Divaricatic Acid Research Articles

Xerophytic Lichens from Gypsiferous Outcrops of Arid Areas of Andalusia as a Source of Anti-Phytopathogenic Depsides.

In a survey to evaluate the potential of lichens associated with gypsum areas as sources of new antifungal metabolites, six species of lichens were collected in the gypsum outcrops of the Sorbas Desert (Diploschistes ocellatus and Seirophora lacunosa) and the Tabernas Desert (Cladonia foliacea, Acarospora placodiformis, Squamarina lentigera and Xanthoparmelia pokornyi) in southern Spain. Raw lichen acetone extracts were tested against a panel of seven phytopathogenic fungi, including Botrytis cinerea, Colletotrichum acutatum, Fusarium oxysporum f.sp cubense TR4, Fusarium ploriferaum, Magnaporthe grisea, Verticillium dahliae and Zymoseptoria tritici. Active extracts of Cladonia foliacea, Xanthoparmelia pokornyi and Squamarina lentigera were analyzed by HPLC-MS/MS and Molecular Networking to identify possible metabolites responsible for the antifungal activity. A total of ten depside-like metabolites were identified by MS/MS dereplication and NMR experiments, of which one was a new derivative of fumaroprotocetraric acid. The compounds without previously described biological activity were purified and tested against the panel of fungal phytopathogens. Herein, the antifungal activity against fungal phytopathogens of 4'-O-methylpaludosic acid, divaricatic acid and stenosporic acid is reported for the first time. Stenosporic and divaricatic acids displayed a broad antifungal spectrum against seven relevant fungal phytopathogens in a micromolar range, including the extremely resistant fungus F. oxysporum f. sp. cubense Tropical Race 4 (TR4). 4'-O-methylpaludosic acid exhibited specific antifungal activity against the wheat pathogen Z. tritici, with an IC50 of 38.87 µg/mL (87.1 µM) in the absorbance-based assay and 24.88 µg/mL (55.52 µM) in the fluorescence-based assay.

Larvicidal activity and docking study of Ramalina complanata and Cladonia verticillaris extracts and secondary metabolites against Aedes aegypti

The Aedes aegypti mosquito is the main vector of the arboviruses that cause Zika, Yellow Fever, Dengue, and Chikungunya, incapacitating diseases that may even be fatal. There are still no vaccines for any of these viruses. Therefore, the only way to contain outbreaks is to control the vector that transmits them. In the present study, we investigated the larvicidal activity of lichen extracts (Ramalina complanata (Sw.) Ach., 1810 and Cladonia verticillaris (Raddi) Fr.), isolating components that were used against larvae of the mosquito A. aegypti. The ether extract from R. complanata exhibited an LC50 = 5.9 µg.ml−1, while a compound isolated from this species, divaricatic acid, had an LC50 = 27.1 µg.ml−1. The acetone extract of C. verticilaris exhibited an LC50 = 17.4 µg.ml−1 and the isolated compound fumarprotocetraric acid (FUM) had an LC50 = 13.6 µg.ml−1. These results demonstrate that extracts and isolated compounds from the two lichen species have strong larvicidal activities. FUM is the most active compound in our investigation. The molecular docking studies of divaricatic acid and FUM demonstrated that they bind to the active site of AaAChE1 in an energetically favorable manner. The TRP286 residue may have contributed to the more pronounced activity of fumarprotocetraric acid compared to divaricatic acid. Other aspects related to the more pronounced activity of fumarprotocetraric acid are its molecular weight and higher solubility. Our results provide evidence of the importance of studying lichen secondary metabolites as natural sources of insecticides and investigating possible interactions with AaAChE1.

