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The interaction of (gentisic acid) GA with (bovine serum albumin) BSA has been studied by different spectroscopic techniques. GA is a monoanionic specie at the working pH of 7.4, it was determined by combining UV–Vis absorption spectroscopy and theoretical calculations. A set of fluorescence quenching experiments at different temperatures was carried out employing the native fluorescence of BSA. A Stern–Volmer constant (KSV) of (2.07 ± 0.12) × 104 mol−1 L and a binding constant (Ka) of (8.47 ± 4.39) × 103 were determined at 310 K. The static quenching caused by the BSA–GA complex formation seems to play a significant role in the overall quenching process. A single binding site on BSA for GA was observed. ΔH = −55.6 ± 0.2 kJ mol−1 and ΔS = −104.3 ± 0.6 J mol−1 K−1 were determined in a set of experiments on the dependence of Ka with the temperature. The binding process is, therefore, spontaneous and enthalpy-driven. Van der Waals forces and hydrogen bonds could also play the major role in the binding mode. The secondary structure changes of BSA in the absence and presence of GA were studied by FTIR and UV–Vis absorption spectroscopy.

a b s t r a c t Crocus sativus is a triploid sterile plant and autumnal flowering geophyte with corms. As a subterranean organ, the corm is susceptible to diseases caused by fungi, bacteria, nematodes and viruses. Fusarium corm rot incited by F. oxysporum is the most destructive disease in saffron, having caused severe yield losses in saffron producer's countries. Infected plants die off early, resulting in reduction of corm yield, quality and flower and stigma production. Little is known about the formae speciales attacking saffron and less about the relationship among the fungus and the possible hosts. In this study we investigate the formae speciales which colonize saffron and their relationship with some members of iridaceae such as C. vernus (ornamental crocus), gladiolus and narcissus using pathogenicity tests; we determine whether different pathogenic isolates of F. oxysporum can be distinguished by ISSR, and we analyze the genetic relationships and variability among some isolates of these pathogens. We found two formae speciales iridiacearum and croci which attack different iridaceous crops and Crocus sp., respectively and we suggested the creation of a new formae speciales saffrani which shows only pathogenicity on saffron corms. From ISSR analysis, the unweighted paired group method with arithmetic averages cluster analysis (UPGMA) was used to discriminate the F. oxysporum isolates, we were able to differentiate among f. sp. from saffron corms and other formae speciales of F. oxysporum but not among formae speciales iridiacearum, croci and saffrani. Furthermore, we searched for fum1, tri5, tri7 and tri13 genes using PCR assays, however, all the isolates from saffron corms were negative.

Ethnopharmacological relevance The Helianthemum genus contains approximately one hundred taxa. Some of them are important medicinal plants used in several countries for many different purposes. However, studies addressing the phytochemistry of many of these species or their biological activities are currently nonexistent. Aim of the study To perform a comparative analysis of the qualitative composition of secondary metabolites and biological activities of the leaves of the most commonly distributed and used Spanish Helianthemum taxa in order to find a relationship between chemotype, biological activity and uses. Materials and methods water and 80% methanolic extracts derived from 11 different Helianthemum taxa were analyzed for their phytochemical composition using standard methods. Furthermore, HPLC analysis was performed for the estimation of gallic acid, ellagic acid, tannins and flavonols as marker compounds. The antioxidant activity was measured by employing the scavenging activity on DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonate) radicals. The 80% methanolic extracts were evaluated for antibacterial (Gram-positive Staphylococcus aureus , Enterococcus faecalis and Listeria monocytogenes and Gram-negative Escherichia coli and Salmonella enterica ) activity using the micro dilution technique. Results The total polyphenolic content and antioxidant capabilities differed significantly among the Helianthemum leaf extracts. A strong correlation between total phenolic content, antioxidant properties and antimicrobial activity was found. The polyphenolic profile was specific for each taxon. Whereas Helianthemum alypoides , Helianthemum cinereum subsp. rotundifolium , Helianthemum hirtum , Helianthemum asperum , and Helianthemum marifolium subsp. marifolium were characterized by the presence of gallic acid, egallic derivatives and ellagitannins; the polyphenolic profile of Helianthemum apenninum subsp. c avanillesianum , Helianthemum syriacum and Helianthemum polygonoides was mostly based on flavonoids. Helianthemum cinereum , Helianthemum alypoides and Helianthemum marifolium consistently presented the strongest radical scavenging activity (in water extracts EC 50 ranges from 29.88 to 38.1 against DPPH and from 8.11 to 20.8 against ABTS, and in 80% MeOH extracts from 25.3 to 31.8 against DPPH and from 6.15 to 8.6 against ABTS), total phenol content (>117 mg GAE/l) and antimicrobial activities. Conclusion The Helianthemum taxa used in folk medicine did not cluster in a unique section, being equally distributed in two out of the four sections analysed. There was not a clear relationship between the chemotype, based on the polyphenolic composition of the taxa, and their taxonomical classification. However, the composition of the methanolic and water extracts from the leaves of plants belonging to the Helianthemum genus was strongly related to their medicinal uses.

