Arbuscular mycorrhizal fungi alter the content and composition of secondary metabolites in Bituminaria bituminosa L.

Secondary metabolites may be affected by arbuscular mycorrhizal fungi (AMF), which are beneficial symbionts associated with the roots of most plant species. Bituminaria bituminosa (L.) C.H.Stirt is known as a source of several phytochemicals and therefore used in folk medicine as a vulnerary, cicatrising, disinfectant agent. Characteristic metabolites found in B. bituminosa are furanocoumarins and pterocarpans, which are used in cosmetics and as chemotherapeutic agents. Here we address the question whether AMF inoculation might affect positively the synthesis of these phytochemicals. B. bituminosa plants were inoculated with different AMF and several metabolites were assessed during full vegetative stage and flowering phase. Pigments (chlorophylls and carotenoids), polyphenols and flavonoids were spectrophotometrically determined; specific isoflavones (genistein), furanocoumarins (psoralene and angelicin), pterocarpans (bitucarpin A and erybraedin C) and plicatin B were assessed with HPLC; leaf volatile organic compounds were analysed using SPME and identified by GC-MS. During the vegetative stage, the inoculated plants had a high amount of furanocoumarins (angelicin and psoralen) and pterocarpans (erybraedin C and bitucarpin A). The analysis of volatile organic compounds of inoculated plants showed different chemical composition compared with non-mycorrhizal plants. Given the important potential role played by furanocoumarins and pterocarpans in the pharmaceutical industry, AMF inoculation of B. bituminosa plants may represent a suitable biotechnological tool to obtain higher amounts of such metabolites for pharmaceutical and medicinal purposes.

Phytochemical study of Bituminaria basaltica aerial parts, an Italian endemism.

The first phytochemical investigation of the aerial parts of Bituminaria basaltica, an endemic species from the Aeolian Islands, led to the isolation and identification of eight compounds including plicatin B (3), two furanocoumarins: angelicin (1), psoralen (2), three pterocarpans: erybraedin C (4), 3,9-dihydroxy-4-isoprenyl-pterocarpan (5), bitucarpin A (8) and two flavonoid glycosides: isoorientin (6), daidzin (7). Their structures were elucidated by spectroscospic techniques and compared with data reported in the literature. Sesquiterpenes characterised the essential oil composition of the title plant where ß-caryophyllene and germacrene D were the main constituents.