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1.
Braz. j. med. biol. res ; 34(11): 1453-1456, Nov. 2001. ilus
Article in English | LILACS | ID: lil-303321

ABSTRACT

The biflavonoids 6,6"-bigenkwanin, amenthoflavone, 7,7"-dimethoxyagastisflavone and tetradimethoxybigenkwanin isolated from Ouratea species were tested for inhibitory activity on Aspergillus flavus cultures. Suspensions of Aspergillus flavus spores were inoculated into 50 ml of YES medium at different biflavonoid concentrations: 5 and 10 æg/ml for 6,6"-bigenkwanin, amenthoflavone and 7,7"-dimethoxyagastisflavone, and 5, 10, 15 and 20 æg/ml for tetradimethoxybigenkwanin. The four biflavonoids showed inhibitory activity on aflatoxin B1 and B2 production (P<0.001), but did not inhibit fungal growth at the concentration tested (P>0.05). These results show that biflavonoids can be used for the development of agents to control aflatoxin production


Subject(s)
Aflatoxin B1 , Aflatoxins , Aspergillus flavus , Flavonoids , Plant Extracts , Analysis of Variance , Aspergillus flavus , Flavonoids , Plant Extracts
2.
Braz J Med Biol Res ; 34(11): 1453-6, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11668356

ABSTRACT

The biflavonoids 6,6"-bigenkwanin, amenthoflavone, 7,7"-dimethoxyagastisflavone and tetradimethoxybigenkwanin isolated from Ouratea species were tested for inhibitory activity on Aspergillus flavus cultures. Suspensions of Aspergillus flavus spores were inoculated into 50 ml of YES medium at different biflavonoid concentrations: 5 and 10 microg/ml for 6,6"-bigenkwanin, amenthoflavone and 7,7"-dimethoxyagastisflavone, and 5, 10, 15 and 20 microg/ml for tetradimethoxybigenkwanin. The four biflavonoids showed inhibitory activity on aflatoxin B1 and B2 production (P<0.001), but did not inhibit fungal growth at the concentration tested (P>0.05). These results show that biflavonoids can be used for the development of agents to control aflatoxin production.


Subject(s)
Aflatoxin B1/biosynthesis , Aflatoxins/biosynthesis , Aspergillus flavus/drug effects , Flavonoids/pharmacology , Plant Extracts/pharmacology , Analysis of Variance , Aspergillus flavus/metabolism , Flavonoids/chemistry , Plant Extracts/chemistry
3.
Braz J Med Biol Res ; 29(5): 647-50, 1996 May.
Article in English | MEDLINE | ID: mdl-9033817

ABSTRACT

Crude extracts of leaves and fruits of Guarea guidona were tested for antiviral activity against pseudorabies virus and foot-and-mouth disease virus in the IB-RS-2 pig cell line and against bovine herpesvirus-1 (BHV-1) in the GBK bovine cell line. The highest nontoxic doses of extracts from fruits and leaves were 125 micrograms/ml and 500 micrograms/ml. respectively. Crude extracts presented antiviral activity against pseudorabies virus with a decrease in virus titer of 3.0 log units at 500 micrograms/ml. Virucidal activity was not observed at 62.5 micrograms/ml. Preformed cell monolayers showed no cytotoxic effect after 48 h in the presence of 500 micrograms/ml in pig cells. G. guidona leaves did not induce an antiviral state but exhibited antiviral effects during the early stage of viral infection.


Subject(s)
Antiviral Agents/pharmacology , Aphthovirus/drug effects , Herpesvirus 1, Bovine/drug effects , Herpesvirus 1, Suid/drug effects , Plant Extracts/pharmacology , Animals , Cattle , Cell Line/drug effects , Cells, Cultured , Microbial Sensitivity Tests , Plant Extracts/toxicity , Swine
4.
Braz. j. med. biol. res ; 29(5): 647-50, May 1996. tab, graf
Article in English | LILACS | ID: lil-182550

ABSTRACT

Crude extracts of leaves and fruits of Guarea guidona were tested antiviral activity against pseudorabies virus and foot-and-mouth disease virus in the IB-RS-2 pig cell line and against bovine herpesvirus-1 (BHV-1) in the GBK bovine Cell line. The highest nontoxic doses of extracts from fruits and leaves were 125 mug/ml and 500 mug/ml, respectively. Crude extracts presented antiviral activity against pseudorabies virus with a decrease in virus titer of 3.0 log units at 500 mug/ml. Virucidal activity was not observed at 62.5 mug/ml. Preformed cell monolayers showed no cytotoxic effect after 48 h in the presence of 500 mug/ml in pig cells. G. guidona leaves did not induce an antiviral state but exhibited antiviral effects during the early stage of viral infection.


Subject(s)
Animals , Cattle , Antiviral Agents/pharmacology , Aphthovirus/drug effects , Herpesvirus 1, Bovine/drug effects , Herpesvirus 1, Suid/drug effects , Plant Extracts/pharmacology , Cell Line/drug effects , Cells, Cultured , Microbial Sensitivity Tests , Plant Extracts/toxicity , Swine
5.
Planta Med ; 61(3): 217-20, 1995 Jun.
Article in English | MEDLINE | ID: mdl-7617762

ABSTRACT

Two biflavonoids were isolated from the EtOH extract from leaves of Ouratea spectabilis. Their structures were established to be the novel 6,6"-bigenkwanin and 7,7"-dimethoxyagathisflavone on the basis of spectroscopic data. The inhibition of bovine lens aldose reductase exerted by these biflavones has been studied.


Subject(s)
Aldehyde Reductase/antagonists & inhibitors , Flavonoids/pharmacology , Lens, Crystalline/enzymology , Plants, Medicinal , Animals , Cattle , Flavonoids/isolation & purification , Kinetics , Molecular Structure , Plant Leaves , Structure-Activity Relationship
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