KATA PENGANTAR i

ABSRAK Iii

ABSTRACT Iv

DAFTAR ISI V

DAFTAR LAMPIRAN Vii

DAFTAR GAMBAR Viii

DAFTAR TABEL X

I. PENDAHULUAN 1

II. TINJAUAN PUSTAKA 4

II.1.

II.1.1. Morfologi 4

II.1.2. Stereocaulon 4

II.1.3. Stereocaulon halei Lamb. 4

II.1.4. Potensi dan pemanfaatan lichen 5

II.2. 7

II.3. 9

II.4. 10

II.5. 11

II.6.

oksidase

12

III. METODE PENELITIAN

III.1. 17

III.2.

III.2.1. Alat 17

III.2.2. Bahan 17

III.3.

III.3.1. Penyiapan sampel uji 18

III.3.1.1. 18

III.3.1.2. 18

III.3.1.3. 19

III.3.2. Pengujian aktivitas enzim xantin oksidase 19

III.3.2.1. 19

III.3.2.2. 20

III.3.2.3. 21

3.3.3. Perhitungan nilai % inhibisi dan IC50 aktivitas enzim

xantin oksidase

22

3.3.4. Penentuan kinetika penghambatan enzim 23

IV. HASIL DAN PEMBAHASAN

IV.1. 24

IV.2. 26

IV.2.1. Penyiapan sampel uji 26

IV.2.2. Pengujian aktivitas enzim xantin oksidase 26

IV.2.3. Penentuan kinetika penghambatan enzim 30

V. KESIMPULAN DAN SARAN

V.1. 33

V.2. 33

DAFTAR PUSTAKA 34

LAMPIRAN 37

A research on developing anti-gout drug throught examine xanthine oxidase activity of the extracts and isolates of lichen Stereocaulon halei Lamb. have been conducted. Extract of lichen S. halei which yield by gradient solvent extraction from hexan, ethyl acetate, aceton, methanol and also isolate atranorin, lobaric acid and methyl orcinol carboxylate (MOC) were examined that activity, allopurinol was used as comparison control. The activity of enzym was examine continuous spectrophotometric rate method using microplate 96-well and the absorbances were measured using a microplate reader (BioRad Xmark). Extract of ethyl acetate provided the strongest inhibitory activity against the enzyme xanthine oxidase compared to other extracts with 81% inhibition at a concentration of 250 ug/mL. While the isolates, lobaric acid provides the strongest inhibition activity compared to all the isolates against xanthine oxidase activity by 0,7% inhibition at a concentration of 10 ug/mL. Inhibition of xanthine oxidase activity from extracts and isolates lichen S. halei were smaller than allopurinol at a concentration of 10 ug/mL which provides 99% inhibition of the xanthine oxidase activity. Examine on the kinetics of ethyl acetate extract and lobaric acid showed both have inhibitory mechanism uncompetitif to the substrate (xanthine).