• Natural Product Sciences
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• 제6권3호
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• pp.122-125
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• 2000

Allenic and epoxy carotenoid, fucoxanthin (1) was isolated from the marine bacillariophycean microalga Hantzschia marina and the structure was assigned on the basis of comprehensive spectroscopic analyses. Fucoxanthin was detected only from diatom among three families (green algae, diatom and blue-green algae) of the marine microalgae tested. Fucoxanthin showed free radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and peroxynitrite $(ONOO^-)$ with $IC_{50}$ values of $32\;{\mu}M\;and\;60\;{\mu}M$, respectively.

• Natural Product Sciences
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• 제2권2호
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• pp.106-114
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• 1996

Four polymethoxyfavones were isolated from the leaves of Citrus deliciosa, three of which (nobiletin, 5-O-demethylnobiletin, and tangeritin) are bioactive. The fourth (7,4'-dihydroxy-5,6,8,3'-tetramethoxyflavone) is reported for the first time in the genus Citrus and is a potential chemotaxonomic marker. The structures of these flavones were confirmed by analysing their spectral data and comparison with similar compounds. The previously reported $^{13}C$ NMR assignment of 5-O-demethylnobiletin has been revised on the basis of 2D NMR experiments (HETCOR, COSY, and COLOC). The chemotaxonomic value of the present finding is verified.

• Fisheries and Aquatic Sciences
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• 제2권1호
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• pp.58-65
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• 1999

Fibrocapsa japonica (Raphidophyceae) is regarded as a harmful algal bloom organism in Japanese waters, where it has been linked to fish kills. Fibrocapsa is a common species in New Zealand coastal waters, particularly in the Hauraki Gulf, where it has regularly bloomed in the spring under E1 Nino climate conditions for the past six years. The New Zealand isolate had 1.4 times more total polyunsaturated acids than the Japanese isolate under the same growth conditions, suggesting that eicosapentaenoic acid in particular coold be used as a discriminating chemotaxonomic marker. The molecular probes tested showed no differential binding of the raphidophytes to lectins, but oligonucleotide probes targeted F. japonica ribosomal RNA bound specifically to both isolates. Neither strain was toxic in mouse or neuroblastoma bioassays. There is no evidence that the New Zealand F. japonica isolates investigated to date produce ichthyotoxins.

• ALGAE
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• 제36권2호
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• pp.123-135
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• 2021

The taxonomy of green microalgae relies traditionally on morphological traits but has been rapidly changing since the advent of molecular methods. Stichococcus Nägeli is a cosmopolitan terrestrial algal genus of the class Trebouxiophyceae that has recently been split into seven lineages, which, along with Pseudostichococcus, comprise the Stichococcuslike group; there is a need to further characterize these genera, since they are morphologically enigmatic. Here we used organic osmolytes as chemotaxonomic marker to verify the phylogenetic position of Stichococcus-like strains and were also able to exclude a strain hitherto identified as Gloeotila contorta from this group. Stichococcus-like organisms, including those recently revised, were characterized by the production of the polyol sorbitol and the disaccharide sucrose in high amounts, as is typical of Prasiola-clade algae. The results demonstrate that organic osmolyte chemotaxonomy can support green algal taxonomic designations as fundamental research.

• ALGAE
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• 제26권1호
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• pp.21-32
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• 2011

Studies of the red algal genus Bostrychia over the last 15 years have made it a model system for many evolutionary processes within red algal species. The combination of newly developed, or first employed methods, in red algal species studies has made Bostrychia a pioneer genus in intraspecific studies. Bostrychia was the first genus in which a mitochondrial marker was used for intraspecific red algal phylogeny, and the first for which a 3-genome phylogeny was undertaken. The genus was the first red alga used to genetically show maternal plastid and mitochondria inheritance, and also to show correlation between cryptic species (genetically divergent intraspecific lineages) and reproductive incompatibility. The chemotaxonomic use, and physiological function of osmolytes, has also been extensively studied in Bostrychia. Our continuous studies of Bostrychia also highlight important aspects in algal species studies. Our worldwide sampling, and resampling in certain areas, show that intensive sampling is needed to accurately assess the genetic diversity and therefore phylogeographic history of algal species, with increased sampling altering evolutionary hypotheses. Our studies have also shown that long-term morphological character stability (stasis) and character convergence can only be correctly assessed with wide geographic sampling of morphological species. While reproductive incompatibility of divergent lineages supports the biological species nature of these lineages, reproductive incompatibility is also seen between isolates with little genetic divergence. It seems that reproductive incompatibility may evolve quickly in red algae and the unique early stages of fertilization (e.g., gametes covered by walls, active movement of spermatium nuclei to the distant egg nucleus), also well investigated in Bostrychia,. may be key to our understanding of this process.

