• Microbiology and Biotechnology Letters
• /
• v.23 no.1
• /
• pp.98-103
• /
• 1995

During the screening of antifungal antibiotics from microbial metabolites, we selected Pseudomonas aeruginosa KGM-100 showing powerful antagonistic activity against various phytopathogenic fungi. Antibiotics KGM-100A and KGM-100B were purified from the culture broth of Pseudomonas aeruginosa KGM-100 by diaion HP-20 column chromatography, ethyl acetate extraction, silica gel column chromatography, preparative TLC and recrystallization. KGM-100A which was recrystallized in MeOH showed antimicrobial activities against a broad spectrum of fungi and bacteria. Physico-chemical properties of KGM-100A were determined and identified to be phenazine-l-carboxylic acid by UV, IR, $^{1}$H-NMR, $^{13}$C-NMR, mass spectrum, and elemental analyses.

• Microbiology and Biotechnology Letters
• /
• v.23 no.2
• /
• pp.209-213
• /
• 1995

During the screening of inhibitors of melanin biosynthesis from microbial secondary metabolites, a fungal strain MR-93 which was capable of producing high level of an inhibitor was selected from plant leaf. Based on taxonomic studies, the fungus could be classified as a strain of Trichoderma sp.. The active compound (MR-93D) was purified from the culture broth by Diaion HP-20 column chromatography, ethylacetate extraction, Sephadex LH-20 column chromatography and HPLC. The inhibitor was identified as 4-hydroxy-8-isocyano-l-oxaspiro[4-4]cyclonon-8-en-2- one by spectroscopic methods of UV, $^{1}$H-NMR, ESIMS and IR. MR-93D showed a strong tyrosinase inhibitory activity with 0.03 $\mu$g/m of IC$_{50}$ value. It also inhibited melanin biosynthesis with 35 mm inhibition zone at 30 $\mu$g/paper disc in Streptomyces bikiniensis, a bacterium used as an indicator organism in this work.

• Proceedings of the PSK Conference
• /
• 2002.10a
• /
• pp.335.3-336
• /
• 2002

To find ${\alpha}$-Glucosidase Inhibitors produced by Actinomycetes, 20 soil samples were tested and 53 Actimycetes were isolated. One of 53 Actinomycetes (strain PM718) showed very potent inhibitory activity in vitro. The morphological and physiological characteristics of strain PM 718 were investigated. The spore morphology. spore chain morphology and spore surface were observed by scanning electron microscope. The inhibitory activity of strain PM718 in vivo has been studied in mice made hyperglycemia by Streptozotocin treatment. The strain PM718 showed signficant reduction of blood glucose level(more than 30%) in mice loaded with maltose.

• Asian-Australasian Journal of Animal Sciences
• /
• v.3 no.1
• /
• pp.27-31
• /
• 1990

Influences of plant phenolic acids and their possible metabolites(non-phenolic aromatic acids involved) in the rumen on the cellulolytic activity of mixed rumen populations were examined by a simple in vitro culture technique. Initial concentrations of aromatic acids were 1, 5, 10 and 20 mM/l. All the tested aromatic acids reduced microbial cellulose digestion especially at the higher initial concentration. P-Coumaric acid, ferulic acid and cinnamic acid, those having unhydrogenated propenoic side chain were more inhibitory than were 3-phenylpropinic acid and phloretic acid, those having hydrogenated propanoic side chain. Lag-time for cellulose digestion was prolonged by former three acids by 16 h. Apparent reduction in p-coumaric acid concentration was observed at 24 h when cellulose digestion began. Volatile fatty acid productions from cellulose fermentation were shifted by former three aromatic acids to produce more acetate and less propionate. This suggests that the selection of celluloytic organisms was induced by these aromatic acids.

• Journal of Microbiology
• /
• v.39 no.4
• /
• pp.254-264
• /
• 2001

Sponges are host organisms for various symbiotic microorganisms such as archaea, bacteria, cyano-bacteria and microalgae. Sponges are also sources of a wide variety of useful natural products like cyto-toxins. antifouling agents, antibiotics, and anti-inflammatory and antiviral compounds, Symbiotic microorganisms is sponges can be sources of various natural products, because metabolites previously ascribed to sponges have recently been demonstrated to be biosynthesized by symbionts. If a symbiotic microorganisms from which some natural products are derived can be cultured, the microorganism could be used in a mass production of the bioactive comopounds. We summarize recent research on iso-lation and cultivation of sponge-symbiotic microorganisms and the symbiotic relationship.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.6
• /
• pp.814-817
• /
• 2012

In the continued search for melanogenesis inhibitors from microbial metabolites, we found that the culture broth of Clitocybe sp. MKACC 53267 inhibited melanogenesis in B16F10 melanoma cells. The active component was purified by solvent extraction, silica gel chromatography, Sephadex LH-20 column chromatography, and finally by preparative HPLC. Its structure was determined as 5-pentyl-2-furaldehyde on the basis of the UV, NMR, and MS spectroscopic analysis. The 5-pentyl-2-furaldehyde potently inhibited melanogenesis in B16F10 cells with an $IC_{50}$ value of 8.4 ${\mu}g/ml$, without cytotoxicity.

