Specialized Metabolites of the Lichen Vulpicida pinastri Act as Photoprotective Agents.

The extreme resiliency of lichens to UV radiations makes them an interesting model to find new photoprotective agents acting as UV-blockers and antioxidant. In this research, using a new in vitro method designed to overcome the shortage of material associated to many studies dealing with natural products, we show that the three major compounds isolated from the lichen Vulpicida pinastri, vulpinic acid, pinastric acid and usnic acid, were UV blocker agents. Antioxidant assays evidenced superoxide anion scavenging activity. Combination of the most promising compounds against UVB and UVB radiations, usnic acid, vulpinic acid and pinastric acid, increased the photoprotective activity. At the same time, they were found not cytotoxic on keratinocyte cell lines and photostable in the UVA and UVB ranges. Thus, lichens represent an attractive source to find good candidate ingredients as photoprotective agents. Additionally, the uncommon scalemic usnic acid mixture in this Vulpicida species was proven through electronic circular dichroism calculation.

Letharia vulpina, a vulpinic acid containing lichen, targets cell membrane and cell division processes in methicillin-resistant Staphylococcus aureus.

CONTEXT: Antibiotic resistance in humans is a major concern. Drugs that target traditional sites and pathways are becoming obsolete; thus, compounds affecting novel targets are needed. Screening lichen metabolites for antimicrobials has yielded promising antimicrobial compounds, yet their mode of action is poorly understood. Letharia vulpina (L.) Hue (Parmeliaceae) has traditionally been used to poison predators, and treat stomach disorders; more recently L. vulpina extracts have demonstrated promising antimicrobial properties. OBJECTIVE: This study investigates the mode of action of L. vulpina acetone extract against a methicillin-resistant Staphylococcus aureus (MRSA). MATERIAL AND METHODS: We treated MRSA with L. vulpina extracts at 1×, 5×, and 10 × MIC values (MIC = 31.25 µg/ml) for 24 h and optical density (OD660) was measured over time to determine bacteriolytic activity; counted colony forming units (CFUs) to determine time kill dynamics; the propidium iodide (PI) assay and transmission electron microscopy were used to assess membrane-damage potential, and thin-layer chromatography was used to identify secondary compounds. RESULTS: Bacteriolytic assays showed that L. vulpina extracts, containing only vulpinic acid, do not cause cell lysis, even at 10 × MIC values but there was 92% reduction in bacterial CFUs when treated with increased concentrations of lichen extracts over 24 h at 4 h intervals. Our data indicate that the L. vulpina extract compromises membrane integrity of the MRSA isolate and disrupts cell division processes. DISCUSSION AND CONCLUSION: Based on this study, detailed examination of acetone extracts of L. vulpina as well as pure extracts of vulpinic acid as potential antibacterial compounds merit further study.

Metabolites from the endophytic fungus HP-1 of Chinese eaglewood.

AIM: To study the chemical constituents from the fermentation of the endophytic fungus HP-1 of Chinese eaglewood. METHODS: The chemical constituents were isolated by column chromatography on silica gel and Sephadex LH-20, and their structures were elucidated on the basis of spectroscopic analysis. RESULTS: Four compounds were isolated and identified as 3α, 3ß, 10ß-trimethyl-decahydroazuleno[6, 7]furan-8, 9, 14-triol (1), 4-hydroxyphenylacetic acid (2), 4-hydroxyphenethyl alcohol (3), and 5-hydroxymethyl-2-furancarboxaldehyde (4). CONCLUSION: Compound 1 was a new compound. Compound 2 showed antibacterial activity against Staphylococcus aureus.

Cytotoxic caffeic acid derivatives from the rhizomes of Cimicifuga heracleifolia.

Activity profiling of the n-BuOH extract from Cimicifuga heracleifolia rhizomes led to the identification of three cytotoxic caffeic acid derivatives, carboxymethyl isoferulate (2), cimicifugic acid A (3), and cimicifugic acid B (4) together with a series of structurally related inactive compounds. The extract was separated by time-based fractionation in a gradient HPLC condition, and cytotoxicity of each fraction was evaluated using HCT116 colon cancer cells in vitro. HPLChyphenated spectroscopy including LC/NMR and LC/PDA/MS provided structural information for phenolic compounds contained in the extract, and further preparative isolation of active compounds 2-4 was achieved by semi-preparative HPLC. Compounds 2-4 showed cytotoxic activity against cancer cells in a dose-dependent manner at the concentrations of 2.5-40 µM, and western blotting analysis showed that these compounds increased expression of cleaved poly ADP ribose polymerase (PARP), a critical apoptosis marker.

Anti-hyperglycemic effect of Opuntia streptacantha Lem.

