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An HPLC-PDA method was developed for the determination of the flavonoids in the flowers of Primula veris from Epirus, Greece. The aim was to investigate the chemical content of the over-harvested P. veris populations of Epirus and to develop and optimize an extraction protocol to allow fast, exhaustive, and repeatable extraction. Qualitative analysis revealed that the P. veris flowers from Epirus were particularly rich in flavonoids, especially flavonol triglycosides including derivatives of quercetin, isorhamnetin, and kaempferol. A phytochemical investigation of a 70% hydromethanolic extract from the flowers afforded a new flavonoid, namely, isorhamnetin-3-Ο-β-glucopyranosyl-(1 → 2)-β-glucopyranosyl-(1 → 6)-β-glucopyranoside, which is also the main constituent of the flower extracts. Its structure elucidation was carried out by means of 1D and 2D NMR and mass spectrometry analyses. The HPLC-PDA method was developed and validated according to the International Council for Harmonisation guidelines. Since the main flavonol glycoside of the plant is not commercially available, rutin was used as a secondary standard and the response correction factor was determined. Finally, the overall method was validated for precision (% relative standard deviation ranging between 1.58 and 4.85) and accuracy at three concentration levels. The recovery ranged between 93.5 and 102.1% with relative standard deviation values

In this study, the chemical content of the threatened Cretan endemic Chaerophyllum creticum Boiss. & Heldr. was investigated by High Performance Liquid chromatography-Photodiode Array-Mass Spectrom...

The phenolic profile of Greek chamomile populations was investigated by HPLC-PDA-MS. For comparison, three commercial varieties (Banatska, Lutea and Goral) cultivated under the same conditions were included in the study. All samples exhibited similar qualitative patterns but differed in their quantitative characteristics. Overall, 29 constituents were detected, belonging to phenolic acids, flavonol glycosides, flavone glycosides (mainly apigenin derivatives) and acylated polyamines. Quantitative results showed that both Greek populations had a high content in apigenin derivatives (0.39 and 0.31 %w/w) and caffeoylquinic acids (0.96 and 0.81 %w/w), whereas they had the highest amount of flavonol glycosides among the tested samples. Greek populations were comparable to the Banatska variety, while they were superior to the Lutea and Goral varieties cultivated under the same conditions. Results demonstrate that Greek chamomile populations studied here, are an excellent source of a wide range of phenolics which contribute to the medicinal and antioxidant properties of this herbal remedy. Antioxidant tests showed that chamomile extracts from the studied materials, especially from the Greek populations possess antioxidant activity, corresponding to their polyphenol content. This is the first report on the phenolic constituents of Matricaria recutita growing in Greece and well-established chamomile varieties.

Aim of this work was the chemical profiling of six Stachys taxa from Balkan Peninsula: S. recta subsp. nitens, S. atherocalyx, S. beckeana, S. zepcensis (all four belonging to S. recta group), S. alpina subsp. dinarica and S. plumosa. Dry ethanol extracts of aerial flowering plant parts were qualitatively and quantitatively characterized for their phenolic composition using the HPLC-DAD-ESI-MS technique. In total, 44 phenolic compounds were detected, belonging to three main classes of constituents: phenolic acids, phenylethanol glycosides (PhGs) and flavonoids. Chlorogenic acid was the main phenolic acid in all samples. Regarding PhGs, in all investigated extracts acteoside and lavandulifolioside were present. In S. recta group, extracts of S. atherocalyx, S. recta subsp. nitens and S. beckeana showed similar pattern considering phenylethanol glycosides, while S. zepcensis contained only the two aforementioned compounds. PhGs profile of S. plumosa extract comprised the same compounds from S. recta group, but it was also characterized by the presence of few high-molecular compounds. PhGs composition of S. alpina subsp. dinarica extract was somewhat similar with those of S. recta group and also with S. plumosa, but still specific by the presence of echinacoside and leucosceptoside A. The main flavonoids in extracts of Stachys recta group as well as in S. alpina subsp. dinarica extract were 8-hydroxyflavone glycosides (7-O-allosylglucosides of isoscutellarein and hypolaetin and their 4′-methyl derivatives). In addition, in the extract of S. alpina subsp. dinarica two luteolin-7-O-hexosides were also present. On the other hand, S. plumosa extract differed considerably containing mainly derivatives of chrysoeriol and apigenin, while 8-hydroxyflavones (isoscutellarein derivatives) were detected in traces. The results confirmed the importance of flavone 7-O-allosylglucosides at the sectional level of Stachys genus.

Inorganic cells bearing calcium silicate membranes were prepared and resembled closed chemical gardens. It was demonstrated that these inorganic cells can successfully be loaded with natural products, proteins and plasmid DNA, and their cargo can be released in a controlled manner. These cells demonstrated the ability of chemical gardens to act as platforms for the sustained delivery of biomolecules and are expected to introduce chemical gardens in the field of biosciences.

