Cytotoxic constituents and a new hydroxycinnamic acid derivative from Leontodon saxatilis (Asteraceae, Cichorieae)

In our ongoing research for the discovery of new constituents with antimyeloma activity, we investigated 15 compounds present in the aerial parts of Leontodon saxatilis for their cytotoxic potential against NCI-H929, U266, and OPM2 cell lines. One of the isolated compounds displayed a new natural product and was identified as 5-feruloyl-2α-hydroxyquinic acid after LC-MS and NMR experiments. Of the remaining compounds, cichoric acid and three flavone glycosides, apigenin 4′-O-β-d-glucoside, luteolin 7-O-β-d-glucoside and luteolin 4′-O-β-d-glucoside, showed moderate cytotoxic activity, whereas the effects of two aglyones apigenin and luteolin were more pronounced. Though the cytotoxic potential of the two aglycones (against other cell lines) was reported in various studies, our work moreover showed that cooccurrence of these two compounds with similar components of lower activity led to comparable results and at the same time minimized the damage of healthy fibroblast cells. Thus, our work could be a starting point for additional studies on the synergistic effect of similar components against myeloma cell lines.

Phytochemical investigation of the aerial parts of Leontodon saxatilis yielded six compounds with antimyeloma activity as well as crepidiaside A as a chemophenetic marker and 5-feruloyl-2α-hydroxyquinic acid as a new hydroxycinnamic acid derivative.

7-Isopentenyloxycoumarin: What Is New across the Last Decade

7-Isopentenyloxycoumarin is among the most widespread naturally occurring prenyloxy umbelliferone derivatives. This secondary metabolite of mixed biosynthetic origin has been typically isolated from plants belonging to several genera of the Rutaceae and Apiaceae families, comprising widely used medicinal plants and in general plants with beneficial effects on human welfare, as well as edible fruits and vegetables. Although known for quite a long time (more than 50 years), only in the last two decades has this natural compound been revealed to exert powerful and promising pharmacological properties, such as active cancer chemopreventive, antibacterial, antiprotozoal, antifungal, anti-inflammatory, neuroprotective, and antioxidant properties, among the activities best outlined in the recent literature. The aim of this comprehensive miniature review article is to detail the novel natural sources and the effects described during the last decade for 7-isopentenyloxycoumarin and what has been reported on the mechanisms of action underlying the observed biological activities of this oxyprenylated secondary metabolite. In view of the herein described data, suggestions on how to address future research on the abovementioned natural product and structurally related derivatives in the best ways according to the authors will be also provided.

A novel and efficient subcritical butane extraction method and UHPLC analysis of oxyprenylated phenylpropanoids from grapefruits peels

Biologically active prenyoxyphenylpropanoids are well known to be biosynthesized by Citrus species, for which they have been found most abundantly in fruit peels. Although several extraction methodologies have been described, the development of novel and alternative extraction processes is a field of research of current interest. In this preliminary communication, we studied the performance of the subcritical butane promoted extraction of selected oxyprenylated phenylpropanoids from grapefruit peels under a counter-current mode using a handmade extraction apparatus coupled to UHPLC analysis. The application of such a method yielded 7-isopentenyloxycoumarin, auraptene, and boropinic acid in quantities higher than those recorded for other extraction methodologies like the ultrasound- and microwave-assisted macerations (0.234, 1.035, and 0.211 mg/g of dry extract respectively). The use of subcritical butane as the extraction solvent for oxyprenylated phenylpropanoids is reported herein for the first time and can be easily adopted for several other food matrices.

Gercumin synergizes the action of 5-fluorouracil and oxaliplatin against chemoresistant human cancer colon cells

Advanced colon cancer is extremely difficult to cure, underscoring the need to develop novel therapeutic agents. Prenylated curcumins that are semisynthetic curcumin derivatives with significant anti-cancer potential have been studied herein to assess their therapeutic potential for colon cancer and tested to this aim in vitro for their growth inhibitory properties against 5-fluorouracil + oxaliplatin resistant human colon cancer CR-HT29 and HCT-116 cells. The resulting most active product, gercumin (mono-O-geranylcurcumin), has been further tested for its synergistic effects with FOLFOX (a combination of 5-fluorouracil and oxaliplatin) on the same cell lines. Activity of this combination on colonosphere formation was also investigated. Gercumin was able to suppress the growth of cancer cells with a potency similar to that of curcumin. A synergistic effect of this compound and FOLFOX was also observed. doses tested for synergy in the colonosphere assays did not show greater suppression of colonosphere formation than independent treatment with either reagent alone. Only one of the combinations was shown to be more effective at suppressing colonosphere formation [gercumin 5  μM + FOLFOX (2x)]. Thus, the growth inhibitory effects of curcumin against human cancer cells can be modulated and enhanced by the introduction of hydrophobic chains, normally found in several natural compounds, like the geranyl one. Such compounds are also able to synergize with known chemotherapeutics.

