Methyl Β-orcinol Carboxylate Research Articles

1H and 13C NMR conformational properties calculated by Spartan 18, and 400/125.77 MHz experimental data of methyl β-orcinolcarboxylate and atranorin, a comparative study

Propiedades conformacionales de RMN de 1H y 13C calculadas con Spartan 18 y datos experimentales de 400/125,77 MHz de β-orcinolcarboxilato de metilo y atranorina, un estudio comparativo . Los parámetros estructurales del metil β-orcinolcarboxilato y la atranorina se determinaron mediante B3LYP con el conjunto base 6-31G*. Se presentan los resultados de la estructura molecular optimizada y se comparan con los datos de rayos X disponibles de las moléculas. Se expone y discute un análisis comparativo de los espectros de RMN 1H y 13C experimentales y los valores calculados. Los cálculos cuánticos teóricos dieron como resultado un buen enfoque de determinación estructural predictiva para moléculas orgánicas pequeñas.

Photoprotective Activity of Lichen Extracts and Isolated Compounds in Parmotrema Tinctorum

Lichens are an excellent source for the discovery and development of new photoprotective compounds. However, investigation on their bioactivities remains limited, especially in Vietnam. In this study, six lichen extracts (Parmotrema poolii, P. sancti-angelii, P. tinctorum, Usnea baileyi, U. pulvinulata, U. undulata) and five isolated compounds from commonly distributed species P. tinctorum (methyl β-orcinol carboxylate (1), atranorin (2), lecanorol (3), salazinic acid (4), 1β-acetoxyhopan-3β,22-diol (5)) have been screened in vitro for their photoprotective activity. The photoprotective potential was investigated by determination of their absolute (UV-PF, c, UVA-PF) and relative indexes (SUI, ISP). The structures of isolated compounds were elucidated by spectroscopic methods and confirmed by X-ray diffraction. The results showed that P. poolii, P. sancti-angelii, P. tinctorum, U. baileyi, U. undulata, and compounds of methyl β-orcinol carboxylate (1) and salazinic acid (4) acted as strict UVB filters, and their photoprotective activities are comparable to that of the commercial UVB filter (4-methylbenzylidene camphor). Meanwhile, U. pulvinulata acted as a UVA booster. Compound (3) presented characteristics of a UVA filter, (2) protected well from both UVA and UVB while (5) exhibited a weak photoprotective activity. For the first time, this work successfully extracted several highly potential solar photoprotective compounds from Vietnam's lichens.

New bioactive monoterpene indole alkaloid from Rinorea yaundensis Engl.

Extraction of the aerial part of Rinorea yaundensis has led to the isolation of a new monoterpene indole alkaloid (1) along with 10 known compounds (2–11) for the first time from this plant. Their structures were determined by HRMS and NMR spectroscopic analyses as yaundentine hydrochloride (1), N b-oxide of iso-reserpiline (2), iso-reserpiline (3), iso-carapanaubine (4), lichenxanthone (5), stigmastane-3,6-dione (6), methyl β-orcinol carboxylate (7), β−sitosterol-3-O-β-D-glucoside (8), betulinic acid (9), ursolic acid (10) and benzoic acid (11) while the stereochemistry and absolute configuration of 1 was confirmed by single crystal x-ray crystallography and circular dichroism CD spectrum. Yaundentine hydrochloride (1) exhibited pronounced antioxidant, urease and lipoxygenase inhibitory activities with IC50 values of 35.6 ± 0.23, 20.3 ± 0.58 and 29.6 ± 0.77 µM, respectively. Compound 1 also showed good antimicrobial activity against some Gram positive and negative bacteria.

Efficiency and selectivity of ionic liquids in microwave-assisted extraction of major lichen phenolic compounds: a scalable process with recycling of ionic liquids.

