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Masahiko Isaka - One of the best experts on this subject based on the ideXlab platform.
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isariotins g j from cultures of the lepidoptera pathogenic fungus Isaria tenuipes
Phytochemistry Letters, 2011Co-Authors: Taridaporn Bunyapaiboonsri, Jennifer J Luangsaard, Nigel L Hyweljones, Seangaroon Yoiprommarat, Urarat Srisanoh, Wilunda Choowong, Kanoksri Tasanathai, Masahiko IsakaAbstract:Four new alkaloids isariotins G–J (1–4), together with the known isariotins, were isolated from cultures of the Lepidoptera pathogenic fungus Isaria tenuipes. The structures were elucidated on the basis of NMR spectroscopic and mass spectrometry data. Compounds 1–4 exhibited antimalarial and cytotoxic activities.
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Isariotins G–J from cultures of the Lepidoptera pathogenic fungus Isaria tenuipes
Phytochemistry Letters, 2011Co-Authors: Taridaporn Bunyapaiboonsri, J Jennifer Luangsa-ard, Nigel L Hywel-jones, Seangaroon Yoiprommarat, Urarat Srisanoh, Wilunda Choowong, Kanoksri Tasanathai, Masahiko IsakaAbstract:Four new alkaloids isariotins G–J (1–4), together with the known isariotins, were isolated from cultures of the Lepidoptera pathogenic fungus Isaria tenuipes. The structures were elucidated on the basis of NMR spectroscopic and mass spectrometry data. Compounds 1–4 exhibited antimalarial and cytotoxic activities.
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a beauvericin hot spot in the genus Isaria
Fungal Biology, 2009Co-Authors: Jennifer J Luangsaard, Pitchapa Berkaew, Rungpet Ridkaew, Nigel L Hyweljones, Masahiko IsakaAbstract:Beauvericin is a naturally occurring cyclohexadepsipeptide originally described from Beauveria bassiana but also reported from several Fusarium species as well as members of the genus Isaria. Twenty-six isolates of Isaria species and its Cordyceps teleomorph, and ten taxonomically close strains including Beauveria, Nomuraea and Paecilomyces species were sequenced and tested for beauvericin production. Trees using ITS rDNA and β-tubulin sequence data were constructed and used to infer the phylogenetic distribution of beauvericin production. A group comprising Isaria tenuipes and its known teleomorph Cordyceps takaomontana, Isaria cicadae and its Cordyceps teleomorph, Isaria japonica and Isaria fumosorosea, showed positive beauvericin production which correlated well with combined ITS rDNA and β-tubulin phylogenies. The results suggested that beauvericin can serve as a chemotaxonomic marker for these limited species of the I. tenuipes complex.
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A beauvericin hot spot in the genus Isaria.
Mycological research, 2009Co-Authors: J Jennifer Luangsa-ard, Pitchapa Berkaew, Rungpet Ridkaew, Nigel L Hywel-jones, Masahiko IsakaAbstract:Beauvericin is a naturally occurring cyclohexadepsipeptide originally described from Beauveria bassiana but also reported from several Fusarium species as well as members of the genus Isaria. Twenty-six isolates of Isaria species and its Cordyceps teleomorph, and ten taxonomically close strains including Beauveria, Nomuraea and Paecilomyces species were sequenced and tested for beauvericin production. Trees using ITS rDNA and beta-tubulin sequence data were constructed and used to infer the phylogenetic distribution of beauvericin production. A group comprising Isaria tenuipes and its known teleomorph Cordyceps takaomontana, Isaria cicadae and its Cordyceps teleomorph, Isaria japonica and Isaria fumosorosea, showed positive beauvericin production which correlated well with combined ITS rDNA and beta-tubulin phylogenies. The results suggested that beauvericin can serve as a chemotaxonomic marker for these limited species of the I. tenuipes complex.
