• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2002년도 춘계 국제 학술대회
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• pp.55-56
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• 2002

Aflatoxin is a secondary fungal metabolite and is a public health hazard because it is a human carcinogenic and has many deleterious effects in men and animals. Rice is one of the better substrates for the fungus which can produce aflatoxins. This study was performed to investigate aflatoxin reduction during the cooking and processing of rice. Aflatoxin was produced by Aspergillus parasiticus ATCC 15517 on well-milled rice(Japonica type) at the level of 13.2 ppb. Cooked rice, rice cakes (baek-sol-gi, plain steamed rice bread), fermented rice (sik-hye, sweet rice beverage), and popped rice were prepared from the aflatoxin-contaminated rice. Aflatoxin content in the samples was determined by high performance liquid chromatography. The total aflatoxin level was decreased to 46.9％ in the cooked rice, 85.6％ in the rice cakes, 11.4％ in the fermented rice, and 7.6％ in the popped rice, respectively (p＜0.05). This reduction brought the level of aflatoxins down to below the Standard and Specification of Korea (10 ppb), except for the rice cakes. These results indicate that washing, steaming, fermentation, and popping of rice was helpful in reducing the aflatoxin level in the rice and the most helpful factors were high temperature & high pressure. More research is needed to understand why the preparation of rice cakes did not reduce the level of aflatoxin as much as the other cooking methods.

• Natural Product Sciences
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• 제21권4호
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• pp.282-288
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• 2015

Viriditoxin is a fungal metabolite isolated from Paecilomyces variotii, which was derived from the giant jellyfish Nemopilema nomurai. Viriditoxin was reported to inhibit polymerization of FtsZ, which is a key protein for bacterial cell division and a structural homologue of eukaryotic tubulin. Both tubulin and FtsZ contain a GTP-binding domain, have GTPase activity, assemble into protofilaments, two-dimensional sheets, and protofilament rings, and share substantial structural identities. Accordingly, we hypothesized that viriditoxin may inhibit eukaryotic cell division by inhibiting tubulin polymerization as in the case of bacterial FtsZ inhibition. Docking simulation of viriditoxin to ${\beta}-tubulin$ indicated that it binds to the paclitaxel-binding domain and makes hydrogen bonds with Thr276 and Gly370 in the same manner as paclitaxel. Viriditoxin suppressed growth of A549 human lung cancer cells, and inhibited cell division with G2/M cell cycle arrest, leading to apoptotic cell death.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1993년도 제2회 신약개발 연구발표회 초록집
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• pp.34-35
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• 1993

The Development of new asymmetric induction methods useful for syntheses of biologically active natural products and drugs, using C4-chiral 1,3-th-iazolidine-2-thiones, has been a recent focus of interest. 1-8) The present account describes the significance of particular heterocycles in the synthetic development of new 1${\beta}$-substituted carbapenems. A fungal metabolite, (＋)-thienamycin (1) has attracted one's attention as a hopeful candidate for new-generation antibiotic drugs because of its strong antimicrobial activities and wide antimicrobial spectra due to the extensive inhibition against various ${\beta}$-lactamases. However, it has been serious problems toward a practically useful drug that (＋)-thienamycin is fairly labile in the solution and can be metabolized by renal dehydropept- idase-I (DHP-I). Recently, a Merck Sharp ＆ Dohme research group exploited a non-natural ${\beta}$-lactam, imipenem (2) which has been appeared in the drug market as the first carbapenem-type antibiotic drug. 9) However 2 must be used with a DHP-I inhibitor, cilastatin sodium (3).9) Thus, a 1,${\beta}$-methyl- carbapenem derivative 4 has been disclosed by the same group. 10) It seems to be more hopeful candidate as a new-generation antibiotic because it can directly resist against metabolism by the renal DHP-1 without an enzyme inhibitor 3. 10)

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2000년도 The 7th International Symposium
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• pp.96-113
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• 2000

