Identification of a Taq DNA polymerase inhibitor from the red seaweed Symphyocladia latiuscula

Two inhibitors of Taq DNA polymerase were isolated from the marine red alga Symphyocladia latiuscula. The inhibitors were purified by methanol extraction, molecular fractionation below 3000 MW and reverse-phase HPLC. The purified compound SL-1 containing three bromines was identified as 2,3,6-tribromo-4,5-dihydroxybenzyl alcohol (C7H5Br3O3: MW374) by NMR and MS analyses. The purified compound SL-2 was identified as 2,3, 6-tribromo-4,5-dihydroxybenzyl methyl ether(C8H7Br3O3: MW388). In a 25-microl reaction mixture containing 1.5 units of Taq DNA polymerase, the enzyme was completely inhibited by 0.5 microg SL-1 or 5 microg SL-2.