Soytong, Kasem

Preferred name

Soytong, Kasem

Alternative Name

Soytong, K.

kasem.so@kmitl.ac.th

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Cytotoxic and antibacterial depsidones from the endophytic fungus Chaetomium brasiliense isolated from Thai rice
(2022-01-01)
Promgool, Trinop
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Kanokmedhakul, Kwanjai
;
Leewijit, Thianrat
;
Song, Jiaojiao
;
Soytong, Kasem
Four new depsidones, mollicellins V-Y (1-4), together with eight known depsidones (5-12) were isolated from the endophytic fungus, Chaetomium brasiliense, detached from stems of Thai rice. Their structures were determined by extensive spectroscopic methods. Mollicellins X, H, and F (3, 8 and 10) showed potent cytotoxicity against the human oral epidermoid carcinoma (KB) cell line, and mollicellin F (10) also showed a potent cytotoxicity against the human hepatocellular carcinoma (HepG2) cell line. Besides, mollicellin B (11) exhibited cytotoxicity against the colorectal adenocarcinoma (HT-29) cell line. Moreover, most of the isolated depsidones displayed potent antibacterial activity against Gram-positive bacteria, Bacillus cereus and Bacillus subtilis, and several of them showed moderate activity against Methicillin-resistant Staphylococcus aureus (MRSA) and clinical isolates of S. aureus. In addition, a few of them also showed moderate activity against a Gram-negative bacteria Pseudomonas aeruginosa.
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Chaetomium siamense sp. nov., a soil isolate from Thailand, produces a new chaetoviridin, G
(2011-01-01)
Pornsuriya, Chaninun
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Soytong, Kasem
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Poeaim, Supattar
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Kanokmedhakul, Somdej
;
Khumkomkhet, Primmala
Chaetomium siamense sp. nov., isolated from soil in a pineapple plantation in Thailand, is described and illustrated. The new species is similar to C. cupreum in having superficial globose or ovate ascomata with red circinate ascomatal hairs but can be distinguished by its fusiform ascospores with two apical germ pores. Phylogenetic analysis of ITS rDNA sequence data also supports C. siamense as distinct. Investigation of the secondary metabolites of C. siamense led to the isolation of one new (chaetoviridin G) and seven known compounds (ergosterol, 24(R)-5á,8á-epidioxyergosta-6-22-diene- 3â-ol, ergosterylplamitate, cochliodone D, chaetoviridin A, chaetoviridin F, chrysophanol). © 2011. Mycotaxon, Ltd.
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Elucidation of high micro-heterogeneity of an acidic-neutral trichotoxin mixture from Trichoderma harzianum by electrospray ionization quadrupole time-of-flight mass spectrometry
(2000-01-01)
Suwan, Sathorn
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Isobe, Minoru
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Kanokmedhakul, Somdej
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Lourit, Nuttaya
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Kanokmedhakul, Kwanjai
The high micro-heterogeneity of an acidic-neutral trichotoxin mixture from T. harzianum, PC01, was elucidated using a modern tandem mass spectrometer equipped with an electrospray ionization source, a hybrid quadrupole-orthogonal accelerator and a reflectron time-of-flight analyzer. The trichotoxins appeared predominantly in six possible doubly charged pseudo molecular ions with three different adducts (H, Na and K) as [M + 2H]2+, [M + H + Na]2+, [M + H + K]2+, [M + 2Na]2+, [M + Na + K]2+ and [M + 2K]2+. The singly charged pseudomolecular ions, [M + H]+, [M + Na]+ and [M + K]+, occurred only in low abundance when the cone voltages were higher than 30 V. Additional singly charged fragments, b<inf>12</inf> and y′6 (complementary N- and C-terminal fragments), were obtained in high abundance using high cone voltages. The peak patterns of both singly and doubly charged molecular adducts revealed that this trichotoxin mixture contained several components having 6-7 molecular masses with a consecutive 14 u difference among members in the same molecular adduct series. Furthermore, well resolved isotopic peaks of every doubly or