Hypericin and pseudohypericin concentrations of a valuable medicinal plant Hypericum perforatum L. are enhanced by arbuscular mycorrhizal fungi

Hypericum perforatum L. (St. John’s-wort, Hypericaceae) is a valuable medicinal plant species cultivated for pharmaceutical purposes. Although the chemical composition and pharmacological activities of H. perforatum have been well studied, no data are available concerning the influence of arbuscular mycorrhizal fungi (AMF) on this important herb. A laboratory experiment was therefore conducted in order to test three AMF inocula on H. perforatum with a view to show whether AMF could influence plant vitality (biomass and photosynthetic activity) and the production of the most valuable secondary metabolites, namely anthraquinone derivatives (hypericin and pseudohypericin) as well as the prenylated phloroglucinol—hyperforin. The following treatments were prepared: (1) control—sterile soil without AMF inoculation, (2) Rhizophagus intraradices (syn. Glomus intraradices), (3) Funneliformis mosseae (syn. Glomus mosseae), and (4) an AMF Mix which contained: Funneliformis constrictum (syn. Glomus constrictum), Funneliformis geosporum (syn. Glomus geosporum), F. mosseae, and R. intraradices. The application of R. intraradices inoculum resulted in the highest mycorrhizal colonization, whereas the lowest values of mycorrhizal parameters were detected in the AMF Mix. There were no statistically significant differences in H. perforatum shoot mass in any of the treatments. However, we found AMF species specificity in the stimulation of H. perforatum photosynthetic activity and the production of secondary metabolites. Inoculation with the AMF Mix resulted in higher photosynthetic performance index (PItotal) values in comparison to all the other treatments. The plants inoculated with R. intraradices and the AMF Mix were characterized by a higher concentration of hypericin and pseudohypericin in the shoots. However, no differences in the content of these metabolites were detected after the application of F. mosseae. In the case of hyperforin, no significant differences were found between the control plants and those inoculated with any of the AMF applied. The enhanced content of anthraquinone derivatives and, at the same time, better plant vitality suggest that the improved production of these metabolites was a result of the positive effect of the applied AMF strains on H. perforatum. This could be due to improved mineral nutrition or to AMF-induced changes in the phytohormonal balance. Our results are promising from the biotechnological point of view, i.e. the future inoculation of H. perforatum with AMF in order to improve the quality of medicinal plant raw material obtained from cultivation

Cation exchange HPLC analysis of desmosines in elastin hydrolysates

Desmosine crosslinks are responsible for the elastic properties of connective tissues in lungs and cardiovascular system and are often compromised in disease states. We developed a new, fast, and simple cation exchange HPLC assay for the analysis of desmosine and isodesmosine in animal elastin. The method was validated by determining linearity, accuracy, precision, and desmosines stability and was applied to measure levels of desmosines in porcine and murine organs. The detection and quantification limits were 2 and 4 pmol, respectively. The run-time was 8 min. Our cation exchange column does not separate desmosine and isodesmosine, but their level can be quantified from absorbance at different wavelengths. Using this assay, we found that desmosines levels were significantly lower in elastin isolated from various organs of immunodeficient severe combined immunodeficiency mice compared with wild-type animals. We also found that desmosines levels were lower in lung elastin isolated from hyperhomocysteinemic Pcft−/− mice deficient in intestinal folate transport compared with wild-type Pcft+/+ animals

Syntéza a fyzikálně-chemické vlastnosti [(1R,2S,5R)-2-isopropyl-5-methylcyklohexyloxy]-thiofen-5-yl-substituovaných tetrapyrazinoporfyrazinů s manganatými ionty

Tetrapyrazinoporphyrazine with peripheral menthol-thiophenyl substituents was synthesized using Linstead conditions and purified by flash column chromatography. The optimized synthetic and purification procedures allowed us to obtain a new macrocycle with 36% yield. Tetrapyrazinoporphyrazine derivative was characterized by UV-Vis and NMR spectroscopy, as well as MS spectrometry. Complex NMR studies using 1D and 2D NMR techniques allowed the analysis of the bulky menthol-thiophenyl substituted periphery of the new macrocycle. Further, photochemical stability and singlet oxygen quantum yield were determined by indirect method with diphenylisobenzofuran. The new tetrapyrazinoporphyrazine revealed low generation of singlet oxygen with a quantum yield of singlet oxygen formation at 2.3% in dimethylformamide. In turn, the macrocycle under irradiation with visible light presented very high stability with quantum yield for photostability of 9.59 x 10(-6) in dimethylformamide, which figures significantly exceed the border for its classification as a stable porphyrinoid (10(-4)-10(-5)).Byly syntetizovány tetrapyrazinoporfyraziny s postranními menthol-thiofenovými substituenty, produkty byly čištěny sloupcovou chromatografií. Deriváty byly charakterizovány UV-Vis a NMR spektroskopií. Byly stanoveny fotochemická stabilita a kvantový výtěžek singletového kyslíku

Synthesis and biological activity of novel phthalocyanines with dietheroxy and nitroimidazolylethoxy moieties