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isariotins e and f spirocyclic and bicyclic hemiacetals from the entomopathogenic fungus Isaria tenuipes bcc 12625
Journal of Natural Products, 2009Co-Authors: Taridaporn Bunyapaiboonsri, Nigel L Hyweljones, Seangaroon Yoiprommarat, Kamolphan Intereya, Pranee Rachtawee, Masahiko IsakaAbstract:New spirocyclic and bicyclic hemiacetals, isariotins E (1) and F (2), together with TK-57-164A (3) were isolated from the entomopathogenic fungus Isaria tenuipes BCC 12625. The absolute configuration of 3 was addressed by application of the modified Mosher’s method. Isariotin F (2) exhibited activity against the malaria parasite Plasmodium falciparum K1 with an IC50 value of 5.1 μM and cytotoxic activities against cancer cell lines (KB, BC, and NCI-H187) and nonmalignant (Vero) cells with respective IC50 values of 15.8, 2.4, 1.6, and 2.9 μM.
Qiongbo Hu - One of the best experts on this subject based on the ideXlab platform.
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Diversity and virulence of soil-dwelling fungi Isaria spp. and Paecilomyces spp. against Solenopsis invicta (Hymenoptera: Formicidae)
Biocontrol Science and Technology, 2020Co-Authors: Qiongbo Hu, Guohua ZhongAbstract:Abstract To comprehend the diversity and potential control of soil-dwelling fungi, Isaria and Paecilomyces, against the red imported fire ant Solenopsis invicta (Hymenoptera, Formicidae), an investigation was carried out between 2004 and 2008. From 258 soil samples collected from 16 central and southern provinces and cities in China, a total of 171 isolates of the genra Isaria and Paecilomyce were isolated, and the species I. javanicus, P. marquandii and I. fumosoroseus were found more abundant than I. cateniobliquus, P. carneus, P. inflatus and P. lilacinus. Geographic differences of isolating rates were observed as well. Samples from the southern areas had higher fungal isolating rates than those from the central areas. Subsequently, 47 isolates were further tested for pathogencity against the red imported fire ant. All isolates except P115 showed certain pathogenic potential (the mean is 52.3% at 4000 conidiospores/mL) to the ant. I. javanicus was the most effective species with a mean pathogenicity of...
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secondary metabolites and the risks of Isaria fumosorosea and Isaria farinosa
Molecules, 2019Co-Authors: Qunfang Weng, Xiaofeng Zhang, Wei Chen, Qiongbo HuAbstract:Isaria fumosorosea and Isaria farinosa are important entomopathogenic fungi with a worldwide distribution and multiple host insects. However, the concerns about the safety risks of myco-pesticides have been attracting the attention of researchers and consumers. Secondary metabolites (SMs), especially the mycotoxins, closely affect the biosafety of Isaria myco-insecticides. In the last forty years, more than seventy SMs were identified and isolated from I. fumosorosea and I. farinose. The SMs of I. fumosorosea include the mycotoxins of non-ribosomal peptides (NRPs) (beauvericin and beauverolides), terpenes (trichocaranes and fumosorinone), lactone compounds (cepharosporolides), acids (dipicolinic acid and oxalic acid), etc. Meanwhile, the NRP mycotoxins (cycloaspeptides) and the terpene compounds (farinosones and militarinones) are the main SMs in I. farinosa. Although several researches reported the two Isaria have promised biosafety, the bioactivities and the safety risks of their SMs have not been studied in detail so far. However, based on existing knowledge, most SMs (i.e., mycotoxins) do not come from Isaria myco-insecticide itself, but are from the host insects infected by Isaria fungi, because only the hosts can provide the conditions for fungal proliferation. Furthermore, the SMs from Isaria fungi have a very limited possibility of entering into environments because many SMs are decomposed in insect cadavers. The biosafety of Isaria myco-insecticides and their SMs/mycotoxins are being monitored. Of course, SMs safety risks of Isaria myco-insecticides need further research.