Malaria treatment and control have become increasingly difficult because of the spread of drug-resistant strains of Plasmodium falciparum and Plasmodium vivax. Thus, there is a continuous need to develop new combination therapies such as artemisinin-based combination therapies (ACTs) to contrast the emergence of resistant Plasmodium strains. Despite ACT has been recommended by the World Health Organization since 2001, its overall deployment in poor endemic areas is very slow, principally due to its high cost. In the malaria endemic areas, plant remedies are still widely used mostly without assurance of their efficacy and/or safety. A variety of widespread herbal drugs or natural products were already reported for their possible plasmodicidal activities, but the studies concerning their activity in combination with artemisinins are very scarce. The antimalarial activity of papaya is mostly anecdotal, and the present study is aimed at investigating the antiplasmodial activity of a decoction obtained by traditional recipe from the mature leaves of Carica papaya. The decoction was analyzed by HPLC-DAD-MS (high performance liquid chromatography coupled with diodoarray detector and mass spectrometry) showing the presence of caffeoyl derivatives and di- and triglycosides of flavonols. The extract was found to be active against P. falciparum 3D7 strains with a synergism in the presence of artemisinin. In vivo activity against the murine malaria model of Plasmodium berghei was disclosed both for the dried extract alone (250, 500, and 750 mg/kg/d) and for its combination with artesunate (250 mg/kg/d papaya plus 10 mg/kg/d artesunate). This combination displayed the greatest antimalarial activity in terms of reduction of parasitemia and prevention of recrudescence in animals recovered from the infection.

In this study, the chemical content of the threatened Cretan endemic

Malassezia spp. are lipophilic fungi that are part of the normal flora of the human skin and are the etiological agents of dandruff and seborrheic dermatitis. beta-Carbonic Anhydrases (CAs; EC 4.2.1.1) expressed from the pathogenic fungi are an alternative/complementary drug target. Previous work by our groups demonstrated that flavonoids and depsides can effectively inhibit Malassezia globosa beta-CA (MgCA). In continuation of this study herein we report the inhibitory activity of a variety of phenols from Origanum dictamnus L. and Thymus vulgaris L. against beta-MgCA, among them I4-II7-di-carvacrol, a new natural product. Structure elucidation of the compounds was performed by 1 D, 2 D NMR and spectrometric analyses. Xanthomicrol and rosmarinic acid were active in the (sub)micromolar range (K-IS 0.6 and 2.2 mu M, respectively vs 40.0 mu M of the standard inhibitor acetazolamide). Finally, the compounds were not cytotoxic, but showed in vitro no activity against Malassezia furfur.

Saturn's satellite Enceladus is proposed to have a soda-type subsurface ocean with temperature able to support life and an iron ore-based core. Here, it was demonstrated that ocean chemistry related to Enceladus can support the development of Fe-based hydrothermal vents, one of the places suggested to be the cradle of life. The Fe-based chemical gardens were characterized with Fourier-transform (FT)IR spectroscopy and XRD. The developed chemobrionic structures catalyzed the condensation polymerization of simple organic prebiotic molecules to kerogens. Further, they could passively catalyze the condensation of the prebiotic molecule formamide to larger polymers, suggesting that elementary biochemical precursors could have emerged in Enceladus.

Andrographis paniculata is a herbal drug of Asian traditional medicine largely employed for the treatment of several diseases. Recently, it has been introduced in Europe for the prophylactic and symptomatic treatment of common cold and as an ingredient of dietary supplements. The active principles are diterpenes with andrographolide as the main representative. In the present study, an analytical protocol was developed for the determination of the main constituents in the herb and preparations of A. paniculata. Three different extraction protocols (methanol extraction using a modified Soxhlet procedure, maceration under ultrasonication, and decoction) were tested. Ultrasonication achieved the highest content of analytes. HPLC conditions were optimized in terms of solvent mixtures, time course, and temperature. A reversed phase C18 column eluted with a gradient system consisting of acetonitrile and acidified water and including an isocratic step at 30 °C was used. The HPLC method was validated for linearity, limits of quantitation and detection, repeatability, precision, and accuracy. The overall method was validated for precision and accuracy over at least three different concentration levels. Relative standard deviation was less than 1.13%, whereas recovery was between 95.50% and 97.19%. The method also proved to be suitable for the determination of a large number of commercial samples and was proposed to the European Pharmacopoeia for the quality control of Andrographidis herba.

Targeted isolation based on a combination of NMR and HPLC-PDA-MS of a dichloromethane extract of Thymus vulgaris Varico 3 aerial parts afforded one new p-cymene dimer, 6,3′,4′-trihydroxy-5,5′-diisopropyl-2,2′-dimethylbiphenyl (1), together with two known p-cymene derivatives (2 and 3), as well as five known compounds, namely, thymol (4), oleanolic acid (5), ursolic acid (6), cirsimaritin (7), and xanthomicrol (8). The structural elucidation of all compounds was performed by spectroscopic analyses, including 1D and 2D NMR, and HRESIMS experiments. The biphenyls were assayed for their inhibitory activity on tyrosinase. Compounds 2 and 3 showed negligible activity on tyrosinase, while compound 1 effectively inhibited the enzyme with 35% (± 0.3) inhibitory activity, higher than the inhibition of the reference compound kojic acid (18.6 ± 0.02).