• Toxicological Research
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• 제23권1호
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• pp.79-86
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• 2007

The isolated plantamajoside from Plantago asiatica that is often used as a marker compound in chemotaxonomic studies has various bioactivites such as the inhibitions of cyclic AMP phosphodi-esterase and 5-lipoxygenase, microbial growth and inflammation, and currently demands the generation of toxicity data. The purpose of this study was to examine the toxicities of the single and 14 days repeated dose toxicity in Sprague-Dawley rats orally administrated with plantamajoside at dose levels of 0, 500, 1000, and 2000 mg of dried material/kg body weight/day. The results showed that there was no difference in body weight change, food intake, water consumption, or relative organ weight among different dose groups. Also we observed no death and abnormal clinical signs were observed during the experimental period. Between the groups orally administered Plantago asiatica and the control group, there was no statistical significance in hematological test or serum biochemical values. There were no gross findings at final sacrifice. There was no evidence of histopathological alteration mediated by 14 days treatment with Plantago asiatica. These results suggest that no observed adverse effect level (NOAEL) of the oral application was considered to be more than 2000 mg/kg in rats under the conditions employed in this study. Another observation was performed to investigate the safety of Plantago asiatica in respect of genotoxicity. This substance was examined that Salmonella typhimurium reversion assay (Ames test) in strain TA98, TA100, TA1535. In the reverse mutation test, Plantago asiatica did not induce mutagenicity in Samonella typhimurium with and without metabolic activation. These results indicated that Plantago asiatica had no genotoxicity.

• 한국해양학회지:바다
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• 제17권2호
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• pp.87-94
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• 2012

만의 대부분이 조간대(약 75%)인 전라북도 곰소만 내 해수와 퇴적물 중 미세조류의 생체량과 군집조성의 월 변화를 비교하기 위해서 1999년 2월부터 2000년 1월까지는 매월, 2000년 2월부터 12월까지는 격월로 high-performance liquid chromatograph(HPLC)를 이용하여 광합성색소 분석을 실시하였다. 또한 해수 중 미세조류의 군집구조를 조절하는 환경요인을 조사하기 위해서 수온, 염분, 영양염류, 용존산소, 화학적산소요구량을 분석하였다. 해수 중 미세조류의 월별 분포는 대체로 담수의 유입으로 인한 영양염류의 공급이 많은 시기에 높은 생체량(chlorophyll a)을 보였다. 퇴적물 중 저서미세조류의 생체량은 국내외 다른 갯벌지역에 비해서 상대적으로 낮았으며, 단위 면적당 적분한 해수 중 미세조류의 생체량에 비해서 2-3배 낮게 나타났다. 해수와 퇴적물 중 미세조류의 색소분석 결과, 규조류의 주요색소인 fucoxanthin 농도가 가장 높았으며, fucoxanthin과 chlorophyll a의 월 변화가 유사한 양상을 보여 곰소만 내 갯벌과 해수 중 미세조류는 규조류가 우점하는 것으로 판단된다. 그러나 조하대 표층 해수 중 미세조류 생체량(chlorophyll a)의 월 변화는 갯벌에 서식하는 저서미세조류 생체량의 월 변화와 다른 양상을 보였으며, 현미경 관찰을 통한 해수 중 미세조류의 종조성 분석 결과, 저서미세조류의 우점종인 저서성 규조류는 거의 관찰되지 않았다. 본 연구결과는 곰소만 갯벌에서 재부유되어 조하대로 공급되는 저서미세조류가 조하대 표층 생태계에 서식하는 생물에게 먹이원으로서의 기여도는 상대적으로 낮다는 것을 시사한다. 갯벌에서 재부유되어 조하대로 공급되는 미세조류의 정확한 평가와 함께 조하대에서 이들의 수직, 수평 거동과 관련된 심도 깊은 연구가 필요할 것으로 판단된다.