• The Plant Pathology Journal
• /
• v.38 no.2
• /
• pp.53-77
• /
• 2022

The global nematicides market is expected to continue growing. With an increasing demand for synthetic chemical-free organic foods, botanical nematicides are taking the lead as replacements. Consequently, in the recent years, there have been vigorous efforts towards identification of the active secondary metabolites from various plants. These include mostly glucosinolates and their hydrolysis products such as isothiocyanates; flavonoids, alkaloids, limonoids, quassinoids, saponins, and the more recently probed essential oils, among others. And despite their overwhelming potential, variabilities in quality, efficacy, potency and composition continue to persist, and commercialization of new botanical nematicides is still lagging. Herein, we have reviewed the history of botanical nematicides and regional progresses, the potency of the identified phytochemicals from the key important plant families, and deciphered some of the impediments involved in standardization of the active compounds in addition to the concerns over the safety of the purified compounds to non-target microbial communities.

• Biomolecules & Therapeutics
• /
• v.17 no.4
• /
• pp.430-437
• /
• 2009

Metabolites of Soyasaponin I, a major constituent of soybean, by human intestinal microflora were investigated by LC-MS/MS analysis. We found four peaks, one parental constituent and three metabolites: m/z 941 [M-H]$^-$, m/z 795 [M-rha-H]$^-$, m/z 441 [aglycone-$H_2O$+H]$^+$, and m/z 633 [M-rha-gal-H]$^-$, which was an unknown metabolite, soyasapogenol B 3-$\beta$-D-glucuronide. When soyasaponin I was incubated with the human fecal microbial fraction from ten individuals for 48 h, soyasaponin I was metabolized to soyasapogenol B via soyasaponin III and soyasapogenol B 3-$\beta$-D-glucuronide or via soyasaponin III alone. Both soyasaponin I and its metabolite soyasapgenol B exhibited estrogenic activity. Soyasaponin I increased the proliferation, mRNA expression of c-fos and pS2, in MCF7 cells more potently than soyasapogenol B. However, soyasapogenol B showed potent cytotoxicity against A549, MCF7, HeLa and HepG2 cells, while soyasaponin I did not. The cytotoxicity of soyasapogenol B may prevent its estrogenic effect from increasing dose-dependently. These findings suggest that orally administered soyasaponin I may be metabolized to soyasapogenol B by intestinal microflora and that soyasapogenol B may express a cytotoxic effect rather than an estrogenic effect.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.4
• /
• pp.465-474
• /
• 2010

The effects of four types of tropical protein-rich trees on nutrient digestibility, nitrogen (N) balance, urinary purine derivative (PD) excretion and blood metabolites in four Thai Brahman cattle (290${\pm}$2.5 kg) were studied. The animals were fed twice daily, with each feeding consisting of 1 kg (fresh weight) rice straw and one of the four dietary supplements: i) 1.98 kg oven-dried rain tree pods (RTP) and 20 g premix (RTPP), ii) 980 g RTP and 1 kg sun-dried leucaena leaves and 20 g premix (LLRT), iii) 980 g RTP and 1 kg sun-dried cassia leaves and 20 g premix (CLRT) and iv) 980 g RTP and 1 kg sun-dried mulberry leaves and 20 g premix (MLRT). The apparent dry matter (DM) and organic matter (OM) digestibilities were higher (p<0.05) in cattle fed the CLRT supplement than in those fed the other supplements, whilst the apparent digestibility of neutral detergent fibre (NDF) was higher (p<0.05) in cattle fed the CLRT and MLRT supplements than in those fed the other supplements. The N-balance of cattle fed LLRT and CLRT supplements was higher (p<0.05) than in cattle fed RTPP and MLRT supplements, whilst the apparent digestibility of N was highest (p<0.05) in cattle fed RTPP supplement, compared to the other supplements. Allantoin and PD excretion in the urine, and the ratios of allantoin/DOMI and PD/DOMI were higher (p<0.05) in cattle fed RTPP and MLRT than for those fed LLRT and CLRT supplements. Plasma ${\beta}$-hydroxy butyrate (${\beta}$-HBA) and insulin concentrations were higher (p<0.05) in cattle fed RTPP supplement than in those fed the other supplements. The study demonstrated the value of using local multipurpose trees (MPTs) to improve Brahman cattle feeding systems in the tropics.

• Applied Biological Chemistry
• /
• v.21 no.3
• /
• pp.197-203
• /
• 1978

In order to investigate mechanisms related to the microbial degradation of 3,4-dichloroaniline, it was incubated with a soil fungus, Chaetomium globosum and the following results were obtained. (1) 3,4-Dichloroacetanilide turned out to be the major metabolite, indicating that acetylation is the major scheme. (2) The presence of trace amounts of 3,4-dichloronitrobenzene, 3,3', 4,4'-tetrachloroazo-benzene, 3,4-dichloroaniline is suggestive of the aromatic amine oxidation as the minor pathway. (3) Other metabolites with m/e 112, 114, and 279 were also isolated, but their identities are under investigation. (4) Dechlorination occurring during incubation indicates the possibility of forming hydroxylated and other metabolites.