Malaria treatment and control have become increasingly difficult because of the spread of drug-resistant strains of Plasmodium falciparum and Plasmodium vivax. Thus, there is a continuous need to develop new combination therapies such as artemisinin-based combination therapies (ACTs) to contrast the emergence of resistant Plasmodium strains. Despite ACT has been recommended by the World Health Organization since 2001, its overall deployment in poor endemic areas is very slow, principally due to its high cost. In the malaria endemic areas, plant remedies are still widely used mostly without assurance of their efficacy and/or safety. A variety of widespread herbal drugs or natural products were already reported for their possible plasmodicidal activities, but the studies concerning their activity in combination with artemisinins are very scarce. The antimalarial activity of papaya is mostly anecdotal, and the present study is aimed at investigating the antiplasmodial activity of a decoction obtained by traditional recipe from the mature leaves of Carica papaya. The decoction was analyzed by HPLC-DAD-MS (high performance liquid chromatography coupled with diodoarray detector and mass spectrometry) showing the presence of caffeoyl derivatives and di- and triglycosides of flavonols. The extract was found to be active against P. falciparum 3D7 strains with a synergism in the presence of artemisinin. In vivo activity against the murine malaria model of Plasmodium berghei was disclosed both for the dried extract alone (250, 500, and 750 mg/kg/d) and for its combination with artesunate (250 mg/kg/d papaya plus 10 mg/kg/d artesunate). This combination displayed the greatest antimalarial activity in terms of reduction of parasitemia and prevention of recrudescence in animals recovered from the infection.

The HIV-1 nucleocapsid protein (NC) is a desirable target in antiretroviral therapy due to its high conservation among HIV-1 strains, and to its multiple and crucial roles in the HIV-1 replication cycle. Natural products represent a valuable source of NC inhibitors, with the catechol group being a privileged scaffold in NC inhibition. By coupling molecular modeling with NMR spectroscopy and fluorescence-based assays, we disclosed lithospermic acid, a catechol derivative extracted from Salvia miltiorrhizza, as a potent and chemically stable non-covalent inhibitor of the NC. Being different from other catechol derivative reported so far, lithospermic acid does not undergo spontaneous oxidation in physiological conditions, thus becoming a profitable starting point for the development of efficient NC inhibitors.

Around 50 % of the worldwide population is affected by dandruff, which is triggered by a variety of factors. The yeast Malassezia globosa has been labeled as the most probable causative agent for the onset of dandruff. The β-carbonic anhydrase (CA) of MgCA was recently validated as an anti-dandruff target, with its inhibition being responsible for in vivo growth defects in the fungus. As classical CA inhibitors of the sulfonamide type give rise to permeability problems through biological membranes, finding non-sulfonamide alternatives for MgCA inhibition is of considerable interest in the cosmetic field. We recently screened a large library of human (h) CA inhibitors for MgCA inhibition, including different chemotypes, such as monothiocarbamates, dithiocarbamates, phenols, and benzoxaboroles. Herein, we expanded the research toward new MgCA inhibitors by considering a set of natural polyphenols (including flavones, flavonols, flavanones, flavanols, isoflavones, and depsides) that exhibited MgCA inhibitory activity in the micromolar range, as well as selectivity for the fungal isozyme over off-target human isoforms. The binding mode of representative derivatives within the MgCA catalytic cleft was investigated by docking studies using a homology-built model.

The repeated exposure to the anticancer drug oxaliplatin induces a disabling, painful neuropathy. The current pharmacological treatments are unsatisfactory and unable to modify the complex nervous damage induced by the platin derivative. Recently, we described a system of cellular measures of oxidative stress as a method for studying features of oxaliplatin neurotoxicity and screening new compounds able to reduce oxaliplatin-induced neuropathy. Based on this experimental design, the protective properties of Astragali radix were studied comparing aqueous and two hydroalcoholic root extracts. Aqueous and the 20 % hydroalcoholic (20 % water) extract were prepared from plant material, while the 50 % hydroalcoholic (50 % water) extract was a commercial one. All of the extracts were characterized in terms of drug extract ratio and content of typical isoflavonoids, Astragaloside IV, and related saponins. Furthermore, the molecular weight of the polysaccharide fraction was evaluated by light scattering analysis. Oxaliplatin increased the superoxide anion production both in the neuronal-derived cell line SH-SY5Y and in primary cultures of rat cortical astrocytes. Aqueous and the 50 % hydroalcoholic extract (50 µg/mL) showed significant antioxidant effects. In astrocytes, aqueous and the 50 % hydroalcoholic extract showed protective effects against oxaliplatin-induced lipid peroxidation (malonyl dialdehyde levels), protein (carbonylated proteins), and DNA oxidation (8-OH-2-dG levels). The 50 % hydroalcoholic extract was the most active in preventing the activation of the apoptotic enzyme caspase-3 and it was the only able to stimulate astrocyte viability. None of the tested extracts interfered with the toxicity elicited by oxaliplatin in the human colon adenocarcinoma cell line HT-29. The pharmacological profile of Astragali radix extracts, in particular, the aqueous and 50 % hydroalcoholic extracts, makes these natural products candidates as therapeutic adjuvant agents against oxaliplatin neurotoxicity.