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Secondary metabolites (SMs) of Isaria cicadae and Isaria tenuipes
RSC Advances, 2018Co-Authors: Xiaofeng Zhang, Qiongbo Hu, Qunfang WengAbstract:Both Isaria cicadae and Isaria tenuipes are important entomopathogenic fungi used in health foods and traditional herbal medicines in East Asia. However, the safety concerns for both fungal species have been attracting significant attention. Thus, surveying their secondary metabolites (SMs) will be beneficial to improving the safety of their fungal products. In the case of I. cicadae, its SMs mainly include nucleosides, amino acids, beauvericins, myriocin, and oosporein. In contrast, trichothecene derivatives, isariotins, cyclopenta benzopyrans and PKs, are found in the case of I. tenuipes. Among them, beauvericins, myriocin, oosporein and many trichothecene derivatives are toxic compounds. The toxicity and side effects of the fungal products may be related to these SMs. Thus, to ensure the safety of fungal products, the residues standards of SMs need to be reported. Furthermore, methods for the detection of their SMs and biological identification of their strains must be considered. This review gives new insight into the secondary metabolites of medical and edible fungi.
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expression of dsrna in recombinant Isaria fumosorosea strain targets the tlr7 gene in bemisia tabaci
BMC Biotechnology, 2015Co-Authors: Xiurun Chen, Qiongbo Hu, Bowen Zhang, Lin Li, Wei Wu, Junxi JiangAbstract:Background RNA interference (RNAi) technology shows a great potential in controlling agricultural pests, despite the difficulty of introducing exogenous dsRNA/siRNA into target pests. Isaria fumosorosea is a common fungal pathogen of the B-biotype Bemisia tabaci (whitefly), which is a widespread pest. Entomopathogenic fungi directly penetrate the cuticle and invade insect hemocoel. Application of I. fumosorosea expressing dsRNA of whitefly immunity-related gene may aid in developing RNAi technology to effectively control whiteflies.
Walker A. Jones - One of the best experts on this subject based on the ideXlab platform.
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Isaria poprawskii sp nov hypocreales cordycipitaceae a new entomopathogenic fungus from texas affecting sweet potato whitefly
Mycoscience, 2013Co-Authors: Enrique H Cabanillas, Richard A Humber, Jesse H De Leon, Daniel K Murray, Walker A. JonesAbstract:Abstract Isaria poprawskii is described as a new entomopathogenic species similar to Isaria javanica (= Paecilomyces javanicus ). It was discovered on the sweet potato whitefly, Bemisia tabaci biotype B in the Lower Rio Grande Valley of Texas (LRGV), USA. Morphological and DNA examinations indicated the distinctness of I. poprawskii from the ex-type isolate of I . javanica. I. poprawskii produced light yellow young colonies to darker yellow with a grayish-violet center to a taupe or a brownish-gray mature conidial mass; conidia hyaline, one-celled, 3.9 (2.9–4.6) μm long × 1.6 (1.4–2.1) μm wide; colored synnemata, but I. javanica ex-type produced white colony, hyaline conidia and no synnemata. A phylogenetic position of I. poprawskii was inferred by a nucleotide sequence analysis of β-tubulin along with standard β-tubulin sequences from GenBank. Fifteen unsequenced isolates, including eight from the LRGV, were investigated. The analysis confirmed that I . poprawskii could be recovered from LRGV fields, and that both I. javanica and I. poprawskii are present in the LRGV in sympatry. I. poprawskii was shown to be closely related to I. javanica ; however, it formed its own unique clade, thus confirming its status as a new fungal species.
