Screening of leaves extracts from Calamus aromaticus for their antimicrobial activity by disc diffusion assay.

The current research investigates the anti-microbial activities of different solvent extracted samples from the leaves of Calamus aromaticus against Gram positive, Gram negative bacteria and fungi using 500, 1000 and 2000 µg disc-1 concentrations. Escherichia coli, Citorbacter freundii and Candida albicans showed resistivity to crude methanolic extract and the same microbes were more susceptible to water extracted fractions. Maximum activity was measured by hexane extracted fractions against Pseudomonas aeruginosa, Bacillus subtilis and Xanthomonas campestris and minimum growth inhibition by water extracted fractions. Maximum growth of Klebsiella pneumoniae and Staphylococcus aureus was measured by ethyl acetate fraction. Majority of the tested microbes were resistant to water and butanol extracted fractions. Staphylococcus aureus revealed maximum susceptibility among gram positive bacteria and Bacillus subtilis showed minimum. Among Gram negative bacteria, Citorbacter freundii was more susceptibile while Xanthomonas campestris revealed resistively.

Cytotoxic Steroidal Glycosides from the Whole Plant of Calamus acanthophyllus.

A new steroidal glycoside, callaphylloside (1), together with seven known glycosides (2-8), was isolated from the whole plant of Calamus acanthophyllus. The structure of the new compound was elucidated by spectral data analyses and chemical transformations. Compounds 5 and 8 exhibited strong cytotoxic activity against four cancer cell lines (0.7 ≤ IC50 ≤ 3.4 µM). Evaluation of the structure-activity relationship among steroidal glycosides revealed that the structure of spirostanol with an α-L-rhamnopyranosyl linked to C-2 of the inner glucopyranosyl residue both play a critical role in the effects of these compounds on the cancer cell lines.

Antioxidant and anti-inflammatory phenylpropanoid derivatives from Calamus quiquesetinervius.

Eight new phenylpropanoid derivatives [quiquesetinerviusides A (1), B (2), C (3), D (4), and E (5), as well as quiquesetinerviusins A (6), B (7), and C (8)] and seven known compounds (8-15), were isolated from an EtOAc extract of Calamus quiquesetinervius stems. The structures of 1-8 were elucidated on the basis of 1D- and 2D-NMR spectroscopic data analysis. Bioassay results showed that 1-5 possess weak DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activity, but potent (·)OH radical scavenging activity (IC(50) 3.6-8.4 µM). Of the tested isolates, compounds 4-6 and 9 showed potent inhibition (IC(50) 9.2-29.5 µM) of LPS-stimulated NO production when compared with a positive control substance, quercetin (IC(50) 34.5 µM).

Quiquelignan A-H, eight new lignoids from the rattan palm Calamus quiquesetinervius and their antiradical, anti-inflammatory and antiplatelet aggregation activities.

Eight new lignin derivatives, termed quiquelignan A-H (1-8), comprising three tricin-type flavonolignans (1-3) and five 8-O-4' neolignans (4-8), were isolated from the ethanol extract of Calamus quiquesetinervius stems. Structural elucidation of the new isolates was accomplished on the basis of spectroscopic data. Compounds 1-8 showed strong-to-moderate antioxidant activity against the hydroxy radical (()OH). Among them, compound 5 showed significantly higher hydroxy radical scavenging activity (IC(50) 4.4microg/mL). Compounds 2-4 and 6-8 dose-dependently suppressed the LPS-stimulated production of nitric oxide (NO) in RAW 264.7 cells. The anti-inflammatory potency of 4 and 6 was 2.7-4.5-fold higher compared with quercetin. Compounds 2-4, 6 and 8 also exhibited mild collagen-antagonistic activity, but were inactive with respect to thrombin-induced platelet aggregation.

Biomorphous porous hydroxyapatite-ceramics from rattan (Calamus Rotang).

