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  • 1
    Electronic Resource
    Electronic Resource
    Ecdysone 20-monooxygenase in mitochondria and microsomes of Manduca sexta (L.) Midgut: Is the dual localization real? (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Archives of Insect Biochemistry and Physiology 2 (1985), S. 385-396 
    Details
    ISSN: 0739-4462
    Keywords: ecdysone 20-monooxygenase ; NADPH-cytochrome c reductase ; Manduca sexta ; tobacco hornworm ; midgut ; Chemistry ; Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The dual localization of ecdysone 20-monooxygenase in mitochondria and microsomes of Manduca sexta larval midgut was investigated. Cosubstrate requirements and response to osmolarity of the microsomal ecdysone 20-monooxygenase system were found to be different from those previously reported for the mitochondrial enzyme system. The microsomal monooxygenase utilized NADPH and, less efficiently, NADH as cosubstrates. NADPH and NADH effects were neither additive nor synergistic. NADPH yielded identical activities in isotonic and hypotonic incubations. Mitochondria and microsomes showed no synergistic interaction for ecdysone 20-hydroxylation. After washing of the mitochondria, a large proportion of their ecdysone 20-monooxygenase activity was lost. The extent of the loss was inversely correlated to the concentration of mitochondria in the incubation mixture. The addition of bovine serum albumin to the incubations (2 mg/ml) largely restored the original activities. The microsomal contamination in mitochondrial pellets after each of three successive washings was determined by measuring the activity of a microsomal marker enzyme, NADPH-cytochrome c reductase. At each step of the purification, the ecdysone 20-monooxgenase activity of the mitochondrial preparations far exceeded the activity attributable to the microsomal contamination. These results confirm the existence of two independent ecdysone 20-monooxygenase systems in the midgut of M. sexta larvae.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/arch.940020406
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  • 2
    Electronic Resource
    Electronic Resource
    Profiles of free and conjugated ecdysteroids and ecdysteroid acids during pupal-adult development of Manduca sexta (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Archives of Insect Biochemistry and Physiology 12 (1989), S. 63-74 
    Details
    ISSN: 0739-4462
    Keywords: [14C]cholesterol ; HPLC ; ecdysteroid titers ; ecdysteroid metabolism ; epimerization ; hydroxylation ; oxidation ; epiecdysteroid acids ; epiecdysteroid phosphates ; Chemistry ; Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The levels of individual free and conjugated ecdysteroids and ecdysteroid acids, labeled from [14C]cholesterol, in five different age groups of male Manduca sexta during pupal-adult development were determined by HPLC. Eight free ecdysteroids, eight ecdysteroid phosphates, and two ecdysteroid acids were identified. Newly ecdysed pupae contained predominantly 3-epiecdysteroids in each of the free, conjugated, and acidic ecdysteroid fractions. The titer of each ecdysteroid fraction rose sharply by day 4, and this was particularly noteworthy with respect to free ecdysone and 3-epi-20-hydroxyecdysonoic acid. This stage demonstrated high degrees of ecdysone biosynthesis, oxidative catabolism, and phosphorylation. As development proceeded to day 16, total ecdysteroid titer remained constant; a decreasing free ecdysteroid titer was accompanieid by increasing titers of both conjugates and acids resulting from the metabolic processes of hydroxylation, oxidation, epimerization, and phosphorylation. The predominant metabolites throughout development were 3-epi-20-hydroxyecdysonoic acid and the phosphate conjugates of 3-epi-20-hydroxyecdysone and 3-epi-20,26-dihydroxyecdysone. The ultimate inactivation of the ecdysteroids of M. sexta during pupal-adult development is possibly mediated by two pairs of metabolically-linked processes, one leading to a 3-epiecdysteroid acid, and the other to 3-epiecdysteroid phosphates.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/arch.940120106
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  • 3
    Electronic Resource
    Electronic Resource
    Metabolism of 26-[14C]hydroxyecdysone 26-phosphate in the tobacco hornworm, Manduca sexta L., to a new ecdysteroid conjugate: 26-[14C]hydroxyecdysone 22-glucoside (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Archives of Insect Biochemistry and Physiology 4 (1987), S. 1-15 
    Details
    ISSN: 0739-4462
    Keywords: [14C]cholesterol ; radiolabeled ecdysteroid conjugates ; 26-hydroxyecdysone 22-glucosidel ; 26-hydroxyecdysone 26-phosphate ; 3-epi-26-hydroxyecdysone ; 3-epi-20,26-dihydroxyecdysone ; enzymatic hydrolysis ; Chemistry ; Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Following injection into female Manduca sexta pupae, [14C]cholesterol is converted to a radiolabeled C21 nonecdysteroid conjugate as well as ecdysteroid conjugates, which in ovaries and newly-laid eggs consist mainly of labeled 26-hydroxyecdysone 26-phosphate. During embryogenesis, as the level of 26-hydroxyecdysone 26-phosphate decreases there is a concurrent increase in the amount of a new, labeled ecdysteroid conjugate. This conjugate, which is the major ecdysteroid conjugate (9.4 μg/g) in 0- to 1-hour-old larvae was identified as 26-hydroxyecdysone 22-glucoside by nuclear magnetic resonance and chemical ionization mass spectrometry. This is the first ecdysteroid glucoside to be identified from an insect. The disappearance of 26-hydroxyecdysone 26-phosphate in 0- to 1-hour-old larvae indicates that the 26-hydroxyecdysone 22-glucoside is derived from 26-hydroxyecdysone 26-phosphate. 3-Epi-26-hydroxyecdysone was the major free ecdysteroid isolated from these larvae and 3-epi-20,26-dihydroxyecdysone was the next most abundant ecdysteroid isolated. Interestingly, the 0- to 1-hour-old larvae contained the highest levels of 3α-ecdysteroids per gram of insect tissue (8.7 μg/g) to be isolated from an insect, yet there was a complete absence of the corresponding free 3β-epimers. The ecdysteroid conjugate profiles of ovaries and 0- to 1-hour-old larvae are discussed. Methodology is presented that permits the efficient separation of free and conjugated ecdysteroids and nonecdysteroid conjugates (C21-steroid conjugates).