Insecticidal activity of the ether extract from the lichen Ramalina complanata and an isolated metabolite (divaricatic acid) against Sitophilus zeamais (Coleoptera, Curculionidae)

The aim of the present study was to evaluate the insecticidal activity of ether extract from the lichen Ramalina complanata, and an isolated metabolite (divaricatic acid), against the maize weevil, Sitophilus zeamais. The evaluation of ingestion toxicity was performed using an artificial diet composed of the extract or compound (4 mg/g, 8 mg/g, or 12 mg/g) mixed with wheat flour. After 7 days of incubation, we determined the mortality rates and nutritional parameters. In the fumigation assay, the insects were incubated for 7 days in sealed chambers containing either the extract or divaricatic acid in 0.195–3.125 mg/L of air. The ingestion of the extract led to a maximum mortality rate of 33.33% (12 mg/g) and the extract had a deterrent effect ranging from weak (feeding deterrent index, FDI: 50%) at 4 mg/g to strong (FDI: 71%) at 12 mg/g. The mortality rate of the insects that ingested divaricatic acid reached 52.50% (12 mg/g) and the insects were also unable to convert the food into biomass. A moderate deterrent effect (FDI: 51%) of the divaricatic acid was found at a concentration of 12 mg/g. In the fumigation test, the mortality rates with the extract and divaricatic acid were 43.33-50.00% and 33.33-63.33%, respectively. An LC50 of 1.658 mg/L of air was determined for divaricatic acid. The results highlight the need for further studies on these kinds of compounds for the control of this insect, as well as for the investigation of the mechanisms by which lichen preparations work.

Schistosomicidal effect of divaricatic acid from Canoparmelia texana (Lichen): In vitro evaluation and ultrastructural analysis against adult worms of Schistosoma mansoni

In this study we evaluated the in vitro effect of divaricatic acid against coupled worms of Schistosoma mansoni. The schistosomicidal effect was evaluated through the bioassay of motility and mortality, cellular viability of the worms and ultrastructural analysis through Scanning Electron Microscopy. To evaluate the cytotoxicity of divaricatic acid, a cell viability assay was performed with human peripheral blood mononuclear cells. Divaricatic acid proved effect against S. mansoni after 3 hours of exposure. At the end of 24 h the concentrations of 100 - 200 μM presented lethality to the worms. Motility changes were observed at sublethal concentrations. The IC50 obtained by the cell viability assay for S. mansoni was 100.6 μM (96.24 - 105.2 μM). Extensive damage to the worm's tegument was observed such as peeling, erosion, bubbles, edema, damage and loss of tubercles and spines, fissures and tissue ruptures. No cytotoxicity was observed in human peripheral blood mononuclear cells. This report provides data showing the schistosomicidal effect of divaricatic acid on S. mansoni, causing death, motile changes and ultrastructural damage to worms. In addition, divaricatic acid was shown to be non-toxic to human peripheral blood mononuclear cells at concentrations effective on S. mansoni.

<p><strong>The genus <em>Ramalina</em> Acharius </strong><strong>(Ascomycota, Lecanoromycetes, Ramalinaceae) </strong><strong>in northern South America</strong></p>

Fifty three taxa of Ramalina Acharius have been found in northern South America (including Colombia and Venezuela), with 8 varieties and 48 species. Seven species and four varieties are described as new to science viz. R. anteojina V. Marcano & A. Morales sp. nov. (Venezuela), R. canaguensis V. Marcano & A. Morales var. colombiana Marcano & Morales var. nov. (Colombia), R. canaguensis Marcano & Morales var. guascasensis Marcano & Morales var. nov. (Colombia), R. canaguensis V. Marcano & A. Morales var. mucumpisensis V. Marcano & A. Morales var. nov. (Colombia and Venezuela), R. reducta Krog & Swinscow var. colombiana V. Marcano & A. Morales var. nov. (Colombia), R. maegdefraui V. Marcano & A. Morales sp. nov. (Venezuela), R. mirandensis V. Marcano & A. Morales sp. nov. (Venezuela), R. subcalcarata V. Marcano & A. Morales sp. nov. (Venezuela), R. tenaensis V, Marcano & Morales sp. nov. (Colombia), R. venezuelensis V. Marcano & A. Morales sp. nov. (Venezuela), and R. victoriana V. Marcano & L. Castillo sp. nov. (Venezuela); 8 taxa are reported for first time from Venezuela: R. anceps Nylander, R. bogotensis Nylander, R. chilensis Bertero, R. holstii Krog & Swinscow, R. rigida Persoon ex Acharius, R. sorediosa (Bouly de Lesdain) Landrón, R. subfraxinea Nylander var. subfraxinea, and R. tenella Müller Argoviensis, whereas 5 taxa are reported for the first time from Colombia: R. africana (Stein) Dodge, R. asahinae W. Culberson & C. Culberson, R. subfraxinea Nylander var. confirmata, R. tenuissima V. Marcano & A. Morales and R. vareschii V. Marcano & A. Morales. A key to the species is presented together with data on morphology, anatomy, chemistry, variation, taxonomy, habitat and distribution. The chemical analyses show that the sekikaic (24 taxa), boninic (16 taxa) and homosekikaic (15 taxa) acids are the most common depsides found. Divaricatic acid is present in 10 of the taxa but is frequently replaced by sekikaic acid and its aggregates. The most common depsidones are salazinic acid (22 taxa), and protocetraric acid (25 taxa). The distribution of the secondary compounds reveals they are able to produce quite different substances which appears be not dependent to the habitat where occur the species, neither to the occurrence of minute morphological or anatomical differences at similar species. Often, several chemical strains (chemosyndromes) can be recognized within a single population of a particular species, but have no correlation with morphology or ecology. Biogeographic data indicate that of the 53 taxa known from northern South America, 28.3% (15) are known only from Venezuela, 7.5% (4) are known only from Colombia and 18.9% (10) are known only from Venezuela and Colombia. Of the 50 taxa known from Venezuela, 70% (37) of the taxa have their main distribution in the Andean region. The high concentration of Ramalina species seen in the Andes indicates that this region constitutes an important centre for speciation and endemism of Ramalina both in northern South America but also throughout the world.

