Studies On The Bioactive Constituents From Holothuria Impatiens And Actinopyga Mauritiana

Holothuria impatiens and Actinopyga mauritiana are abundant sea cucumbers widely distributed in South China Sea. The chemical constituents in the two marine organisms and their bioactivities have been kept unknown untill now. As parts of our continous searching for the lead compounds with anticancer or antifungal activities from the marine organisms in South China Sea, H. impaties and A. mauritiana have been investigated by various chromatographic methods including LPLC, MPLC, preparitive HPLC on silica gel, ODS C₁₈, Sephadex LH-20 gel and YMC Pack ODS-A respectively. Twenty compounds had been isolated and their chemical structures had been elucidated by chemical and spectral analysis (IR, EI-MS, ESI-MS, HRESI-MS, ¹H NMR, ¹³C NMR, ¹H-1H COSY, DQCOSY, TOCSY, HMQC, HMBC, NOESY, etc.).From the ethanolic extracts of H. impatiens, eleven compounds were isolated and structurally identified, including nine triterpene glycosides: 3-O-[3-O-methyl-β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→4)-β-D-quinovopyranosyl-(1→2)-4-O-sodium sulfate-β-D-xylopyranosyl]-22, 25-epoxy-holosta-9(11)-ene-3β, 12α-diol (HI-1, 17-Dehydroxyholothurin A); 3-O-[3-O-methyl-β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→4)-β-D-quinovopyranosyl-(1→2)-4-O-sodium sulfate-β-D-xylopyranosyl]-holosta-9(11)-ene-3β, 12α-diol (HI-2, Pervicoside C); 3-O-[3-O-methyl-β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→4)-β-D-quinovopyranosyl-(1→2)-4-O-sodium sulfate-β-D-xylopyranosyl]- 22, 25-epoxy-holosta-9(11)-ene-3β, 12α, 17α-triol (HI-3, Holothurin A); 3-O-[3-O-methyl-β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→4)-β-D-quinovopyranosyl-(1→2)-4-O-sodium sulfate-β-D-xylopyranosyl]-holosta-9(11)-ene-3β, 12α, 17α, 22-tetrol (HI-4, Holothurin A1); 3-O-[β-D-quinovopyranosyl-(1→2)-4-O-sodium sulfate-β-D-xylopyranosyl]- 22, 25-epoxy-holosta-9(11)-ene-3β, 12α, 17α-triol (HI-5, Holothurin B); 3-O-[β-D-quinovopyranosyl-(1→2)-4-O-sodium sulfate-β-D-xylopyranosyl]- 22, 25-epoxy-holosta-9(11)-ene-3β, 12α-diol (HI-6, Holothurin B3); (3β,8β)-3-{(3-O-methyl-β-D-glucopyranosyl)-(1→3)-O- (β-D-glucopyranosyl)-(1→4)-O-(β-D-quinovopyranosyl)-(1→2)-[(3-O-methyl-β-D-glucopyranosyl)-(1→3)-O-(β-D-glucopyranosyl)-(1→4)]-O-(β-D-xylopyranosyl)}oxy-18-oxo-18,20-epoxylanosta-9(11), 24(25)-diene (HI-7, Impatienside A); (3β,8β)-3-{(3-O-methyl-β-D-glucopyranosyl)-(1→3)-O- (β-D-glucopyranosyl)-(1→4)-O-(β-D-quinovopyranosyl)-(1→2)-[(3-O-methyl-β-D-glu copyranosyl)-(1→3)-O-(β-D-glucopyranosyl)-(1→4)]-O-(β-D-xylopyranosyl)}oxy-18-oxo-18,20-epoxylanosta-9-ene (HI-8, Bivittoside D); (3β,9β)-3-{(3-O-methyl-β-D-glucopyranosyl)-(1→3)-O-(β-D-xylopyranosyl)-(1→4)-O-(β-D-glucopyranosyl)-(1→2)-[(3-O-methyl-β-D-glucopyranosyl)-(1→3)-O-(β-D-glucopyranosyl)-(1→4)]-O-(β-D-xylopyranosyl)}oxy-18-oxo-23S-acetoxy-18,20-epoxylanosta-7-ene (HI-9, Stichloroside B1). An aglycone, Holosta-22, 25-epoxy-7(8), 9(11)-diene-3β, 17α-diol, had been prepared by acid hydrolysis of holothurin A(HI-10, 22,25-oxidoholothurinogenin). A common physiological substance of adenosine (HI-11, Adenosine) had also been obtained.From the ethanolic extracts of A. mauritiana, nine compounds had been isolated and structurally elucidated, including six triterpene glycosides: 3-O-[3-O-methyl-β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→4)-β-D-quinovopyranosyl-(1→2)-4-O-sodium sulfate-β-D-xylopyranosyl]-holosta-9(11)-ene-3β, 12α,17α-triol (AM-1, Echinoside A); 3-O-[3-O-methyl-β-D-glucopyranosyl-(1→3)-β-D-glucopyranosyl-(1→4)-β-D-quinovopyranosyl-(1→2)-4-O-sodium sulfate-β-D-xylopyranosyl]- 22, 25-epoxy-holosta-9(11)-ene-3β, 12α, 17α-triol (AM-2, Holothurin A); 3-O-[4-O-sodium sulfate-β-D-quinovopyranosyl-(1→2)-4-O-sodium sulfate-β-D-xylopyranosyl]- 22, 25-epoxy-holosta-9(11)-ene-3β, 12α, 17α-triol (AM-3, Mauritianoside A); 3-O-[β-D-quinovopyranosyl-(1→2)-4-O-sodium sulfate-β-D-xylopyranosyl]- 22, 25-epoxy-holosta-9(11)-ene-3β, 12α, 17α-triol (AM-4, Holothurin B); 3-O-[β-D-quinovopyranosyl-(1→2)-4-O-sulfonic acid -β-D-xylopyranosyl]-holosta-9(11)-ene-3β, 12α,17α-triol (AM-5, Mauritianoside B); 3-O-[β-D-quinovopyranosyl-(1→2)-4-O-sodium sulfate-β-D-xylopyranosyl]-holosta-9(11)-ene-3β, 12α,17α-triol (AM-6, Echinoside B). The other three componds were 3-acetoxy-3,4-dihydronaphthalene-2-sulfonic acid (AM-7), 2'-deoxyuridine (AM-8) and thymidine (AM-9).All these compounds were first reported from the two species, and HI-1, HI-7, AM-3 and AM-5 are new triterpene glycosides named as 17-Dehydroxyholothurin A, Impatienside A, Mauritianoside A and Mauritianoside B, respectively.Three triterpene glycosides HI-7, HI-8 and HI-9 exhibited significant in vitro cytotoxic activities (IC50=0.371-2.752μg/ml) against seven human cancer cells including HCT-116 cells, human colon cancer HT-29 cells, human lung cancer A549 cells, human hepatoma HepG2 cells, human prostate cancer DU145 cells, human breast cancer MCF-7 cells and human cancer KB cells, which were almost correspondent to VP-16, a clinical anticancer drugs. Compound HI-6 only showed week cytotoxic activities against on human lung cancer A549 cells. Compound HI-10 showed no cytotoxic activities against human lung cancer A549 and HL-60 tumor cell. In the anti-fungal activity test HI-1, HI-3, HI-5 and HI-9 indicated inhibitory effect against eight fungi lines, while HI-10 didn't show inhibitory effect.Our studies focused on bioactive constituents of H. impatiens and A. mauritiana, and had established a foundation for further research and development of these two sea cucumbers with abundant resources in South China Sea, and also provided important leading compounds for the development of new anti-cancer and anti-fungus drugs.