Pseudevernia furfuracea, a lichen used classically for cosmetic applications, contains interesting metabolites possessing antimicrobial and anti-inflammatory or antioxidant properties. Ionic liquid combined to microwave-assisted extraction (IL-MAE) was successfully applied for metabolites extraction from Pseudevernia furfuracea. Three imidazolium and pyridinium-based ionic liquids (ILs): 1,3-dimethylimidazolium methylsulphate [C1 C1 Im][MeSO4 ], 1-ethyl-3-methylimidazolium ethylsulphate [C2 C1 Im][EtSO4 ], and N-ethylpyridinium ethylsulphate [C2 Py][EtSO4 ] were assessed for this process. The efficiency of the extraction method was evaluated using thin-layer chromatography (TLC) coupled to a Camag® spectrophotodensitometer and using high-performance liquid chromatography (HPLC) analysis. ILs under MAE showed extraction time efficiency (15 min vs. 24 h for conventional heating) and high selectivity in extracting the targeted metabolites: atranorin (AT), methyl-β-orcinol carboxylate (MOC), fumarprotocetraric acid (Fum. Ac.), and physodic acid (Phys. Ac.) despite the increased degradation of AT under MAE. We showed a tunable selectivity of ILs towards extracting metabolites by changing anion or cation due to the modification of the interaction between the IL and the metabolites. While [C2 Py][EtSO4 ] was the most efficient IL and could extract all the targeted metabolites, [C2 C1 Im][EtSO4 ] was the most selective. It fully extracted AT and partially Fum. Ac. Moreover, the lichen prepared by mixing procedure provided AT and Fum. Ac. more than the milled one. A 100 times scale-up extraction was successfully performed on mixed samples with full IL recycling after back extraction. IL-MAE is reliable for lichen metabolites extraction. The method is reproducible, scalable, with possible IL recycling, opening the door for potential industrial applications.

Lichens as promising resources of enzyme inhibitors: A review

Inhibition of some enzymes seems to be one of the therapeutic strategies for the management of certain diseases or conditions such as diabetes, Alzheimer’s disease, cancer and obesity. In this review, an updated information on the enzyme inhibitory activity of lichen extracts and lichen compounds by an intensive literature survey is presented. Crude solvent extracts and isolated compounds from lichens were shown to be effective in causing inhibition of several enzymes such as amylase, lipase, lipoxygenase, aromatase, cyclooxygenase, trypsin, β-glucoronidase, prolyl endopeptidase, monoamine oxidase, urease, tyrosinase, xanthine oxidase, Thioredoxin reductase, glucosidase, topoisomerase, pancreatic elastase, phosphodiesterase, telomerase and acetylcholinesterase. Lichen metabolites such as usnic acid and its derivatives, lobaric acid, physodic acid, ramalin, protolichestrinic acid, salazinic acid, atranorin, evernic acid, zeorin, diffractic acid, psoromic acid, methyl β-orcinolcarboxylate, methylorsellinate, and anziaic acid were shown to be inhibitors of some enzymes. In conclusion, lichens can be employed as promising therapeutic agents in terms of their potential to inhibit the activity of certain enzymes that are involved in some diseases or disorders. In vitro culturing of lichen symbionts in optimized media can be carried out to isolate enzyme inhibitors in larger scale and to develop effective therapeutic agents. Keywords: Lichens, lichen substances, enzyme inhibitors, enzyme inhibitory activity

A new epicatechin glucopyranoside derivative from Styrax suberifolius

A new derivative of epicatechin glucopyranoside, (2R,3R)-3,7,4'-trihydroxy-5,3'-dimethoxyflavan 7-O-β-d-glucopyranoside (1), together with three mononuclear phenolic acid esters, methyl orsellinate (2), ethyl orsellinate (3) and methyl β-orcinolcarboxylate (4) were isolated from the bark of Styrax suberifolius. The structures of 1–4 were determined on the basis of extensive analysis of NMR and MS spectra combined with chemical hydrolysis. The antifungal activities of the isolated compounds against three plant pathogenic fungi, Alternaria solani, Fusarium oxysporum and Phomopsis cytospore were evaluated using radial growth inhibition assay. Compounds 2, 3 and 4 exerted selective inhibitory activities against the tested fungi. Among of them, methyl β-orcinolcarboxylate (4) exhibited obvious inhibitory effect against P. cytospore, with an inhibition rate of 86.72% at 100 μg/ml.