The three-dimensional, highly oriented pore channel anatomy of native rattan (Calamus rotang) was used as a template to fabricate biomorphous hydroxyapatite (Ca(5)(PO(4))(3)OH) ceramics designed for bone regeneration scaffolds. A low viscous hydroxyapatite-sol was prepared from triethyl phosphite and calcium nitrate tetrahydrate and repeatedly vacuum infiltrated into the native template. The template was subsequently pyrolysed at 800 degrees C to form a biocarbon replica of the native tissue. Heat treatment at 1,300 degrees C in air atmosphere caused oxidation of the carbon skeleton and sintering of the hydroxyapatite. SEM analysis confirmed detailed replication of rattan anatomy. Porosity of the samples measured by mercury porosimetry showed a multimodal pore size distribution in the range of 300 nm to 300 microm. Phase composition was determined by XRD and FT-IR revealing hydroxyapatite as the dominant phase with minimum fractions of CaO and Ca(3)(PO(4))(2). The biomorphous scaffolds with a total porosity of 70-80% obtained a compressive strength of 3-5 MPa in axial direction and 1-2 MPa in radial direction of the pore channel orientation. Bending strength was determined in a coaxial double ring test resulting in a maximum bending strength of approximately 2 MPa.

Cardiovascular protective flavonolignans and flavonoids from Calamus quiquesetinervius.

Tricin-type flavonolignans, (2S)-dihydrotricin 4'-O-(erythro-beta-guaiacylglyceryl) ether, (2S)-dihydrotricin 4'-O-(threo-beta-guaiacylglyceryl) ether, (2S)-dihydrotricin 4'-O-(threo-beta-4-hydroxyphenylglyceryl) ether, tricin 4'-O-(erythro-beta-4-hydroxyphenylglyceryl) ether, tricin 4'-O-(threo-beta-4-hydroxylphenylglyceryl) ether, and (2S)-dihydrotricin 4'-O-(beta-6''-methoxy-4''-oxo-chroman-3''-yloxy) ether namely calquiquelignan A-F, respectively, were isolated and characterized from the EtOAc extract of Calamus quiquesetinervius. Additionally, six known phenolic compounds, including dihydrotricin, tricin, salcolin A, p-hydroxybenzoic acid, (2S, 3S)-trans-dihydrokapempferol and (2S)-naringenin, were also obtained and identified from the extract. Structures of the flavonolignans were assigned based on spectroscopic analyses that included 1D and 2D NMR spectroscopic techniques, such as HMQC, HMBC, and NOESY. Bioassay results showed that calquiquelignan A, dihydrotricin and (2S)-naringenin exhibited significant vasodilatory potencies, as indicated by 60.3%, 80.3% and 60.9% relaxations, respectively, at 100 microM. Salcolin A showed potent platelet aggregation inhibition, compared with aspirin. Most of the tricin-type derivatives (calquiquelignan A-B, dihydrotricin and tricin) also exhibited more potent hydroxyl radical ((.)OH) scavenging activity than trolox as characterized by the ultraweak chemiluminescence assay.

Steroidal saponins from Calamus insignis, and their cell growth and cell cycle inhibitory activities.

Three novel spirostanol-type (2, 3, and 5) and a furostanol-type (4) steroidal saponins were isolated from the stems of Calamus insignis (Palmae), along with a known steroidal saponin (1) by bioassay guided purification. The chemical structures of 1-5 were established on the basis of spectroscopic analysis and the result of acidic hydrolysis. Compounds 1, 2, 3, and 5 showed cell growth inhibitory activity against HeLa cells at a concentration of less than 10 microM, and 1 exhibited a cell cycle inhibitory effect at the G2/M stage at concentrations of 1.5 and 2.9 microM by flow cytometric analysis. This effect seems to be correlated with large expression of p21 and inhibition of dephosphorylation of cdc2 according to the result of Western blotting analysis.

Quantitative determination of beta-asarone in calamus by high-performance thin-layer chromatography.

A quantitative high-performance thin-layer chromatographic method for determination of beta-asarone in Calamus rhizome was developed and validated. The method is suitable for proper identification of Acorus calamus. Through the use of caffeine-modified silica gel as the stationary phase and toluene-ethyl acetate (93 + 7, v/v) as the mobile phase, beta-asarone is baseline separated from its isomer alpha-asarone. Scanning densitometry with absorption measurement at 313 nm allows specific, accurate, and precise quantification of beta-asarone. The working range of 40 to 200 ng absolute of the target substance is sufficient to establish whether a given sample passes the limit test of 0.5% maximum as required by the Swiss Pharmacopoeia.