Specialized metabolites of the United States lichen Niebla homalea and their antiproliferative activities

Three undescribed stictanes, nieblastictanes A−C, two flavicanes, nieblaflavicanes A and B, together with three already reported stictanes, along with the known compounds (+)-usnic acid, sekikaic acid, divaricatic acid, and divaricatinic acid methyl ester were isolated from an ethyl acetate extract of the western North American lichen Niebla homalea. The structures of the new and known compounds were established by spectroscopic methods including nuclear magnetic resonance spectroscopy, mass spectrometry and electronic circular dichroism. Among the compounds isolated, usnic acid exhibited moderately potent antiproliferative activities against the A2780 ovarian (IC50 3.8 μM) and MCF-7 breast cancer (IC50 6.8 μM) cell lines. A plausible mode of formation of the chlorine-containing compound nieblastictane C is provided and the contribution of the isolated compounds to the chemotaxonomy of United States lichen species of the genus Niebla is also discussed.

Cytotoxic Activity of Compounds from Lichens of the Cerrado Biome in Brazil

Lichens are sources of numerous biologically active compounds and many of these have demonstrated antitumor potential. The purposes of this study were to evaluate the antiproliferative activity and selectivity of the following compounds isolated from lichens: atranorin and diffractaic, divaricatic, perlatolic, psoromic, norstictic, and protocetraric acids. Cytotoxicity tests based on sulforhodamine B were performed on normal cells (NIH/3T3, fibroblast) and cancer cell lines 786-0 (renal), MCF7 (breast), HT-29 (colon), PC-3 (prostate), and HEp2 (laryngeal). Diffractaic acid exhibited GI 50 values in the 58.6-98.9 µM range. Divaricatic and perlatolic acids were the most active compounds, with GI 50 values of 9.8 and 15.5 µM for PC-3 and MCF7 cells, respectively. Protocetraric acid proved active only against HEp2 cells (GI 50 = 41.4 µM). Atranorin, psoromic acid, and norstictic acids were inactive against all the cells tested. Chemometrics was used to evaluate the effect of the compounds against the cell lines tested. PCA (Principal Component Analysis) based on GI 50 values ​​separated compounds into two groups compared to doxorubucin, while HCA (Hierarchical Cluster Analysis) separated them into three groups based on SI values. DOI: http://dx.doi.org/10.17807/orbital.v12i1.1397

A molecular phylogenetic evaluation of theRamalina siliquosacomplex, with notes on species circumscription and relationships withinRamalina