Antioxidant Activity and Protective Effect on Cell and DNA Oxidative Damage of Substances isolated from Lichens of Colombian páramo

The páramo ecosystem is situated in northwest of South America, and it is well known for distribution of lichens. It is documented that lichens produce antioxidant activity, and protect cells from oxidative stress by scavenging free radical. Hence we checked the antioxidant and protective abilities to prevent cell and DNA damage by oxidative stress of Lobariella pallida and Stereocaulon strictum var. compressum extracts. Additionally, the active constituents namely lobariellin (1), methyl orsellinate (2), stereocaullin (3), methyl haematommate (4), methyl β-orcinol carboxylate (5), porphyrilic acid (6) and atranorin (7), were isolated from both extracts and their antioxidant activity was evaluated. The DPPH·, ferric reducing power and inhibition of lipid peroxidation model were used to determined the antioxidant activity of extracts and isolated compounds. The cell and DNA protective effects of extracts and isolated compounds were investigated by exposing keratinocytes, neurons and pUC18 plasmid to hydroxyl radicals, and examined cell viability or DNA cleavage of sample. The findings exhibits that the compounds 1, 4 and 6 scavenged free radicals, inhibited lipid peroxidation and reduced ferric ions at maximum level compared to other isolated compound and extracts. Additionally, 1 and 4 protected cells from oxidative damage and 1 also preserved DNA. These results suggest that 1 and 4 imparts antioxidant activity to prevent oxidative skin and neurodegenerative damage.

Dereplication of depsides from the lichen Pseudevernia furfuracea by centrifugal partition chromatography combined to 13C nuclear magnetic resonance pattern recognition

Lichens produce a diversity of secondary metabolites, among them depsides comprised of two or more hydroxybenzoic acid units linked by ester, ether, or CC-bonds. During classic solid support-based purification processes, depsides are often hydrolyzed and in many cases time, consuming procedures result only in the isolation of decomposition products. In an attempt to avoid extensive purification steps while maintaining metabolite structure integrity, we propose an alternative method to identify the major depsides of a lichen crude extract (Pseudevernia furfuracea var. ceratea (Ach.) D. Hawksw., Parmeliaceae) directly within mixtures.Exploiting the acidic character of depsides and differences in polarity, the extract was fractionated by centrifugal partition chromatography in the pH-zone refining mode resulting in twelve simplified mixtures of depsides. After 13C nuclear magnetic resonance analysis of the produced fractions, the major molecular structures were directly identified within the fraction series by using a recently developed pattern recognition method, which combines spectral data alignment and hierarchical clustering analysis. The obtained clusters of 13C chemical shifts were assigned to their corresponding molecular structures with the help of an in-house 13C NMR chemical shift database, resulting in six unambiguously identified compounds, namely methyl β-orcinolcarboxylate (1), atranorin (2), 5-chloroatranorin (3), olivetol carboxylic acid (4), olivetoric acid (5), and olivetonide (6).

Phytochemical investigation of Tephromela atra: NMR studies of collatolic acid derivatives

Six known compounds, atranorin ( 1) and its derivatives methyl β-orcinol carboxylate ( 2) and methyl haematommate ( 3), the depsidones α-alectoronic acid ( 4) and α-collatolic acid ( 5), with its hydrolysis derivative β-collatolic acid ( 6), and a new compound, deoxycollatolic acid ( 7) have been isolated from the lichen Tephromela atra (Huds.) Hafellner (syn. Lecanora atra). The characterization of the new compound 7 was carried out by extensive NMR studies using COSY, HMQC, HMBC in addition to other spectroscopic methods. 1H NMR spectra recorded at low temperature showed β-collatolic acid ( 6) was corresponding to an equilibrium of conformers. Compounds 5 and 6 showed a better superoxide anion scavenging activity (IC 50 = 463 and 122 μM, respectively) than quercetin (IC 50 = 754 μM).