AIM OF THE STUDY: This experiment studied two extracts of Opuntia streptacantha, a plant used by the Mexican population to treat type 2 diabetes, in different assays to contribute to the understanding of the hypoglycemic mechanism of this plant. MATERIALS AND METHODS: Two different extracts were prepared and tested: the first extract was a filtrate of the traditional liquefied extract (LE) preparation of the cladode; and the second filtrate extract (FE) is a filtered sample of the first. Both extracts contained a newly identified compound for Opuntia (4-hydroxy)-phenyl acetic acid derivate, they were tested on streptozotocin (STZ)-diabetic rats in a series of two tests. The first test was performed to confirm if STZ-diabetic rats presented a hypoglycemic effect after administration of the extracts (LE 135 mg/kg and FE 27 mg/kg). In the second experiment, the extracts were administered before an oral glucose tolerance test (OGTT) to confirm if they have an anti-hyperglycemic effect (LE 135 mg/kg, FE 12 and 27 mg/kg). RESULTS: The extracts administered to STZ-diabetic rats did not produce a significant hypoglycemic effect compared to the control group, while the same extracts administered before an OGTT produced an anti-hyperglycemic effect compared to the control group. CONCLUSIONS: The filtered, traditional LE of the cladode of Opuntia streptacantha produces an anti-hyperglycemic effect when administered before a glucose challenge, and this anti-hyperglycemic effect is maintained after filtering the extract. Administration of both plants can improve glycemic control by blocking the hepatic glucose output, especially in the fasting state. These data support the traditional use of the plants as "agua de uso", a cold infusion of the plant consumed over the course of a day.

[Study on chemical constituents of the Ixeris chinensis].

OBJECTIVE: To study the chemical constituents of the Ixeris chinensis . METHODS: The constituents were isolated by silica gel column chromatography, HPLC and recrystallization and their structures were elucidated on the basis of spectral analysis. RESULTS: Fifteen compounds were isolated and identified as Methyl-4-hydroxyphenylacetate (1), Daucosterol (2), Sitosterol (3), Luteolin-7-O-beta-D-glucoside (4), 15-hydroxy-2-oxoguaia-1 (10), 3,11 (13)-triene-12,6-lactone (5), Chinensiolide B (6), Chinensiolide E (7), Ixerochinoside (8), Chinensiolide C (9), 10alpha-hydroxy-guaia-4(15)-ene-12,6-lactone (10), 10alpha-hydroxy-guaia-4 (15), 11 (13)-diene-12,6-lactone-3beta-O-beta-D-(6'-p-hydroxyphenylacetyl) glucopyranoside (11), Epiloliolide (12), Apigenin-O-beta-D-glucopyranoside (13), Luteolin (14), Lutein (15). CONCLUSION: Compounds 1,10,11,12 and 15 are isolated from this plant for the first time.

[Studies on the chemical constituents of extract with water from Forsythia suspensa].

OBJECTIVE: To study the chemical constituents of the extract with water from Forsythia suspensa. METHODS: The compounds were isolated and repeatedly purified on TLC, silica gel column chromatograph, gel column chromatography, and preparative HPLC, and the structures were elucidated by physico-chemical properties and NMR. RESULTS: Eight compounds were obtained and elucidated as stearic acid(I), ursolic acid(II),p-hydroxyphenyl acetic acid(III),3-(4-ehtoxoy-3-hydroxyphenyl)acrylic acid(IV),isolariciresinol(V), epipinoresinol-4-O-beta-D-glucoside(VI),(+)-epipinoresionl(VII),(+)-pinoresinol(VIII). CONCLUSION: Compound III is isolated from this genus for the first time.

Fukinolic acid derivatives and triterpene glycosides from black cohosh inhibit CYP isozymes, but are not cytotoxic to Hep-G2 cells in vitro.

Black cohosh (Actaea racemosa L. [syn. Cimifuga racemosa L.]) extracts (BCE) are marketed worldwide for the management of menopausal symptoms. However, recently more than 75 cases of hepatotoxicity associated with black cohosh ingestion have been reported. While these cases have not been fully substantiated for causality, the data suggest that herb-drug interactions may be involved rather than a direct hepatotoxic event. This work describes the in vitro inhibition of four CYP450 enzymes (1A2, 2D6, 2C9, 3A4) by black cohosh extracts and identifies the active inhibitory constituents. Ethanol extracts (75 and 80% ethanol) and a 40% isopropanol extract induced a concentration-dependent inhibition of all CYP450 isozyme activities, with median inhibitory concentrations (IC(50)) ranging from 21.9 microg/ml to 65.0 microg/ml. Isolation of the active chemical constituents, showed that the triterpene glycosides were weakly active (IC(50) 25-100 microM), while fukinolic acid and cimicifugic acids A and B strongly inhibited all CYP isozymes (IC(50) 1.8-12.6 microM). None of the extracts inhibited the growth of Hep-G2 cells in concentrations up to 50 microg/ml. These data suggest that BCEs are not directly hepatotoxic, but may have the potential to induce herb-drug interactions, which may in turn explain the rare cases of hepatotoxicity observed in women using multiple medications and dietary supplements, including black cohosh.