Protein and peptide-based vaccines provide rigorously formulated antigens. However, these purified products are only weakly immunogenic by themselves and therefore require the addition of immunostimulatory components or adjuvants in the vaccine formulation. Various compounds derived from pathogens, minerals or plants, possess pro-inflammatory properties which allow them to act as adjuvants and contribute to the induction of an effective immune response. The results presented here demonstrate the adjuvant properties of novel saponins derived from the Spanish saffron Crocus sativus. In vivo immunization studies and tumor protection experiments unambiguously establish the value of saffron saponins as candidate adjuvants. These saponins were indeed able to increase both humoral and cellular immune responses to protein-based vaccines, ultimately providing a significant degree of protection against tumor challenge when administered in combination with a tumor antigen. This preclinical study provides an in depth immunological characterization of a new saponin as a vaccine adjuvant, and encourages its further development for use in vaccine formulations.

The Crocus genus, which comprehends approximately 80 species, is known mainly for the triploid sterile plant C. sativus, whose dried stigmas provide us with the spice called saffron. Among the species belonging to the C. sativus L. aggregate, C. cartwrightianus cv. albus shares morphological and cytological characters with both C. sativus and C. cartwrightianus, although its positions seem to be uncertain. Due to the complexity of the genus, few studies have revised the classification proposed by Mathew in 1982. In the present study, intersimple sequence repeat (ISSR) and HPLC–ESI-MS analyses have been used in an attempt to clarify the taxonomical position of cv. albus. No differences were found between C. sativus and C. cartwrightianus cv. albus using 12 ISSR primers. Results on apocarotenoid contents from HPLC analysis showed some quantitative differences. According to our findings, C. cartwrightianus cv. albus is more related to C. sativus than to C. cartwrightianus and may be an albinic saffron. These data agree with other authors who reached the same conclusion using different techniques. The results obtained in this work may be used in improving programme of saffron spice.

Saffron, the desiccated stigmas of Crocus sativus, is highly appreciated for its peculiar colour, flavour and aroma. Several studies have been conducted with the spice, but little is known about the evolution of volatile and non-volatile compounds generated during the development of the stigma. In this study, we have followed these compounds, with special attention to those of isoprenoid origin (carotenoids and monoterpenes), which are responsible for the organoleptic properties of saffron. The main compounds that accumulated throughout stigma development in C. sativus were crocetin, its glucoside derivatives and picrocrocin, all of which increased as stigmas reached a fully developed stage. The volatile composition of C. sativus stigmas changed notably as stigmas developed with each developmental stage being characterized by a different volatile combination. In red stigmas, beta-cyclocitral, the 7,8 cleavage product of beta-carotene, was highly produced, suggesting the implication of both beta-carotene and zeaxanthin in crocetin formation. As stigmas matured, hydroxy-beta-ionone and beta-ionone were produced while safranal, the most typical aroma compound of the processed spice, was only detected at low levels. However, a safranal-related compound 2,2,2-trimethyl-2-cyclohexene-1,4-dione (4-oxoisophorone) increased rapidly at the anthesis stage and also in senescent stigmas. Monoterpenes were mainly emitted at the time of anthesis and the emission patterns followed the expression patterns of two putative terpene synthases CsTS1 and CsTS2. Fatty acid derivates, which predominated at the earlier developmental stages, were observed at low levels in later stages.