Multivariate analysis of the effects of soil parameters and environmental factors on the flavonoid content of leaves of Passiflora incarnata L.

Passiflora incarnata L. (Passifloraceae) leaves are relevant raw materials for phytomedicines in Brazil and this species is also described in several European pharmacopoeias. The Passiflora flavonoids are associated with their pharmacological properties, and therefore the total flavonoid content is one important parameter with respect to the quality assessment of Passiflora phytomedicines.

In order to assess the feasibility of producing raw material for the phytopharmaceutical industry through commercial cultivation of P. incarnata in subtropical climate (Brazil, SP state), the effect of soil characteristics (pH, macro- and micro-nutrients), environmental factors (temperature, humidity, period of the year and time of day of collection) and meteorological conditions (rain, sun, cloud and cloud/rain) on the flavonoid content of leaves of Passiflora incarnata L. were evaluated. Samples of leaves of mature plants were harvested and the environmental factors and meteorological conditions during each collection of the material were monitored. The total flavonoid contents of leaf samples harvested were quantified by HPLC-UV/PAD, according to a method developed in our laboratory [1], and the chromatography data acquired were submitted to chemometric analysis. Chemometric treatment of the data by PCA (principal component analysis) and HCA (hierarchic cluster analyses) showed that the samples do not have a specific classification in relation to the environmental and soil variables studied, and that the environmental variables were not significant for describing the data set. On the other hand, the levels of Fe, B and Cu in the soil showed an inverse correlation with the total flavonoid content of the leaves of P. incarnata. To the best of our knowledge the present study is the first relating to the application of chemometric methods to data derived from the HPLC analysis of flavonoids from a species of Passiflora.

Acknowledgements: FAPESP, CNPq, Anidro do Brasil Extrações Ltda.

Reference: [1] Pereira, C.A.M. et al. (2004) Phytochem. Anal. 15:241–248.