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  • 1
    Electronic Resource
    Electronic Resource
    Kinetics and mechanism of azobenzene formation (1975)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 97 (1975), S. 368-373 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00835a025
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  • 2
    Electronic Resource
    Electronic Resource
    A new 14:15-seco-15-norpregnane derivative from Mandevilla illustris Woodson (Apocynaceae) (1999)
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 55 (1999), S. 827-829 
    Details
    ISSN: 1600-5759
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0108270199000529
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  • 3
    Electronic Resource
    Electronic Resource
    cis-8,10-Di-n-propyllobelidiol Hydrochloride Dihydrate (1996)
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 52 (1996), S. 1223-1225 
    Details
    ISSN: 1600-5759
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0108270195014636
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  • 4
    Electronic Resource
    Electronic Resource
    Inhibition of rat paw oedema and pleurisy by the extract fromMandevilla velutina (1991)
    Springer
    Inflammation research 33 (1991), S. 272-278 
    Details
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract This study reports the oral anti-inflammatory profile of the crude extract (CE) ofMandevilla velutina, a plant which has been previously demonstrated to selectively antagonize bradykinin response of the isolated tissues on rat paw oedema and pleurisy caused by different phlogistic agents. The CE (50 to 200 mg/kg), given 60 min before, inhibited in a dose-dependent manner bradykinin (BK) and cellulose sulphate-induced paw oedema, maximal inhibition of 59% and 65%, respectively. In the same range dose the CE also significantly antagonized pleural exudate and cell infiltration caused by these substances, maximal inhibition of 34% and 46%, respectively. In addition, the CE (100 and 200 mg/kg) also inhibited paw oedema induced by serotinin, PAF-acether and zymozan, maximal inhibition of 55%, 38% and 46%, respectively, but enhanced histamine oedema. However, the CE revealed only partial or no inhibition in pleural exudate caused by these agents. The CE (100 and 200 mg/kg) also inhibited in a dose and time-dependent manner carrageenan-induced paw oedema with a maximal inhibition of 44%, but only partially affected carrageenan-induced pleural exudate. The CE also partially inhibited dextran oedema, but even at a higher dose (400 mg/kg) it failed to interfere withBothrops Jaracaca-induced paw oedema. The CE inhibited BK and to a lesser extent cellulose sulphate-induced cell migration, but failed to interfer with the differential leukocyte migration in the pleural cavity. These findings provide evidence that the CE fromM. velutina, besides antagonizing kinin action, exhibit an oral anti-oedematogenic activity against a variety of phologistic agents, but it was more effective in inhibiting those models where kinins are more involved.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01986573
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  • 5
    Electronic Resource
    Electronic Resource
    In vitro effect of the extract and the 1,7-dihydroxy-2,3-dimethoxy xanthone from Polygala cyparissias on the contractions induced by inflammatory mediators and ovalbumin in normal and actively sensitised trachea from guinea pig (1999)
    Springer
    Inflammation research 48 (1999), S. 218-223 
    Details
    ISSN: 1420-908X
    Keywords: Key words:Polygala cyparissias— Crude extract — 1,7-Dihydroxy-2,3-dimethoxy xanthone — Guinea-pig trachea — Allergy — Inflammatory mediators
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Objective: This study describes the in vitro action of the hydroalcoholic extract and the 1,7-dihydroxy-2,3-dimethoxy xanthone isolated from P. cyparissias on agonist and ovalbumin induced contractions in trachea, from normal and actively sensitised guinea pigs.¶Results: The hydroalcoholic extract of P. cyparissias (0.125 to 1mg/ml), incubated with the guinea-pig trachea for 20 min, had no effect on the resting tone of the preparations, but caused a concentration-dependent, reversible and non competitive inhibition of contractions induced by acetylcholine, histamine, compound 48/80, bradykinin, substance P, prostaglandin E2 and the stable analogue of thromboxane A2 mimetic U 46619. The calculated mean IC50 values for the hydroalcoholic extract were: 0.37, 0.51, 0.06, 0.32, 0.48, 0.3 and 0.17 mg/ml, respectively. Also, the extract of P. cyparissias (0.125 to 0.5 mg/ml) antagonised, in a graded manner (IC50 of 0.46mg/ml) ovalbumin-induced contractions in guinea-pig trachea obtained from animals which had been actively sensitised to this antigen. Pre-incubation of the preparations with the purifed xanthone isolated from P. cyparssias (2.5 to 80 μg/ml; 10.0 to 310.0 μM) caused significant and concentration-dependent, reversible and non-competitive inhibition of the contractile responses elicited by acetylcholine, histamine, bradykinin, substance P, U 46619 and prostaglandin E2. The calculated mean IC50 values for these effects were: 132.0, 73.0, 9.2, 32.0, 110.6 and 66.0 μM, respectively. At very high concentrations (155.0-620.0 μM) the xanthone also antagonised contraction induced by KCl in guinea-pig trachea (IC50 of 190.0 μM).