UHPLC-UV/Vis Quantitative Analysis of Hydroxylated and O-prenylated Coumarins in Pomegranate Seed Extracts

A simple and rapid analytical UHPLC methodology with spectrophotometric (UV/Vis) detection, coupled with different extraction procedures, has been perfected to investigate the presence of biologically active O-prenylated umbelliferone derivatives, such as auraptene and umbelliprenin, in pomegranate (Punica granatum L.) seed extracts. Absolute ethanol was the most efficient extraction solvent in terms of yields, after a short ultrasound-assisted. The highest concentration values recorded under these experimental conditions were 1.99 μg/g of dry extract and 6.53 μg/g for auraptene and umbelliprenin, respectively. The parent metabolite umbelliferone was also detected (0.67 μg/g). The extraction and UHPLC analytical methodology set up in the present study proved to be an efficient, powerful, and versatile technique for the simultaneous qualitative analysis and quantification of oxyprenylated coumarins in pomegranate seed extracts. The characterization of such secondary metabolites in the mentioned phytopreparation represents, to the best of our knowledge, the first example in the literature.

A Survey of the Anti-microbial Properties of Naturally Occurring Prenyloxyphenylpropanoids and Related Compounds

O-Prenylphenylpropanoids represent a group of rare natural products. During the last twenty years, such phytochemicals have been revealed to possess a great pharmacological potential. These compounds have been obtained for the most part from plant species of the Rutaceae, Apiaceae, and Fabaceae families, as well as from fungi and bacteria. In this review we wish to detail the state of the art about O-prenylphenylpropanoids having in vitro and in vivo anti-microbial properties from different points of view. The herein cited natural products are effective in inhibiting the virulence of human oral pathogens.

HPLC Analysis and Skin Whitening Effects of Umbelliprenin-containing Extracts of Anethum Graveolens, Pimpinella Anisum, and Ferulago Campestris

Umbelliprenin has recently been shown to have great potential as a skin whitening agent. Wishing to investigate the same effect in plant species known to biosynthesize this coumarin, three plants belonging to the Apiaceae family, namely Anethum graveolens L. (dill), Pimpinella anisum L. (anise), and Ferulago campestris (Besser) Grecescu (field ferula) were screened by HPLC analysis for their respective content of umbelliprenin in extracts obtained with different solvent mixtures and by maceration and ultrasound-assisted processes. EtOH was shown to be the best solvent, providing umbelliprenin yields ranging from 1.7% to 14.4% (with respect to the total amount of extract obtained). Extracts with the highest content of this farnesyloxycoumarin were then assayed as modulators of melanogenesis in cultured murine Melan A cells employing the same umbelliprenin obtained by chemical synthesis as the reference. A parallelism between the content of the coumarin and the recorded depigmenting effect (60% for the EtOH extract of F. campestris as the best value) was revealed for all plants extracts when applied at a dose of 100 μg/mL. Our results demonstrate that the same potential of umbelliprenin can be ascribed also to umbelliprenin-enriched plant extracts which reinforces enforce the widespread use of phyto-preparations for cosmetic purposes (e.g., A. graveolens).

Phytochemistry of the Genus Trichocolea

The genus Trichocolea (Fam. Trichocoleaceae) comprise 31 species of liverworts, most of which are endemic in a wide geographical area of the southern Pacific Ocean including New Zealand, Tasmania, and South Australia. Although few reports have been reported on the phytochemistry and pharmacognosy of these briophytes, data reported so far show a great pharmacological potential for their secondary metabolites. Phytochemicals isolated from Trichocolea spp. include benzoate esters, flavonoids, and diterpenes. The reported biological activities of these natural compounds refer to cancer cells growth inhibitory, antibacterial, anti-fungal, and anti-oxidant effects. The aim of this short review is to examine in detail from a phytochemical and pharmacological point of view what is reported in the current literature about the properties of phytopreparations or individual chemicals obtained from liverworts belonging to the Trichocolea genus.