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/arch.940040102
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  • 4
    Electronic Resource
    Electronic Resource
    In vitro ecdysteroid conjugation by enzymes of Manduca sexta midgut cytosol (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    Archives of Insect Biochemistry and Physiology 3 (1986), S. 109-126 
    Details
    ISSN: 0739-4462
    Keywords: Ecdysteroid phosphoester ; Manduca sexta ; midgut ; C18 SEP-PAK ; β-glucuronidase ; sulphatase ; acid phosphatase ; ATP:ecdysteroid phosphotransferase ; Chemistry ; Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: In incubations with 80,000g supernatant of Manduca sexta midgut homogenates, [3H]ecdysone was converted to 3-[3H]epiecdysone and tritiumlabeled highly polar metabolites. C18 SEP-PAK cartridges were found suitable for the separation and purification of the free ecdysteroids and of the highly polar metabolites. Eighty to ninety percent of the metabolites were hydrolyzed by enzyme mixtures (mainly β-glucuronidase, sulphatase, and acid phosphatase) from molluscs, even when β-glucuronidase activity was completely inhibited by D-saccharic acid 1,4-lactone, or various human acid phosphatases (free of sulphatase activity). In each experiment, the hydrolysate contained a much higher proportion of 3-epiecydsone than the free (unconjugated) ecdysteroid fraction. [3H]ecdysone was not metabolized in anaerobic incubations of midgut supernatant that had been filtered through Sephadex G-25. Addition of 5 mM ATP and 5 mM Mg2+ restored the conjugate formation in incubations of Sephadex-filtered supernatant. Four ecdysone conjugates and two 3-epiecdysone conjugates were resolved by reversedphase ion-pair high-performance liquid chromatography. It is concluded that the midgut cytosol contains several ATP:ecdysteriod phosphotransferases. This is the first demonstration of the formation of ecdysteroid phosphoconjugates in a cell-free system.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/arch.940030202
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  • 5
    Electronic Resource
    Electronic Resource
    Isolation and identification of 26-hydroxyecdysone 2-phosphate: An ecdysteroid conjugate of eggs and ovaries of the tobacco hornworm, Manduca sexta (1987)
    New York, NY [u.a.] : Wiley-Blackwell
    Archives of Insect Biochemistry and Physiology 4 (1987), S. 183-190 
    Details
    ISSN: 0739-4462
    Keywords: [14C]cholesterol ; radiolabeled ecdysteroid conjugates ; 26-hydroxyecdysone 2-phosphate ; enzymatic hydrolysis ; Chemistry ; Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: Maturing eggs (48 to 64 h old) of the tobacco hornworm, Manduca sexta, contain at least three ecdysteroid conjugates, two of which have been previously identified as 26-hydroxyecdysone 26-phosphate (the major conjugate) and 26-hydroxyecdysone 22-glucoside. In this study we have isolated and identified the third conjugate as 26-hydroxyecdysone 2-phosphate by XAD-2 chromatography, C18 SEP-PAK separation, ion suppression reversed-phase high-performance liquid chromatography, nuclear magnetic resonance, and fast atom bombardment mass spectrometry. This compound is the second most abundant conjugate of ovaries from 4-day-old adult females. The possible role for this ecdysteroid conjugate is discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/arch.940040304
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  • 6
    Electronic Resource
    Electronic Resource
    New ecdysteroid conjugate: Isolation and identification of 26-hydroxyecdysone 26-phosphate from eggs of the tobacco hornworm, Manduca sexta (L.) (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Archives of Insect Biochemistry and Physiology 2 (1985), S. 227-236 
    Details
    ISSN: 0739-4462
    Keywords: 26-hydroxyecdysone 26-phosphate ; enzymatic hydrolysis ; ecdysteroid phosphate isolation ; ecdysteroid conjugate ; Manduca sexta ; Chemistry ; Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: The major ecdysteroid conjugate present in eggs (48-64 h old) of the tobacco hornworm has been purified by XAD-2 chromatography, C18 SEP-PAK separations, and ion suppression reversed-phase high-performance liquid chromatography. Enzymatic hydrolysis of the conjugate with acid phosphatase from human seminal fluid gave 26-hydroxyecdysone. The conjugate was identified as 26-hydroxyecdysone 26-phosphate by nuclear magnetic resonance and fast atom bombardment mass spectrometry. This compound is also the major conjugate of newly laid eggs (0-1 h old) of the tobacco hornworm. The role for ecdysteroid conjugates is discussed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/arch.940020302
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