Acrylic acid-methyl methacrylate (2.5:7.5/2:8) enteric copolymer for colon targeted drug delivery.

Enteric copolymers of acrylic acid and methyl methacrylate (2.5:7.5 and 2:8) were prepared using tetrahydrofuran as solvent and AIBN as free radical initiator for colon targeting. FTIR and (1)H NMR spectra of the copolymers showed absence of vinyl bond/protons present in the monomers suggesting successful polymerization. Flurbiprofen sodium microspheres (M1 and M2) made with the copolymers, by oil/oil solvent evaporation, were spherical, anionic (zeta potential -57.8 and -53.7 mV) and contained 5.47 and 5.89% drug. FTIR spectrum of microspheres showed peaks for aromatic C = C stretching and substituted benzene ring, indicating entrapment of flurbiprofen. PXRD revealed crystalline structure of flurbiprofen while copolymer and microspheres were amorphous. DSC thermograms showed a sharp melting endotherm of flurbiprofen sodium at 129.26°C against broad endotherms of copolymers and microspheres. The microspheres released 43 and 36% drug at pH 6.8 in 2 h and 99 and 96% at pH 7.4 in next 3-4 h.The microspheres did not adhere on gastric-mucosa at pH 1.2 but showed mucoadhesion time of 18 min and 9 min on intestinal mucosa at pH 6.8. Thus, the microspheres on oral administration, would release the drug in colon, suggesting the potential of the hemocompatible copolymers for pH dependent colon targeted drug delivery system.

Acrylic acid-methyl methacrylate copolymer for oral prolonged drug release.

Acrylic acid (AA)-methyl methacrylate (MMA) based copolymers, in different molar ratios (3:7, 4:6, 5:5, 6:4, and 7:3) were synthesized using tetrahydrofuran as solvent and AIBN as free radical initiator. Increase in acrylic acid concentration promoted pH-dependent swelling of copolymer and copolymer AA:MMA (3:7) was selected due to minimum swelling. ATR/FTIR and (1)H NMR spectra of the copolymer showed absence of vinyl bond/protons present in the monomers suggesting successful polymerization. The copolymer was hemocompatible. Flurbiprofen sodium microspheres made with the copolymer, by oil/oil solvent evaporation, were spherical, anionic (zeta potential -59.0 mV) and contained 4.53% drug. ATR spectrum of microspheres showed peaks for aromatic C=C stretching and substituted benzene ring, indicating entrapment of flurbiprofen. XRD analysis revealed crystalline structure of flurbiprofen while copolymer and microspheres were amorphous. DSC thermograms showed a sharp melting endotherm of flurbiprofen sodium at 129.26 degrees C against broad endotherms of copolymer and microspheres having peaks at 82.24 and 86.59 degrees C, respectively. The thermogram of microspheres did not show the melting peak of flurbiprofen. The microspheres exhibited no drug release at pH <6.8 and released 83.4 and 99% drug at pH 6.8 and 7.4 in 3 h. The microspheres did not adhere on gastric mucosa at pH 1.2 but showed mucoadhesion time of 28 min on intestinal mucosa at pH 6.8. Thus, the microspheres on oral administration, would release the drug in distal ileum, suggesting the potential of the hemocompatible copolymer for enteric coating for prolonged drug release.

Chemical composition and antimicrobial activity of fatty acid methyl ester of Quercus leucotrichophora fruits.

Natural fats and dietary oils are chief source of fatty acids and are well known to have antimicrobial activities against various microbes. The chemical composition and antimicrobial activities of fatty acids from fruits of white Oak (Quercus leucotrichophora) are yet unexplored and therefore the present study for the first time determines the fatty acid composition, and the antibacterial and antifungal activities of fatty acid methyl esters (FAME) of the white Oak plant found along the Himalayan region of Uttarakhand, India. The GCMS analysis revealed the presence of higher amount of saturated fatty acids than unsaturated fatty acids. FAME extract of fruits of Q. leucotrichophora demonstrated better antibacterial activity against Gram-positive bacteria than the Gram-negative bacteria. The present studies clearly establish the potential of the fruits of Q. leucotrichophora for use in soap, cosmetics and pharmaceutical industries.