In the present study an HPLC-DAD method was developed for the determination of the main carotenoid, zeaxanthin dipalmitate, in the fruits of Lycium barbarum. The aim was to develop and optimize an extraction protocol to allow fast, exhaustive, and repeatable extraction, suitable for labile carotenoid content. Use of liquid N2 allowed the grinding of the fruit. A step of ultrasonication with water removed efficiently the polysaccharides and enabled the exhaustive extraction of carotenoids by hexane/acetone 50:50. The assay was fast and simple and permitted the quality control of a large number of commercial samples including fruits, juices, and a jam. The HPLC method was validated according to ICH guidelines and satisfied the requirements. Finally, the overall method was validated for precision (% RSD ranging between 3.81 and 4.13) and accuracy at three concentration levels. The recovery was between 94 and 107% with RSD values2%, within the acceptable limits, especially if the difficulty of the matrix is taken into consideration.

Origanum dubium Boiss. is a flavouring herb widely used in Cyprus. In this study, both lipophilic and polar extracts of the aerial parts of O. dubium were investigated for their chemical contents and their antioxidant potential. Overall, 20 constituents were isolated and identified, belonging mainly to three significant classes of compounds: terpenes, phenolic derivatives, such as hydroquinone glycosides and flavonoids and alicyclic derivatives. None of them was previously reported as constituent of O. dubium The inhibitory potencies of all total extracts and the isolated compounds on lipid peroxidation and their interaction with 1,1-diphenyl-picrylhydrazyl (DPPH) activity is discussed. The polar extract showed strong interaction with DPPH stable radical and significant inhibition of lipoxygenase and lipid peroxidation.

The protein coded by the open-reading-frame 3a of SARS coronavirus has been demonstrated to form a cation-selective channel that may become expressed in the infected cell. The activity of the channel is involved in the mechanism of virus release. Drugs that inhibit the ion channel can, therefore, inhibit virus release, and they could be a source for development of novel therapeutic antiviral agents. Various drugs found in Chinese herbs that are well known as anticancer agents also have an antiviral potency. Here we tested the flavonols kaempferol, kaempferol glycosides, and acylated kaempferol glucoside derivatives with respect to their potency to block the 3a channel. We used the Xenopus oocyte with a heterologously expressed 3a protein as a model system to test the efficacy of the flavonols. Some of these drugs turned out to be potent inhibitors of the 3a channel. The most effective one was the glycoside juglanin (carrying an arabinose residue) with an IC50 value of 2.3 µM for inhibition of the 3a-mediated current. Kaempferol derivatives with rhamnose residue also seem to be quite effective. We suggest that viral ion channels, in general, may be a good target for the development of antiviral agents, and that, in particular, kaempferol glycosides are good candidates for 3a channel proteins of coronaviruses.

Sesquiterpene lactones, especially guaianolides, are widespread in the genus Crepis L. We have undertaken the chemical investigation of Crepis commutata (Spreng.) Greuter, an edible plant in Crete. From the non-polar extract of the aerial flowering parts of C. commutata five sesquiterpene lactones: 8-epi-grosheimin (1), 8-epi-isoamberboin (2), 8-epi-isolipidiol (3), 3-acetyl-8-epi-isolipidiol (4), integrifolin 3-O-β-D-glucopyranoside (5), two flavonoids: luteolin (6), luteolin 7-O-β-D-glucuronide (7), and three phenolic acids: p-anisic acid (8), p-hydroxyphenylacetic acid (9) and E-caffeic acid (10) were isolated. The structures of the isolated compounds were elucidated by high-field NMR spectroscopy.

Major processes contributing to subtleties of ephemeral flowers of Asphodelus ramosus are related to chemical constituents detected in tepals which expand during cold and wet seasons in the eastern Mediterranean. Luteolin, caffeic acid, chlorogenic, and p-hydroxy-benzoic acids are the main constituents, whereas alkanes, ketones, and fatty acids appear in low amounts.

Twenty-nine compounds were isolated from the aerial parts of the Greek plant C. zuccariniana DC. The structures of the isolated compounds were established by means of NMR- ((1) H,(1) H-COSY, (1) H,(13) C-HSQC, HMBC, NOESY, and ROESY) and mass-spectral analyses. These compounds comprise 13 sesquiterpene lactones, 14 flavonoids, two lignans, and one simple lactone. Among the isolated sesquiterpene lactones, three are new, namely one heliangolide, (1E,4Z)-15-hydroxy-8α-O-(4'-acetoxy-3'-hydroxy-2'-methylidenebutanoyl)-6βH,7αH-germacra-1,4,11(13)-trien-6,12-olide; and two eudesmanolides, 8α-(4',5'-diacetoxyangeloyl)sonchucarpolide and one unusual eudesmanolide with an oxygenated bridge linking C(1) and C(4), named zuccarinin. The main sesquiterpene lactones were malacitenolide, cnicin, and 4'-O-acetylcnicin. These results are in agreement with those obtained from the previously studied Greek Centaurea sp. belonging to the section Acrolophus (Cass.) DC.; this finding could be of chemotaxonomic significance for the genus Centaurea. The in vitro antimicrobial activities of the isolated new sesquiterpene lactones were against eight bacteria and eight fungal species. A 96-well microbioassay procedure for fast and easy evaluation of antibacterial and antifungal activities was applied to compare these compounds with commercial antibiotic and fungicide standards, and with previously isolated analogous sesquiterpene lactones tested by the same bioassay. All of the compounds tested showed moderate antibacterial, but significant antifungal activities; the present results corroborate with previous data, indicating that these types of compounds exhibit low or moderate antibacterial, but potent antifungal activities. The unusual eudesmanolide zuccarinin proved to be the most potent among the present tested sesquiterpene lactones, as well as among all previously tested eudesmanolides isolated from Greek Centaurea sp.

