Kehau Hagiwara

Accelerated Identification of Halogenated Monoterpenes from Australian Specimens of the Red Algae Plocamium hamatum and Plocamium costatum

Two species of red algae belonging to the genus Plocamium, P. hamatum from Moreton Bay, Queensland, and P. costatum, from Pandalowie Bay, South Australia, were investigated to assess their chemical variation and as potential sources of new halogenated monoterpenes. The hyphenated technique HPLC-UV-MS-SPE-NMR was used to assess the algal extracts and to determine its potential for accelerated identification of halogenated monoterpenes generally. A combination of the hyphenated and traditional chromatographic techniques resulted in the isolation and characterization of a total of 10 halogenated monoterpene metabolites, eight of which are reported for the first time. Their structures, including configurations, were determined through interpretation of their 1D and 2D NMR, mass spectrometric, infrared, and X-ray data. The two species of Plocamium produced different secondary metabolites and contained a significant number of new polyhalogenated monoterpenes. The investigation also showed the hyphenated technique HPLC-UV-MS-SPE-NMR to be useful for preliminary investigation of the chemical content of algal extracts.

Puupehenol, a potent antioxidant antimicrobial meroterpenoid from a Hawaiian deep-water Dactylospongia sp. sponge.

From the organic extract of a deep-water Hawaiian sponge Dactylospongia sp., a new potent antioxidant and antimicrobial meroterpenoid, puupehenol (1), was isolated. The structure of 1 was determined using spectroscopic techniques ((1)H and (13)C NMR, MS, IR, UV, [α]D). The known compound puupehenone (2) was also isolated and suggested as a probable artifact of the isolation procedures. Complete unambiguous (1)H and (13)C NMR data are provided for compounds 1 and 2. Bioassays performed with 1 and 2 showed them both to be very effective antioxidants and to have antimicrobial properties.

Half a Century of Hawaiian Marine Natural Products

The following review covers the primary literature concerning marine natural products isolated for the first time from organisms collected around the islands of Hawaii published in the 51-year period 1964 to July 2015. The review is divided into seven main sections based on major taxonomic groupings; algae, sponges, mollusks, miscellaneous invertebrates, cyanobacteria, bacteria, and fungi. The aim of the review is to discuss the compounds and information concerning their original biological activity and other potentially interesting properties. The majority of the 320 structures of isolated compounds are not shown directly in the review but are contained in the Supporting Information section in 22 figures, Figs. 1 S-22 S. The Supporting Information section also contains Table 1 S that has information relating to the taxonomic identification of the source organism of each compound, collection location of the source organism, a trivial or semi-systematic name for each compound, as well as its general structural class. The authors hope that this review will be the spawning ground for other reviews and the basis for a great deal more research into the marine life found in Hawaiian waters.

Comparative analysis of the antioxidant properties of Icelandic and Hawaiian lichens.

Antioxidant activity of symbiotic organisms known as lichens is an intriguing field of research because of its strong contribution to their ability to withstand extremes of physical and biological stress (e.g. desiccation, temperature, UV radiation and microbial infection). We present a comparative study on the antioxidant activities of 76 Icelandic and 41 Hawaiian lichen samples assessed employing the DPPH- and FRAP-based antioxidant assays. Utilizing this unprecedented sample size, we show that while highest individual sample activity is present in the Icelandic dataset, the overall antioxidant activity is higher for lichens found in Hawaii. Furthermore, we report that lichens from the genus Peltigera that have been described as strong antioxidant producers in studies on Chinese, Russian and Turkish lichens also show high antioxidant activities in both Icelandic and Hawaiian lichen samples. Finally, we show that opportunistic sampling of lichens in both Iceland and Hawaii will yield high numbers of lichen species that exclusively include green algae as photobiont.

Draft Genome Sequence of Marine Sponge Symbiont Pseudoalteromonas luteoviolacea IPB1, Isolated from Hilo, Hawaii

ABSTRACT We report here the 6.0-Mb draft genome assembly of Pseudoalteromonas luteoviolacea strain IPB1 that was isolated from the Hawaiian marine sponge Iotrochota protea. Genome mining complemented with bioassay studies will elucidate secondary metabolite biosynthetic pathways and will help explain the ecological interaction between host sponge and microorganism.

Tea Leaf Age, Shade and Characteristic Levels of l-Theanine, Caffeine, (−)-Epigallocatechin Gallate (EGCG), (−)-Epigallocatechin (EGC), (−)-Epicatechin (EC), and (−)-Epicatechin Gallate (ECG)

Abstract In this review the reported effects of shade levels on the amounts of reputed biologically active potential key chemical markers l -theanine and caffeine, and the four catechin-polyphenols, (−)-epicatechin (EC), (−)-epicatechin gallate (ECG), (−)-epigallocatechin (EGC), and (−)-epigallocatechin gallate (EGCG) found in the bud and first two leaves during development of tea ( Camellia sinensis ) grown on a Hawaiian plantation are discussed. Also discussed is the antioxidant activity of the overall extract of the tea leaf bud, and first and second leaves, together with the importance of employing 1 H NMR spectroscopy as an analytical tool for the determination of the validity of reference materials.