singly charged ions and their reproducible peak intensity allowed the identification of the mixing of acidic trichotoxins 1 u molecular mass heavier than the neutral counterparts in the sample. Tandem mass spectrometric (MS/MS) analyses of various singly charged b<inf>12</inf> and y′6 ions supported the sequence deduction of the major and minor components and also the position of Glu in the sequences of these acidic molecules. The setting of either low or high resolution of the quadrupole mass filter unit together with a suitable variation of the collision voltage for any MS/MS precursor were the tools for extracting a number of mixed components and obtaining the major and minor sequences of these precursor peaks. The nature of the MS/MS fragmentation and the data assignment of three major doubly charged ions, [M + 2H]2+, [M + K + H]2+ and [M + 2K]2+, are demonstrated. Eleven new sequences of both acidic and neutral trichotoxins are reported. Copyright © 2000 John Wiley & Sons, Ltd.
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Antifungal activity of microbial nanoparticles derived from Chaetomium spp. against Magnaporthe oryzae causing rice blast
(2020-01-01)
Song, Jiao Jiao
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Soytong, Kasem
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Kanokmedhakul, Somdej
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Kanokmedhakul, Kwanjai
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Poeaim, Supattra
The Magnaporthe oryzae isolate PO2 was proven to cause rice blast var. PSL 2 in this study. Chaetomium elatum, Chaetomium lucknowense and Chaetomium brasiliense were antagonised to M. oryzae. The hexane extract of C. brasiliense gave the highest inhibition of the spore production with an ED<inf>50</inf> of 35 ppm, the EtOAC extract of C. lucknowense inhibited the spore production at 57 ppm and the EtOAC extracts of C. elatum inhibited the spore production at 106 ppm. The nano-CLM (C. lucknowense) inhibited the spore production at 5.24 ppm, the nano-CBH (C. brasiliense) inhibited the spore production at 6.86 ppm and the nano-CEE (C. elatum) inhibited the spore production at 7.89 ppm. The rice leaves treated with nano-CBH from C. brasiliense produced Sakuranertin and Oryzalexin B as seen on the thin layer chromatography where the Rf value was 0.08 assumed to be Sakuranertin, and the R<inf>f</inf> value of 0.28 supposed to be Oryzalexin B. It was found that the nanoparticles act as elicitors to induce immunity in rice plants through the production of phytoalexin.
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A bioactive triterpenoid and vulpinic acid derivatives from the mushroom Scleroderma citrinum
(2003-06-01)
Kanokmedhakul, Somdej
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Kanokmedhakul, Kwanjai
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Prajuabsuk, Thirada
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Soytong, Kasem
;
Kongsaeree, Palangpon
A new lanostane-type triterpenoid, (20S,22S,23E)-22-O-acetyl-25-hydroxylanosta-8,23(E)-dien-3-one (1), isolated as a new natural product for the first time, methyl 4,4′-dimethoxyvulpinate (2), together with the known compound 4,4′-dimethoxyvulpinic acid (3) were isolated from the mushroom Scleroderma citrinum. Their structures were determined using spectroscopic and chemical methods, and an X-ray analysis was performed to confirm structure of 1. Compound 1 exhibited significant antiviral activity against Herpes simplex type 1. Compound 3 and two of its derivatives, the dibromo derivative 5 and acetate derivative 6, exhibited activity towards Mycobacterium tuberculosis. In addition, 5 and 6 also showed cytotoxicity against the NCI-H187 cell line.
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A new xanthone from the fungus Apiospora montagnei
(2017-01-01)
Arthan, Supakorn
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Tantapakul, Cholpisut
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Kanokmedhakul, Kwanjai
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Soytong, Kasem
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Kanokmedhakul, Somdej
