Sonneratinone: A new antimicrobial benzofuranone derivative from the endophytic fungus Aspergillus niger isolated from the mangrove plant Sonneratia apetala Buch.-Ham | Author : T. R. Nurunnabi, S. Al-Majmaie, L. Nahar, I. Nakouti, S. M. Mahbubur rahman, M. Hossain Sohrab, M. Morsaline Billah, F. M. Ismail, G. P. Sharples and S. D. Sarker | Abstract | Full Text | Abstract :A new antimicrobial benzofuranone derivative, named, sonneratinone (1), was isolated from the endophytic fungus Aspergillus niger, obtained from the leaves of Sonneratia apetala, a mangrove plant from the Sundarbans. Whilst the fungal strain was identified by macroscopic, microscopic and molecular techniques, the structure of the new compound was elucidated by spectroscopic means, e.g., 1D and 2D NMR, and HRESIMS. Sonneratinone (1) showed considerable antimicrobial activity against Micrococcus luteus, Staphylococcus aureus and Candida albicans in the resazurin 96-well microtitre plate antimicrobial assay. |
| Evaluation of triterpenes isolated from stems of Pouteria macahensis T. D. Penn. against Proteus mirabilis | Author : G. da Silva Amaral, H. Dantas dos Santos, A. Oliveira da Conceição, F. Faustino de Oliveira and R. Aparecida de Oliveira | Abstract | Full Text | Abstract :This article presents the results from a phytochemical study on an acetonic extract from the stems of Pouteria macahensis T.D. Penn., an endemic species of the Brazilian Atlantic Rainforest. By means of the bioautography method, this extract was evaluated against Acinetobacter baummanii, Proteus mirabilis, Escherichia coli and Staphylococcus epidermidis bacteria, of which only the P. mirabilis was found to be susceptible. The acetonic extract was chromatographed on a silica gel column, eluted with hexane and ethanol, producing 14 groups, allowing the isolation of the following compounds: friedelin, 3ß-friedelinol and 3ß-erythrodiol linoleate, arachidate and linolenate. Their structures were elucidated based on data of IR, 1H NMR, 13C NMR, including DEPT-135, HSQC and HMBC techniques. The minimum inhibitory concentrations of the compounds tested against P. mirabilis growth, were 500.0 µg mL-1 for friedelin and erythrodiol and 600.0 µg mL-1 for 3ß-friedelinol and esterified 3ß-erythrodiol. Based on these results, the potential of these compounds to inhibit the growth of this bacterium was confirmed.
|
| A review of 13C NMR spectra of drimane sesquiterpenes | Author : S. A. Opiyo | Abstract | Full Text | Abstract :Drimane sesquiterpenes are important group of phytochemicals with a wide range of medicinal properties including antibacterial, antifungal, anti-inflammatory, antioxidant, antiplasmodial, antileishmanial, molluscicidal, antifeedant and insecticidal features. Due to their wide range of medicinal activities, scientists are prompted to continuously search for novel drimane sesquiterpenes since most of the currently available anti-infective agents have drawbacks such as drug resistance and side effects. Structure determination of new compounds relies on accurate interpretation of spectroscopic data which is quite challenging but can be simplified by comparison with the data of known related compounds from the reliable databases. A large number of drimane sesquiterpenes have been examined by 13C NMR spectroscopy but such data are scattered in the literature making it hard for researchers to use them. This paper provides a review on previously reported drimane sesquiterpenes and a compilation of their 13C NMR data. It also provides a brief discussion on the substituent effect on the 13C shielding of the drimane sesquiterpenes.
|
| Cymbopogon citratus Stapf (DC) extract attenuates gasoline vapour-induced low-triiodothyronine syndrome, oxidative stress and lipid peroxidation in rats | Author : C. E. Ekpenyong and U. Essiet | Abstract | Full Text | Abstract :Cymbopogon citratus Stapf (DC) (Lemongrass) is a widely distributed aromatic perennial plant that has the potential to mitigate xenobiotic-induced systemic disorders. However, whether C. citratus has any ameliorative effect on gasoline vapour (GV)-induced thyroid gland dysfunction has not been previously evaluated. Therefore, the present study aimed to assess the effect of C. citratus leaf decoctions on GV-induced thyroid gland disorders. Thirty-five Albino rats were segregated into 5 groups (n=7 per group). Animals in group 1 served as unexposed control, while animals in group 2 were exposed to GV alone for 4 weeks. Animals in groups 3, 4 and 5 in addition to being exposed to GV for 4 weeks, were treated with different concentrations of C. citratus leaf extracts for 2 weeks. Animals exposed to GV alone had significant decrease in serum levels of catalase, while serum levels of malondialdehyde significantly (p<0.05) increased. Serum levels of thyroid stimulating hormone significantly (p<0.05) increased and decreased in male and female rats respectively exposed to GV alone. Serum levels of triiodothyronine decreased in both male and female rats exposed to GV alone, whereas serum levels of thyroxine decreased only in female rats. In addition, exposure to GV alone caused significant alterations in the normal histo-morphology of the thyroid gland. Co-administration of C. citratus leaf decoctions caused reversal of these changes, as well. This study showed that C. citratus leaf extract has the potential to attenuate GV-induced thyroid gland disorders and oxidative stress due to its natural bioactive constituents.
