibakteri Staphylococcus aureus  dengan metode difusi. Hasil penelitian menunjukian bahwa ekstrak etanol kayu kuning mengandung senyawa alkaloid, flavonoid, tanin, saponin,dan steroid/terpenoid. Hasil penentuan kadar flavonoid total pada estrak kayu kuning pada kosentrasi 50% sebesar 0,815200888±0,02445546 mg QE/g, kosentrasi 70% sebesar 1,0660462967±0,03265799 mg QE/g dan pada kosentrasi 96% sebesar 1,6781149±0,0085 mg QE/g. Uji antibakteri pada ekstrak kayu kuning 96% mendapatkan zona hambat sebesar 18,05 mm dengan katagori kuat.