AbstractLichens of theRamalina siliquosacomplex dominate seashore cliffs in Europe and South-East Asia, but their taxonomy has been vigorously debated for over a century. On many cliffs, they exhibit a bewildering zonation of chemotypes that resembles the classic zonation of organisms that occupy the littoral zone below. Do the chemotypes represent separate species, or infraspecific variation? To better understand the systematics of this group, sequences from four genetic loci (ITS, IGS,RPB1andRPB2) were obtained for 59 samples from Denmark, France, Iceland, Norway, UK, Japan and Korea, including all major chemotypes. Maximum likelihood analysis of these sequences, together with sequences from 36 otherRamalinaspecies, reveals that the complex comprises two distinct phylogenetic lineages, each including multiple chemotypes. These two putative species-level lineages correspond to the currently accepted taxaR. cuspidataandR. siliquosa. There is no evidence that these two taxa are phylogenetic sister species. Consequently, the explanation of this chemotype complex as an example of ‘sibling speciation’ is rejected. Specimens traditionally called ‘R.siliquosa’ from South-East Asia form a third clade, identified here asR.semicuspidata, with an additional, divaricatic acid chemotype. Other results include a robustly supported clade ofRamalinaspecies that produce medullary depsides and depsidones; this clade includes another well-supported clade of south-eastern United States coastal plain and tropicalRamalinaspecies. By contrast, large, strap-shapedRamalinaspecies that lack medullary depsides and depsidones occur in separate lineages. In addition, close relationships between the following groups of species are indicated:R. farinaceawithR. subfarinacea;R.fraxineawithR. leptocarpha,R. menziesiiandR. subleptocarpha;R. sinensiswithR. unifolia. Furthermore, a new, variolaric acid-only chemotype is reported forR.farinacea, and a new, acid-deficient chemotype is reported for a more broadly circumscribedR. culbersoniorum.

Lepraria juanfernandezii, a new lichen species from the Southern Hemisphere

AbstractLepraria juanfernandezii is described as a new species. It differs from all other species of Lepraria by its aggregate thallus with sparse prothallus hyphae, the absence of a hypothallus, the presence of divaricatic acid and the absence of zeorin, and its occurrence in the Southern Hemisphere. A key to all species of Lepraria containing divaricatic acid is given.

Toxicological effects of Ramalina aspera (lichen) on Biomphalaria glabrata snails and Schistosoma mansoni cercariae

In this study, the molluscicidal activities against Biomphalaria glabrata and cercaricidal activities against Schistosoma mansoni of the ether extract of Ramalina aspera were evaluated. Additionally, toxicity parameters were evaluated at sublethal doses in terms of the influence of the extract on the fertility and fecundity of snails, as well as morphological alterations and quantification of their immunological cells. A test with Artemia salina was also carried out, in order to verify the environmental toxicity of the compound. The ether extract of R. aspera, in which divaricatic acid was identified as the major compound, demonstrated molluscicidal activity at low concentrations against both embryos (LC90 of 22.78, 24.23, 16.63 and 16.03 μg mL−1 for the gastrula, blastula, trochophore and veliger, respectively) and against adult snails (LC90 of 8.66 μg mL−1), after 24 h of exposure. At the sublethal doses, it was possible to observe a decrease in fecundity and quantitative and morphological changes in the defense cells of the exposed snails. In addition, the extract of R. aspera showed a cercaricidal effect on S. mansoni from the concentration of 5.0 μg mL−1, while showing low toxicity to Artemia salina. The ether extract of R. aspera demonstrated effective molluscicidal activity on embryos and adult snails of the species B. glabrata, cercariae of S. mansoni, and presenting low toxicity on Artemia salina. In this way, it could be considered a promising compound in the development of future molluscicidal and cercaricidal agents, thus helping to combat schistosomiasis.

Antarvedisides A-B from Manglicolous Lichen Dirinaria consimilis (Stirton) and their Pharmacological Profile

The chemical examination of acetone extract of Dirinaria consimilis resulted in isolation of six depsides of which two novel metabolites namely antarvediside A (1) and antarvediside B (2) and four known metabolites i.e. sekikaic acid (3), atranorin (4), divaricatic acid (5) and 2’-O-methyl divaricatic acid (6). From the pharmacological screening of the isolates (1-6), it was found that 1 and 2 exhibited better inhibition of ABTS and superoxide free radicals than that of the standard and compound 4 showed significant inhibition of protein denaturation with IC50 value of 390 mg/mL with respect to indomethacin with 110 mg/mL. From the SRB assay results, the better IC50 values was determined by compound 2 of 10.5, 11.50 and 12.50 μg/mL on HeLa, MCF-7 and FADU cancer cell lines, respectively. Thus, the outcomes revealed that the D. consimilis is a new source to treat free radicals, inflammation and cancer.

