[Studies on chemical constituents of Laurencia tristicha ( II )].
OBJECTIVE
To search for chemical constituents with structural diversity from Laurencia tristicha to supply for biological assay.


METHODS
Compounds were isolated by means of column chromatography over normal phase silica gel and Sephadex LH-20, recrystallization and HPLC. Structures were identified by spectroscopic methods including 1D NMR, IR and MS. Cytotoxicities of the purified compounds were evaluated by MTT method.


RESULTS
Seven compounds were isolated from L. tristicha. Their structures were elucidated as cholesterol (1), cholesta- 5-en-3beta, 7alpha-diol (2), beta-stigmasterol (3), phytol (4), zeaxanthin (5), 4 -hydroxybenzaldehyde (6), indolyl-3-carbaldehyde (7). In the cytotoxic assay compound 2 was active against human cancer cell lines HCT-8, Bel-7402, BGc-823, A549 and HELA with IC50 values of 1.90, 2.02, 1.99, 6.52 and 1.20 microg x mL(-1), respectively. Compound 4 showed cytotoxicity against HCT-8 and HELA with IC50 value of 3.51 and 2.04 microg x mL(-1), and other compounds were inactive ( IC50 > 10 microg x mL(-1)).


CONCLUSIONS
Compounds 1-7 were isolated from L. tristicha for the first time. In additon, compounds 2 and 4 were cytotoxic against several human cancer cell lines.
Sun
Jie
J
College of Life Science, Ludong Univercity, Yantai 264025, China.
Han
Li-Jun
LJ
Yang
Run-Ya
RY
Shi
Da-Yong
DY
Uan
Zhao-Hui
ZH
Shi
Jian-Gong
JG
D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D045744:Cell Line, Tumor / Q000187:drug effects; D002782:Cholestenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D002784:Cholesterol / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D006801:Humans; D020128:Inhibitory Concentration 50; D044722:Laurencia / Q000737:chemistry*; D010836:Phytol / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
D000970:Antineoplastic Agents; D002782:Cholestenes; C540791:cholesta-5-en-3,7-diol; D010836:Phytol; D002784:Cholesterol