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pathogenicity of Isaria sp hypocreales clavicipitaceae against the sweet potato whitefly b biotype bemisia tabaci hemiptera aleyrodidae
Crop Protection, 2009Co-Authors: Enrique H Cabanillas, Walker A. JonesAbstract:Abstract The pathogenicity of a naturally occurring entomopathogenic fungus, Isaria sp., found during natural epizootics on whiteflies in the Lower Rio Grande Valley of Texas, against the sweet potato whitefly, Bemisia tabaci (Gennadius) biotype B, was tested under laboratory conditions (27 °C, 70% RH and a photoperiod of 14:10 h light:dark). Exposure of second-, third- and fourth-instar nymphs to 20, 200, and 1000 spores/mm 2 , on sweet potato leaves resulted in insect mortality. Median lethal concentrations for second-instar nymphs (72–118 spores/mm 2 ) were similar to those for third-instar nymphs (101–170 spores/mm 2 ), which were significantly more susceptible than fourth-instar nymphs (166–295 spores/mm 2 ). The mean time to death was less for second instars (3 days) than for third instars (4 days) when exposed to 1000 spores/mm 2 . Mycosis in adult whiteflies became evident after delayed infections of sweet potato whitefly caused by this fungus. These results indicate that Isaria sp. is pathogenic to B. tabaci nymphs, and to adults through delayed infections caused by this fungus. Its low lethal concentrations and high virulence against B. tabaci make this fungus a promising biocontrol agent to control whitefly.
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Effects of Temperature and Culture Media on Vegetative Growth of an Entomopathogenic Fungus Isaria sp. (Hypocreales: Clavicipitaceae) Naturally Affecting the Whitefly, Bemisia tabaci in Texas
Mycopathologia, 2009Co-Authors: H. Enrique Cabanillas, Walker A. JonesAbstract:The effects of temperature and mycological media on mycelial growth and estimates of spore production of an indigenous entomopathogenic fungus, Isaria sp., found during natural epizootics on whiteflies in the Lower Rio Grande Valley of Texas, were investigated. The radial growth (mm/day) of Isaria sp. as a function of temperature fits a linear model; with faster growth on Sabouraud dextrose agar with yeast extract, SDAY slopes (0.23) than on Sabouraud maltose agar, SMA slopes (0.14) from 20 to 30°C, with an optimal temperature of 30°C (SDAY: 4.1 mm, SMA: 3.1 mm). Moderate growth occurred at 25°C (SDAY: 3.4 mm, SMA: 2.7 mm). Growth was lowest at 20°C (SDAY: 1.9 mm, SMA: 1.8 mm). No fungal growth was observed at 35°C and 40°C. However, when Isaria sp. was exposed to 35°C for the first 7 days, it could recover and grow when transferred to 25°C (SDAY: 3.5 mm, SMA: 2.8 mm). No recovery or growth occurred after transfer from 40°C to 25°C. The average conidial production on SDAY after 20 days incubation at 25°C and a photoperiod of 14:10 h light: dark was 1.2 × 10^8 conidia/cm^2 with 100% spore viability. When compared on SDAY at 25°C, the radial growth rate of I. javanica ex type CBS 134.22 (5.1 mm/day) was greater than seven Isaria isolates including Isaria sp.; but maximum growth rates were similar among all related Isaria isolates (90–97%). The Isaria sp. fungus tolerates high temperatures (35°C), suggesting that it is naturally selected for the subtropical semi-arid environment, where it could serve as an important natural control agent of the sweet potato whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) biotype B, one of the most invasive and economically damaging insects to agriculture.
Conchita Toriello - One of the best experts on this subject based on the ideXlab platform.
