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.