Sesquiterpenes from the Red Alga Laurencia tristicha

Abstract

Seven new sesquiterpenes (1-7), together with seven known sesquiterpenes, aplysin (8), aplysinol (9), gossonorol (10), 7,10-epoxy-ar-bisabol-11-ol (11), 10-epi-7,10-epoxy-ar-bisabol-11-ol (12), johnstonol (13), and laurebiphenyl (14), have been isolated from the red alga Laurencia tristicha. The structures of new compounds were established as laur-11-en-2,10-diol (1), laur-11-en-10-ol (2), laur-11-en-1,10-diol (3), 4-bromo-1,10-epoxylaur-11-ene (4), cyclolauren-2-ol (5), laurentristich-4-ol (6), and ar-bisabol-9-en-7,11-diol (7) by means of spectroscopic methods including IR, HRMS, and 1D and 2D NMR techniques. Compound 6 possessed a novel rearranged skeleton. All compounds were tested against several human cancer cell lines including lung adenocarcinoma (A549), stomach cancer (BGC-823), hepatoma (Bel 7402), colon cancer (HCT-8), and HELA cell lines. Laurebiphenyl (14) showed moderate cytotoxicity against all tested cell lines, with IC(50) values of 1.68, 1.22, 1.91, 1.77, and 1.61 microg/mL, respectively. Other compounds were inactive (IC(50) > 10 microg/mL).

Phytochemical and Biological Properties of Sesquiterpene Constituents From the Marine Red Seaweed Laurencia: A Review

“…Compound 112, having a novel rearranged cyclolaurane skeleton was also reported recently from L. okamurai [78]. Compound 114 exhibited moderate cytotoxicity against several human cancer cell lines, while all other compounds were inactive [12]. The Chinese species L. tristicha produced aplysin-9-ene (115), epiaplysinol (116) and debromoepiaplysinol (117).…”

“…In 2007, L. microcladia (Chios Is., North Aegean Sea) afforded the hydroxyl derivative of β -bisabolene, (66) [60], while, (5S)-5-acetoxy-β -bisabolene (67), was isolated, recently, from L. okamurai Yamada [61]. L. tristicha (Naozhou Island, China) yielded ar-bisabol-9-en-7,11-diol (68) [12]. On the other hand, L. scoparia (S˜ao Paulo, Brazil) was the source of compounds (69)(70)(71).…”

“…The compounds 12-hydroxy isolaurene (93), isolauraldehyde (94) [73][74][75]. In the same year, 2005, L. tristicha (Naozhou Island, China) was the source of laur-11-en-2,10-diol (107), laur-11-en-10-ol (108), laur-11-en-1,10-diol (109), 4-bromo-1,10-epoxylaur-11-ene (110), previously reported as a synthetic racemate [76], cyclolauren-2-ol (111) and laurentristich-4-ol (112), along with the formerly known compounds aplysin (113), aplysinol (100), and the dimeric cyclolaurane sesquiterpene laurebiphenyl (114) [77,12]. Compound 112, having a novel rearranged cyclolaurane skeleton was also reported recently from L. okamurai [78].…”

“…The Chinese species L. tristicha produced aplysin-9-ene (115), epiaplysinol (116) and debromoepiaplysinol (117). Compound 117 displayed selective cytotoxicity to the HeLa cell line [79]. Another collection of L. tristicha (Shanwei, Guangdong Province, China) yielded the stereoisomers 4-bromolaur-11-en-1,10 β -diol (118) and 4-bromolaur-11-en-1,10 β -diol (119), along with the known laur-11-en-1,10 β -diol (120), but reported for the first time as a natural product [80,81].…”

Antitumour Effect of Sesquiterpene (+)-chabranol on Four Human Cancer Cell Lines by Inducing Apoptosis and Autophagy

“…27 Another study indicated that a new sesquiterpene from the fruits of Daucus carota also displayed weak cytotoxic activity against BGC-823, with an inhibition rate of 13.3%. 28 We hypothesized that (+)-chabranol may disrupt DNA synthesis and reduce mitotic activity in BGC-823 cells, both of which Transmission electron microscopic analysis of the subcellular structure showed that cells exposed to (+)-chabranol were filled with autophagy vacuoles and lipid droplets.…”