Viguiera

 Asteraceae

©The World Botanical Associates Web Page
Prepared by Richard W. Spjut
August 2004, January 2006; Oct 2006

Viguiera deltoidea

Baja California Sur: SW Coast
Between Todos Santos and
Cabo San Lucas, Mar 1979
Spjut 5404

 

Viguiera laciniata
Near Catavina, BCN
May 1980

Viguiera parishii
Black Mts., AZ,
with Crossosoma bigelovii
April 1973

Viguiera parishii
Morongo Valley, CA
March 1972

 

Viguiera stenoloba

Big Bend Natl. Park, TX, Nov. 1978

 

Viguiera reticulata
S of Death Valley, CA
Spjut & Casterline 15744
Mar 2004

 

Guimarães D. O., W. S. Borges, C. Y. Kawano, P. H. Ribeiro, G. H. Goldman, A. Nomizo, G. H. Thiemann, G. Oliva, N. P. Lopes and M. T. Pupo. 2007. Biological activities from extracts of endophytic fungi isolated from Viguiera arenaria and Tithonia diversifolia.  FEMS Immunol. Med. Microbiol. Dec. “A total of 39 endophytic fungi have been isolated from Viguiera arenaria and Tithonia diversifolia, both collected in São Paulo State, Brazil. The isolates were identified based on their ribosomal DNA sequences. The ethyl acetate (EtOAc) extracts of all endophytic fungi were evaluated for their antimicrobial, antiparasitic and antitumoral activity. Antimicrobial screening was conducted using an agar diffusion assay against three pathogenic microorganisms: Staphylococcus aureus, Escherichia coli and Candida albicans. Antiparasitic activity was determined by enzymatic inhibition of gGAPDH of Trypanosoma cruzi and adenine phosphorybosiltransferase (APRT) of Leishmania tarentolae. Antitumoral activity was tested against human T leukemia cells by the Mosmann colorimetric method. All extracts showed activity in at least one assay: 79.5% of the extracts were cytotoxic against leukemia cells, 5.1% of the extracts were active against S. aureus, 25.6% against E. coli and 64.1% against Candida albicans. Only one extract showed promising results in the inhibition of parasitic enzymes gGAPDH (95.0%) and three were found to inhibit APRT activity. The cytotoxic extract produced by the strain VA1 (Glomerella cingulata) was fractionated and yielded nectriapyrone and tyrosol. Nectriapyrone showed relevant cytotoxic activity against both human T leukemia and melanoma tumor cell lines.