A new xanthone derivative, methyl 8-hydroxy-3-hydroxymethylxanthone-1-carboxylate (1), and seven known compounds, 8-hydroxy-3-methylxanthone-1-carboxylate (2), methyl 8-hydroxy-6-methylxanthone-1-carboxylate (3), ergosterol (4), cyathisterone (5), ergosta-4,6,8(14),22-tetraen-3-one (6), calvasterone (7) and 2-hexyl-3-methylmaleic anhydride (8) were first isolated from the fungus Apiospora montagnei. Their structures were elucidated on the basis of spectroscopic analysis (UV, IR, MS, 1D, and 2D NMR). Compounds 5 and 6 showed weak to very weak cytotoxicity against cancer cell lines, NCI-H187 and KB.
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Microbial elicitors to induce immunity for plant disease control in chilli and tomato
(2014-03-01)
Soytong, Kasem
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Kanokmedhakul, Somdej
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Rattanacherdchai, Kanchalika
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Charoenporn, Chamaiporn
The induced immunity in long cayenne pepper in terms of phytoalexin production using microbial elicitors as chaetoglobosin C from Chaetomium globosum, chaetomanone A from Chaetomium lucknowense, and trichotoxin A50 from Trichoderma harzianum PC01 was investigated in pot experiments. Stem inoculation of chilli plants with Colletotrichum capsici isolate C208 resulted in necrosis and accumulation of capsidiol, a phytoalexin. Stem inoculation of chilli plants resulted in different degrees of sensitivity to C. capsici, expressed as necrosis along the stems. The microbial elicitors chaetoglobosin C, chaetomanone A, and trichotoxin A50 induced an immunity response against C. capsici. Qualitative analysis of capsidiol accumulation in the upper part of the chilli plant was detected by thin-layer chromatography and showed that capsidiol had accumulated in the chilli plant at 5 and 10 days after treatment with the microbial elicitors, whereas no capsidiol was detected in the noninoculated and untreated plants. Chilli cultivation of long cayenne pepper in vivo was conducted by spraying chaetoglobosin C, chaetomanone A, and trichotoxin A50, and the findings were compared with cultivation using a chemical fungicide (difenoconazole). The results showed that application of each microbial elicitor reduced disease incidence by 42-55 % when compared with an inoculated control, whereas difenoconazole reduced disease incidence by 33 %. Additionally, the yield increased by 47-55 % when compared with the yield for the inoculated control. Chilli cultivation of long cayenne pepper in vivo using the biological fungicides Bio-CG from C. globosum N0802, Bio-CLT from C. lucknowense CLT, and Bio-T from T. harzianum PC01 resulted in reduction of disease incidence by 39-55 % when compared with the inoculated control, whereas difenoconazole reduced disease incidence by 33 %. Moreover, treatment with Bio-CG, Bio-CLT, and Bio-T increased the yield by 39-53 % when compared with yield for the inoculated control. Moreover, the bioactive compounds chaetoglobosin C, chaetomanone A, and trichotoxin A50 were used as microbial elicitors to elicit α-tomatine in tomato. α-Tomatine was detected by high-performance liquid chromatography after treatment with the bioactive compounds. Chaetoglobosin C, chaetomanone A, and trichotoxin A50 were sprayed onto inoculated tomato seedling variety Sida inoculated with Fusarium oxysporum f. sp. lycopersici NKSC01, and plant disease immunity and quantity of α-tomatine were assessed. The results revealed that plant disease immunity of tomato seedlings treated with chaetoglobosin C, chaetomanone A, and trichotoxin A50 at a concentration of 50 μg/ml after 10 days was 44.97, 35.18, and 39.43 %, respectively, whereas tomato seedlings treated with prochloraz that showed plant disease immunity of 29.95 %. The stems and leaves of tomato were extracted and spotted on thin-layer chromatography paper and produced a green spot with a retention factor of 0.23, the same as for a spot of standard α-tomatine. Tomato extracts were analyzed for α-tomatine by high-performance liquid chromatography. The α-tomatine quantification data were analyzed using a linear regression curve. Tomato treated with chaetoglobosin C, chaetomanone A, and trichotoxin A50 at 15 days expressed α-tomatine at levels of 207.87, 