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Results and Discussion
Conclusion and Future work
Acknowledgment Introduction Countries and territories affected by malaria, 2010 Facts about Malaria 1. Malaria is the world’s most severe parasitic infection - more than 1 million deaths & 500 million cases annually.
2.Malaria is caused by infection of red blood cells by protozoan parasites
3. Resistance to antimalarials has been documented for P. falciparum, P. malariae and P. vivax. In P. falciparum, resistance has been observed in: amodiaquine, chloroquine, mefloquine & quinine.
4. Although artemisinin-based monotherapies and combination therapies (ACTs) with other antimalarial drugs have been used for over 10 years. Artemisinin resistance has been detected in Thailand and Cambodia with pressure to contain it. ACT's are still however widely used Artemisinin 1. Artemisinin (Qinghao) is the precursor to more potent substances such as artemether, artesunate, dihydroartemisinin and several others.
2. Artemisinin is extracted mostly from the upper parts of the Artemisia annua plants, which grows in temperate climates-China, the US, Russia, India, Brazil, and some other countries.
3. Artemisinin and artemisinic acid have been found to be located in the glandular trichomes on the leaf surface.
3.The total amount of artemisinin found in different varieties of A. annua is between 0.01 and 1.4 wt % based on dry leaf mass.
4. In 2011, the average price of artemisinin was around £361/kg. The global market for the production and extraction of Artemisia/artemisinin was between £54.18 million and £61.4 million. Extraction and Purification process Solubility of artemisinin in solvent Hexane solubility test Aims and objectives To determine the stability of artemisinin in 8 organic solvents: ethyl acetate, 5% ethyl acetate in hexane, acetone, acetonitrile, hexane, ethanol, chloroform and petroleum ether 60-80°C
To investigate the effect of temperature on the stability of artemisinin at: room temperature, 40 °C and at boiling points for each of the solvents
To investigate the effect of time on the stability of artemisinin over a duration of upto 5 hours for the elevated temperatures and 2 weeks for the room temperature experiments. Experimental procedure Experimental design 8 solvents
3 temperatures: Room temp, 40 and boiling
Solvents: ACN, Acetone, Hexane, Chloroform, Ethyl acetate, 5% EA in Hexane, Petroleum Ether & Ethanol Room temperature Warm- 40 °C Step 1: Weigh out artemisinin into 250 ml bottle using a spatula. Boiling point Results Anike Akinrinlade
Dr Rachel Gomes
24/04/2013 Step 1: Pour solvent into 60 ml bottle containing artemisinin (500 ug/ml). Wrap bottle in foil. Step 2: Mix the 60 ml bottles on a reciprocating mixer for 5 mins to ensure Artemisinin dissolved in solvent Step 3: Store the samples for a minimum of 2 weeks at room temperature before analyzing. Took samples after 5min mix and after two weeks Acknowledgments East Africa(15T): Uganda, Kenya, Madagascar India (3T) China (130T) Vietnam (18T) Artemisinin Approaches to extract Artemisinin Enzymes Hydroflurocarbons (HFC's) Microwave assisted hydrocarbon extraction
Enzymes used a wide variety of industries to improve: Purity, Yield and specificity of reactions.
Variety of enzymes can be used : Pectinases, Laccases, Xylanases
Conversion of artemisinic acid/arteannuin B to artemisinin
Use of enzymes has the potential to increase the efficiency of artemisinin production
Enzyme can be used prior to solvent extraction or after: increase efficiency of process and reduce the amount of solvent used in process. Emerging technology: lab and pilot scale
High cost to run and capital cost to purchase machinery
Potential for high efficiency of extraction
Problematic to scale up - short penetration depth of the microwave irradiation. Physiochemical properties:
Low thermal stability
Low chemical stability
Poor solubility in Water
Good solubility in organic solvents Non flammable, low toxicity and zero ozone deleting potential
Environmental considerations: High global warming potential therefore complete capture and recycle of solvent within process is important Organic solvent Commercially used in industry
Variability in solubility i.e. Water 0.048 g/l, Ethyl acetate 100 g/l & Hexane 0.46 g/l.
Usually carried out in warm conditions 30-45 °C for around 4-48 h for example dependent on process.
A number of extraction cycles are carried out to increase the amount of artemisinin extracted. Step 2 Once 100 ml of solvent has been poured into 250ml bottle, place in Water bath at 40 °C. Take samples at 1.5, 3hr and 5 hrs. Method changes 1. 60 ml bottles were used for 4 solvents: 50ml solvent & 0.025 g of artemisinin
2. Artemisinin was rinsed from the weighing boat directly into the 60 ml container using a burette
3. Time zero samples were taken & room temperature experiment shortened to 3 days
4. Take 2ml sample and place into 7ml vial to cool
500 ug/ml of artemisinin in solvent
Samples taken at 1.5hr, 3 hrs and 5 hrs. Future work 1. Enzyme assisted extraction: pre solvent step, look into solvent stable enzymes
2. Improve experimental design
Time zero samples: artemisinin fully dissolved
Set up control experiment: Does our sampling method have an effect?
Ensure artemisinin stock is homogenous
Use of NMR or LC-MS to explore nature of degradants if any. Table 1: Mole fraction Solubility of artemisinin, 10^3-x, in Different Organic Solvents between(284.15 and 323.15) K Measuring solubility in Hexane
1. Weigh out 0.005 g into 10 mls of hexane for each sample time: 5 hours and 24 hours
2. Place 14ml vial on reciprocating stirrer at 170 rpm
3. Take 1 ml sample from vial into HPLC vial and reconstitute in ACN
4. Integrate peaks to obtain peaks areas Dr Rachel Gomes
Natural Products Research Group
Dr Rebekah Smith McGloin Delinana Dahnum, Haznan Abimanyu and Ahmad Senjaya: Isolation of Artemisinin as Antimalarial Drugs from Artemisia annua L. Cultivated in Indonesia, IJBAS-IJENS Vol 12, No:04
Synthetic Biology: Livelihoods and Biodiversity, Artemisinin. ETC group Results Warm -40 °C Dr Pascal Ringwald: Global Malaria Programme- WHO Update on artemisinin resistance - April 2012
Dr P. Olumese: WHO Guidelines for the treatment of Malaria, 2nd Edition- 2010 Public Health Information and Geographic Information Systems WHO- 2012 Joseph Nti-Gyabaah, Kodzo Gbewonyo and Yee C.Chiew. J. Chem. Eng. Data 2010, 55, 3356-3363 Alexi A. Lapkin et al: Screening of new solvents for artemisinin extraction process using ab initio methodology. Green Chemistry 2010, 12, 241-251
Alexi Lapkin et al: Comparative Assessment of Technologies for Extraction of Artemisinin. Journal of Natural Products, 2006, Vol 69, No 11 Methodology Warm -40 °C Conclusion Trend of stability of artemisinin in solvent at 40 °C over 5 hour period
Room temperature results support 40 °C exp for petroleum ether, ethanol and hexane.
Ethyl acetate addition to hexane may have possibly increased the solubility of artemisinin.