The antibacterial and antifungal activities of an ample number of phenolic compounds isolated from Quercus ilex leaves, belonging to the classes of flavonoids, proanthocyanidins, and phenolic acids, are discussed. The isolation of A type proanthocyanidin, (+)-epigallocatechin-(2β→O→7, 4β→8)-(+)-catechin is reported for the first time. Its structure was established by means of highfield NMR (correlation spectroscopy, heteronuclear single quantum correlation, heteronuclear multiple bond correlation, and rotating frame Overhauser effect spectroscopy) and MS spectral analyses, while its absolute configuration was determined by circular dichroism measurements. The isolated compounds were tested for their antimicrobial effects against eight human bacterial species and 14 fungal species. In a second step, the most potent compounds were tested in combination with the conventional fungicides, bifonazole and ketoconazole, to evaluate possible synergistic effects. Results showed that proanthocyanidins 3 and 4 when combined with bifonazole and ketoconazole increase the activity of both of these conventional fungicides. Moreover, the pharmacokinetic profile of the isolated compounds was investigated using computational methods.

Two coumarins, scopoletin (1) and isoscopoletin (2), two simple phenolic acids, protocatechuic acid (3) and isovanillic acid (4) and one flavonoid, eriodictyol (5) were isolated from the aerial parts of Centaurea spruneri. The structure of the compounds was established by spectroscopic methods. The in vitro antimicrobial activity of the isolated compounds was tested against eight bacteria and eight fungal species, using a microdilution method. All compounds tested showed moderate antibacterial and antifungal activities. Their minimum inhibitory concentrations were in the range 0.655 - 2.38 ?mol ml-1 and their minimal bactericidal concentrations ranged from 0.694 to 4.15 ?mol ml-1 against the tested bacterial species. All compounds showed fungistatic activity at 0.259 - 2.38 ?mol ml-1 and fungicidal at 0.69 - 2.6 ?mol ml-1 against all fungi tested.

The genus Eryngium belongs to the Apiaceae family (Umbelliferae), subfamily Saniculoideae, which consists of about 300 species [1]. Plants of this genus have shown various activities such as anti-inflammatory [2], antimalaria and antifungal [3], antioxidant and antimicrobial [4], antidiabetic [5], and analgesic properties [6]. Air-dried and powdered aerial parts (1.5 kg) of Eryngium triquetrum Vahl. were macerated at room temperature with MeOH–H2O (70:30, v/v) for 24 h three times. After filtration and concentration, the residue was dissolved in water (600 mL). The resulting solution was extracted successively with CHCl3, EtOAc, and n-butanol. Concentration in vacuo led to the following extracts: CHCl3 (0.8 g), EtOAc (1.3 g), and n-butanol (11 g). The butanolic extract of Eryngium triquetrum (11 g) was column chromatographed on polyamide SC6 with a gradient of toluene–MeOH with increasing polarity; Fr. 4 (70 mg), obtained from 85% toluene, was subjected to silica gel column chromatography eluted with EtOAc–MeOH–H2O (10:1:0.5), leading to two subfractions: Fr. 1 and Fr. 2. Subfraction 1 was separated by silica gel column chromatography eluted with CH2Cl2–MeOH (8:2) to afford compound 1 (10 mg). Subfraction 2 yielded compound 2 (60 mg), which was obtained as a yellow precipitate. Fraction 6 (70 mg), obtained from 80% toluene, was further subjected to silica gel column chromatography eluted with EtOAc–MeOH–H2O (10:1:0.5) to give compound 3 (40 mg). The ethyl acetate extract (1.3 g) was column chromatographed on silica gel with a gradient of CHCl3–MeOH with increasing polarity. Fraction 2 (30 mg) and Fr. 3 (35 mg), obtained from 95% and 90% CHCl3 successively, were separated by silica gel column chromatography eluted with EtOAc–MeOH–H2O (10:1:0.5) to afford compounds 4 (9 mg) and 5 (8.5 mg). The structures of compounds 1–5 were established by chemical and spectral analysis, UV, NMR, acid hydrolysis, and HPLC-UVDAD-MS, as well as by comparing their spectroscopic data with those reported in the literature. Acid Hydrolysis. The pure compounds were treated with 2M HCl at 100 C for 1 h. The hydrolysates were extracted with EtOAc, and the aglycons were identified by their UV spectra in methanol and by comparison of their Rf with authentic samples. Sugars were identified in the aqueous residue by comparison with authentic samples on silica gel TLC impregnated with 0.2 M NaH2PO4, solvent Me2CO–H2O (9:1), revealed with aniline malonate. Compound 1. C21H20O11. UV (MeOH, max, nm): 267, 347; +NaOH: 275, 325, 401; +AlCl3: 273, 398; +AlCl3/HCl: 273, 397; +NaOAc: 274, 377; +H3BO3: 268, 355. 1H NMR (250 MHz, CD3OD, , ppm, J/Hz): 8.09 (2H, d, J = 8.9, H-6 , 2 ), 6.91 (2H, d, J = 8.9, H-5 , 3 ), 6.42 (1H, d, J = 1.9, H-8), 6.22 (1H, d, J = 1.9, H-6), 5.28 (1H, d, J = 7.3, Glc H-1 ), 3.26–4.14 (sugar protons). This compound was characterized as kaempferol 3-O-D-glucoside [7]. Compound 2. C30H26O13. UV (MeOH, max, nm): 267, 315; +NaOH: 274, 368; +AlCl3: 274, 403; +AlCl3/HCl: 273, 403; +NaOAc: 274, 372; +H3BO3: 272, 371. 1H NMR (400 MHz, CD3OD, , ppm, J/Hz): 7.97 (2H, d, J = 8.9, H-6 , 2 ), 7.39 (1H, d, J = 15.9, H-7 ), 7.28 (2H, d, J = 8.6, H-2 , 6 ), 6.79 (2H, d, J = 8.9, H-5 , 3 ), 6.77 (2H, d, J = 8.6, H-3 , 5 ), 6.27 (1H, d, J = 1.7, H-8), 6.11 (1H, d, J = 1.7, H-6), 5.24 (1H, d, J = 7.2, Glc H-1 ), 4.32 (1H, d, J = 11.5, H-6 a), 4.19 (1H, dd, J = 12.5, 5.6, H-6 b), 3.20–4.40 (sugar protons). In addition, HPLC-UV-DAD permitted the characterization of the compound as kaempferol 3-O-[6 -O-E-p-coumaroyl]-D-glucopyranoside [8]. Compound 3. C27H30O16. UV (MeOH, max, nm): 269, 314; +NaOH: 276, 321, 365; +AlCl3: 276, 399; +AlCl3/HCl: 277, 399; +NaOAc: 275, 374; +H3BO3: 275, 372. 1H NMR (400 MHz, CD3OD, , ppm, J/Hz): 7.95 (2H, d, J = 8.9, H-6 , 2 )