¶Conclusions: Taken together these and our previous in vivo results are consistent with the view that the active principles present in P.cyparissias, including the 1,7-dihydroxy-2,3-dimethoxy xanthone, antagonise, in a non competitive but, reversible manner the contractions induced by chemical inflammatory mediators in the guinea pig trachea in vitro. Thus, these results might explain at least in part, the medicinal use of this plant in the management of inflammation, asthma and allergy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000110050449
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  • 6
    Electronic Resource
    Electronic Resource
    Anti-allergic effects and oedema inhibition caused by the extract of Drymis winteri (1997)
    Springer
    Inflammation research 46 (1997), S. 509-514 
    Details
    ISSN: 1420-908X
    Keywords: Key words:Drymis winteri extract — Medicinal plant — Allergy — Anti-inflammatory — Paw oedema
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract. Objective: To study the acute anti-inflammatory and anti-allergic properties of an extract of D. winteri.¶Material and Methods: Paw oedema induced in rats with various stimuli and anaphylactic shock in mice.¶Results: The hydroalcoholic extract (HE) of D. winteri (Winteraceae) (30 to 100 mg/kg, p.o., 1 h prior) inhibited carrageenan (300 μg/paw) and dextran (100 μg/paw)-induced paw oedema formation in a dose-dependent manner, with mean ID50 values of 49 and 〈 30 mg/kg, respectively. The HE of D. winteri (30 to 100 mg/kg) also inhibited paw oedema induced by bradykinin (BK) (3 nmol), substance P (SP) (10 nmol) and PAF-acether (PAF) (10 nmol), in a dose-dependent manner, with mean ID50 values of 56, 63, and 58 mg/kg, respectively. However, the HE inhibited the rat paw oedema induced by prostaglandin E2 (PGE2) (10 nmol) (29 ± 7 and 33 ± 2% at 60 and 240 min) to a smaller extent, and had no effect on oedema elicited by histamine (100 nmol). In adrenalectomized animals, the inhibition by the HE of D. winteri (100 mg/kg, p.o., 1 h prior) of BK-elicited oedema (3 nmol/paw) was significantly smaller when compared with that observed in control animals. When assessed in rats actively sensitised to ovalbumin (OVO), the oedema caused by OVO (6 μg/paw) was significantly inhibited by HE of D. winteri (30 to 100 mg/kg, p.o.), with a mean ID50 of about 65 mg/kg. The HE of D. winteri (100 and 200 mg/kg, p.o.) significantly increased survival rate when assessed in anaphylactic shock in mice actively sensitised to the antigen. The protective effect was long-lasting, being observed for up to 15 h. Dexamethasone, used as positive control (0.5, 1 and 2 mg/kg) produced a long-lasting (up to 24 h) increase in the survival rate of the animals.¶Conclusions: These results confirm and extend our previous studies, and demonstrate the clear oral anti-inflammatory and anti-allergic properties of the active principle(s) present in the barks of D. winteri, thus confirming its reported medicinal use in folk medicine for the management of airway diseases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s000110050234
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  • 7
    Electronic Resource
    Electronic Resource
    Addition of hydroxylamine to cyclohexanone and bicyclic ketones. Steric, electronic and hydrogen bonding effects on the general mechanism of addition of amines to carbonyl compounds (1991)
    Chichester : Wiley-Blackwell
    Journal of Physical Organic Chemistry 4 (1991), S. 107-112 
    Details
    ISSN: 0894-3230
    Keywords: Organic Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Three different types of pH-rate profiles were observed for the addition of amines to carbonyl compounds, depending on the relative predominance, at weakly acidic pH, of either a concerted or a stepwise mechanism. The predominant mechanism depends on the basicity of the amine and the mutual equilibrium affinity for adduct formation between the carbonyl compound and the amine. The reaction of hydroxylamine with cyclohexanone and bicyclic ketones was studied in order to examine the roles of steric and electronic effects in this mechanism. Cyclohexanone and 3-chlorobicyclo [2.2.1] heptan-2-one exhibit the profile expected for a single change in the rate-determining step with increasing pH from uncatalysed attack of the amine on the carbonyl group to hydronium ion-catalysed dehydration of the carbinolamine. In contrast, both bicyclo [2.2.1] heptan-2-one and bicyclo [2.2.2] octan-2-one show an unexpected profile with two negative breaks and five kinetically significant regions. This profile is explained by stabilization of the zwitterionic intermediate T± by intramolecular hydrogen bonding, leading to the formation of the carbinolamine by a stepwise mechanism at weakly acidic pH.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/poc.610040207
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