Rapid and Sensitive HPLC Method for the Determination of Polyphenols in Various Lichen Species of Himalayan Origin

A reversed‐phase high performance liquid chromatograph (HPLC) with photodiode array detection method was developed to determine bioactive polyphenolic substances, methyl β‐orcinolcarboxylate (MBO) and ethyl haematommate (EH) in thalli of various lichen species. The MBO and EH were separated by RP‐HPLC (C18 column, 150 mm×4.6 mm, 5 µm) using isocratic elution systems of acetonitrile:water (0.1% acetic acid). Base line separation of the compounds was obtained in less than 20 min. The method was validated for linearity, repeatability, limits of detection (LOD), and limits of quantification (LOQ). Repeatability (inter‐ and intra‐day, n=6) showed less than 1.5% relative standard deviation (RSD). The LOD and LOQ were found to be 5.97 and 15.51 ng for MBO and 42.63 and 69.03 ng for EH, respectively. The validated HPLC method was employed to quantify MBO and EH in eleven lichen species, used in folklore/traditional systems of medicine collected from the Himalayan region of India.

Histochemical detection of an haematommoyl alcohol dehydrogenase in the lichen Evernia prunastri

Atranorin, one of the most abundant phenols of Evernia prunastri, is mainly located in the cortex together with evernic acid. Atranorin is produced by esterification of two different precursors, methyl β-orcinol carboxylate and haematommic acid. This last compound is produced from methyl-3-orsellinate by the successive action of an oxidase and an alcohol dehydrogenase. This alcohol dehydrogenase oxidizes haematommoyl alcohol to haematomic acid, and catalyzes the reduction of the aldehyde function in the atranorin molecule. Other analogs of haematommoyl alcohol, such as orcinol or methyl β-orcinol carboxylate, were not used as substrate by this alcohol dehydrogenase. The enzyme has been located in the medullary hyphae, especially in those immediately above the lower cortex. Thus, haematommoyl alcohol dehydrogenase activity seems to be restricted to the fungal partner in the lichen thallus. This enzyme is here described for the first time in lichens.

Lichen metabolites. 2. Antiproliferative and cytotoxic activity of gyrophoric, usnic, and diffractaic acid on human keratinocyte growth.

The sensitivity of the human keratinocyte cell line HaCaT to several lichen metabolites isolated from Parmelia nepalensis and Parmelia tinctorum was evaluated. The tridepside gyrophoric acid (6), the dibenzofuran derivative (+)-usnic acid (1), and the didepside diffractaic acid (5) were potent antiproliferative agents and inhibited cell growth, with IC50 values of 1.7, 2.1, and 2.6 microM, respectively. Methyl beta-orcinolcarboxylate (2), ethyl hematommate (3), the didepside atranorin (4), and (+)-protolichesterinic acid (7) did not influence keratinocyte growth at concentrations of 5 microM. Keratinocytes were further tested for their susceptibility to the action of the potent antiproliferative agents on plasma membrane integrity. The release of lactate dehydrogenase activity into the culture medium was unchanged as compared to controls, documenting that the activity of gyrophoric acid (6), (+)-usnic acid (1), and diffractaic acid (5) was due to cytostatic rather than cytotoxic effects.

2-Deacetoxytaxinine B: A New Taxane from Taxus wallichiana

A new taxane derivative, 2-deacetoxytaxinine B (1), has been isolated from Taxus wallichiana, along with β-sitosterol, sciadopitysin, and methyl β-orcinolcarboxylate.

Structure of 2-methoxy methyl β-orcinol carboxylate (methyl 4-hydroxy-2-methoxy-3,6-dimethylbenzoate)

C 11 H 14 O 4 cristallise dans P2 1 /c avec a=7.931, b=7.950, c=8.929A, β=102.81°, Z=2; affinement jusqu'a R=0.040. Le cycle phenyl est incline sue le groupe carboxylate de 71.7°, et le groupe methoxy de 75.3°; ces deux groupes etant inclines de 53.4° l'un par rapport a l'autre. Les molecules reliees par un axe vis d'ordre deux sont liees par une liaison hydrogene intermoleculaire entre le substituant 4-hydroxy et le groupe carbonyl du carboxylate

