Proceedings of the XLVII Italian Society of Agricultural Genetics - SIGA Annual Congress

Verona, Italy - 24/27 September, 2003

ISBN 88-900622-4-X

Poster Abstract - 3.22

STRATEGIES FOR THE IDENTIFICATION OF BIOACTIVE MOLECOLES IN PASSIFLORA SSP.

F. GUZZO*, S. CEOLDO*, F. ANDREETTA*, A.M. MARCONI**, M. LEVI*

*) Università di Verona, Dipartimento Scientifico e Tecnologico, Strada le Grazie 15, Cà Vignal 1, 37134 Verona

**) Laboratori Agro-Alimentari Consorzio ZAI, Via Sommacampagna, Verona

Passiflora ssp, bio-guided fractionation, antimicobial activity

The genus Passiflora comprises several hundred species, grouped in 21 subgenera. Only some species of the genus (P. edulis, P. quadrangularis, P. ligularis) are widely studied for their economic importance and are chiefly cultivated for production of fruit juice. P. incarnata is well known for its sedative properties and several other species are of ethnobotanical importance (see The Phytochemical and Ethnobotanical Databases, at http://www.ars-grin.gov/cgi-bin/duke/ethnobot.pl). Most of the species are almost completely unstudied.

Unfortunately, in temperate countries, plants of only few species of the Passiflora genus are available and are commonly grown as garden or pot plants. For most of the Passiflora species, only the dehydrated seeds can be readily purchased. However, dehydrated seeds of many Passiflora species may require many months, and up to two years to germinate (Vanderplank, Passiflora Society International Meeting, Rome, 15-16 september 2001). In order to produce an in vitro culture collection of Passiflora species together with a green house collection of plants as a source of starting material, we set up a zygotic embryo culture technique. Of the 61 species available, we obtained stable undifferentiated calli from twenty eight species, fourteen of which also regenerated plants; for five of these fourteen species (P. foetida, P. palmeri, P. coriacea, P. tenuifila, P. apetala) regenerated plants material was enough for chemicals extraction and bioactivity determination. One more specie (P. nitida) did not regenerate but produced one plant through in vitro embryo germination, and this plant was .screened as well for the biological activity.

A biological assay was developed for screening of potential antibacterial compounds, based on growth inhibition of wild type E. coli strains. In this assay the growth inhibition is determined through the spectrophotometric determination of broth turbidity at 600nm. As initial screening, crude methanolic extracts from the 6 Passiflora species indicated above were tested, and two species (P. palmeri and P. nitida) showed to have antibacterial activity. The assay was also used for bio-assay guided fractionation of the extracts. The crude extract from P. nitida was fractionated by Solid Phase Extraction and HPLC, and only one active fraction was identified in both cases.

Cytometric determination of live and dead bacteria showed that the extracts caused cell death very rapidly.