PENTACYCLIC TRITERPENOIDS FROM THE STEM-BARK OF ALBIZIA CHEVALIERI HAMS (MIMOSACEAE)

Objective: This research is focused towards isolation and identification of pure compounds from the extracts fractions of Albizia chevalieri through the means of gravity column chromatography and other chromatographic processes.Methods: the stem bark was extracted exhaustively with hexane and subsequently with methanol. The methanolic extract was fractionated into ethyl acetate (EA) and n-butanol (NB) soluble parts, after which the hexane extracts were subjected to silica gel gravity column chromatography for the isolation of pure bioactive molecules.The major compounds isolated, were then determined and identified by the use of spectrometric analysis of HR-ESIMS, 1HNMR, [13]CNMR, IR and UV spectra.Results: Investigation of the stem bark hexane extract fraction of A. chevalieri led to the isolation of three known pentacyclic triterpenoids: friedelin (HXC1), Friedelan-3-ol (HXC2) and Lupeol (HXC3), for the first time in the plant.Conclusion: The results obtained will be useful in the evaluation (bioassay) of the isolated compounds against the list of folklore therapeutic claims of A. chevalieri (which include its use as purgative, taenicidal, remedies of cough, dysentery, cancer, diabetes mellitus, tuberculosis and snake bite), and thereby providing scientific basis for its used for treatment of the aforementioned ailments.Keywords: Friedelin, Friedilan-3-ol, Lupeol, Isolation, Spectrometr

Studies of In vitro Antioxidant and Cytotoxic Activities of Extracts and Isolated Compounds from Parinari curatellifolia (Chrysobalanaceae)

Parinari curatellifolia (family: chrysobalanaceae) is a plant used in Nigerian folk medicine for treatment of cancer and other diseases. In our search for pharmacologically active compounds, we have isolated and characterized compounds through column chromatography and spectroscopic techniques (MS, NMR and IR). We have evaluated the in vitro antioxidant activity of the different extracts and the pure compounds using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical model. The in vitro cytotoxic activity of the extracts and the pure compounds using the sodium 3’-[1-(phenylamino-carbonyl) -3,4-tetrazolium]-bis-[4-methoxy-6-nitro] benzene sulfonic acid hydrate (XTT) colorimetric method on cervical cancer (HeLa) cell line have also been assessed. The extracts and pure compounds have displayed moderate to excellent antioxidant and cytotoxic activities.  The biological results suggest that these compounds may be suitable candidates for further drug development and investigation. The results obtained have provided a promising scientific basis for the use of P. curatellifolia in traditional medicine for treatment of cancer. Keywords: Parinari curatellifolia, Cytotoxicity, HeLa Cell line, Antioxidant, DPPH Free Radica

Isolation and Characterization of Triterpenes from Petroleum Ether and Ethyl acetate Extracts of Stem Bark of Parinari curatellifolia Planch Ex. Benth (Chrysobalanaceae)

Parinari curatellifolia (Chrysobalanaceae) is a plant used in Nigerian folk medicine for cancer treatment. Through series column chromatography, betulin (lup-20(29)-en-3?,28-diol) and betulinic acid (3?-hydroxy-lup-20(29)-en-28-oic acid) have been isolated from petroleum ether and ethyl acetate extracts of the stem bark of Parinari curatellifolia respectively. The compounds were characterized on the basis of 1D-NMR (1HNMR, 13CNMR and DEPT-45, 90 and 135), 2D-NMR (HSQC, HMBC, 1H-1H COSY,  1H-1H NOESY), MS and IR spectroscopic studies. These two compounds are reported for the first time as constituents in Parinari curatellifolia. Key words: Parinari curatellifolia, Chrysobalanaceae, Betulin, Betulinic acid and Triterpene

Isolation and Characterization of Steroids from Petroleum Ether Extract of Stem Bark of Parinari curatellifolia Planch ex. Benth (Chrysobalanaceae)

In our search for biologically active compounds, three steroids have been isolated from the stem bark of Parinari curatellifolia through series of column chromatography. Compound C1, C2 and C3 where characterized as ?-sitosterol (22,23-dihydrostigmasterol), stigmast-4-en-3-one and stigmasterol, respectively, on the basis of 1D-NMR (1HNMR, 13CNMR and DEPT-135), 2D-NMR (HSQC, HMBC, 1H-1H COSY,  1H-1H NOESY), mass spectroscopy (MS) and IR spectroscopy. These compounds are reported for the first time as constituents in Parinari curatellifolia. Keywords: Parinari curatellifolia, ?-sitosterol, stigmast-4-en-3-one and stigmastero