Coleus forskohlii Briq. of the family Lamiaceae yields a valuable secondary metabolite known as forskolin which is a labdane diterpenoid. Coleus forskohlii is the only known source of this compound. Forskolin is used in medicine for the treatment of glaucoma, congestive cardiomyopathy and asthma. Morphogenic callus was induced from young leaves on MS medium augmented with NAA and BA. These calli, when subcultured on MS with KN alone gave rise to shoots. The regenerated shoot developed good root system on MS medium fortified with NAA. The fully grown plantlets were transferred to soil for acclimatization. Coleus plant is mainly infected by a fungi Lasiodiplodia theobromae which causes root of disease. The fungal culture filterate (FCF) of Lasiodiplodia theobromae, has been used in regeneration media to find the MIC and further to select resistant plants to the pathogen. In the present study 40% FCF in the medium showed maximum inhibition and is there fore considered as the MIC level of Coleus forskohlii. This data could prove to be useful for the future for selecting a resistant C,forskohlii plant against the root disease caused by L.theobromae.

• Mycobiology
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• 제35권2호
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• pp.82-86
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• 2007

Ergone, a fungal metabolite derived from ergosterol, was previously isolated and identified from Polyporus umbellatus. Ergone is a major component of P. umbellatus known to have anti-aldosteronic diuretic effect and also displays cytotoxic activities. Most of mushroom's fruit bodies used for test contained less than 10 ${\mu}g/g$ of ergone. But P. umbellatus have larger amount of ergone than any other mushrooms. In order to improve the ergone production from the submerged culture of P. umbellatus, several factors including medium composition, culture conditions (temperature and pH) and different combinations of co-cultivation with various mycelia were studied. Among various carbon sources examined, starch proved to be most effective for the production of mycelia. The optimum pH and temperature for a flask culture of P. umbellatus mycelia were found to be 4.5 and $25^{\circ}C$, respectively. Under the optimized culture conditions, both the ergone production (86.9 ${\mu}g/g$) and mycelial growth (3.5 g/l) increased when P. umbellatus was cultured with Armillariella mellea. When the optimized conditions were applied, both mycelium and ergone production were significantly enhanced.

• 한국식품과학회지
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• 제38권2호
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• pp.256-261
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• 2006

20여종의 Monascus속의 균주로 부터 mevinolin의 생산능이 우수하면서도 곰팡이 독소성분 citrinin을 생산하지 않는 우량균주를 선발하였으며, 콩시료에 대한 고상발효를 최적화하기 위한 영양배지의 조성물이 검토되었다. 선발된 M. pilosus IFO 480으로 발효시킨 홍국콩 발효물에 함유된 mevinolin의 주요 화합물은, 약리학적 활성형(drug)의 mevinolinic acid 밝혀졌다(91.8%). 따라서 홍국 발효콩은 생체활성형의 항 콜레스테롤 성분을 최대 0.22% 까지 함유하는, 안전한 건강 기능성식품 소재로서의 활용가능성이 높은 것으로 평가할 수 있다.

• The Plant Pathology Journal
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• 제36권6호
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• pp.570-578
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• 2020

Rhizopus rot is a serious postharvest disease of various crops caused by Rhizopus spp. and controlled mainly by synthetic fungicides. We detected the antifungal activity of a culture extract of Setosphaeria rostrata F3736 against Rhizopus oryzae. The active ingredient was identified as moriniafungin, a known sordarin derivative, which showed minimum inhibitory concentrations of 1-8 ㎍/ml against Colletotrichum spp. and 0.03-0.13 ㎍/ml against Rhizopus spp. in vitro. Moriniafungin showed protective control efficacies against Rhizopus rot on apple and peach fruits. Treatment with 25 ㎍/ml moriniafungin delimited the lesion diameter significantly by 100% on R. oryzae-inoculated apple fruits compared with the non-treated control. Treatment with 0.04 ㎍/ml of moriniafungin reduced the lesion diameter significantly by 56.45%, and treatment with higher concentrations of 0.2-25 ㎍/ml reduced the lesion diameter by 70-90% on Rhizopus stolonifer var. stolonifer-inoculated peach fruit. These results suggest moriniafungin has potential as a control agent of postharvest diseases caused by Rhizopus spp.

