Polibotánica ISSN: 1405-2768 [email protected] Departamento de Botánica México Herrera Arrieta, Yolanda; Cháirez Hernández, Isaias Flavonoids of the genus Bouteloua (Poaceae) from Mexico Polibotánica, núm. 20, diciembre, 2005, pp. 17-29 Departamento de Botánica Distrito Federal, México Available in: http://www.redalyc.org/articulo.oa?id=62102002 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Núm.20, pp.17-29, ISSN 1405-2768; México, 2005 FLAVONOIDS OFTHE GENUS Bouteloua (POACEAE) FROM MEXICO Yolanda Herrera Arrieta Isaias Cháirez Hernández CIIDIR Unidad Durango, COFAA- Instituto Politécnico Nacional, Sigma s.n. Frac. 20 de Noviembre II, Durango, Dgo. 34220 México RESUMEN this genus. Most were glycosylated derivatives of the flavones luteolin, Se analizó cualitativamente e identificó el apigenin mono-glycosides in the 5, 6, 7 and contenido de flavonoides en poblaciones 8 positions, and tricin mono-glycosides in naturales de las especies de Bouteloua de the 5 and 7 positions. Two flavonols Q 3- México. Se separaron 19 flavonoides en 30 O rutinoside and Q 3-O glucoside were taxa deeste género, 12 de ellos se identificaron determined. Flavonoid patterns provided químicamente. La mayoría resultaron ser a good additional taxonomic character for derivados glicosilados de las flavonas species separation. Phenetic analysis of luteolina, apigenina monoglicosada en las flavonoid content provided support to posiciones 5, 6, 7 y8, ytricina monoglicosada conclude that Bouteloua deserves a en las posiciones 5 y 7. Se determinaron dos generic level, and it is composed of two flavonoles Q 3-O rutinosida yQ 3-O glucosida. subgenera: Bouteloua and Chondrosum. Los patrones de flavonoides resultantes aportaron un buen carácter taxonómico Key words:Bouteloua, Poaceae, Gramineae, adicional para la separación de especies. El flavonoids, chemosystematics. análisis fenético del contenido de flavonoides dio soporte para concluir que Bouteloua INTRODUCTION merece ser reconocida a nivel genérico y que está compuesta por dos subgéneros: The genus Bouteloua, aprimarycomponent Bouteloua y Chondrosum. of grasslands and prairies, is ecologically one of the most important grasses in North Palabras clave: Bouteloua, Poaceae, America. It is one of the most important Gramineae, flavonoides, quimiosistemática. genera of Poaceae, which has 42 recognized species and 14 varieties. Most of them are ABSTRACT xeromorphic living forms in arid lands of the New World. Thirty seven species and 14 Flavonoid contents of natural populations varieties occur in Mexico, 20 of these of Bouteloua species from Mexico were species and 4 varieties are endemisms or identified and qualitatively analized. occur in restricted areas in Mexico, Nineteen flavonoids were separated and 12 whereas the rest are extended into the were chemically identified from 30 taxa of southwestern United States, 6 also into 17 Núm. 20:17-29 Diciembre 2005 South America and 3 occur in the West mine the flavonoid characters of the taxa Indies. They are primary components of within Bouteloua in order to clarify species grasslands in Mexico, being considered the boundaries and determine relationships producers of high quality beef in free-range within the genus. The species and livestock. Many species of Bouteloua are populations included in the study are listed significant elements of natural grassland in Table 1 and their approximate locations associations and they have a high forage shown in fig.1 (species not found in field quality for livestock. Species with the widest collections were excluded from the analysis). distribution and economical importance are B. curtipendula (sideoats grama, banderilla MATERIAL AND METHODS or triguillo), B. gracilis (blue grama, navajita), B. hirsuta (hairygrama, navajita peluda) and A survey of the flavonoid content in the B. eriopoda (black grama, navajita negra). species of the genus Bouteloua was At least one of these four species can be conducted over 148 populations. Bulk found in all grasslands of Mexico. samples (ca. 50 g) of ground, air-dried plant material were taken from field collections of Previous taxonomic treatments of the genus plants at the flowering stage. The powder are conflicting, two subgenera were was extracted in 80% MeOH and then 50% recognized: Bouteloua sensu str. and MeOH for 24 h each. The extracts were Chondrosum Desv. [Gould, 1979], while combined, concentrated and surveyed for Clayton and Renvoize [1986] proposed the flavonoid composition using standard 2-D division of the genus and raised the rank of paper chromatography (BAW and 15% these to subgenera. Another author, based HOAc). At least one population from each