Perylenequinones from an endophytic Alternaria sp. of Pinus ponderosa.

The differential solvent extraction and further purification of fractions of endophytic Alternaria sp. isolated from Pinus ponderosa led to the isolation of further two perylenequinone compounds as 3,6,6a,9,10-pentahydroxy-7,8-epoxy-4-oxo-4,5,6,6a,6b,7,8,9-octahydroperylene (1) and 3,6,6a,7,10-pentahydroxy-4,9-dioxo-4,5,6,6a,6b,7,8,9-octahydroperylene (2). Structure of compounds 1-2 was determined on the basis of detailed spectroscopic analysis, as well as by comparison with literature reports. The antimicrobial, antileismanial, antimalarial and cytotoxic activities of compound 1 and 2 were evaluated.

Gracilone, a new sesquiterpene lactone from Tanacetum gracile (Tansies).

The methanolic extract of the Tanacetum gracile afforded the isolation of new sesquiterpene lactone, named gracilone (1) along with four known compounds as 14α-taraxeran-3-one (2), 14α-taraxeran-3-ol (3), apigenin (4) and ß-sitosterol (5). The structure of compound 1 was elucidated on the basis of 1D, 2D NMR and MS spectroscopic analysis. Antimicrobial, antioxidant and anticancer activities of all compounds were evaluated, from which gracilone (1) showed a moderate antibacterial activity, while apigenin (4) showed comparatively more antibacterial activity against both gram-positive and gram-negative tested strains.

Crocetenone, a new rotenoid with an unusual trans-fused ring system from Iris crocea.

Crocetenone, a new rotenoid (1), along with five known compounds apocyanin (2), tectorigenin (3), 5,2',3'-trihydroxy-7-methoxy flavanone (4), tectoridin (5) and tectoridin glycoside (6), were isolated from the methanolic extract of the root of Iris crocea. The structure of compounds was elucidated on the basis of 1D- and 2D-NMR spectroscopic and MS analysis. Antibacterial and antioxidant activities of compounds 1-6 were evaluated. Crocetenone (1) showed a prominent antibacterial activity.

New phenolics from the root of Scutellaria prostrata JACQ. ex BENTH.

Scutellaria prostrata (Lamiaceae), a perennial herb growing as a lonely species in Kashmir, Himalayas, was subjected to repetitive column and flash chromatographic isolation for its chemical documentation-cum-bioevaluation. The methanolic extract of S.prostrata afforded the isolation of ten compounds (1-10), including two new compounds - scutellapbiflavanone (1) and scutellaprostin M (2). The known compounds were found to be scutellarin (3), hispidulin-7-O-ß-D-glucopyranoside (4), baicalin (5), wogonoside (6), scutellaprostin C (7), acetoside (8), martynoside (9) and scutellaric acid-3-O-ß-D-glucopyranoside (10). Isolation of biflavonoids, phenolics and phenylethanoid compounds from S. prostrata seals a deal of chemotaxonomic importance of this particular species. The characterisation of the compounds was achieved by (1)H, (13)C, (1)H-(1)H DFQ COSY, HMBC, HSQC, HMQC and ROESY NMR experiments. All the compounds were tested for antioxidant, antimicrobial and cytotoxic activities.

Hepatoprotective activity of LC-ESI-MS standardized Iris spuria rhizome extract on its main bioactive constituents.

The study was designed to evaluate the hepatoprotective activity of Iris spuria against paracetamol induced toxicity at two different doses 100 and 200 mg/kg. The extract showed significant protective activity (p>0.01) at both the doses in dose dependent manner. Administration of the plant extract restored the paracetamol induced elevated levels of serum marker and distorted hepatic tissue architecture. The lipid peroxides (LPO) and glutathione (GSH) levels were also restored towards normal in liver tissue significantly. The main chemical constituents of the extract identified by the liquid chromatography-tandem mass spectrometry (LC-ESI-MSMS) were found to be flavones and isoflavonoids. Tectoridin and iristectorigenin A were the principal compounds present in the methanolic extract of Iris spuria.

Acylated flavonol glycosides from Epimedium elatum, a plant endemic to the Western Himalayas.

Herba Epimedii is a well-known Botanical preparation used over long time in traditional Chinese medicine. The extracts and chemical constituents from Epimedium species are aphrodisiac as well as to treat many ailments. Chemical investigation of lonely species growing in Kashmir Himalaya Epimedium elatum was undertaken to evaluate its chemical profile. Two unusual substituted acylated flavonol glycosides named Elatoside A (1) and Elatoside B (2) have been isolated from the ethanolic extract of E. elatum along with 23 previously known ones (3-25). All isolates were evaluated for antimicrobial and PPAR-γ ligand binding activity, and some of them appeared to be modestly active.

Acetyl-11-keto-ß-boswellic acid (AKBA); targeting oral cavity pathogens.