Antimicrobial Activity of Divaricatic Acid Isolated from the Lichen Evernia mesomorpha against Methicillin-Resistant Staphylococcus aureus.

One hundred and seventy seven acetone extracts of lichen and 258 ethyl acetate extracts of cultured lichen-forming fungi (LFF) were screened for antimicrobial activity against Staphylococcus aureus and Enterococcus faecium using a disk diffusion method. Divaricatic acid was isolated from Evernia mesomorpha and identified by LC-MS, 1H-, 13C- and DEPT-NMR. Purified divaricatic acid was effective against Gram + bacteria, such as Bacillus subtilis, Staphylococcus epidermidis, Streptococcus mutans, and Enterococcus faecium, with the minimum inhibitory concentration (MIC) values ranging from 7.0 to 64.0 μg/mL, whereas vancomycin was effective in the MICs ranging from 0.78 to 25.0 μg/mL. Interestingly, the antibacterial activity of divaricatic acid was higher than vancomycin against S. epidermidis and E. faecium, and divaricatic acid was active against Candida albicans. In addition, divaricatic acid was active as vancomycin against S. aureus (3A048; an MRSA). These results suggested that divaricatic acid is a potential antimicrobial agent for the treatment of MRSA infections.

Laboratory assessment of divaricatic acid against Biomphalaria glabrata and Schistosoma mansoni cercariae

In this study, the molluscicidal and antiparasitic activities of divaricatic acid was evaluated, targeting the mollusc Biomphalaria glabrata and cercariae of the helminth Schistosoma mansoni. In addition, the environmental toxicity of divaricatic acid was assessed by bioassay using the microcrustacean Artemia salina. Divaricatic acid showed high toxicity against both adult snails (5μg/mL) and embryos (20μg/mL after 6h of exposure). Similar activity was observed in Schistosoma mansoni cercariae after only a short exposure time (10μg/mL after 30min of exposure). The divaricatic acid did not show toxicity in the acute test using Artemia salina at concentrations equal to or below 200μg/mL. The divaricatic acid proved to be a promising substance for the elimination of the snail Biomphalaria glabrata, an intermediate host of schistosomiasis, as well as the cercariae of the pathogen, while being non-toxic to the Artemia salina at the same concentrations. This is the first experimental observation of the molluscicidal and cercaricide activity of divaricatic acid.

THE LICHENS DIVERSITY IN TRIANGULATION OF ALAS PURWO NATIONAL PARK, EAST JAVA

<p>The lichen flora of tropical areas is still much underworked Java in general and Alas Purwo in East Java for specially is no exception. Alas Purwo National Park is representative of a typical lowland tropical rain forest ecosystem in Java. . It is famous with peculiar and endemic species of plant include sawo kecik (Manilkara kauki) and manggong bamboo (Gigantochloa manggong). , beside among the other plants also ketapang (Terminalia cattapa), nyamplung (Calophyllum inophyllum), kepuh (Sterculia foetida), and keben (Barringtonia asiatica). Moreover, in lowland tropical rain forest ecosystem have reported the lichens species diversity is very high and may include over 200 species in 1 ha. There is no reported have found concerning the lichens richness in Alas Purwo. Recently preliminary study of Lichens diversity have been done at triangulation Zone Alas Purwo National Park , East Java. The lichens of the study area have not been treated comprehensively. We explored the lichenological characteristics of putative”tropical lowland cloud forest” (LCF) in a lowland area (0–20ma.s.l.) near Triangulation using macrolichens (cortocoulous species) as indicator taxa We analyzed lichen diversity on 20 trees in two 0,25 ha plots. In tropical lowland forests, corticolous green algal lichens are abundant and highly diverse. This may be related to adaptation to prevailing microenvironmental conditions including, for example, high precipitation and low light intensities. In the understory of a tropical lowland rain forest in Alas Purwo , we studied the morphology and anatomy of corticolous lichens and microcristal test. We found that from Tetrasigma sp , Serbella otodans, Hemandia feltata Baringtonia aciatika Pandanaceae Manilcara cauci Swetinia mahagoni trees there are 30 species of lichens, dominated by Dyorigma sp Graphis and Glyphis from familia of Graphidaceae and Dirinaria Physcia Pyxine Ramalina from familia of Parmeliaceae. The thallus calour was variety from Green-grey, Green-bllue, green, light green, grey, brown, dark green to orange. They have vegetative as wel as generative reproduction such as isidia, soralia, soredia, chypellae, histerothecia, perithecia,and apothecia. The lichenic acids contain such as gyrophoric acid, barbatic acid, usnic acid, atranorin, acid, divaricatic acid and lecanoric acid, </p><p><strong>Keywords</strong>: Alas Purwo, lichens and lichenic acid.</p>