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RESEARCH ARTICLE An Isaria fumosorosea SCAR marker for evaluation of soil, insect, and airborne samples
2020Co-Authors: Teresa Mier, Conchita Toriello, T. Robledo-retana, Departamento El HombreAbstract:Molecular detection markers are needed for ecological studies of entomopathogenic fungi. In this study, a sequence-characterized amplified region (SCAR) marker of Isaria fumosorosea was used to detect the fungus in soil, insects, and airborne samples. These were artificially added with different fungal conidial concentrations. Specificity and sensitivity were tested with semi-nested PCR using oligonucleotides E-AA/M-CTA124 F and E-AA/M-CTA124 R for the first amplification and E-AA/M-CTA124 F and E-AA/M-CTA103 R for the second amplification. Specificity assays showed a specific band of 103 bp for DNA samples from 10 I. fumosorosea strains used. Negative results were observed for DNA samples from other species of Isaria, including I. amoene-rosea, I. farinosa, and Paecilomyces carneus as well as with other entomopathogens such as Metarhizium acridum, M. anisopliae, M. majus, M. flavoviride Type E, and Lecanicillium lecanii. Sensitivity assays showed that the specific SCAR marker detected 10 4 conidia from I. fumosorosea EH-511/3 that were artificially mixed with soil, from 1 to 10 4 conidia artificially mixed with Galleria mellonella (Lepidoptera: Pyralidae), and from 10 to 10 5 conidia in Melinex tape for airborne samples. The marker was also able to detect conidia in airborne samples from cotton wicks in a mini wind tunnel. These SCAR markers for I. fumosorosea had excellent specificity and sensitivity and are relevant tools for ecological studies of this fungus.
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survival and immune response of the chagas vector meccus pallidipennis hemiptera reduviidae against two entomopathogenic fungi metarhizium anisopliae and Isaria fumosorosea
Parasites & Vectors, 2016Co-Authors: Laura A Floresvillegas, Conchita Toriello, Margarita Cabrerabravo, Martha Irene Buciotorres, Paz Maria Salazarschettino, Alex CordobaaguilarAbstract:Background Chagas disease is a key health problem in Latin America and is caused and transmitted by Trypanosoma cruzi and triatomine bugs, respectively. Control of triatomines has largely relied on the use pyrethroids, which has proved to be ineffective in the long term. Alternatively, the use of entomopathogenic fungi has been implemented to control triatomine bugs. These fungi are highly efficient as they induce a reduction in immune response on insects. Meccus pallidipennis is the main triatomine vector of Chagas disease in Mexico. In this work we investigated the effects of two entomopathogenic fungi, Metarhizium anisopliae and Isaria fumosorosea, on M. pallidipennis nymphs in terms of insect survival and immune response.
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potent anti calmodulin activity of cyclotetradepsipeptides isolated from Isaria fumosorosea using a newly designed biosensor
Natural Product Communications, 2015Co-Authors: Abraham Madariagamazon, Conchita Toriello, Martin Gonzalezandradeb, Hortensia Navarrobarranco, Rachel MataAbstract:: Seven cyclotetradepsipeptides, namely beauverolides C (1), F (2), I (3), Ja (4), L (5), M (6), and N (7), were isolated from the entomopathogenic fungus Isaria fumosorosea. The beauverolides were evaluated as potential calmodulin (CaM) inhibitors using the newly designed CaM biosensor hCaM M124C-AF350; these peptides displayed high affinity to the protein with dissociation constants (Kd) ranging from 0.078 μM to 3.44 μM. Beauverolide Ja, the only one containing a tryptophan residue in its structure, showed the highest affinity. The docking study predicted that beauverolides could bind to CaM in the same site of interaction as chlorpromazine, a well-known calmodulin ligand.
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fungal growth development index and ultrastructural study of whiteflies infected by three Isaria fumosorosea isolates of different pathogenicity
Revista Mexicana de Micología, 2013Co-Authors: Judith Castellanosmoguel, Teresa Mier, Maria Del Rocio Reyesmontes, Hortensia Navarro Barranco, Armando Zepeda Rodriguez, Armando Pereztorres, Conchita TorielloAbstract:The infection process whereby Isaria fumosorosea colonizes whitefly (Trialeurodes vaporariorum) nymphs was investigated using light and scanning electron microscopy. The fungal growth development index was used to determine pathogenicity of the isolates studied. The ultrastructural findings allowed us to examine the course of colonization of T. vaporariorum by this fungus through the formation of cuticular penetration structures. I. fumosorosea produced structures that resemble appressoria in shape, and isolates cause serious cuticular damage suggesting of enzymatic action. The results of this study suggest isolate EH-506/3 as suitable for whitefly biocontrol.
