Studies On Chemical Constituents Of The Algae Hydroclathrus Clathratus And The Marine Sponge Phakellia Fusca

The chemical constituents of the algae Hydroclathrus clathratus and the sponge Phakellia fusca collected from the South China Sea were studied in the paper. Seven compounds have been isolated and identified from the algae Hydroclathrus clathratus. The stereo structure of compound 1 was established by X-ray diffraction analysis. Compound 1 and 4 were isolated from natural resources for the first time. Compound 2 and 3 and 5 and 6 were isolated from this algae for the first time. Two new compounds were isolated and identified from the sponge Phakellia fusca.Seven compounds isolated from the algae Hydroclathrus clathratus were established as (6R,7a5)-6-hydroxy-4,4,7a-trimethyl-2,4,5,6,7,7a-hexahydrobenzofuran-2-one (1), 1 -glyceryl hexadecanoate (2), N-(2'-hydroxy-r-methylolpentadecane)icosananiide (3), 2-phenylamino-1,4-naphthoquinone (4), 1 -(2-deoxy--D-ribofuranosyl)-5 -methyl-1,2,3,4-tetrahydropyrimi dine-2,4-dione(5),uracil(6),mannitol(7)byUV, IR, 'HNMR, 13CNMR, 'H-'HCOSY, HMQC, HMBC, EIMS, HRMS.The absolute configuration of compound 1 was established by a single-crystal X-ray diffraction experiments and polarimetric analysis. The crystal belongs to monoclinic system, space group P2, with a = 6.0774(12),= 11.695(2), c = 7.8763(16) A, F=527.51 (18) A3, Z= 2, M=196.24, Dc= 1.235 mg/m3, F(000) = 212, u(MoKa) = 0.089 mm"1, A, = 0.71073 A. The structure was solved by direct methods and refined to R = 0.0296 and wR = 0.0761 for 1652 observed reflections. The maximum and minimum peaks in the final difference Fourier map are 0.135 and -0.121 e/A3, respectively. X-ray diffraction analysis reveals that the molecule is composed of a six-membered ring (chair conformation) and a five-membered lactone (planar conformation) ring with a methyl and a hydroxyl group at the two asymmetrical carbons located on the same side of the nucleus.One triglycosylceramides was isolated from the sponge Phakellia fusca. Its structure was established as N-(2',3'-dihydroxy-l '-methylolpentatriacontane)-2-hydroxyhexanamide-l '-O-a-D-glucopyranosyl-(l4)-[2-acetamide-a-D-galactopyranoside]-(l2)-a-D-glucopyranoside (8).