The Bits of Silence : Redundant Traffic in VoIP

Human conversation is characterized by brief pauses and so-called turn-taking behavior between the speakers. In the context of VoIP, this means that there are frequent periods where the microphone captures only background noise – or even silence whenever the microphone is muted. The bits transmitted from such silence periods introduce overhead in terms of data usage, energy consumption, and network infrastructure costs. In this paper, we contribute by shedding light on these costs for VoIP applications. We systematically measure the performance of six popular mobile VoIP applications with controlled human conversation and acoustic setup. Our analysis demonstrates that significant savings can indeed be achievable - with the best performing silence suppression technique being effective on 75% of silent pauses in the conversation in a quiet place. This results in 2-5 times data savings, and 50-90% lower energy consumption compared to the next better alternative. Even then, the effectiveness of silence suppression can be sensitive to the amount of background noise, underlying speech codec, and the device being used. The codec characteristics and performance do not depend on the network type. However, silence suppression makes VoIP traffic network friendly as much as VoLTE traffic. Our results provide new insights into VoIP performance and offer a motivation for further enhancements, such as performance-aware codec selection, that can significantly benefit a wide variety of voice assisted applications, as such intelligent home assistants and other speech codec enabled IoT devices.Peer reviewe

Cause for concern in the use of non-steroidal anti-inflammatory medications in the community -a population-based study

Background: Non-steroidal anti-inflammatory (NSAID) medications are a common cause of reported adverse drug side-effects. This study describes the prevalence of non-steroidal anti-inflammatory (NSAID) use (other than low-dose aspirin) and the presence of co-existing relative contraindications to NSAID use and chronic conditions in a representative population sample. Methods: Data were analysed from 3,206 adults attending first follow-up of the North West Adelaide Health Study (NWAHS) in 2004 - 2006, a longitudinal representative population study. Medications were brought into study clinic visits by participants. Clinical assessment included measured blood pressure, kidney function, serum cholesterol, blood glucose. Questionnaires assessed demographics, lifestyle risk factors, physician-diagnosed chronic conditions. Data were weighted to census measures by region, age group, gender, and probability of selection in the household, to provide population representative estimates. Pearson's Chi-square tests determined significant differences in proportions. Multiple logistic regression was used to examine associations of socio-demographic characteristics with use of NSAIDs. Results: Of 3,175 participants, 357 (11.2%), and 16% of those aged > 55 years, reported using either non-specific NSAIDs or COX-2 inhibitors, other than low-dose aspirin. Among people using NSAIDs, 60.8% had hypertension, 30.8% had Stage 3 or higher chronic kidney disease, 17.2% had a history of cardiovascular disease (CVD) and 20.7% had a > 15% 10-year CVD risk. The prevalence of NSAID use among people with hypertension was 16%, with kidney disease 15.9%, and a history of CVD 20.0%. Among people taking diuretics, 24.1% were also taking NSAIDs, and of those taking medications for gastro-esophageal reflux, 24.7% were on NSAIDs. Prescription-only COX-2 inhibitors, but not other NSAIDs, were used more by people > 75 years than by 35-54 year olds (OR 3.7, 95% CI 2.0, 6.7), and also were more commonly used by people with hypertension, cardiac and kidney disease. Conclusions: There is a high prevalence of current NSAID use among groups at-risk for significant drug-related adverse events or who have major chronic conditions that are relative contraindications to NSAID use. Assessment of absolute risks regarding cardiovascular and kidney disease need to take into account use of medications such as NSAIDs. The potential to make a substantial impact on chronic disease burden via improved use of NSAIDs is considerable.Robert J Adams, Sarah L Appleton, Tiffany K Gill, Anne W Taylor, David H Wilson and Catherine L Hil

Human rights, health and the state in Bangladesh

BACKGROUND: This paper broadly discusses the role of the State of Bangladesh in the context of the health system and human rights. The interrelation between human rights, health and development are well documented. The recognition of health as a fundamental right by WHO and subsequent approval of health as an instrument of welfare by the Universal Declaration of Human Rights (UDHR) and the International Covenant on Social, Economic and Cultural Rights (ICSECR) further enhances the idea. Moreover, human rights are also recognized as an expedient of human development. The state is entrusted to realize the rights enunciated in the ICSECR. DISCUSSION: In exploring the relationship of the human rights and health situation in Bangladesh, it is argued, in this paper, that the constitution and major policy documents of the Bangladesh government have recognized the health rights and development. Bangladesh has ratified most of the international treaties and covenants including ICCPR, ICESCR; and a signatory of international declarations including Alma-Ata, ICPD, Beijing declarations, and Millennium Development Goals. However the implementation of government policies and plans in the development of health institutions, human resources, accessibility and availability, resource distribution, rural-urban disparity, the male-female gap has put the health system in a dismal state. Neither the right to health nor the right to development has been established in the development of health system or in providing health care. SUMMARY: The development and service pattern of the health system have negative correlation with human rights and contributed to the underdevelopment of Bangladesh. The government should take comprehensive approach in prioritizing the health rights of the citizens and progressive realization of these rights