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indice de crecimiento y desarrollo fungico y estudio ultraestructural de mosquitas blancas infectadas por tres aislados de Isaria fumosorosea de diferente patogenicidad
Revista mexicana de micología, 2013Co-Authors: Judith Castellanosmoguel, Teresa Mier, Maria Del Rocio Reyesmontes, Hortensia Navarro Barranco, Armando Zepeda Rodriguez, Armando Pereztorres, Conchita TorielloAbstract:The infection process whereby Isaria fumosorosea colonizes whitefly (Trialeurodes vaporariorum) nymphs was investigated using light and scanning electron microscopy. The fungal growth development index was used to determine pathogenicity of the isolates studied. The ultrastructural findings allowed us to examine the course of colonization of T. vaporariorum by this fungus through the formation of cuticular penetration structures. I. fumosorosea produced structures that resemble appressoria in shape, and isolates cause serious cuticular damage suggesting of enzymatic action. The results of this study suggest isolate EH-506/3 as suitable for whitefly biocontrol.
Tomasz Janeczko - One of the best experts on this subject based on the ideXlab platform.
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cascade biotransformation of estrogens by Isaria fumosorosea kch j2
Scientific Reports, 2019Co-Authors: Ewa Kozlowska, Monika Dymarska, Edyta Kostrzewasuslow, Tomasz JaneczkoAbstract:: Estrone, estradiol, ethynylestradiol and estrone 3-methyl ether underwent a biotransformation process in the submerged culture of Isaria fumosorosea KCh J2. Estrone was transformed into seven metabolites, four of which were glycosylated. Estradiol was selectively glycosylated at C-3 and then transformed to D-ring lactone. Ethynylestradiol was coupled with methylglucoside and 6β-hydroxyderivative was obtained. Estrone 3-methyl ether was not transformed indicating that a free hydroxyl group at C-3 is necessary for glycosylation. Baeyer-Villiger oxidation combined with hydroxylation and glycosylation was observed. All glycosides obtained in this study are 3-O-β-methylglucosides.
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glycosylation of 3 hydroxyflavone 3 methoxyflavone quercetin and baicalein in fungal cultures of the genus Isaria
Molecules, 2018Co-Authors: Monika Dymarska, Tomasz Janeczko, Edyta KostrzewasuslowAbstract:Flavonoids are plant secondary metabolites with a broad spectrum of biological activities. In nature, they occur mainly in the form of glycosides, but their extraction is often difficult and expensive, as is chemical synthesis. We have shown that biotransformations are an excellent method for obtaining flavonoid glycosides. We are the first team to describe the use of Isaria microorganisms in biotransformations of flavonoid compounds. In the present study as biocatalysts, we used one strain of Isaria fumosorosea KCH J2 isolated from a spider carcass in green areas of Wroclaw and two strains of I. farinosa (J1.4 and J1.6) isolated from insects found in already unused mines in Lower Silesia. The substrates were 3-hydroxyflavone, 3-methoxyflavone, quercetin (3,3′,4′,5,7-pentahydroxyflavone), and baicalein (5,6,7-trihydroxyflavone). For all the substrates that were used in this study, we obtained 4-O-methylglucopyranosides. In the case of substrates with a hydroxyl group in the third position, O-β-d-glucopyranosides were also formed. Isoquercetin that was obtained by biotransformation was used as a substrate to check the kinetics of the formation of flavonoid 4-O-methylglucopyranosides in I. fumosorosea KCH J2 culture. We did not observe the attachment of the methyl group to glucose unit in isoquercetin. Our finding suggest that the attachment of 4-O-methylglucopyranose occurs in one step.
