Filiferol, a chalconoid analogue from Washingtonia filifera possibly involved in the defence against the Red Palm Weevil Rhynchophorus ferrugineus Olivier.

A chalconoid analogue, 1,3,5-benzentriol 2-[(2S,3R)-3-(3,4-dihydroxylphenyl)-2,3-dihydroxylpropyl], named filiferol (1), has been isolated and purified for the first time from the leaf basal tissues of the palm species Washingtonia filifera. The chemical structure of the isolated compound has been elucidated unambiguously by spectroscopic and chemical methods. Filiferol has been based on a flavonol structure with the reduction of the common flavonoid keto group to give an unprecedented methylene carbon on the three carbon chain. An analogous compound with S stereochemistry at C3 has been obtained as synthetic intermediate for developing an enantioselective synthesis of (2R,3S)-(+)-catechin. Even though 1 proved to be deprived of antifungal properties, it displays a very effective larvicidal activity against Red Palm Weevil, Rhynchophorus ferrugineus, an important pest affecting cultivated and ornamental palms. 1 has been isolated from leaf tissues of W. filifera, a species resistant to this pest, but this molecule seems instead undetectable in tissues of other palm species susceptible to the parasite. The presence of 1 could therefore account for W. filifera natural resistance to the attacks of the Red Palm Weevil (R. ferrugineus).

Endogenous isoflavone methylation correlates with the in vitro rooting phases of Spartium junceum L. (Leguminosae).

Spartium junceum L. (Leguminosae) is a perennial shrub, native to the Mediterranean region in southern Europe, widespread in all the Italian regions and, as a leguminous species, it has a high isoflavone content. An in vitro culture protocol was developed for this species starting from stem nodal sections of in vivo plants, and isoflavone components of the in vitro cultured tissues were studied by means of High Performance Liquid Chromatography (HPLC) analytical techniques. Two main isoflavones were detected in the S. junceum tissues during the in vitro propagation phases: Genistein (4',5,7-Trihydroxyisoflavone), already reported in this species, and its methylated form 4',5,7-Trimethoxyisoflavone, detected for the first time in this plant species (0.750 ± 0.02 mg g(-1) dry tissue). The presence of both of these compounds in S. junceum tissues was consistently detected during the in vitro multiplication phase. The absence of the methylated form within plant tissues in the early phases of the in vitro adventitious root formation was correlated with its negative effect displayed on root induction and initiation phases, while its presence in the final "root manifestation" phase influenced positively the rooting process. The unmethylated form, although detectable in tissues in the precocious rooting phases, was no longer present in the final rooting phase. Its effect on rooting, however, proved always to be beneficial.

Inhibition of in vitro growth and arrest in the G0/G1 phase of HCT8 line human colon cancer cells by kaempferide triglycoside from Dianthus caryophyllus.

The effects of phytoestrogens have been studied in the hypothalamic-pituitary-gonadal axis and in various non-gonadal targets. Epidemiologic and experimental evidence indicates a protective effect of phytoestrogens also in colorectal cancer. The mechanism through which estrogenic molecules control colorectal cancer tumorigenesis could possibly involve estrogen receptor beta, the predominantly expressed estrogen receptor subtype in colon mucosa.To validate this hypothesis, we therefore used an engineered human colon cancer cell line induced to overexpress estrogen receptor beta, beside its native cell line, expressing very low levels of ERbeta and not expressing ERalpha; as a phytoestrogenic molecule, we used kaempferide triglycoside, a glycosylated flavonol from a Dianthus caryophyllus cultivar. The inhibitory properties of this molecule toward vegetal cell growth have been previously demonstrated: however, no data on its activity on animal cell or information about the mechanism of this activity are available. Kaempferide triglycoside proved to inhibit the proliferation of native and estrogen receptor beta overexpressing colon cancer cells through a mechanism not mediated by ligand binding dependent estrogen receptor activation. It affected HCT8 cell cycle progression by increasing the G(0)/G(1) cell fraction and in estrogen receptor beta overexpressing cells increased two antioxidant enzymes. Interestingly, the biological effects of this kaempferide triglycoside were strengthened by the presence of high levels of estrogen receptor beta.Pleiotropic molecular effects of phytoestrogens may explain their protective activity against colorectal cancer and may represent an interesting area for future investigation with potential clinical applications.