The Technique of Distillation Isolation of Volatile Oils from Spices by Steam Distillation and Bioassay for Biological Activity Introduction The spices cloves cinnamon ginger nutmeg and tumeric will be provided There are many other possible spices such as caraway cumin or thyme Feel free to bring in 10 grams of a spice of your choice There is no guarantee that a particular spice will yield much volatile oil or that the components of this oil will have biological activity but it will be fun to see if they do If you don t get anything from your spice you can continue the procedure with some clove oil that is available Activities Read the Introduction section of the Distillation Experiment found in Chapter 5 of the Lab Guide In the first lab Day One you will use steam distillation to separate any volatile oils from your spice of choice you may work in teams for this distillation only In preparation for this read the theory of steam distillation presented below You will be using a variation of the distillation set up as in Procedures 1A and 1B in Chapter 5 of the Lab Guide In place of the liquid mixtures toluene cyclohexane or ethanol water you will use water and your solid spice to carry out steam distillation However typical distillation data for simple and fractional distillation is provided below and you will plot these for your Final Report see last page of this handout You are responsible for understanding how simple and fractional distillations are done and the advantages and disadvantages of these types of distillations as well as steam distillation You will inoculate sterile agar plates with Bacillus Cereus bacteria and incubate them to test biological activity The component that you isolated from the spice will be tested for antibacterial activity You will use GC and GC MS to characterize your volatile oil In preparation for product analysis using these methods read Sections 11 7 and 11 7 1 on gas chromatography Sections 11 2 1 11 2 4 on mass spectral interpretation and section 11 8 on gas chromatography mass spectrometry of Chapter 11 in the Lab Guide If you do not have time to finish the GC and or GC MS runs sign up for time outside of lab time to complete these analyses In the second lab Day Two you will be carrying out Procedure 3 p 116 of the Lab Guide a microscale fractional distillation of an unknown mixture work individually This second distillation will give you experience with the fractional distillation technique PreLab Your chemical data table should include the chemicals mentioned on page 116 of your Lab Guide and also eugenol thymol and quinine Hand in a photocopy of the completed Common Shelf Chemical Date Table with your PreLab Answer the PreLab questions in Chapter 5 p 106 of the Lab Guide Modeling the Drug Discovery Process Adapted from William H Miles Department of Chemistry Lafayette College Easton PA 18042 milesw mail lafayette edu and Patricia M Smiley Southern Lehigh High School 5800 Main Street Center Valley PA 18034 smileyp solehi k12 pa us J Chem Ed 2002 79 90 Chemistry and Medicine Since ancient times humankind has sought medicines from nature Quinine the antimalarial compound isolated from the bark of the cinchona tree and reserpine the antidepressant from the Indian plant Rauwolfia serpentina represent two of the more famous natural products used in modern medicine 1 Today pharmaceutical companies use several approaches for the discovery of new compounds to treat human illness including the screening of natural products derived from bacteria fungi plants or animals not puppies or even mice but animals like slugs or sponges simple multi cellular bottom dwelling animals called Porifera For example extraction of a marine sponge with an organic solvent can yield a complex mixture of organic compounds which can then be tested for biological activity or are bioassayed If the mixture shows promising biological activity the components of the complex mixture may be separated and purified When further testing identifies the active component its chemical structure can be determined using modern spectroscopic techniques IR NMR Mass Spectrometry X ray crystallography Even if the new compound has side effects that render it unsuitable as a drug candidate the pharmaceutical chemists will use the compound as a guide for the synthesis of new drug candidates with similar structures The synthesis of organic compounds whether of natural products or of unnatural products compounds that are not found in nature has been a primary goal of organic chemists Some of the first synthetic compounds produced industrially were dyes fragrances and flavorings It was not until the twentieth century that synthetic drugs were successfully developed The synthesis of the antisyphilitic drug arsphenamine Compound 606 by Ehrlich in 1910 was a dramatic demonstration of the power of chemistry to attack a medical problem Yes arsphenamine contains arsenic Not good stuff but remember you re dying of syphilis so you can t be fussy Since then many new compounds including biologically active compounds found in nature have been synthesized in the laboratory and have become useful drugs For example Ritalin is used for the treatment of attention deficit disorder ADD 5 fluorouracil is a potent anti cancer drug and L DOPA is used to treat Parkinson s disease Essential oils which are isolated by steam distillation of volatile organic compounds present in plants and animals have a long and rich history in medicine Typically complex mixtures of organic compounds essential oils have been used to treat a variety of illnesses for thousands of years In some cases these essential oils do have therapeutic utility by modern medical standards The essential oils of cloves and thyme contain phenolic compounds organic molecules that have an OH group attached to an aromatic ring which are effective antiseptics germ killers Even before the establishment of the germ theory the antiseptic power of both thyme oil and clove oil was recognized Joseph Lister whose name is immortalized by the mouthwash Listerine used synthetic phenol carbolic acid to prevent infection during surgical procedures in the mid nineteenth century 2 revolutionizing the medical treatment of wounds He recognized that antiseptic chemicals can prevent infection and proved the value of some of the old herbal remedies Phenolic compounds both synthetic phenol and thyme oil were used as antiseptics until World War I The clove tree produces flower