Regulation mechanisms of phenolic production in the lichen Himantormia lugubris, as deduced from the analysis of metabolite accumulation

HPLC analysis of the phenolic fraction of the lichen Himantormia lugubris reveals that atranorin, barbatolic acid and methyl β- orcinol carboxylate are mainly accumulated in the thallus. Samples floated in the dark on acetate actively synthesize barbatolic acid from the beginning of the incubation, and atranorin after an initial loss during the first hour of incubation. The amount of the atranorin precursor, methyl β-orcinol carboxylate, remains unchanged after an initial decrease similar to that found for atranorin. Active production of both atranorin and barbatolic acid is inhibited by white light and recovered by adding 3-(3′-dichlorophenyl)-1,1-dimethylurea (DCMU) or ATP to the incubation media. The supply of exogenous ATP strongly activates the accumulation of methyl β-orcinol carboxylate. This possibly indicates that ATP behaves as a limiting factor for the steps catalyzed by acetyl-CoA carboxylase and methionine adenosyltransferase, related to the production of this last phenolic. A glucose supply in the dark assures the ability of lichen thalli for phenolic synthesis whereas this process is strongly decreased by exogenous cyclic AMP.

Pigment analysis of sun and shade populations of Cladonia verticillaris

The natural occurrence of the lichen Cladonia verticillaris as sunny and shaded populations implies changes in the pigment content. Shade specimens contain more chlorophyll a and b as well as more α- and β-carotene than those found in unshaded lichens. However, lichens growing in sunny locations contain more methyl β-orcinol carboxylate, orcinol and fumarprotocetraric acid than those found in lichens growing under low light intensities. No structural differences in the chloroplasts of the two species bave been detected.

Methyl β-Orcinolcarboxylate and Depsides from Parmelia furfuracea

Methyl β-Orcinolcarboxylate and Depsides from Parmelia furfuracea

The Utilization of Urea by the Lichen Cladonia sandstedei

The production of both ribitol (which is the translocatable form of reduced carbon) and mannitol (which is the main accumulation form of carbon) by thallus samples of Cladonia sandstedei increases when exogenous urea is supplied to the lichen. In addition, the synthesis of atranorin and its precursor, methyl β-orcinol carboxylate, is also enhanced by urea. A hypothetical action of ammonia released from this nitrogen source on these metabolic processes is suggested.

Isolation of 30-nor-21 α-hopan-22-one (isoadiantone) from the lichen Platismatia glauca

The nor-triterpene ketone, 30-nor-21α-hopan-22-one, the depsides atranorin and chloroatranorin, and the aromatic compounds methyl β-orcinolcarboxylate and chloroatranol, as well as a series of normal, aliphatic hydrocarbons ( n-C 14 n-C 33) have, been isolated from the lichen Platismatia glauca.

Studies on antispetics for foodstuff. LXXI. Studies on orsellinic acid ester, beta-orcinolcarboxylic acid ester and olivetonide as a preservative for sake

Antibacterial tests against Hiochi bacteria of Japanese Sake were made with 13 kinds of compounds which are derivatives of lichen components, including orsellinic acid esters, β-orcinolcarboxylic acid esters, and olivetonide. Butyl orsellinate showed about 4 times the antibacterial action of n-butyl p-hydroxybenzoate and about 8-16 times that of salicylic acid. Hexyl and octyl orsellinates showed a strong antibacterial activity, about 60 times that of butyl p-hydroxybenzoate and about 125-250 times that of salicylic acid. The antibacterial action of methyl β-orcinolcarboxylate was about 10 times that of butyl p-hydroxybenzoate and about 20-40 times that of salicylic acid, while that of its ethyl ester was about 20 times that of butyl p-hydroxybenzoate and about 40-80 times that of salicylic acid. Olivetonide also showed an antibacterial action, about 8 times that of butyl p-hydroxybenzoate and 15-30 times that of salicylic acid. This test has shown that these compounds all had a strong antibacterial action against Hiochi bacteria.