• Journal of Microbiology and Biotechnology
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• 제33권11호
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• pp.1437-1447
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• 2023

A recently bioinformatic analysis of genomic sequences of fungi indicated that fungi are able to produce more secondary metabolites than expected. Despite their potency, many biosynthetic pathways are silent in the absence of specific culture conditions or chemical cues. To access cryptic metabolism, 108 fungal strains isolated from various sites were cultured with or without Streptomyces sp. 13F051 which mainly produces trichostatin analogues, followed by comparison of metabolic profiles using LC-MS. Among the 108 fungal strains, 14 produced secondary metabolites that were not recognized or were scarcely produced in mono-cultivation. Of these two fungal strains, Myrmecridium schulzeri 15F098 and Scleroconidioma sphagnicola 15S058 produced four new compounds (1-4) along with a known compound (5), demonstrating that all four compounds were produced by physical interaction with Streptomyces sp. 13F051. Bioactivity evaluation indicated that compounds 3-5 impede migration of MDA-MB-231 breast cancer cells.

• Journal of Microbiology and Biotechnology
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• 제32권5호
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• pp.541-550
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• 2022

Filamentous marine fungi have proven to be a plentiful source of new natural products. Chaetomium, a widely distributed fungal genus in the marine environment, has gained much interest within the scientific community. In the last 20 years, many potential secondary metabolites have been detected from marine-derived Chaetomium. In this review, we attempt to provide a comprehensive summary of the natural products produced by marine-derived Chaetomium species. A total of 122 secondary metabolites that were described from 2001 to 2021 are covered. The structural diversity of the compounds, along with details of the sources and relevant biological properties are also provided, while the relationships between structures and their bioactivities are discussed. It is our expectation that this review will be of benefit to drug development and innovation.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1995년도 식물학심포지움 식물로부터 유용 2차대사산물의 생산 PRODUCTION OF USEFUL SECONDARY METABOLITES FROM PLANTS
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• pp.40-56
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• 1995

During the past two decades, China has seen her great progress in plant biotechnology. Since the Chinese market of herb medicine is huge, while the plant resources are shrinking, particular emphasis has been placed in plant tissue and cell cultures of medicinal plants, this includes fast propagation, protoplast isolation and regeneration, cell suspension cultures and large scale fermentation. To optimize culture conditions for producing secondary compounds in vitro, various media, additives and elicitors have been tested. Successful examples of large scale culture for the secondary metabolite biosynthesis are quite limited : Lithospermum ery throrhizon and Arnebia euchroma for shikonin derivatives, Panax ginseng, P. notoginseng, P. quinquefolium for saponins, and a few other medicinal plants. Recent development of genetic transformation systems of plant cells offered a new approach to in vitro production of secondary compounds. Hairy root induction and cultures, by using Ri-plasmid, have been reported from a number of medicinal plant species, such as Artemisia annua that produces little artemisinin in normal cultured cells, and from Glycyrrhiza uralensis. In the coming five years, Chinese scientists will continue their work on large scale cell cultures of a few of selected plant species, including Taxus spp. and A. annua, for the production of secondary metabolites with medicinal interests, one or two groups of scientists will be engaged in molecular cloning of the key enzymes in plant secondary metabolism.

• 한국자기공명학회논문지
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• 제8권2호
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• pp.115-126
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• 2004

Four secondary metabolites from an unidentified tunicate were isolated by treatment with trichloroethyl chloroformate(TECF) or acetic anhydride in pyridine. Their structures were determined by an extensive NMR analysis and the configuration of diacetyl derivatives(3a, 4a) was assigned by comparing with NMR data of a similar compound. Three new naturally occurring compounds (1, 3, 4) showed potent brine shrimp lethality and antifungal effect against Candia albicans.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 춘계학술대회
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• pp.34-34
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• 2019

About 60% of the present drugs were developed from natural products with unique chemical diversity and biological activities. Hence, discovery of new bioactive compounds from natural products is still important for the drug development. On the other hand, breakthrough made in synthetic biology has also begun to supply us with many useful compounds through manipulation of biosynthetic gene for secondary metabolites. Theoretically, this approach can also be exploited to generate new unnatural compounds by intermixing genes from different biosynthetic pathway. Considering the potential, we are studying about bioactive compounds in natural sources, as well as the biosynthesis of natural products including engineering of the secondary metabolite enzymes to make new compounds in order to construct the methodological basis of the synthetic biology. In this symposium, engineering of secondary metabolite enzymes that are involved in the biosynthesis of plant polyketides to generate new compounds in our laboratory will be mainly introduced.

• 한국해양바이오학회지
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• 제1권4호
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• pp.225-231
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• 2006

The secondary metabolites from Taiwanese marine soft corals and sponges have attracted much attention because they possess considerable potential biological activities. To explore the origin of bioactivity, many cytotoxic natural products were isolated and characterized in the past few years. For examples, The lipophilic extracts from marine sponges Petrosia elastica and Ircinia formosana were found active against several human tumor cells. The investigation of the gorgonian Junceela has also resulted in the discovery of a series of new juncenolides. Bioassay-directed fractionation of Clavularia viridis yielded seven new prostanoids. These compounds have been tested and evaluated as potential antitumor agents. The soft corals of the genus Cespitularia produced novel secondary metabolites with diverse chemical structures and interesting biological activities. Four new norditerpenoids, designated cespitulactones and cespihypotins were isolated from Cespitularia hypotentaculata. Cespitulactones are novel structures having a bond cleavage between C-10 and C-11. In addition, three novel diterpenes were isolated from C. taeniata and designated cespitulactams A, B and C having a phenylethyl amino side chain.