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biotransformation of steroids by entomopathogenic strains of Isaria farinosa
Microbial Cell Factories, 2018Co-Authors: Ewa Kozlowska, Monika Dymarska, Edyta Kostrzewasuslow, Jordan Sycz, Monika Urbaniak, Jakub Grzeszczuk, łukasz Stepien, Elzbieta Pląskowska, Tomasz JaneczkoAbstract:Steroid compounds are very interesting substrates for biotransformation due to their high biological activity and a high number of inactivated carbons which make chemical modification difficult. Microbial transformation can involve reactions which are complicated and uneconomical in chemical synthesis, and searching for a new effective biocatalyst is necessary. The best known entomopathogenic species used in steroid modification is Beauveria bassiana. In this study we tested the ability of Isaria farinosa, another entomopathogenic species, to transform several steroids. Twelve strains of the entomopathogenic filamentous fungus Isaria farinosa, collected in abandoned mines located in the area of the Lower Silesian Voivodeship, Poland, from insects’ bodies covered by fungus, were used as a biocatalyst. All the tested strains effectively transformed dehydroepiandrosterone (DHEA). We observed 7α- and 7β-hydroxy derivatives as well as changes in the percentage composition of the emerging products. Due to the similar metabolism of DHEA in all tested strains, one of them was selected for further investigation. In the culture of the selected strain, Isaria farinosa KCh KW1.1, transformations of androstenediol, androstenedione, adrenosterone, 17α-methyltestosterone, 17β-hydroxyandrost-1,4,6-triene-3-one and progesterone were performed. All the substrates were hydroxylated with high yield and stereoselectivity. We obtained 6β-hydroxyandrost-4-ene-3,11,17-trione, 15α,17β-dihydroxy-6β,7β-epoxyandrost-1,4-diene-3-one and 6β,11α-dihydroxyprogesterone. There is no evidence of either earlier microbial transformation of 17β-hydroxyandrost-1,4,6-triene-3-one or new epoxy derivatives. Isaria farinosa has a broad spectrum of highly effective steroid hydroxylases. The obtained 7-hydroxydehydroepiandrosterone has proven high biological activity and can be used in Alzheimer’s disease and as a key intermediate in the synthesis of aldosterone antagonists. Transformation of progesterone leads to high yield of 6β,11α-dihydroxyprogesterone and it is worth further study.
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Isaria fumosorosea kch j2 entomopathogenic strain as an effective biocatalyst for steroid compound transformations
Molecules, 2017Co-Authors: Ewa Kozlowska, Monika Dymarska, Edyta Kostrzewasuslow, Tomasz JaneczkoAbstract:The catalytic activity of enzymes produced by an entomopathogenic filamentous fungus (Isaria fumosorosea KCh J2) towards selected steroid compounds (androstenedione, adrenosterone, progesterone, 17α-methyltestosterone and dehydroepiandrosterone) was investigated. All tested substrates were efficiently transformed. The structure of the substrate has a crucial impact on regio- and stereoselectivity of hydroxylation since it affects binding to the active site of the enzyme. Androstenedione was hydroxylated in the 7α-position to give a key intermediate in the synthesis of the diuretic-7α-hydroxyandrost-4-ene-3,17-dione with 82% conversion. Adrenosterone and 17α-methyltestosterone were hydroxylated in the 6β-position. Hydroxylated derivatives such as 15β-hydroxy-17α-methyltestosterone and 6β,12β-dihydroxy-17α-methyltestosterone were also observed. In the culture of Isaria fumosorosea KCh J2, DHEA was effectively hydroxylated in the C-7 position and then oxidized to give 7-oxo-DHEA, 3β,7α- and 3β,7β-dihydroxy-17a-oxa-d-homo-androst-5-ene-17-one. We obtained 7β-OH-DHEA lactone with 82% yield during 3 days transformation of highly concentrated (5 g/L) DHEA.