on recent molecular studies, has proposed species was subjected to exhaustive Bouteloua as a more inclusive genus, which analysis. In all cases the population chosen includes these two taxa as well as the genera contained the greatest number of of the tribe Boutelouinae [Columbus, 1999]. flavonoids. In a few instances more than In order to draw evolutionism inferences for one population had to be extracted so that this genus from Mexico a systematic study all of the flavonoids could be analyzed. was carried out: a) anatomical featuresin foliar In the exhaustive analysis, the concentrated epidermis [Rosales-Carrillo and Herrera- extracts were partitioned successively with Arrieta, 1996] and culm transversal sections chloroform and ethyl acetate. Flavonoids [Siqueiros-Delgadoand Herrera-Arrieta, 1996], from all fractions were separated and purified b) morphological characters [Herrera-Arrieta using standard methods of paper and thin- and De la Cerda-Lemus (1997), Esparza- layer chromatography. Most flavonoids SandovalandHerrera-Arrieta (1996)]in order were found in the ethyl acetate fraction. todraw evolutionism inferencesfor thegenus. Identification of flavonoids was As part of an ongoing survey of the Mexican accomplished using standard spectral and species sponsored by Comisión Nacional para hydrolytic techniques [Mabry et al. (1970), el Conocimiento y Uso de la Biodiversidad Markham (1982)]. Rf values were determined (CONABIO), nearly3 000 specimens from field on Whatmann # 1 paper in four solvent collections and herbaria samples were systems, 4:1:5 (butanol: acetic acid: H2O- reviewed and scored to produce a data base. BAW), H2O, 15% acetic acid, 80% phenol. The objective of the present study is to exa- Unknown cases were co-chromatographed 18 Herrera y Cháirez: Flavonoids of the genus Bouteloua (Poaceae) from Mexico against rutin (quercetin 3-O rutinoside) because of low concentration found in standard. Hydrolyzed sugars were identified plants, these compounds does not appear by co-chromatography against standard atTable2andarementionedinTable3as sugars on cellulose TLC (Polygram Cel 300) compounds: 14, 15, 16, 17, 18 and 19. The in 18:18:3.5:10.5 (pyridine: ethyl acetate: acetic flavonoid profiles of the species are acid: H2O) followed bystaining with aniline summarized in Table 3, where the presence diphenylamine phosphate. Suspected C- of each compound was registered. glycosyl flavones were chromatographed with 15% HOAc on cellulose plates (TLC), The number after the species name refers to and sprayed with NA reagent [Markham, the number of populations freshly collected 1982] to check for Wessley-Moser and analyzed for each species. Little rearrangement products [Mabryet al. (1970), intraspecific variation was detected as Markham (1982)]. indicated in Table 3, resulting in generally uniform profiles within a taxon, which An overall similarity analysis, using Jaccard’s therefore, are taxonomically useful. coefficient to compute similarities, was Generated data can be taken as an indicator performed on the data set of Table 3, followed of the variability process within the genus. bya cluster analysis using unweighted pair- A more complete population sampling is group mathematical average (UPGMA) of the needed for an interspecific analysis. similarity matrix. Analyses were performed using Multivariate Statistical Package The results of the cluster analysis based on [Kovach, 1987]. the 19 compounds listed in tables 2 and 3 are presented in the form of a dendrogram RESULTSANDDISCUSSION (fig. 2). Profiles ofthe taxa are all verysimilar, with most of the variation occurring in Species names and approximate locations of number and type of sugar attached to the the148 population samples (Table1) are shown molecule. In general, the genus is relatively in fig. 1. For summarizing speciesrelationships, homogenous, lacking substantial differences phenetic analysis of the 19 compounds, among the taxa. In the case of varieties, qualitativelyidentified in these populations was flavonoid profiles were consistently similar performed using the unweighed pair group within species. The dendrogram (fig. 2) method of averaging (UPGMA), to interpret suggests that the 36 analysed taxa seem to variation in flavonoid expression. Vouchers be part of a natural group. were deposited at CIIDIR herbarium. Found compounds are shown in Table 2. As can be seen from fig. 2, some groups inside an homogeneous tree are perceived, Nineteen flavonoid compounds were based on flavonoid data, with all species isolated from whole plant extracts and 13 having divergent geographic distribution. of them identified (table 2). Eleven of these