Selenylated plant polysaccharides: A survey of their chemical and pharmacological properties

Polysaccharides from plants and fungi are considered nowadays as powerful pharmacological tools with a great therapeutic potential. In the meantime, efforts have been addressed to set up effective chemical modifications of naturally occurring polysaccharides to improve their biological effects as well as to positively modify some key parameters like solubility, bioavailability, pharmacokinetic, and similar. To this concern much attention has been focused during the last decade to the selenylation of natural polysaccharides from plants, algae, and fungi, the use of which is already encoded in ethnomedical traditions. The aim of this review article is to provide a detailed survey of the in so far reported literature data and a deeper knowledge about the state of the art on the chemical and pharmacological properties of selenylated polysaccharides of plant, algal, and fungal origin in terms of anti-oxidant, anti-cancer, anti-diabetic, and immunomodulatory activities. In all cases, literature data revealed that selenylation greatly improved such properties respect to the parent polysaccharides, indicating that selenylation is a valid, alternative, and effective chemical modification of naturally occurring carbohydrates.

A New Phytochemical and Anti-oxidant and Anti-inflammatory Activities of Different Lactuca sativa L. var. crispa Extracts

The phytochemical composition of Lactuca sativa L. var. crispa, commonly known as crisphead lettuce, from Morocco has been re-investigated for the presence of oxyprenylated cinnamic acid and coumarin derivatives. In the mean time also the anti-oxidant and anti-inflammatory effects of extracts from leaves obtained by the use of a Soxhlet apparatus have been assessed. The extracts had a high content of polyphenols with remarkable differences ranging from 0.19 to 0.38 mg gallic acid eq/mg, while the content of flavonoids ranged from 3.75 to 9.64 mg catechin eq/g. The hydroalcoholic extract with a polarity index of 5.8 displayed the best anti-oxidant, radical scavenging, and anti-inflammatory activities. The same extracts were screened by reverse-phase HPLC-UV/V analysis for the presence of biologically active oxyprenylated phenylpropanoids. Only 4'-geranyloxyferulic acid was recorded in detectable amounts. Results described herein enforce the nutraceutical value and depict a potential chemopreventive dietary feeding role for crisphead lettuce.

A green deep eutectic solvent dispersive liquid-liquid micro-extraction (DES-DLLME) for the UHPLC-PDA determination of oxyprenylated phenylpropanoids in olive, soy, peanuts, corn, and sunflower oil

A green dispersive liquid-liquid microextraction (DLLME) using deep eutectic solvent (DES) as the extracting solvent has been developed and applied for the simultaneous quantification of ferulic acid, umbelliferone, boropinic acid, 7-isopentenyloxycoumarin, 4'-geranyloxyferulic acid (GOFA), and auraptene in some vegetable oils using ultra high performance liquid chromatography (UHPLC) with photodiode array detection (PDA). All parameters in the extraction step, including selection and loading of both extracting and dispersing solvents, amount of both extractant and disperser solvent were investigated and optimized. PhAA/TMG DES achieved higher recovery and enrichment factor compared to other DESs. The validated method showed good linearity with correlation coefficients, r²>0.9990 for all the analytes. Furthermore, this is the first time that eco-friendly solvents are used for the extraction of oxyprenylated phenylpropanoids and the corresponding extract analyzed with ultra high performance liquid chromatography with photodiode array detection.

[Transvaginal echographic evaluation of myometrial invasion in patients with endometrial cancer]

Twenty-one patients with endometrial cancer who underwent laparotomy, were pre-operatively examined by transvaginal sonography. A deep myometrial invasion (> 50%) was noted sonographically in 9 patients (42.3%), with a superficial invasion (< 50%) in 12 (57.2%). A deep invasion was histologically seen in 10 patients (47.6%), with a superficial invasion in 11 (52.4%). In myometrial deep invasion evaluation, transvaginal sonography showed a 90% sensibility, a 73% specificity, a 75% positive predictive value and a 93% negative predictive value. In 3 cases (14.3%) the invasion depth was sonographically overestimated and in 1 case (4.8%) underestimated. These results make possible an important role of transvaginal sonography in staging endometrial cancer, to select patients needing for pelvic and lomboaortic lymphadenectomy over total abdominal hysterectomy with vaginal collar.