|
| Antimicrobial activity and toxicity of Eucalyptus globulus Labill. essential oil against vaginal microorganisms | Author : M. Bogavac, K. Tešanovic, J. Maric, M. Jovanovic and M. Karaman | Abstract | Full Text | Abstract :The antimicrobial potential of commercial essential oil (EO) of Eucalyptus globulus L. was evaluated against six bacterial vaginal isolates (E. coli 1 and E. coli 2, S. aureus 1 and S. aureus 2, P. aeruginosa and P. mirabilis) and two isolates of Candida strains (C. albicans 1 and C. albicans 2). The antimicrobial activity was assessed through double-dilution micro-plate assay to determine the minimum inhibitory (MIC) and minimum bactericidal/fungicidal (???/MFC) concentration. In addition, brine shrimp toxicity assay was performed in order to determine acute toxicity of the examined EO. The isolated strains of pathogens have shown strain specificity to the tested EO. Certain pathogens resistance was noticed toward the tested antibiotic, as well. E. coli isolates showed resistance to the tested antibiotics but did not show resistance against the Eucalyptus EO (E. coli 1 MIC/MBC 12.5/12.5 µL/mL; E. coli 2 MIC/MBC 25/25 µL/mL). Moreover, the Eucalyptus EO showed effectiveness in application against S. aureus 2 (MIC/MBC 6.25/6.25 µL/mL), and C. albicans 1 strains (MIC/MFC 6.25/6.25 µL/mL). Furthermore, brine shrimp lethality bioassay revealed the Eucalyptus oil toxicity at an LC50 value of 2.66 mg/mL. The chemical composition of the separated essential oil was analyzed by gas chromatography combined with mass spectrometry (GC-MS) showing eucalyptol (59.63%), p-cymene (15.55%) and DL-limonene (14.90%) as dominant constituents. Although a number of toxicology trials are needed, these results provide scientific support to examination of Eucalyptus EO as an antimicrobial agent in alternative treatment of multiresistant human pathogens of vaginal origin.
|
| Trials of phenanthrene opioids functionalization with hindered polycyclic carboxylic acids | Author : A. Venditti, A. Pallotti and A. Bianco | Abstract | Full Text | Abstract :In the last decades, the number of patients undergoing pain relief for chronic or degenerative diseases has observed a significant increase, also due to an increase in the average age of the population. Morphine, the widely used opioid in pain therapy, is known to produce over time tolerance with the appearance of hyperalgesia and allodynia, conditions which may affect patient compliance. These phenomena have been re-conducted to one of its metabolite, the 3-O-glucuronide (accounting in humans for 80% of the dose administered), which was found to be an effective neuro-excitatory and a potent activator of microglia, so resulting to be responsible of the development of both hyperalgesia and allodynia. Therefore, the inhibition of glucuronidation represents an interesting pharmacological target to achieve greater therapeutic efficacy by morphine and the synthesis of new active compounds useful in the pain control therapy is still in the limelight. In this context, we observed that codeine and some codeine derivatives (in particular the acetyl and pivaloyl esters) are able to inhibit the formation of morphine-3-O-glucuronide so, in continuation of the previous work, we projected new codeine derivatives as potential useful compounds in the modulation of morphine glucuronidation. In this paper, we report the optimization of the synthetic procedure to obtain codeine esters with hindered polycyclic carboxylic acids by using a suitable alcohol (allyl alcohol) with the same configuration of 6-OH function of the codeine skeleton. Together with the allyl ester derivatives of these acids also the 1-adamantaneacetic acid ester derivative of codeine (4), a new codeine derivative, was finally synthesized following the reported synthetic approach.
|
| Evaluation of cholesterol lowering property of selected herbs in ghee (heat clarified milk fat) | Author : K. M. Shingala, R. V. Lunagariya, B. M. Mehta, V. B. Darji and K. D. Aparnathi | Abstract | Full Text | Abstract :Ghee is a heat clarified milk fat and supply various nutrients. It contains cholesterol which is considered to be associated with various diseases. To the best of our knowledge, the present work focusing on reduction of cholesterol content of ghee using herbs was the first report in literature. In this regard, ghee was treated with various herbs (@0.5%) namely ajwain, betel and curry leaves to evaluate their cholesterol lowering ability. The percent reduction in cholesterol contents in ghee were 4.63%, 10.53% and 4.50% when treated with ajwain, betel and curry leaves respectively. The stage of addition of the herbs in ghee was then standardized. It was observed that the herbs added directly in ghee were able to lower down the cholesterol content from 212.68 mg/100 gm (control) to maximum 175.93 mg/100 gm representing 17.46% reduction in cholesterol content of the ghee sample. Furthermore, among the various stages, herbs which were added in hot ghee at 90 ºC gave maximum reduction in cholesterol content. |
|
|