Halenaquinol sulfate

The yellow pigment halenaquinol sulfate (410) has been isolated from the Okinawan sponge Xestospongia sapra and is a pentacyclic hydroquinone [345]. The absolute stereochemistry was determined to be 6S by comparing the CD spectrum of a derivative with a theoretically calculated spectrum [346]. Theoretical calculation of CD spectra of halenaquinol sulfate (410) isolated from X. exigua and X. sapra determined that the absolute stereostructure was 12bS [347]. The pentacyclic compound, xestoquinol sulfate (411) has been isolated from an Okinawan collection of X. sapra and its structure was elucidated on the basis of spectroscopic data and a chemical conversion [348]. 

The absolute stereostructures of halenaquinone (+)-l, halenaquinol (+)-2, halenaquinol sulfate (-i-)-3, xestoquinone (+)-4, and xestoquinol 62, novel pentacyclic marine natural products isolated from tropical marine sponges, were theoretically determined to be 12bS, respectively, on the basis of the calculation of the CD spectra of naphthalene-diene derivatives by the re-electron SCF-CI-DV MO method. These studies also clarified that the theoretical CD method was applicable to such complex natural products. 

Halenaquinol sulfate is an inhibitor of DNA polymerase (Shioda et al., 1994), and halenaquinone is an inhibitor of phosphatidylinositol-3 kinase and PIA2 (Fujiwara et al., 2001 Longeon et al., 2010). The cytotoxic and antifungal properties of halenaquinone and xestoquinone strongly depend on the presence of carbonyl at position 3, and are negatively correlated with each other. Xestoquinone has no... 

Kobayashi, M., Shimizu, N., Kyogoku, Y, and Kitagawa, I. (1985a) Halenaquinol and halenaquinol sulfate pentacyclic hydroquinones from the Okinawan sponge Xestospongia sapra. Chem. Pharm. Bull., 33,1305-1308. 

Shioda, M., Kano, K., Kobayashi, M., Kitagawa, I Shoji, M Yoshida, S., and Ikegami, S. (1994) Differential inhibition of eukaryotic DNA polymerases by halenaquinol sulfate, a p-hydroquinone sulfate obtained from a marine sponge. FEES Lett., 350, 249-252. 

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