254.25, and 205.04 μg/g, levels which are significantly higher than those resulting from prochloraz and inoculation treatments, for which the quantities of α-tomatine were 131.56 and 77.46 μg/g, respectively. It is shown that the induction of α-tomatine by chaetoglobosin C, chaetomanone A, and trichotoxin A50 in tomato plants implies disease immunity against fusarium wilt of tomato variety Sida through phytoalexin production. The bioactive compounds were tested for their efficacies to control tomato wilt in vivo. The results revealed that all the bioactive compounds at concentrations of 10, 50, and 100 μg/ml could induce plant disease immunity in tomato between 53.80 and 65.15 %, which is significantly higher than the plant disease immunity induced by prochloraz, which was 26.73 %.
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Meroditerpene pyrone, tryptoquivaline and brasiliamide derivatives from the fungus Neosartorya pseudofischeri
(2019-09-01)
Paluka, Jakkapat
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Kanokmedhakul, Kwanjai
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Soytong, Mayamor
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Soytong, Kasem
;
Kanokmedhakul, Somdej
Two new meroditerpene pyrones, chevalone F (1) and 11-hydroxychevalone E (2), a new tryptoquivaline analog, tryptoquivaline V (3) and a new brasiliamide analog, brasiliamide G (4), together with thirteen known compounds, chevalones A-C (5–7), chevalone E (8), 11-hydroxychevalone C (9), pyripyropene A (10), isochaetominine C (11), pyrrolobenzoxazine terpenoids CJ-12662 (12) and CJ-12663 (13), fischerindoline (14), eurochevalierine (15), 1,4-diacetyl-2,5-dibenzylpiperazine-3,7′′-oxide (16) and lecanorin (17) were isolated from the fungus Neosartorya pseudofischeri. Their structures were established on the basis of spectroscopic evidence. Compound 2 showed weak antibacterial activity against Escherichia coli and Salmonella enterica serovar Typhimurium, whereas compounds 7, 12, 13 and 15 showed antibacterial activity against Bacillus cereus and Staphylococcus aureus. In addition, compounds 13 and 14 showed cytotoxicity against KB and MCF-7 cancer cell lines, as well as the Vero cell line.
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Antimycobacterial anthraquinone-chromanone compound and diketopiperazine alkaloid from the fungus Chaetomium globosum KMITL-N0802
(2002-09-01)
Kanokmedhakul, Somdej
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Kanokmedhakul, Kwanjai
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Phonkerd, Nutchanat
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Soytong, Kasem
;
Kongsaeree, Palangpon
Investigation of the fungus Chaetomium globosum KMITL-N0802 led to the isolation of a novel anthraquinone-chromanone compound named chaetomanone along with seven known compounds, ergosterol, ergosteryl palmitate, chrysophanol, chaetoglobosin C, alternariol monomethyl ether, echinuline and isochaetoglobosin D. These compounds were characterized by spectroscopic methods. Chaetomanone and echinulin exhibited activity towards Mycobacterium tuberculosis.
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A new benzyl ester and ergosterol derivatives from the fungus Gymnoascus reessii
(2014-01-01)
Kitchawalit, Sasiwimon
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Kanokmedhakul, Kwanjai
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Kanokmedhakul, Somdej
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Soytong, Kasem
A new benzyl ester, reessiate (1), anthraquinone, islandicin (2), ergosterol and seven ergosterol derivatives (3-9) were isolated from the fungus Gymnoascus reessii. All structures were identified by spectroscopic methods. This is the first report of their isolation from this fungus. Compounds 4-7 and 9 exhibited antimalarial activity against Plasmodium falciparum with IC <inf>50</inf> values in the range of 3.3-4.5 μg/mL. In addition, 4 showed cytotoxicity against KB, MCF7 and NCI-H187 cancer cell lines. It was found that 4 has cytotoxic effect to MCF7 (IC<inf>50</inf> = 7.9 μg/mL) lower than Doxorubicin (IC<inf>50</inf> = 8.5 μg/mL). © 2014 Taylor & Francis.

Soytong, Kasem

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