• 한국분말재료학회지
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• 제27권6호
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• pp.458-463
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• 2020

Hispidin is a secondary metabolite found in numerous medicinal mushrooms that has attracted significant attention, owing to its distinct biological effects, including antioxidant, anti-inflammatory, antitumor, and cytoprotective properties. Experiments are being carried out to study the interaction of detonation nanodiamonds (DNDs) with synthetic and natural hispidin sourced from extracts of Pholiota sp. fungus. The bioluminescence method is used to determine the adsorption/desorption properties of DNDs toward hispidin. It is found that hispidin forms strong conjugates with DNDs, and the use of various eluents does not result in a significant release of the adsorbed hispidin molecules. DND-bovine serum albumin (BSA) complex, where DNDs serve as a carrier for the protein and the latter acts as a hispidin sorbent, has been developed and applied in hispidin adsorption/desorption tests. The results support the use of the DNDs as a carrier for hispidin in medical applications. They also advocate the application of the DND-BSA complex for isolating the substance from fungal extracts.

• The Plant Pathology Journal
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• 제37권4호
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• pp.389-395
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• 2021

Soil is the major source of plant-associated microbes. Several fungal and bacterial species live within plant tissues. Actinomycetes are well known for producing a variety of antibiotics, and they contribute to improving plant health. In our previous report, Streptomyces globisporus SP6C4 colonized plant tissues and was able to move to other tissues from the initially colonized ones. This strain has excellent antifungal and antibacterial activities and provides a suppressive effect upon various plant diseases. Here, we report the genome-wide analysis of antibiotic producing genes in S. globisporus SP6C4. A total of 15 secondary metabolite biosynthetic gene clusters were predicted using antiSMASH. We used the CRISPR/Cas9 mutagenesis system, and each biosynthetic gene was predicted via protein basic local alignment search tool (BLAST) and rapid annotation using subsystems technology (RAST) server. Three gene clusters were shown to exhibit antifungal or antibacterial activity, viz. cluster 16 (lasso peptide), cluster 17 (thiopeptide-lantipeptide), and cluster 20 (lantipeptide). The results of the current study showed that SP6C4 has a variety of antimicrobial activities, and this strain is beneficial in agriculture.

• Journal of Microbiology and Biotechnology
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• 제30권4호
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• pp.571-582
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• 2020

Quorum sensing (QS)-mediated infections cause severe diseases in human beings. The control of infectious diseases by inhibiting QS using antipathogenic drugs is a promising approach as antibiotics are proving inefficient in treating these diseases. Marine fungal (Pestalotiopsis sydowiana PPR) extract was found to possess effective antipathogenic characteristics. The minimum inhibitory concentration (MIC) of the fungal extract against test pathogen Pseudomonas aeruginosa PAO1 was 1,000 ㎍/ml. Sub-MIC concentrations (250 and 500 ㎍/ml) of fungal extract reduced QS-regulated virulence phenotypes such as the production of pyocyanin, chitinase, protease, elastase, and staphylolytic activity in P. aeruginosa PAO1 by 84.15%, 73.15%, 67.37%, 62.37%, and 33.65%, respectively. Moreover, it also reduced the production of exopolysaccharides (74.99%), rhamnolipids (68.01%), and alginate (54.98%), and inhibited the biofilm formation of the bacteria by 90.54%. In silico analysis revealed that the metabolite of P. sydowiana PPR binds to the bacterial QS receptor proteins (LasR and RhlR) similar to their respective natural signaling molecules. Cyclo(-Leu-Pro) (CLP) and 4-Hydroxyphenylacetamide (4-HPA) were identified as potent bioactive compounds among the metabolites of P. sydowiana PPR using in silico approaches. The MIC values of CLP and 4-HPA against P. aeruginosa PAO1 were determined as 250 and 125 ㎍/ml, respectively. All the antivirulence assays were conducted at sub-MIC concentrations of CLP (125 ㎍/ml) and 4-HPA (62.5 ㎍/ml), which resulted in marked reduction in all the investigated virulence factors. This was further supported by gene expression studies. The findings suggest that the metabolites of P. sydowiana PPR can be employed as promising QS inhibitors that target pathogenic bacteria.