Abstract

Three antimicrobial compounds (SL-l, SL-2 and SL-3) were isolated and identified from the marine red alga, Symphyocladia latiuscula. In addition, their biological functionalities such as cytotoxicity and desmutagenic activity were investigated. From the cryophyllized S. JatiuscuJa, SL-l, SL-2 and SL-3 were purified by solvent extractions and HPLC.SL-2 was crystallized in benzene-diethyl ether solvent. On the EI-MS spectra, it was found that they had three bromines in their structure which showed typical signal strength ratios at $M^+, [M+2]^+, [M+4]^+, [M+6]^+ (13: 38: 37: 12)$. $SL-l$ was identified as 2,3,6-tribromo-4,5-dihydroxybenzyl alcohol ($C_8H_7Br_3O_3, MW=374$) by NMR and MS spectra. SL-2 was assigned as 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether ($C_8H_7Br_3O_3, MW=388$) and confirmed by X-ray crystallographic analysis. SL-3 was presumed as an isomer of SL-2. Methanol extract of the S. latiuscula showed antimicrobial activities against all strains tested (bacteria, 15 strains; yeasts, 17 strains; fungi, 4 strains), much or less. The strongest inhibition activity of the methanol extract was to the Vibrio mimicus ($50 {\mu}g/ml$) and V. vulnificus ($50 {\mu}g/ml$). The mice injected intraperitoneally with 3 mg of SL-l and 5 mg of 5L-2 showed no acute toxicity response. SL-2 showed higher desmutagenic activity than SL-l against PhIP and MeIQx.

참보라색우무는 우리나라 연근해에서 쉽게 채취할 수 있는 미이용 해조류로서 해조류에서 새로운 천연항균성물질을 개발하기 위한 기초자료를 얻을 목적으로 항균성물질을 각종 칼럼을 통하여 분리정제하였으며, MS, NMR spectrum에 의하여 구조를 확인하였고, X선회절분석으로 결정구조를 해석하였다. 또한 이들 물질이 가지는 몇가지 특성을 조사하였다. 참보라색우무 670 g 중에서 최종적으로 세 개의 항균성물질(SL-l, SL-2, SL-3)이 각각 85 mg, 135 mg, 27.7 mg을 얻었다. SL-1 및 SL-2는 MS 및 NMR에 의하여 2,3,6-tribromof,5-dihydroxybenzyl alcohol (MW, 374) ,2,3,6-trib romo4,5-dihydroxybenzyl methyl ether (MW, 388)이였으며, 특히 SL-2를 벤젠-디에틸 에테르 용매중에서 결정화하여 X선 결정 해석에 의하여서도 구조가 확인되었다. 한편 SL-3는 SL-2와 MS 및 carbon NMR spectrum에서 잘 일치하였으나 proton NMR에서 signal의 패턴이 약간 달라 SL-2의 어떤 이성질체라고 추정되었다. 참보라색우무 항균성물질의 마우스에 대한 치사독성은 SL-1은 3 mg, SL-2는 5 mg까지는 별다른 영향을 미치지 않았으며, PhIP 및 MeIQx에 대한 돌연변이원성 억제효과는 SL-1은 $200 {\mu}g/ml$의 농도에서는 $17.8 {\%}$ 및 $17.7 {\%}$에 미치지 않았으나SL-2는 $250 {\mu}g/ml$의 농도에서는 높은 억제효과를 나타내어 새로운 보존료로서의 이용가능성을 제시하였다.

Keywords

• Antimicrobial activity;
• Symphyocladia latiuscula;
• 2,3,6-tribromo-4,5-dihydroxybenzyl alcohol;
• 2,3,6-tribromo-4,5-dihydroxybenzyl methyl ether