36B BioOrganic Modifications for Technique Experiments Experiment 5 The Technique of Distillation Isolation of Volatile Oils from Spices by Steam Distillation and Bioassay for Biological Activity Introduction The spices cloves 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 Chem 36 Lab Guide and also read an article by W H Miles and P M Smiley vol 79 J Chem Ed 2002 and Antimicrobial Effects of Spices and Herbs by O Peter Snyder 1997 this article can be found on the web In the first lab you will use steam distillation to separate any volatile oils from your spice of choice In preparation for this read the theory of steam distillation presented below Review Figure 5 3 of your Lab Guide You will be using a variation of this distillation set up shown You are given typical distillation data for simple and fractional distillation ethanol water in this lab supplement You will need to graph this data and provide interpretation for it in your final report You are responsible for understanding how simple and fractional distillations are carried out and the advantages and disadvantages of these types of distillations as well as steam distillation The procedure that was used to obtain the fractional and simple distillation of ethanol water is described on pages 124 127 in your Lab Guide Procedure 1B and Procedure 2B In the second lab you will be carrying out Procedure 3 page 128 of your Lab Guide a microscale fractional distillation of an unknown mixture that will give you experience with the fractional distillation technique You will use prepared sterile agar plates and inoculate them with one of the following aqueous cultures S epidermidis E coli or B cereus Your isolated essential oils will then be added to these inoculated plates to test for antibacterial activity You will use GC and GC MS to characterize your volatile oils In preparation for product analysis using these methods read Sections 11 2 11 7 and 11 8 on gas chromatography and GC MS in the Lab Guide PreLab Your chemical data table should include the chemicals mentioned in Table 5 1 on page 128 of your Lab Guide and also eugenol thymol and quinine Hand in a copy of the completed Common Shelf Chemical Date Table with your PreLab Remember to check your syllabus to see which two questions to answer from the Prelab Exercise list Your third prelab question is listed below 1 After reviewing the assay your essential oil shows antibiotic activity how would you determine which compound s in the oil is are the active ingredient 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 Chemical Relevance Chemistry and Medicine Since ancient times humankind has sought medicines from nature Quinine the antimalarial 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 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 No 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 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 anticancer 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 revolutionizing the medical treatment of