In the present study, a method based on liquid chromatography with diode array detection (HPLC-DAD) coupled to an electrospray ionisation (ESI) interface was developed for the determination of the constituents in the aqueous preparations of Viola odorata L. flowering tops. The developed assay was fast, simple and effective and permitted the quality control of the preparations. The aim of this work was to assess the qualitative and quantitative profile of the investigated preparations, which find until today wide applications in food and cosmetic industry, and to propose a validated method for their quality control. Characteristic constituents of V. odorata flowers are considered to be the anthocyanins; however, a detailed literature research showed that data concerning their chemical content are scarce. HPLC-DAD-ESI-MS analyses supported by extensive preparative chromatographic investigations and 2D NMR analyses revealed the predominance of complex flavonol glycosides and permitted the complete characterisation of the content of V. odorata preparations. This is the first report of detailed analysis of the chemical composition of V. odorata flowers.

From the methanolic extract of Quercus ilex leaves a series of acylated flavonol glucosides were identified, among them five new naturally occurring compounds. The constituents, which were all p-coumaroyl glucosides of kaempferol, were characterised either as pure compounds or as inseparable, complicated mixtures of cis and trans isomers. Their complete structure elucidation was done by 2D NMR (COSY, HSQC, HMBC, ROESY) and HPLC-DAD-MS analyses. 2D NMR spectral data allowed the discrimination between different isomers. Quantitative analysis of the methanolic extract of the plant revealed that it is a rich source of acylated flavonoid glucosides (1.22%). Under the experimental conditions chosen HPLC-DAD-MS analyses showed that cis isomers are less polar than trans isomers and their detailed identification, the first in the literature so far, could serve as a tool for the detailed characterisation of analogous isomers by HPLC-DAD-MS in other complicated plant extracts.

In the present study a method based on liquid chromatography with diode array detection (HPLC/DAD) coupled to an electrospray ionization (ESI) interface for the simultaneous determination of phenolic constituents in three aqueous preparations of the herbal medicinal drug Stachys recta. The developed assay was simple and effective and permitted the quality control of S. recta decoctions and infusion. Overall, 30 constituents were detected and identified, belonging mainly to three classes of compounds: caffeoylquinic acids, phenylethanol glycosides and flavonoids. 15 of them were quantified having a lower limit not less than 0.02% of the lyophilized extracts. Only seven of them were previously reported in this species, while 23 were identified for the first time as constituents of S. recta. HPLC-DAD-ESI-MS analysis provided evidence for the certain identification of the main constituents and in some cases of their isomers. Eight constituents were isolated and their structure elucidated by HPLC-ESI-MS and 1D- and 2D-NMR spectroscopy. Among the investigated preparations, the infusion seems to be the best method to extract the native constituents of the plant, while decoction is a more aggressive treatment and causes partial degradation of some acylated flavonoids.