Hyaluronidase inhibitors from "Cimicifugae Rhizoma" (a mixture of the rhizomes of Cimicifuga dahurica and C. heracleifolia).

From the 80% acetone extract of "Cimicifugae Rhizoma" (a mixture of Cimicifuga dahurica and C. heracleifolia used medicinally), seven new fukiic acid derivatives (1-7) and a new phenylethanoid derivative (8) were isolated along with eight known compounds (9-16). Fukinolic acid (9) and cimicifugic acids A-J (10-16, 5-7) showed stronger hyaluronidase inhibitory activities than the positive control, rosmarinic acid.

Phenolic constituents of the aerial parts of Cimicifuga simplex and Cimicifuga japonica.

Chemical investigation of the aerial parts of Cimicifuga simplex afforded four new fukinolic acid analogues, cimicifugic acids K-N (1-4), and 10 known compounds, and C. japonica afforded three new fukinolic acid analogues, cimicifugic acids K-M (1-3), a new phenolic glycoside, shomaside F (5), and 10 known compounds. Cimicifugic acids K-N showed more potent hyaluronidase inhibitory activities than rosmarinic acid.

Euphorbiasteroid reverses P-glycoprotein-mediated multi-drug resistance in human sarcoma cell line MES-SA/Dx5.

In this study, we evaluated whether euphorbiasteroid isolated from Euphorbia lathyris has the potential to reverse P-glycoprotein (P-gp)-mediated multi-drug resistance (MDR) by using the drug-sensitive human sarcoma cell line MES-SA and its MDR counterpart MES-SA/Dx5. Interestingly, even at low concentrations of euphorbiasteroid (1-3 microM), it efficiently restored the toxicities of anticancer drugs including vinblastine, taxol and doxorubicin in MES-SA/Dx5 cells. Additionally, the computational Bayesian model for predicting potential P-gp substrates or inhibitors revealed that euphorbiasteroid showed 97% probability for substrate likeness having similar molecular features with 50 P-gp substrates. Consistent with this result, the substrate likeness of euphorbiasteroid was also experimentally confirmed by P-gp ATPase activity assay. In conclusion, our finding suggested that euphorbiasteroid could be a transport substrate for P-gp that can effectively inhibit P-gp-mediated drug transport and reverse resistance to anticancer drugs in MES-SA/Dx5 cells.

Chemical constituents of the lichen, Candelaria concolor: a complete NMR and chemical degradative investigation.

A detailed chemical and spectroscopic investigation of the terrestrial lichen Candelaria concolor has yielded several lichenic metabolites belonging to the pulvinic acid series, as well as several depside derivatives including pulvinic dilactone (1), vulpinic acid (4) and calycin (5). The chemical transformation of 1 to pulvinic acid (3) is reported for the first time, as is the conversion of atranorin (6) to 5-chloroatranorin (7) and then finally to 5,5'-dichloroatranorin (8) under very mild conditions. Also presented is the complete 1D and 2D NMR assignment for compounds 1, 3, 4, 5 and 8, including partial NMR chemical shift assignments for the unstable depside (7). Previously, these metabolites had only been partially assigned by NMR spectroscopy.

Two novel compounds from Ardisia punctata Lindl.

To study the chemical constituents of Ardisia punctata, compounds were isolated with a combination of multi-chromatography. Their structures were determined on the basis of spectral analysis and comparison to those of the known compounds. A 1,4-benzoquinone derivative and a alkylphenol were isolated from the petroleum ether extract of the roots of Ardisia punctata. Their structures were elucidated as 2-tridecyl-3-[(2-tridecyl-4-acetoxy-6-methoxy)-phenoxyl] -6-methoxy-1,4-benzoquinone (1) and 2-methoxy-4-hydroxy-6-tridecyl-phenyl acetate (2). The two compounds are both new.

Polyphenolic constituents of Actaea racemosa.

