Seaweed Anti-tumor Anti-bacterial Bio-active Substances

Tens of algae along Shandong coast were collected, and their cytotoxic and antibacterial activities were screened with high throughout screening methods (UTS). As a result, some algae with high activities against tumor cells or bacteria were found. The algae were Leathesia difformes, Polysiphonia urcedala, Scytosiphon lomentarius. Ciloiopcliis furcctla, Rhodomela confervoides etc. The work of isolating, purifying and identifying new leading compounds from Rhodomela confervoides and Scylosiphon lomcnkirins were completed. More than 30 compounds were isolated from them, among which 15 were identified by the combination of IR. MS, and ID. 2D NMR modern spectrum methods. There were 5 new compounds and 1 pure natural compound among the 15 compounds. Furthermore, the cytotoxic activities of these compounds were fulfilled by MTT method, and 9 of them were found to be with selective cytotoxic activities.The recent development of marine antitumor drugs and natural products from macroalgae were briefly reviewed. The studies of antitumor screening in recent years were covered. The bioactive substances in blue algae, dinoflagellate. red algae, brown algae and green algae were summarized, some of them had been applied to preclinic study, such as Scytophycin. Ilalomon, Cryptophycin. Malyngamide and Tolytoxin. About 100 natural products newly isolated from macroalgae in recent four years were also covered, almost all of which showed significant activities.The antitumor activity screening of 96 crude extracts of 39 species of algae was enclosed. Fight species including Symphyocludiii laliuscula. Rhodomela confervoides. I'olvsiphonia urcedala, Gloiopellis furcald. Leathesia difformes, Scylosiphon lomenlarius, Punctcirid latifolia and Diclyopleris divaricala showed potent selectively anlincoplastic activities. The ethanol and chloroform extracts of Polysiphonia nrccc/diii. the ethanol extracts of Scylosiphon lomenlarius and the hexane extracts of Dictyopteris divaricala all showed powerful selectively cytotoxic activities, and their IC50 were less than 4.40 ug/ml. The ethanol extracts of Scylosiphon lomenlarius had also showed strong activities against HT-29 tumor cell, and the IC50 was 1.49 ug/ml.Thin layer chrotnatography (TLC) method was used to study the antibacterial activities against two kinds of bacteria, Excherichifi coli and Sltiphylococcus aureris. The activities of five seaweed extracts were detected, of which brown algae displayed the highest activities. Three bands from Desmiirestiu viridis and Sargassum kjelimanianum(Phaeophyta) exhibited powerful activities against Siaphylococaix utiivnx, the diameter of inhibition cycle was 33mm. 17mm and 17.5 mm. respectively. Two bands from Desmareslia viridix could inhibit the growth of Excherichici coli vigorously. The higher activity was detected in red algae. In comparision with browm and red algae, the activities of green algae were almost negligible.Two species of marine algae, Seytosiphon lomentarius and Rhodomela confervoides. were used to isolate and purify new leading compounds from them. More than ten compounds were isolated from Scvloxiphon lomentarius and identified as pigments, sterols, fatty acids and glycerides. Among them two were identified as (3R,3R')-p p-carotene-3 ,3-diol and fucosterol. respectively. Seventeen compounds were isolated from Rhodomela confervoidc and 14 were identified. Among them. 5 compounds. 3-bromo-4.5-bis(2,3-dibromo-4.5-dihydroxyben7.yl)1.2-ben7,enedoil (Xt'20). 3-broino-4-[2,3-dibromo-4,5-dihydroxyphenyl] methyl-5-(hydroxymethyl) 1,2-bcn/enedoil (XU21). 2-methyl-3(2.3-dibromo-4,5-dihydroxy)-propylaldehyde (XI126). 2-methyl-3(2,3-dibromo-4,5-dihydroxy)-propnal methyl hemiacetal(XU28). 3-bromo-4-|2,3-dibromo-4,5-dihydroxyphenvl]methyl-5-(ethoxymethyl)-l. 2-ben/ene -doil (XU29). were all new. Another compound. 3-bromo-4.5-dihydroxy-ben/.oic acid methyl ester was isolated from natural resources for the first time.The cyloloxic results of all purified compounds and some crude extracts were reported. Two purified compounds D4-...