70 years have passed since the first isolation of the naphthodianthrones hypericin and pseudohypericin from Hypericum perforatum L. Today, they continue to be one of the most promising group of polyphenols, as they fascinate with their physical, chemical and important biological properties which derive from their unique chemical structure. Hypericins and their derivatives have been extensively studied mainly for their antitumor, antiviral and antidepressant properties. Notably, hypericin is one of the most potent naturally occurring photodynamic agents. It is able to generate the superoxide anion and a high quantum yield of singlet oxygen that are considered to be primarily responsible for its biological effects. The prooxidant photodynamic properties of hypericin have been exploited for the photodynamic therapy of cancer (PDT), as hypericin, in combination with light, very effectively induces apoptosis and/or necrosis of cancer cells. The mechanism by which these activities are expressed continues to be a main topic of discussion, but according to scientific data, different modes of action (generation of ROS & singlet oxygen species, antiangiogenesis, immune responces) and multiple molecular pathways (intrinsic/extrinsic apoptotic pathway, ERK inhibition) possibly interrelating are implicated. The aim of this review is to analyse the most recent advances (from 2005 and thereof) in the chemistry and biological activities (in vitro and in vivo) of the pure naphthodianthrones, hypericin and pseudohypericin from H. perforatum. Extracts from H. perforatum were not considered, nor pharmakokinetic or clinical data. Computerised literature searches were performed using the Medline (PubMed), ChemSciFinder and Scirus Library databases. No language restrictions were imposed.

Trypanosomiasis and leishmaniasis pose major public health threats for many countries, particularly those in sub-Saharan Africa and South America. In the present study, we evaluated the in vitro antiprotozoal activity of three irregular, linear sesquiterpene lactones recently isolated from Greek Anthemis auriculata, namely anthecotulide (1), 4-hydroxyanthecotulide (2) and 4-acetoxyanthecotulide (3). Trypomastigote forms of Trypanosoma brucei rhodesiense and T. cruzi as well as axenic amastigotes of Leishmania donovani were used for testing. The cytotoxic potential of the compounds was also assessed against mammalian (rat) skeletal myoblasts (L6 cells). All compounds showed potent trypanocidal and leishmanicidal activity. 4-Hydroxyanthecotulide (2) appeared to be the most active compound against all parasites, particularly towards T. b. rhodesiense (IC(50) 0.56 microg/ml), whereas 4-acetoxyanthecotulide (3) was the least active. All three metabolites possessed toxicity on mammalian cells, which might limit their use as antiprotozoal agents.

From the polar extracts of the leaves of Quercus ilex L., two new proanthocyanidin glycosides, namely afzelechin-(4α→8)-catechin-3-O-β-glucopyranoside (1) and afzelechin-(4α→8)-catechin-3-O-α-rhamnopyranoside (2), were isolated in addition to catechin (3), proanthocyanidin B3 (4), prodelphinidin C (5), dehydrodicatechin A (6), quercetin (7) and six known flavonol glucosides with their acylated derivatives (8–13) and ellagic acid (14). The structures of all isolated compounds were established by spectroscopic means, mainly 1D and 2D NMR, as well as LC/MS and HR-MS spectrometric analyses. The absolute configuration of compound 1 was determined by CD measurements. The proanthocyanidin glycosides are especially interesting, as they possess the sugar in the upper unit of the dimer, which is rare for this type of compounds.

From the aerial parts of Marrubium thessalum, four labdane diterpenes, 13S-preperegrinine, 3alpha-hydroxymarrubiin, 9alpha,13R-15,16-bisepoxy-15beta-methoxy-3-oxo-labdan-6beta,19-olide and 15-methoxyvelutine C, have been isolated together with four known diterpenes and one methoxylated flavone, ladanein. The structures of the isolated compounds were established by means of NMR (COSY, HSQC, HMBC, NOESY, and ROESY) and MS spectral analyses. Complete NMR assignments are reported for 13R-preperegrinine. Characteristic compounds of the plant were peregrinine and ladanein.

Enoyl-ACP reductase (FabI) is a key enzyme of the type II fatty acid biosynthesis (FAS-II) pathway and a validated antimicrobial target. In the current study, three linear sesquiterpene lactones obtained from Anthemis auriculata, namely anthecotulide (1), 4-hydroxyanthecotulide (2) and 4-acetoxyanthecotulide (3) were evaluated for specific inhibitory effects against the FabI enzyme from three pathogenic microorganisms, Plasmodium falciparum (PfFabI), Mycobacterium tuberculosis (MtFabI) and Escherichia coli (EcFabI). In addition, the compounds were also tested against two elongation enzymes from the plasmodial FAS-II system, beta-ketoacyl-ACP reductase (PfFabG) and beta-hydroxyacyl-ACP deydratase (PfFabZ). The compounds showed clear differentiation in inhibition of FabI enzymes from different microorganisms. Anthecotulide (1) was most active against MtFabI (IC(50) 4.5 microg/ml), whereas the oxygenated derivatives thereof (compounds 2 and 3) specifically inhibited plasmodial FAS-II enzymes, PfFabI and PfFabG (IC(50) values 20-75 microg/ml). All compounds were inactive towards EcFabI. In whole cell assays, all three compounds exhibited antimalarial and antibacterial activities.