A world key to Stirtonia (Arthoniaceae), with three new Stirtonia species and one new Crypthonia species from the Neotropics

AbstractA world key to the 21 species of Stirtonia is presented. Three new Stirtonia species are described from the Neotropics: Stirtonia ibirapuitensis Aptroot, Käffer & S. M. Martins, with whitish to cream amoeboid ascigerous areas with lichexanthone on a greenish thallus without lichexanthone and ascospores of 27–32×9·5–12·5 µm; Stirtonia punctiformis Aptroot & Sipman, with ascigerous structures of thallus colour, consisting of one or more brown asci with brown walls with surrounding tissue, in groups or irregular lines and brown ascospores 61–73×27–35 µm; and Stirtonia viridis Aptroot, L. I. Ferraro, Sipman & M. Cáceres, with ascigerous structures mostly linear, branched and anastomosing, whitish, and contrasting with the often greenish thallus and with ascospores 50–58×15–22 µm. In addition, a specimen of S. neotropica is reported that contains some patches of lichexanthone, S. curvata is reported new to the Neotropics from Brazil and the Netherlands Antilles, and S. nivea is reported new to the Northern Hemisphere from Puerto Rico. Also, Crypthonia divaricatica Aptroot & Sipman, with an irregular, thick thallus with divaricatic and usnic acids and flat white ascigerous areas and macrocephalic 5–9-septate ascospores 20–27×9·5–12·5 µm is described from Mexico. While only one Stirtonia species was known from the Neotropics as recently as 2009, the total number of Stirtonia species known from the Neotropics is now 12, an equal number to the 12 species that are known from the Palaeotropics.

Two new genera of Arthoniales from New Caledonia and the Solomon Islands, with the description of eight further species

Two new genera in the Arthoniales are described from the Pacific Islands. Glyphopsis, with the new species G. aurantiodisca from New Caledonia is characterized by a thallus containing divaricatic acid and zeorin and sessile grouped ascomata with bright orange discs and raised lecanorine margins, and the ascospores hyaline and muriform. Gossypiothallon, with the new species G. appendisporum from the Solomon Islands is characterized by a byssoid thallus containing zeorin and pedicillate, simple ascomata with pale pink discs, without differentiated margins and hyaline, bacillar, 3-septate ascospores with two polar, usually curved gelatinous appendages. Eight further corticolous crustose lichens are described from either New Caledonia or the Solomon Islands. Byssoloma xanthonicum is characterized by a thallus containing norstictic acid and lichexanthone and 3-septate ascospores. Cliostomum ovocarpum has orange yellow, convex apothecia and 1-septate ascospores. Crocynia minutiloba has palmately branched lobes on a thick whitish byssoid hypothallus and flat lecideoid apothecia. Megalotremis dolabarata has superficial cylindrical grey pycnidia and simple ellipsoid conidia. Pyrenula filiformis has a thallus with pseudocyphellae covering most part of the ascomata and 11–17-septate, slender fusiform to slightly clavate ascospores. Pyrenula mastigophora has 5-septate ascospores with an up to 25 µm long tail at the lower end. Pyrenula spissitunicata has a thallus with lichexanthone, fused ascomata with common ostioles covered by thallus and ascospores resembling a Pyrgillus. The lichenicolous fungus Pyrenidium coccineum (parasitic on Siphula decumbens) has red ascomata which stain herbarium boxes blue.

