Aktivitas Antioksidan dan Toksisitas Ekstrak Metanol dan Pigmen Kasar Spirulina sp. - Ervia Yudiati; Sri Sejati; Sunarsih Sunarsih; Rani Agustian (Marine Science Department Diponegoro University, 2011)
Penelitian ini bertujuan untuk mengukur aktivitas antioksidan dan menguji toksisitas ketiga ekstrak. Penelitian dilakukan secara laboratoris. Ekstrak Kasar Spirulina sp didapatkan melalui proses maserasi dengan pelarut methanol. Ekstrak pigmen kasar diperoleh melalui partisi dengan pelarut methanol/aseton serta eter. Aktivitas antioksidan dilakukan dengan mengukur IC50 dengan metode spektrofotometri dengan DPPH (1,1-diphenyl-2-picrylhydrazyl) sedangkan kadar toksisitas dilakukan dengan menghitung LC50 dengan uji BSLT (Brine Shrimp Lethality Test). Kromatografi Kolom Terbuka dilakukan untuk mengisolasi pigmen sedangkan identifikasi pigmen dilakukan dengan teknik Kromatografi Lapis Tipis dan metode spektroskopi. Data dianalisis secara deskriptif. Hasil penelitian menunjukkan bahwa ekstrak kasar metanol, ekstrak pigmen kasar methanol/aseton dan eter mempunyai nilai IC50 323,7; 51 dan 34,85 ppm. Nilai LC50 dari ekstrak methanol r, ekstrak kasar pigmen methanol/aseton dan eter berturut-turut adalah 113,20; 65,22 ppm dan 34,11 ppm. Hasil isolasi pigmen dan identifikasi pigmen menunjukkan bahwa pigmen mengandung β-karoten dan klorofil α. Hasil uji fitokimia menunjukkan bahwa ketiga ekstrak positif mengandung senyawa golongan flavonoid dan sterol. Ekstrak pigmen kasar Spirulina sp. selain mempunyai aktivitas antioksidan yang tinggi juga mempunyai toksisitas yang tinggi terhadap nauplii Artemia sp. Kata kunci: Spirulina sp,ekstrak metanol, ekstrak kasar pigmen, IC50, LC50. The aims of this research were to determine the antioxidant activities and level of toxicity of those three extracts. Spirulina sp crude extract has obtained by maseration technique with methanol solution while crude pigment extract has collected by partition technique with methanol/acetone and ether solution. The laboratory experiments of antioxidant activities (IC50) was determine by DPPH (1,1-diphenyl-2-picrylhydrazyl) and spectrophotometrical methods while the level of toxicity was done by BSLT (Brine Shrimp Lethality Test). The pigment was isolated using the Couloumb Chromatography Methods while pigment identification was done by Thin Layer Chromatography Methods and confirmed spectrophotometrically. The data was analized descriptively. The results showed that IC50 of methanol extract, crude pigment methanol/acetone and ether were 323.7; 51 and 34.85 ppm, respectively. Furthermore, the toxicity level LC50 of methanol extract, crude pigment methanol/acetone and ether were 113.20; 65.22 and 34.11 ppm respectively. β-carotene and chlorophyll α was identified and isolated. Those three extract contains flavonoid and sterol. It is concluded that crude pigment extract of Spirulina sp. has a high antioxidant activity as well as toxicity to the nauplii of Artemia sp. Key words: Spirulina sp.,methanol extract, crude pigment extract, IC50, LC50