• Journal of the Korean Magnetic Resonance Society
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• v.10 no.2
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• pp.188-196
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• 2006

A known theonellapeptolide Ie, previously reported in other research group, was isolated from the methanolic extract of the Philippine sponge Theonella swinhoei. The planar structure of this compound was determined on the basis of NMR methods including HMBC and selective HMBC experiments. This is fast and efficient for the dereplication of natural products compared with the MS studies of fragments obtained from complete and partial hydrolysis. The sequence of thirteen amino acids including six N-methyl amino acids in the compound was clearly determined from correlations of extensive HMBC experiments.

• Korean Journal of Pharmacognosy
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• v.31 no.1
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• pp.34-38
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• 2000

Three compounds were isolated from the roots of Astragalus membranaceus (Leguminosae). On the basis of spectroscopic evidences, the structures were characterized as $3-0-{\beta}-D-xylopyranosyl-(2',3'-O-diacetyl)-6-0-{\beta}-D-glucopyranosyl-3{\beta},6{\alpha},16{\beta},25-tetrahydroxy-20(R)$,24(S)-epoxy-cycloartane(Astragaloside I), $3-0-{\beta}-D-xylopyranosyl-(2'-O-acetyl)-6-0-{\beta}-D-glucopyranosyl-3{\beta},6{\alpha},16{\beta},25-tetrahydroxy-20(R)$,24(S)-epoxy-cycloartane(Astragaloside II), $3-0-{\beta}-D-xylopyranosyl-(2',4'-O-diacetyl)-6-0-{\beta}-D-glucopyranosyl-3{\beta},6{\alpha},16{\beta},25-tetrahydroxy-20(R)$,24(S)-epoxycycloartane(Isoastragaloside I). Full data of NMR including HMBC and 1D-TOCSY experiment of these compounds were reported for the first time.

• Natural Product Sciences
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• v.6 no.2
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• pp.61-65
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• 2000

The ethanolic extracts of marine green, brown and red algae collected from Karachi coasts of Arabian Sea afforded a new enol-derivative of N-acylsphingosine named as coelarthenol (1) from Coelarthrum muelleri, two new glucose-derivatives named: botryenal (2) and botryenol (3) from Botryocladia leptopoda, ${\alpha}-tocopherol$ quinone (4) from Codium iyengarii, ${\beta}-sitosterol$ and hexadecanoic acid from Stokeyia indica. The known constituents (4, ${\beta}-sitosterol$ & hexadecanoic acid) have not been reported so far from their corresponding sources and the structures were determined through spectroscopic methods, whereas, the structures of new constituents (1-3) were elucidated with the aid of selective HMBC experiments. The phytotoxicity of 4 was also monitored.