BACKGROUND: Boswellic acids mixture of triterpenic acids obtained from the oleo gum resin of Boswellia serrata and known for its effectiveness in the treatment of chronic inflammatory disease including peritumor edema. Boswellic acids have been extensively studied for a number of activities including anti inflammatory, antitumor, immunomodulatory, and inflammatory bowel diseases. The present study describes the antimicrobial activities of boswellic acid molecules against oral cavity pathogens. Acetyl-11-keto-ß-boswellic acid (AKBA), which exhibited the most potent antibacterial activity, was further evaluated in time kill studies, mutation prevention frequency, postantibiotic effect (PAE) and biofilm susceptibility assay against oral cavity pathogens. FINDINGS: AKBA exhibited an inhibitory effect on all the oral cavity pathogens tested (MIC of 2-4 µg/ml). It exhibited concentration dependent killing of Streptococcus mutans ATCC 25175 up to 8 × MIC and also prevented the emergence of mutants of S.mutans ATCC 25175 at 8× MIC. AKBA demonstrated postantibiotic effect (PAE) of 5.7 ± 0.1 h at 2 × MIC. Furthermore, AKBA inhibited the formation of biofilms generated by S.mutans and Actinomyces viscosus and also reduced the preformed biofilms by these bacteria. CONCLUSIONS: AKBA can be useful compound for the development of antibacterial agent against oral pathogens and it has great potential for use in mouthwash for preventing and treating oral infections.

Antistaphylococcal and biofilm inhibitory activities of acetyl-11-keto-ß-boswellic acid from Boswellia serrata.

BACKGROUND: Boswellic acids are pentacyclic triterpenes, which are produced in plants belonging to the genus Boswellia. Boswellic acids appear in the resin exudates of the plant and it makes up 25-35% of the resin. ß-boswellic acid, 11-keto-ß-boswellic acid and acetyl-11-keto-ß-boswellic acid have been implicated in apoptosis of cancer cells, particularly that of brain tumors and cells affected by leukemia or colon cancer. These molecules are also associated with potent antimicrobial activities. The present study describes the antimicrobial activities of boswellic acid molecules against 112 pathogenic bacterial isolates including ATCC strains. Acetyl-11-keto-ß-boswellic acid (AKBA), which exhibited the most potent antibacterial activity, was further evaluated in time kill studies, postantibiotic effect (PAE) and biofilm susceptibility assay. The mechanism of action of AKBA was investigated by propidium iodide uptake, leakage of 260 and 280 nm absorbing material assays. RESULTS: AKBA was found to be the most active compound showing an MIC range of 2-8 µg/ml against the entire gram positive bacterial pathogens tested. It exhibited concentration dependent killing of Staphylococcus aureus ATCC 29213 up to 8 × MIC and also demonstrated postantibiotic effect (PAE) of 4.8 h at 2 × MIC. Furthermore, AKBA inhibited the formation of biofilms generated by S. aureus and Staphylococcus epidermidis and also reduced the preformed biofilms by these bacteria. Increased uptake of propidium iodide and leakage of 260 and 280 nm absorbing material by AKBA treated cells of S aureus indicating that the antibacterial mode of action of AKBA probably occurred via disruption of microbial membrane structure. CONCLUSIONS: This study supported the potential use of AKBA in treating S. aureus infections. AKBA can be further exploited to evolve potential lead compounds in the discovery of new anti-Gram-positive and anti-biofilm agents.

Isolation, characterisation and antibacterial activity studies of coumarins from Rhododendron lepidotum Wall. ex G. Don, Ericaceae / Estudos de isolamento, caracterização e atividade antibacteriana de cumarinas de Rhododendron lepidotum Wall. ex G. Don, Ericaceae

Six coumarins daphnin (1), daphnetin (2), daphnetin glucoside (3), rhodonetin (4), rhodonin (5) and umbelliferone (6) were isolated from the methanolic extract of Rhododendron lepidotum Wall. ex G. Don, Ericaceae (aerial part). The compounds and their acetyl derivatives were screened for antibacterial activity against Staphylococcus aureus ATCC-29213, methicillin resistant Staphylococcus aureus ATCC-15187, Escherichia coli ATCC-8739, Pseudomonas aeruginosa ATCC-9027 by microdilution method as compared to the reference ciprofloxacin. Compound 2 displayed the best antibacterial activity with MIC 125 μg/mL against S. aureus ATCC-29213 and MRSA ATCC-15187 followed by 4 which exhibited the MIC value of 250 μg/mL against all the four tested strains. All molecules showed better antibacterial activity than their acyl derivatives.

Seis cumarinas dafinina (1), dafinetina (2), dafinetina glicosídeo (3), rodonetina (4), rodonina (5) e umbeliferona (6) foram isoladas do extrato metanólico das partes aéreas de Rhododendron lepidotum Wall. ex G. Don, Ericaceae. Os compostos e seus derivados acetilados foram testados para verificar sua atividade antibacteriana contra Staphylococcus aureus ATCC-29213, Escherichia coli resistente à meticilina, Staphylococcus aureus ATCC-15187, ATCC-8739, Pseudomonas aeruginosa ATCC-9027, pelo método de microdiluição, usando ciprofloxacina como referência. A substância 2 apresentou a melhor atividade antibacteriana com o MIC 125 μg/mL contra S. aureus ATCC-29213 e MRSA ATCC-15187 seguido pela substância 4, que apresentou o valor de CIM de 250 μg/mL contra as quatro cepas testadas. Todas as moléculas apresentaram melhor atividade antibacteriana do que seus derivados acetilados.