The flower parts (i.e. sepals, labellum, gynostemium and isolated pollinia) of four Ophrys species (Ophrys argolica, Ophrys apifera, Ophrys cornuta, and Ophrys delfinensis [O. argolica×O. cornuta]), native in Greece, were examined for the presence of polyphenolic compounds. The chemical composition was studied by chromatographic and spectroscopic techniques (UV–vis and 1D and 2D NMR), whereas the localization of the phenolic compounds was depicted by epifluorescence microscopy. The chemical composition was highly variable among the different flower parts. Pollinia and sepals contained the highest concentrations of flavonoids, while the labellum contained the lowest. Among species, O. apifera showed the highest (up to 6-fold) concentration of flavonoid compounds compared with the other three species. Microscopic observations showed that flavonoids are localized in the protoplast, especially in proximity of the nucleus. They are concentrated on cuticle and cell walls of epidermal cells and in parenchyma cells of the sepals. The pollinia contained high concentrations of flavonols which were deposited in the pollen grains. Three kaempferol (Km) glycosides, Km 3-O-β- d -glucoside, Km 3-O-β- d -rutinoside and Km 3-O-β- d -rhamnoside, were the dominant compounds in the pollinia. The above results suggest a UV-protective role for flavonoids in the flower parts of these plants. Additionally, the pollen-specific flavonols could also be related to the flavonol-depended male fertility known from other plant species.

The volatile composition of Klainedoxa gabonensis Pierre ex Engl., Brachystegia nigerica Hoyle et A. Jones and Acalypha segetalis Muell Arg., has been studied. The essential oils were obtained by hydrodistillation in a modified Clevenger-type apparatus while the analyses were performed by GC and GC/MS. The main constituents of K. gabonensis oils were geranyl acetone (13.8%), β-bourbonene (11.1%) and (?)-α-ionone (10.5%) from the leaves; linalool (17.4%), 1, 8-cineole (9.9%) and 1-octen-3-ol (8.0%) from the stem bark, with 1, 2, 3-trimethylbenzene (9.8%), 1-ethyl-2-methyl benzene (9.1%), pentyl benzene(9.1%) and methyl salicylate (9.1%) occurring in higher proportions in the root oil. The leaf oil of B. nigerica was dominated by α-pinene (17.7%), β-selinene (12.5%) and α-gurjunene (8.8%). The main compounds identified in the oil of A. segetalis were α-pinene (29.8%), 1, 8-cineole (16.2%), (?)-phytol (11.8%) and δ-3-carene (9.8%). The present investigation may represent the first of its kind on the...

Sideritis perfoliata L. subsp. perfoliata is a plant widely used in folk medicine in Greece since antiquity because of its antiinflammatory, antirheumatic, antiulcer, digestive and vasoprotective properties. Phytochemical investigations of the polar extracts afforded four flavonoid glycosides, four phenylpropanoic glycosides, caffeic acid and one iridoid, ajugoside. Reactive oxygen species (ROS) are implicated in the aetiology of several inflammatory processes. In the present study polar fractions and isolated compounds from S. perfoliata subsp. perfoliata were evaluated for their antioxidant activity using DPPH spectrophotometric and TBA lipid peroxidation assays, as well as for their antiinflammatory activity using the soybean lipoxygenase bioassay. All extracts and isolated compounds showed significant antioxidant and inhibitory activity against soybean lipoxygenase. These findings give support to the ethnopharmacological use of the plant in the treatment of several inflammatory ailments. Copyright © 2008 John Wiley & Sons, Ltd.

The volatile constituents of the essential oils of 23 taxa belonging to the Apioideae subfamily were studied in detail. The investigated taxa were Pimpinella serbica (Vis.) Bentham & Hooker, Libanotis montana Cr., Cnidium silaifolium (Jacq.) Simk. ssp. orientale (Boiss.) Tutin, Bupleurum praealtum L., B. sibthorpianum S. S. var. diversifolium (Roch.) Hay, Aegopodium podagraria L., Torilis anthriscus (L.) Gmel., Orlaya grandiflora (L.) Hoffm., Laserpitium siler L., Laser trilobum (L.) Brokh., Chaerophyllum aureum L., C. hirsutum L., C. temulum L., Pastinaca sativa L., P. hirsuta Pancic., Tordylium maximum L., Physospermum cornubiense (L.) DC., Peucedanum alsaticum L., P. oreoselinum (L.) Moench, P. cervaria (L.) Cuss., P. austriacum (Jacq.) Koch, P. longifolium W. et K., and P. officinale L. All of these species grow wild in the central part of the Balkan Peninsula. The essential oils were found to be complex mixtures of various compounds, more than 100 constituents being in each taxon, with contributions of main products never exceeding 25% of the total content. Sesquiterpene hydrocarbons were found to be the main group of constituents of all taxa, except for Peucedanum species, where monoterpene hydrocarbons were identified as the main components. The chemotaxonomic value of the essential-oil composition is discussed according to results of principal-component analysis (PCA). The essential-oil composition mainly reflects current taxonomic relationships between the investigated taxa.

The flavonoid compn. was investigated of all subspecific taxa of Stachys swainsonii (Lamiaceae). Intraspecific variability was examd. by processing more than one population per taxon. The flavonoid content of the closely related subspecies of S. swainsonii shows many similarities. S. argolica produces constituents not found in the other subspecies. Flavonoids of S. argolica are discussed to serve as useful chemotaxonomic markers.

Tyrosinase is a key enzyme in the production of melanins in plants and animals. Forty-five secondary metabolites isolated from Marrubium velutinum and Marrubium cylleneum belonging to the classes of flavonoids, phenylethanoid glycosides, phenolic acids and lignan glycosides were screened for their inhibitory activity against mushroom tyrosinase. Flavonoids and phenylethanoid glycosides showed moderate inhibitory activity, while phenolic acids were less active than phenylethanoid glycosides, suggesting that both phenolic groups are important for the activity.