A new lignan, actaealactone (1), and a new phenylpropanoid ester derivative, cimicifugic acid G (2), together with 15 known polyphenols, protocatechuic acid, protocatechualdehyde, p-coumaric acid, caffeic acid, methyl caffeate, ferulic acid, ferulate-1-methyl ester, isoferulic acid, 1-isoferuloyl-beta-d-glucopyranoside, fukinolic acid, and cimicifugic acids A, B, and D-F, were isolated from an extract of the rhizomes and roots of black cohosh (Actaea racemosa). The structures of the new compounds were determined on the basis of NMR spectroscopic analysis. Compounds 1 and 2 displayed antioxidant activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical assay with IC(50) values of 26 and 37 microM, respectively. Other antioxidants identified from A. racemosa include cimicifugic acid A (3), cimicifugic acid B (4), and fukinolic acid (5). Compounds 1 and 2 also exhibited a small stimulating effect on the growth of MCF-7 breast cancer cell proliferation 1.24-fold (14 microM) and 1.14-fold (10 microM), respectively, compared to untreated cells.

[Studies on the phenolic acid constituents from Chinese medicine "sheng-ma", rhizome of Cimicifuga foetida L].

AIM: To look for new active constituents from Chinese medicine "Sheng-ma", rhizome of Cimicifuga foetida L. METHODS: The compounds were separated and purified by chromatography on silica gel and Sephadex LH-20. Their structures were determined by spectral analysis and chemical reaction. RESULTS: Eight compounds were obtained and identified as cimicifugic acid (1), esculetin (2), caffeic acid methyl ester (3), 4-O-acetyl-caffeic acid (4), sinapic acid (5), caffeic acid (6), ferulic acid (7), isoferulic acid (8). CONCLUSION: Compound 1 is a new compound, and compounds 2-7 were isolated from this plant for the first time.

Estrogenic activity of phenolic compounds from Nigella damascena evaluated using a recombinant yeast screen.

We used a yeast estrogen screen (YES) containing human estrogen receptor to evaluate the estrogenic activity of both crude extracts and simple pure phenolic compounds from Nigella damascena seeds. Estrogenic activity was established in the methanolic and aqueous extracts of the seeds as well as in two simple phenolic compounds isolated from the methanolic extract, 2,4-dihydroxyphenylacetic acid, 3,4-dihydroxy-beta-phenethyl alcohol.

Isolation and in vivo and in vitro antifungal activity of phenylacetic acid and sodium phenylacetate from Streptomyces humidus.

The antifungal substances SH-1 and SH-2 were isolated from Streptomyces humidus strain S5-55 cultures by various purification procedures and identified as phenylacetic acid and sodium phenylacetate, respectively, based on the nuclear magnetic resonance, electron ionization mass spectral, and inductively coupled plasma mass spectral data. SH-1 and SH-2 completely inhibited the growth of Pythium ultimum, Phytophthora capsici, Rhizoctonia solani, Saccharomyces cerevisiae, and Pseudomonas syringae pv. syringae at concentrations from 10 to 50 microg/ml. The two compounds were as effective as the commercial fungicide metalaxyl in inhibiting spore germination and hyphal growth of P. capsici. However, the in vivo control efficacies of the two antifungal compounds against P. capsici infection on pepper plants were similar to those of H(3)PO(3) and fosetyl-AI but less than that of metalaxyl.

A new phenolic compound from Nigella damascena seeds.

A new phenolic ester has been isolated from the seeds of Nigella damascena and the structure was established as 1-O-(2,4-dihydroxy)phenylacetyl glycerol (1) by 1H and 13C-NMR spectral data and EI-MS analysis.

Identification and distribution of m- and p-hydroxyphenylacetic acids in the brain of the rat.

The m and p isomers of hydroxyphenylacetic acid have been identified and quantitated in whole rat brain and in several regions using a capillary column high resolution gas chromatography - mass spectrometry procedure. Their concentrations were: for m-hydroxyphenylacetic acid (mean +/- S.E., number of determinations in parentheses)-whole brain, 2.3 +/- 0.3 ng/g (7); hypothalamus, 1.2 +/- 0.3 ng/g (5); caudate nucleus, 5.5 +/- 0.6 ng/g (5); brain stem, 1.8 +/- 0.1 ng/g (5); cerebellum, 1.2 +/- 0.1 ng/g (5) and the "rest," 1.7 +/- 0.1 ng/g (5); and for p-hydroxyphenylacetic acid-whole brain, 10.6 +/- 0.7 ng/g (7); hypothalamus, 4.5 +/- 0.1 ng/g (4); caudate nucleus, 28.3 +/- 1.6 ng/g (5); brain stem, 8.6 +/- 0.6 ng/g (5); cerebellum, 8.1 +/- 0.4 ng/g (5), and the "rest," 5.3 +/- 0.5 ng/g (5). This heterogeneous distribution parallels closely that exhibited by their respective precursor amines, m- and p-tyramine.