• Journal of Microbiology and Biotechnology
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• 제21권1호
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• pp.5-13
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• 2011

In this study, seven Trichoderma species (33 strains) were classified using secondary metabolite profile-based chemotaxonomy. Secondary metabolites were analyzed by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS-MS) and multivariate statistical methods. T. longibrachiatum and T. virens were independently clustered based on both internal transcribed spacer (ITS) sequence and secondary metabolite analyses. T. harzianum formed three subclusters in the ITS-based phylogenetic tree and two subclusters in the metabolitebased dendrogram. In contrast, T. koningii and T. atroviride strains were mixed in one cluster in the phylogenetic tree, whereas T. koningii was grouped in a different subcluster from T. atroviride and T. hamatum in the chemotaxonomic tree. Partial least-squares discriminant analysis (PLS-DA) was applied to determine which metabolites were responsible for the clustering patterns observed for the different Trichoderma strains. The metabolites were hetelidic acid, sorbicillinol, trichodermanone C, giocladic acid, bisorbicillinol, and three unidentified compounds in the comparison of T. virens and T. longibrachiatum; harzianic acid, demethylharzianic acid, homoharzianic acid, and three unidentified compounds in T. harzianum I and II; and koninginin B, E, and D, and six unidentified compounds in T. koningii and T. atroviride. The results of this study demonstrate that secondary metabolite profiling-based chemotaxonomy has distinct advantages relative to ITS-based classification, since it identified new Trichoderma clusters that were not found using the latter approach.

• 대한약침학회지
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• 제20권3호
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• pp.173-178
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• 2017

Objectives: Medicinal plants are vital sources of bioactive compounds that are useful for the treatment of patients with snake bites or are indirectly applicable for boosting the effects of conventional serum therapy. These plants are being used traditionally by local healers and tribes for the treatment of patients with snake bites and therefore can be used as an alternative against snake envenomation. Scientifically, using the secondary metabolites of plants to neutralize venom enzymes has an extra benefit of being based on traditional knowledge; also, the use of such metabolites for the treatment of patients with snake bites is cheaper and the treatment can be started sooner. Methods: All the available information on various secondary metabolites exhibiting venom neutralizing ability were collected via electronic search (using Google books, Pubmed, SciFinder, Scirus, Google Scholar, and Web of Science) and articles of peer-reviewed journals. Results:Recent interest in different plant has focused on isolating and identifying of different phytoconstituents that exhibit Phospholipase A2 activity and other venom enzyme neutralizing ability. In this support convincing evidence in experimental animal models are available. Conclusion: Secondary metabolites are naturally present, have no side effect, are stable for a long time, can be easily stored, and can neutralize a wide range of snake enzymes, such as phospholipase A2, hyaluronidase, protease, L-amino acid oxidase, 5'nucleotidase, etc. The current review presents a compilation of important plant secondary metabolites that are effective against snake venom due to enzyme neutralization.

• 미생물학회지
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• 제54권3호
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• pp.175-187
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• 2018

점액세균은 포식활동, 자기방어, 세포 간 신호전달 및 아직까지 알려지지 않은 다른 기능을 위해 다양한 이차대사산물을 생산한다. 점액세균에서 분리된 많은 이차대사산물들은 독특한 작용기작을 가지며 항암, 항세균, 항진균 등과 같은 약학적으로 유용한 생리활성을 보인다. 따라서 전 세계적으로 많은 점액세균 균주들이 분리되었고 이들로부터 다양한 생리활성물질들이 탐색되었다. 하지만 16S rRNA 데이터베이스 분석에 의하면 야생에는 지금까지 분리된 종류 이외에도 다양한 점액세균 종류들이 존재할 것으로 추정되며, 유전체 서열 분석에 의하면 각 점액세균들은 기존에 알려진 물질보다 더 많은 물질을 생산할 수 있는 능력이 있는 것으로 나타났다. 본 총설에서는 점액세균 유래 이차대사산물들과 이들의 유전자, 점액세균에서의 기능, 생합성 유전자의 발현을 조절하는 전사조절인자 등에 대한 최근까지의 연구 현황을 살펴보았다.

• 한국식품위생안전성학회지
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• 제33권3호
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• pp.151-156
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• 2018

해양생물에는 육상생물자원에서는 존재하지 않는 다양한 화합물이 많이 존재하는데 이들 화합물은 새로운 치료제 및 대체 치료법을 개발하는데 유용하게 이용될 수 있다. 현재 해조류의 다양한 생리활성에 대한 연구가 진행되고 있으며 최근에는 여러 병원성 및 인체 감염균에 대한 항균효과를 나타내어 신약개발의 보고로 다양한 연구가 진행이 되고있다. 즉, 해조류는 천연물신약 또는 새로운 치료제 개발에 중요한 생물자원이다.