Cytotoxic Evaluation of Phenolic Compounds from Lichens against Melanoma Cells

Atranorin, lichexanthone, and the (+)-usnic, diffractaic, divaricatic, perlatolic, psoromic, protocetraric, and norstictic acids isolated from the lichens Parmotrema dilatatum (VAIN.) HALE, Usnea subcavata MOTYKA, Usnea sp., Ramalina sp., Cladina confusa (SANT.) FOLMM. & AHTI, Dirinaria aspera HÄSÄNEN, and Parmotrema lichexanthonicum ELIASARO & ADLER were evaluated against UACC-62 and B16-F10 melanoma cells and 3T3 normal cells. Sulforhodamine B assay revealed significant cytotoxic activity in protocetraric, divaricatic, and perlatolic acids on UACC-62 cells (50% growth inhibitory concentration (GI(50)) 0.52, 2.7, and 3.3 µg/mL, respectively). Divaricatic and perlatolic acids proved the most active on B16-F10 cells (GI(50) 4.4, 18.0 µg/mL, respectively) and the most cytotoxic to 3T3 normal cells. Diffractaic, usnic, norstictic, and psoromic acids were cytotoxic to UACC-62 cells in the 24.7 to 36.6 µg/mL range, as were protocetraric and diffractaic acids to B16-F10 cells (GI(50) 24.0, 25.4 µg/mL, respectively). Protocetraric acid was highly selective (selectivity index (SI*) 93.3) against UACC-62 cells, followed by norstictic, perlatolic, psoromic, and divaricatic acids, while norstictic and divaricatic acids were more selective against B16-F10 cells. The high SI* value obtained for protocetraric acid on UACC-62 cells makes it a potential candidate for the study of melanomas in experimental models. Chemometric analysis was performed to evaluate the general behavior of the compounds against the cell lines tested.

Contributions to the lichen flora of the Hengduan Mountains, China (5). Anzia rhabdorhiza (Parmeliaceae), a new species

Anzia rhabdorhiza Li S. Wang & M. M. Liang is found to be a species new to science from Hengduan Mountains in southwest China. It is characterized by long and thick rhizines covered with spongiostratum, a central chondroid band in the medulla, and production of atranorin and divaricatic acid. The new species belongs to the Sect. Nervosae of Anzia.

A taxonomic revision of the North American species of Lepraria s.l. that produce divaricatic acid, with notes on the type species of the genus L. incana

The divaricatic acid-producing populations of Lepraria in North America north of Mexico are revised with traditional morphological characters, chemistry, ecology, biogeography, and ITS1, 5.8S, and ITS2 sequence data. Three taxa are accepted: L. cryophila, L. hodkinsoniana sp. nov. and L. pacifica sp. nov. Both Lepraria crassissima and L. incana are excluded from the study area. Noncryptic, semicryptic and fully cryptic species concepts in Lepraria are discussed with emphasis on the practical integration of molecular characters into taxonomic frameworks based on non-molecular characters.

Effect of vicanicin and protolichesterinic acid on human prostate cancer cells: Role of Hsp70 protein

With the aim of identifying novel agents with antigrowth and pro-apoptotic activity on prostate cancer cells, in the present study, we evaluated the effect of five lichen secondary metabolites the depsides atranorin (1), diffrattaic (2) and divaricatic (3) acids, the depsidone vicanicin (4) and the protolichesterinic acid (5) on cell growth in androgen-sensitive (LNCaP) and androgen-insensitive (DU-145) human prostate cancer cells. The cell viability was measured using MTT assay. LDH release, a marker of membrane breakdown, was also measured. For the detection of apoptosis, the evaluation of DNA fragmentation (COMET assay) and caspase-3 activity assay were employed. The expression of Bcl-2, Bax, TRAIL, COX-2, NOS2 and Hsp70 proteins was detected by western blot analysis. Generation of reactive oxygen species was measured by using a fluorescent probe. It was observed that atranorin (1), diffrattaic (2) and divaricatic (3) acids showed a lower activity inhibiting the prostate cancer cells only at more high concentrations (25 and 50μM). Whereas compounds vicanicin (4) and protolichesterinic acid (5) showed a dose–response relationship in the range of 6.25–50μM concentrations in DU-145 and LNCaP cells, activating an apoptotic process. The novel finding, in the present study, is that apoptosis induced by these compounds appears to be mediated, at least in part, via the inhibition of Hsp70 expression, that may be correlated with a modulation of redox-sensitive mechanisms. The combination of vicanicin (4) and protolichesterinic acid (5) with other anti-prostate cancer therapies could be considered a promising strategy that warrants further in vivo evaluation.