Phthalocyanines (Pcs) are aromatic macrocyclic compounds consisting of four isoindole fragments linked together with azomethine groups. These synthetic analogues of natural porphyrinoids are known to possess wide applications in dyes industry, In materials chemistry as sensors, molecular semiconductors and non-linear optical materials, and as photosensitizers in photodynamic therapy. Medical applications of phthalocyanines impose good solubility in water and increased accumulation in pathologic tissues. The structure of Pcs may be modified by introducing substituents at their peripheral and non-peripheral positions, as well as various metal ions into the central cavity of a macrocycle. Good solubility in water can be reached by introducing polyetheric substituents in non-peripheral positions. Increased accumulation in hypoxic tissues such as can tissues can be reached by incorporating nitroimidazole moieties to the structure. New compounds were synthesized according to the procedure shown on Figure 1 [see PDF]. Newly synthesized phthalocyanines Pc-1, Pc-2, Pc-3, Pc-4 as well as the precursor dinitriles 1 and 2 were fully characterized by NMR, UV-Vis, MS, HPLC. Additionally, new dinitryles were characterized by combustion analysis and crystallographic data. New phthalocyanines were tested for photodynamic activity against human oral squamous carcinoma cells HSC-3. The best activity was revealed by compound Pc-3 possessing two types of substituents - dietheroxy and nitroimidazolylethoxy. Pc-3 showed phototoxicity at the level of IC50 0.10 μM. Zinc compound Pc-2 was three times more active than the magnesium Pc-1 and seems to be a promising compound for further research. This study was supported by the National Science Centre under Grant No. N401067238

Synthesis and biological activity of novel phthalocyanines with dietheroxy and nitroimidazolylethoxy moieties

Phthalocyanines (Pcs) are aromatic macrocyclic compounds consisting of four isoindole fragments linked together with azomethine groups. These synthetic analogues of natural porphyrinoids are known to possess wide applications in dyes industry, In materials chemistry as sensors, molecular semiconductors and non-linear optical materials, and as photosensitizers in photodynamic therapy. Medical applications of phthalocyanines impose good solubility in water and increased accumulation in pathologic tissues. The structure of Pcs may be modified by introducing substituents at their peripheral and non-peripheral positions, as well as various metal ions into the central cavity of a macrocycle. Good solubility in water can be reached by introducing polyetheric substituents in non-peripheral positions. Increased accumulation in hypoxic tissues such as can tissues can be reached by incorporating nitroimidazole moieties to the structure. New compounds were synthesized according to the procedure shown on Figure 1 [see PDF]. Newly synthesized phthalocyanines Pc-1, Pc-2, Pc-3, Pc-4 as well as the precursor dinitriles 1 and 2 were fully characterized by NMR, UV-Vis, MS, HPLC. Additionally, new dinitryles were characterized by combustion analysis and crystallographic data. New phthalocyanines were tested for photodynamic activity against human oral squamous carcinoma cells HSC-3. The best activity was revealed by compound Pc-3 possessing two types of substituents - dietheroxy and nitroimidazolylethoxy. Pc-3 showed phototoxicity at the level of IC50 0.10 μM. Zinc compound Pc-2 was three times more active than the magnesium Pc-1 and seems to be a promising compound for further research. This study was supported by the National Science Centre under Grant No. N401067238

Sulfanyl porphyrazines: Molecular barrel-like self-assembly in crystals, optical properties and in vitro photodynamic activity towards cancer cells

Novel sulfanyl porphyrazines with peripheral 4-bromobenzyl and 4-biphenylylmethyl substituents were synthesized, characterized by photochemical methods and evaluated as sensitizers for photodynamic therapy (PDT). The X-ray crystallography study performed for sulfanyl porphyrazine with 4-biphenylylmethyl substituents revealed that the biphenylyl residues from two consecutive molecules form barrel-like cages with a macrocyclic core constituting a bottom and a top of the barrel and pyridine molecules enclosed inside. The optical properties of both porphyrazines were evaluated in various protic and aprotic solvents. To complement the conventional fluorescence measurements excitation-emission maps were recorded. The potential photosensitizing efficiency of the novel sulfanyl porphyrazines was evaluated by assessing the quantum yields of photosensitized singlet oxygen production. For this purpose the emission of light specific for the transition of singlet oxygen to ground state oxygen was measured. Photodynamic activities of porphyrazines and their liposomal formulations with different surface charge toward two oral squamous cell carcinoma cells (CAL 27, HSC-3) and human cervical epithelial adenocarcinoma cells (HeLa) were determined. Sulfanyl porphyrazines incorporated in cationic liposomes showed high activity, in contrast to the lack of activity of the free form porphyrazines in solution. Thus, cationic liposomes composed of 1,2-dioleoyl-3-trimethylammonium-propane and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine can be considered as a promising drug delivery system for the sulfanyl porphyrazines for the photodynamic therapy of cancers

Dendrimeric Sulfanyl Porphyrazines: Synthesis, Physico-Chemical Characterization, and Biological Activity for Potential Applications in Photodynamic Therapy

Sulfanyl porphyrazines substituted at their periphery with different dendrimeric moieties up to their first generation were synthesized and characterized by photochemical and biological methods. The presence of a dendrimeric periphery enhanced the spectral properties of the porphyrazines studied. The singlet-oxygen-generation quantum yield of the obtained macrocycles ranged from 0.02 to 0.20 and was strongly dependent on the symmetry of the compounds and the terminal groups of the dendritic outer shell. The in vitro biological effects of three most promising tribenzoporphyrazines were examined; the results indicated their potential as photosensitizers for photodynamic therapy (PDT) against two oral squamous cell carcinoma cell lines derived from the tongue. The highest photocytotoxicity was found for sulfanyl tribenzoporphyrazine that possessed 4-[3,5-di(hydroxymethyl)phenoxy]butyl substituents with nanomolar IC50 values at 10 and 42 nm against CAL 27 and HSC-3 cell lines, respectively. Topic of cancer: Sulfanyl porphyrazines and tribenzoporphyrazines substituted at their periphery with different dendrimeric moieties up to their first generation were synthesized and characterized by photochemical and biological methods. The in vitro biological effects of three most promising tribenzoporphyrazines were examined and found to exhibit nanomolar IC50 values (see figure)