A spirostanol glycoside from Yucca aloifolia.

From an ethanolic extract of the influorescence of Yucca aloifolia a new spirostanol glycoside has been isolated and characterized as 3-O[(alpha-L-rhamnopyranosyl(1----3)-beta-D-xylopyranosyl(1----2))(beta- D-glucopyranosyl(1----3)-beta-D-glucopyranosyl(1----3)-beta-D-glucopy ranosyl]-25R,5 alpha-spirostan-2 alpha, 3 beta-diol.

Clematoside-S, a triterpenoid saponin from the roots of Clematis grata.

Clematoside-S, a new triterpenoid saponin from the roots of Clematis grata, has been identified by chemical and spectroscopic methods as hederagenin-3-O-beta-D-ribopyranosyl (1----3)-alpha-L-rhamnopyranosyl(1----2)-alpha-L-arabinopyranoside .

Steroidal glycosides from Agave cantala.

Two new steroidal glycosides, agaveside A and B, isolated from the fruits of Agave cantala were characterized as 3 beta-O-[beta-D-xylopyranosyl-(1----2),beta-D-xylopyranosyl-(1----3), beta-D-glucopyranosyl-(1----3)-[beta-D-xylopyranosyl-(1----3)-beta-D- galactopyranosyl-(1----2)]-beta-D-glucopyranosyl]-(25R)-5 alpha-spirostane and 3 beta-O-[beta-D-xylopyranosyl-(1----2), beta-D-xylopyranosyl-(1----3)-beta-D-glucopyranosyl-(1----3)- [beta-D-galactopyranosyl-(1----2)]-beta-D-glucopyranosyl]-(25R)-5 alpha-spirostane. The structures were elucidated by a combination of 13CNMR spectroscopy, chemical degradation and fast atom bombardment mass spectrometry.

A spirostane hexaglycoside from Agave cantala fruits.

A new steroidal glycoside, agaveside D, isolated from the fruits of Agave cantala was characterized as 3 beta-(alpha-L-rhamnopyranosyl-(1----2),beta-D-glycopyranosyl- (1----3)-beta-D-glucopyranosyl[beta-D-xylopyransoyl-(1----4)-alpha -L-rhamnopyranosyl-(1----2)]-beta-D-glucopyranosyl)-25R-5 alpha-spirostane on the basis of chemical degradation and spectrometry.

Iridoid glycosides from Lonicera quinquelocularis.

A new iridoid glycoside 6'-O-beta-apiofuranosylsweroside was isolated from the ethanolic extract of the roots of Lonicera quinquelocularis along with the known compounds loganin and sweroside.

Chemical composition and antifungal activity of Artemisia nilagirica essential oil growing in northern hilly areas of India.

Essential oil extracted from aerial parts of Artemisia nilagirica was analysed by gas chromatography-mass spectroscopy. Forty-three constituents amounting to 98.16% of the total essential oil contents were identified. The essential oil contained approximately 79.91% monoterpenoids and 18.25% sesquiterpenoids. α-Thujone (36.35%), ß-thujone (9.37%), germacrene D (6.32%), 4-terpineol (6.31%), ß-caryophyllene (5.43%), camphene (5.47%) and borneol (4.12%) were identified as the major constituents. The essential oil exhibited significant antifungal activity against Rhizoctonia solani (ED(50), 85.75 mg L(-1)), Sclerotium rolfsii (ED(50), 87.63 mg L(-1)) and Macrophomina phaseolina (ED(50), 93.23 mg L(-1)). This study indicated that A. nilagirica essential oil can be used to control phytopathogenic fungi infesting agricultural crops and commodities.

Analysis and antimicrobial activity of volatile constituents from Quercus leucotrichophora (Fagaceae) bark.

