Antibacterial activity of Salvadora persica against oral pathogenic bacterial isolates.

OBJECTIVE: The objective was to determine the antibacterial activity of Salvadora persica extract against bacteria isolated from dental plaque of patients. MATERIALS AND METHODS: Out of 40 different clinical specimens collected from patients suffering from plaque-induced gingivitis, 12 Staphylococcus aureus and 8 Streptococcus sp. isolates were recovered. The isolates were screened for their biofilm-forming capacity using tissue culture plate (TCP), tube method (TM), and congo red agar (CRA) method. Antibacterial activity of methanolic S. persica extract as well as of commercial antimicrobials against tested isolates was performed. High-performance liquid chromatography-mass spectrometry (HPLC-MS) and gas chromatography-MS (GC-MS) analysis were performed for S. persica crude extract and its volatile oil, respectively, to determine their constituents. RESULTS: Out of 20 isolates, 80%, 85%, and 90% showed positive results using TM, CRA, and TCP, respectively. The highest antimicrobial activity of methanolic S. persica extract was observed at 200 mg/ml. HPLC-MS analysis shows many polyphenols in S. persica extract such as Chrysin-8-c-ß-D-glucopyranoside, ferulic acid, gallic acid, and stigmasterol. Chemical composition of the essential oil of S. persica was determined by GC-MS yield; a mixture of monoterpene and hydrocarbons. The major compounds were butylated hydroxytoluene followed by benzene (isothiocyanatomethyl). CONCLUSION: Methanolic extract of S. persica had significant antibacterial effect against S. aureus and Streptococcus sp. isolates, and it may be gave a good alternative method for controlling oral pathogen.

Extraction and characterization of lignin from oil palm biomass via ionic liquid dissolution and non-toxic aluminium potassium sulfate dodecahydrate precipitation processes.

The objective of this study is to extract and characterize lignin from oil palm biomass (OPB) by dissolution in 1-butyl-3-methylimidazolium chloride ([bmim][Cl]), followed by the lignin extraction through the CO2 gas purging prior to addition of aluminum potassium sulfate dodecahydrate (AlK(SO4)2 · 12H2O). The lignin yield, Y(L) (%wt.) was found to be dependent of the types of OPB observed for all precipitation methods used. The lignin recovery, RL (%wt.) obtained from CO2-AlK(SO4)2 · 12H2O precipitation was, however dependent on the types of OPB, which contradicted to that of the acidified H2SO4 and HCl solutions of pH 0.7 and 2 precipitations. Only about 54% of lignin was recovered from the OPB. The FTIR results indicate that the monodispersed lignin was successfully extracted from the OPT, OPF and OPEFB having a molecular weight (MW) of 1331, 1263 and 1473 g/mol, and degradation temperature of 215, 207.5 and 272 °C, respectively.

Steroidal anti-inflammatory antedrugs: synthesis and pharmacological evaluation of 16 alpha-alkoxycarbonyl-17-deoxyprednisolone derivatives.

In a continuing effort to minimize the systemic adverse effects of potent anti-inflammatory steroids, a series of 16 alpha-alkoxycarbonyl-17-deoxyprednisolone derivatives: methyl (8a), ethyl (8b), isopropyl (8c), and benzyl (8d) 11 beta,21-dihydroxy-3,20-dioxo-1,4-pregnadiene-16 alpha-carboxylate, was synthesized and evaluated for their topical and local anti-inflammatory activities. In the acute croton oil-induced ear edema dose-response bioassay, the topical anti-inflammatory potencies of these esters relative to prednisolone, 1, were: 8a:1.0, 8b:1.3, 8c:4.0, 8a:4.7 and 1:1.0. The putative metabolite, 11 beta,21-dihydroxy-3,20-dioxo-1,4-pregnadiene-16 alpha-carboxylic acid, 7, was inactive in this test. A seven day cotton pellet granuloma bioassay was employed to study the local and systemic anti-inflammatory activities of these steroids. The local anti-inflammatory potencies of these esters relative to prednisolone, 1, were 1.3, 1.5, 2.3, 2.5, and 1.0 for 8a, 8b, 8c, 8d, and 1, respectively. In this semi-chronic study, only prednisolone exhibited significant untoward side effects, such as reduction in thymus weights, normal body weight gain, and normal plasma corticosterone levels. The increase in the topical and local potencies of these steroid esters was consistent with the increase in their 1-octanol/buffer partition coefficient. The ratio of local to systemic anti-inflammatory activity of 8c and 8d was four times that of prednisolone. The effects of increasing the size of the alkoxy group of these new steroids on both topical and local anti-inflammatory activity and their concomitant decrease in untoward systemic effects were unequivocally demonstrated.(ABSTRACT TRUNCATED AT 250 WORDS)

Novel fluorinated antiinflammatory steroid with reduced side effects: methyl 9 alpha-fluoroprednisolone-16-carboxylate.

In an effort to test the hypothesis that 9 alpha-fluorination of a steroidal antedrug would enhance receptor binding affinity and local antiinflammatory activity, without concomitantly increasing adverse systemic effects, a fluorinated analog, 10, of methyl 11 beta, 21-dihydroxy- 3,20-dioxo-1,4-pregnadiene-16 alpha-carboxylate (DP16CM, 1) was synthesized and evaluated. In the acute rat croton oil-induced ear edema bioassay, 10 was found to be twice as potent as 1. This increase in topical potency was consistent with enhanced binding affinity of 10, relative to 1. The IC50 values for displacement of [3H]dexamethasone from glucocorticoid receptors of rat hepatoma tissue culture cells were 0.16, 1.2, and 0.03 microM for 10, 1, and prednisolone, respectively. Following multiple topical ID50 applications of predniosolone, 1, and its new fluorinated analog, 10, in the rat subacute croton oil-induced ear edema bioassay, only prednisolone exhibited significant untoward effects, such as reduction in relative thymus and adrenal weights, plasma corticosterone levels, and normal body weight gain. Thus, while fluroination of 1 enhanced its topical potency, there was not a concomitant increase in untoward systemic effects. This lack of adverse systemic effects is ostensibly due to the presence of the metabolically labile 16-carboxylate ester moiety.