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  • 1
    ISSN: 1420-9071
    Keywords: Gigantecin ; acetogenins ; Goniothalamus giganteus ; Annonaceae ; brine shrimp ; antimitotic ; cytotoxic ; crown gall tumors ; potato disc assay ; 9 ASK
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Gigantecin (I), a novel tetrahydroxy-di-tetrahydrofuran fatty acid γ-lactone (acetogenin), was isolated from an ethanolic extract of the stem bark ofGoniothalamus giganteus Hook. f., Thomas (Annonaceae), by means of activity-directed fractionation (brine shrimp lethality test). This new compound is extremely cytotoxic to human tumor cells, inhibits crown gall tumors on potato discs, and is active in an assay designed to detect antimitotic agents (9 ASK).
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1420-9071
    Keywords: Goniothalamicin ; annonacin ; acetogenins ; Goniothalamus giganteus ; Annonaceae ; brine shrimp ; insecticidal ; cytotoxic ; antileukemic activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Using brine shrimp lethality for activity-directed fractionation, goniothalamicin (I), a new tetrahydroxy-mono-tetrahydrofuran fatty acid γ-lactone (acetogenin), has been isolated from ethanolic extracts of the stem bark ofGoniothalamus giganteus Hook. f., Thomas (Annonaceae). This novel compound was found to be cytotoxic and insecticidal and inhibited the formation of crown gall tumors on potato discs. Annonacin (II), the only other reported mono-tetrahydrofuran acetogenin, was also isolated; the previously reported 9ASK (astrocytoma reversal) activity ofII was confirmed, andII is now also found to be weakly active against 3PS murine leukemia.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1420-9071
    Keywords: Sylvaticin ; acetogenin ; Rollinia sylvatica ; Annonaceae ; brine shrimp ; cytotoxicity ; insecticidal ; striped cucumber beetle ; European corn borer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Sylvaticin (I), a new tetrahydroxy annonaceous acetogenin with nonadjacent tetrahydrofuran rings, has been isolated from the dried fruits ofRollinia sylvatica St. Hil. (Annonaceae). This compound is extremely cytotoxic to human tumor cells and shows promising insect control properties.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 43 (1987), S. 947-949 
    ISSN: 1420-9071
    Keywords: Annonacin ; polyketide ; Annona densicoma ; Annonaceae ; biological activity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A new linear polyketide, Annonacin (I), has been isolated from active extracts of the stembark ofAnnona densicoma Mart. Annonacin (I) is highly cytotoxic and is active in an assay designed to detect antimitotic agents. The structure of (I) was determined by analysis of spectroscopic data.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 23 (1991), S. 907-924 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Methyl tertiary butyl ether (MTBE) has been proposed and is being used as an additive to increase the octane of gasoline without the use of tetraethyl lead and alkylbenzenes. The present experiments have been performed to examine the kinetics and mechanisms of the atmospheric removal of MTBE. The kinetics of the reaction of OH with MTBE was examined by using a relative rate technique in which photolysis of methyl nitrite was used as the source of OH. With n-butane as the reference compound a value of (2.99 ± 0.12) × 10-12 cm3 molecule-1 s-1 at a temperature of 298 K was obtained for the rate constant. The products (and product yields) for the OH reaction with MTBE in the presence of NOx were also determined and found to be t-butyl formate (0.68 ± 0.05), methyl acetate (0.14 ± 0.02), acetone (0.026 ± 0.003), t-butanol (0.062 ± 0.009), and formaldehyde (0.48 ± 0.05) in mols/mol MTBE converted. The OH rate constant for the major product formed, t-butyl formate was also measured and found to be (7.37 ± 0.05) × 10-13 cm3 molecule-1 s-1. Mechanisms to rationalize the formation of the products are presented.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 24 (1992), S. 199-215 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ethyl tertiary butyl ether (ETBE) is being proposed as an additive for use in reformulated gasolines. In this study, experiments were performed to examine the kinetics and mechanism of the atmospheric removal of ETBE. The kinetics of the reaction of ETBE with OH radicals were examined by using a relative rate technique with the photolysis of methyl nitrite to generate OH radicals. With n-hexane as the reference compound, a value of (9.73 ± 0.33) × 10-12 cm3 molecule-1 s-1 was obtained for the rate constant. The OH rate constant for t-butyl acetate, a product of the oxidation of ETBE, was (4.4 ± 0.4) × 10-13 cm3 molecule-1 s-1 at 298 K.The primary products and molar yields for the OH reaction with ETBE in the presence of NOx were t-butyl formate (0.64 ± 0.03), t-butyl acetate (0.13 ± 0.01), ethyl acetate (0.043 ± 0.003), acetaldehyde (0.16 ± 0.01), acetone (0.019 ± 0.002), and formaldehyde (0.53 ± 0.04). Under the described reaction conditions, the formation of t-butyl nitrite was also observed. From these molar yields, approximately 98% of the reacted ETBE could be accounted for by paths leading to these products. Chemical mechanisms to explain the formation of these products are presented.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 27 (1995), S. 453-472 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tertiary-amyl methyl ether (TAME) is proposed for use as an additive to increase the oxygen content of gasoline as stipulated in the 1990 Clean Air Amendments. The present experiments have been performed to examine the kinetics and mechanisms of the atmospheric removal of TAME. The kinetics of the reaction of OH with TAME was examined by using a relative rate technique in which photolysis of methyl nitrite or nitrous acid was used as the source of OH. The OH rate constant for TAME and two major products (t-amyl formate and methyl acetate) were measured and yields for ten products were determined as primary products from the reaction.Values determined for the rate constants for the reaction with OH were 5.48 × 10-12 (TAME), 1.75 × 10-12 (t-amyl formate), and 3.85 × 10-13 cm3 molec-1 s-1 (methyl acetate) at 298 ± 2 K. The primary products (with corrected yields where required) from the OH + TAME that have been observed include (1) t-amyl formate (0.366), methyl acetate (0.349), acetaldehyde (0.43, corrected), acetone (0.036), formaldehyde (0.549), t-amyl alcohol (0.026), 3-methyoxy-3-methyl-butanal (0.044, corrected), t-amyloxy methyl nitrate (0.029), 3-methyoxy-3-methyl-2-butyl nitrate (0.010), and 2-methoxy-2-methyl butyl nitrate (0.004). Mechanisms leading to these products involve OH abstraction from each of the four different hydrogen atoms of TAME. © 1995 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 28 (1996), S. 475-480 
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The gas-phase reaction products of the OH radical with 2-ethoxyethyl acetate (EEA, CH3C(O)OCH2CH2OCH2CH3) have been investigated. 1,2-Ethanediol acetate formate (EAF, CH3C(O)OCH2CH2OC(O)H) and ethyl formate (EF, HC(O)OCH2CH3) were identified as the two main products. A third product, ethylene glycol diacetate (EGD, CH3C(O)OCH2CH2OC(O)CH3), was also observed. EAF, EF, and EGD formation yields were determined to be 0.37 ± 0.03 and 0.328 ± 0.018 and 0.040 ± 0.005, respectively. Proposed reaction mechanisms are discussed and compared with these data. © 1996 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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