The chemical composition of the volatile extract (yield ≈ 0.13%, v/w) from the bark of Quercus leucotrichophora (Fagaceae) was analysed for the first time by GC-MS. Twenty-three constituents, amounting to 93.0% of the total detected contents of the volatile extract, were identified. The volatile extract contained approximately 86.36% monoterpenoids, 6.53% sesquiterpenoids and 0.11% aliphatic aldehydes. 1,8-Cineol (40.359%) followed by γ-terpinene (16.369%) were the major monoterpene constituents of the volatile extract. The residue of volatile extract (0.00025-250 µg mL(-1)) exhibited a potent antimicrobial activity against Streptococcus pyogenes ATCC 19615. This study concludes that residues of the volatile extract of Q. leucotrichophora could serve as an important bioresource for the extraction and isolation of monoterpenoids exhibiting antimicrobial activity, and thus has good potential for use in the pharmaceutical industry.

Bioactive constituents and medicinal importance of genus Alnus.

The genus Alnus has been reviewed for its chemical constituents and biological activities including traditional importance of some common species. The plants of this genus contain terpenoids, flavonoids, diarylheptanoids, phenols, steroids, and tannins. Diarylheptanoids are the dominant constituents within the genus Alnus, few of them exhibited antioxidant effects and inhibitory activity against nuclear factor kappaB activation, nitric oxide and tumor necrosis factor-α production, human umbilical vein endothelial cells, farnesyl protein transferase, cell-mediated low-density lipoprotein oxidation, HIF-1 in AGS cells, and the HIV-1-induced cytopathic effect in MT-4 cells. Some ellagitannines showed hepatoprotective activity even in a dose of 1 mg/kg which is ten-fold smaller compared with the dose of traditional flavonoid-based drugs. The members of genus Alnus are well known for their traditional uses in the treatment of various diseases like cancer, hepatitis, inflammation of uterus, uterine cancer, rheumatism, dysentery, stomachache, diarrhea, fever, etc. The aim of the present review is to summarize the various researches related to the chemistry and pharmacology of genus Alnus.

Antimicrobial activities of essential oil and methanol extract of Coriaria nepalensis.

Plant extracts and products have been used for centuries in traditional medicine; for most of them, in addition to the scant scientific credibility, the chemical composition and spectrum of activity are yet to be explored. To put forward this effort and to identify novel antimicrobial agents, the inhibitory activities of methanolic extract and essential oil from Coriaria nepalensis against various microorganisms including pathogenic yeast, and Gram-positive and negative bacteria were evaluated. Chemical compositions of C. nepalensis methanolic extract and essential oil were analysed by gas chromatography-mass spectrometry. In vitro susceptibility tests against all the tested isolates were performed in terms of minimum inhibitory concentration (MIC), and well diffusion assay using standard protocols. All microorganisms tested were profoundly found susceptible to both the C. nepalensis extract and oil with MIC values of 1.3-2.1 mg mL⁻¹ (Gram-positive bacteria), 1.4-2.2 mg mL⁻¹ (Gram-negative bacteria) and 0.9-1.6 mg mL⁻¹ (yeasts). The extent of inhibition was shown more by methanolic extract than by essential oil. This study is the first to report the antimicrobial activity of extracts obtained from the C. nepalensis. It can be concluded that the observed antimicrobial characteristics of C. nepalensis indicate that it might be a promising antimicrobial agent.

A new triterpenoidal saponin from Acacia auriculiformis.

A new triterpenoidal saponin has been isolated from an aqueous EtOH extract of the legumes of Acacia auriculiformis and characterized as 3-O-([beta-D-xylopyranosyl(1----3)-beta-D-xylopyranosyl(1----4)-alpha-L- rhamnopyranosyl(1----2)]-[alpha-L-rhamnopyranosyl(1----4)]-beta-D- glucopyranosyl)-3,16,21-trihydroxyolean-12-en-28-oic acid [1] by chemical studies and spectral data.

Molluscicidal Saponins of Xeromphis spinosa.

From the ethanolic extract of the defatted leaves of XEROMPHIS SPINOSA (Thunb.) Keay two new oleanolic acid based glycosides have been isolated and characterized with the help of FABMS, (13)C-NMR and chemical studies.

Steroidal saponins from Asparagus curillus fruits.

Methanol extract of defatted fruits of Asparagus curillus Buch-Ham yielded a mixture of Saponins, Oligofurostanosides and Spirostanolglycosides.