United States Department of Agriculture Two-Dimensional Gas Chromatography Characterization of Saw Palmetto Serenoa repens Chemical Composition Roderquita K. Moore Doreen Mann Second dimension (s) dimension Second First dimension (s) Forest Forest Products Research Note September Service Laboratory FPL–RN–0387 2020 Abstract Contents Comprehensive two-dimensional gas chromatography Introduction ..........................................................................1 (GC×GC) is an important technique used to investigate Experimental ........................................................................1 potential medicinal mixtures. The pharmaceutical industry is a trillion-dollar industry, and 25% of this value comes Results and Discussion ........................................................2 from plant-derived chemicals. Saw Palmetto (Serenoa Conclusions ..........................................................................8 repens) berries are known for their medicinal properties. This medicinal alternative aids in treatment of health Acknowledgments ................................................................8 problems such as asthma, benign prostatic hypertrophy, References ..........................................................................10 colds, migraines, prostate cancer, and sore throats. Cancer is a disease where abnormal cells rapidly divide and destroy body tissue. In 2018, an estimated 1.7 million new cases of cancer were diagnosed in the United States and 609,640 people will die from the disease. This disease affects people in different ways. The most common type of cancer is breast cancer, followed by lung and prostate cancer. In 2019, about 174,650 new cases of prostate cancer were diagnosed, and about 31,620 ended in death. One in nine men will be diagnosed with prostate cancer, and it mainly affects older men and African-American men. In this study, the chemical composition of saw palmetto leaves was characterized using GC×GC-time of flight mass spectrometry. Extractions were taken with two different solvents. Similar chemicals were identified in both solvent mixtures. Fatty acids and sterols compounds used to relieve urological disorders were identified in the saw palmetto leaves. Keywords: GC×GC, extractives, bushes, Serenoa repens, extraction September 2020 Moore, Roderquita K; Mann, Doreen. 2020. Two-dimensional gas chromatography characterization of saw palmetto Serenoa repens chemical composition. Research Note FPL-RN-0387. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 10 p. A limited number of free copies of this publication are available to the public from the Forest Products Laboratory, One Gifford Pinchot Drive, Madison, WI 53726-2398. This publication is also available online at www.fpl.fs.fed.us. Laboratory publications are sent to hundreds of libraries in the United States and elsewhere. The Forest Products Laboratory is maintained in cooperation with the University of Wisconsin. The use of trade or firm names in this publication is for reader information and does not imply endorsement by the United States Department of Agriculture (USDA) of any product or service. In accordance with Federal civil rights law and U.S. Department of Agriculture (USDA) civil rights regulations and policies, the USDA, its Agencies, offices, and employees, and institutions participating in or administering USDA programs are prohibited from discriminating based on race, color, national origin, religion, sex, gender identity (including gender expression), sexual orientation, disability, age, marital status, family/parental status, income derived from a public assistance program, political beliefs, or reprisal or retaliation for prior civil rights activity, in any program or activity conducted or funded by USDA (not all bases apply to all programs). Remedies and complaint filing deadlines vary by program or incident. Persons with disabilities who require alternative means of communication for program information (e.g., Braille, large print, audiotape, American Sign Language, etc.) should contact the responsible Agency or USDA’s TARGET Center at (202) 720–2600 (voice and TTY) or contact USDA through the Federal Relay Service at (800) 877–8339. Additionally, program information may be made available in languages other than English. To file a program discrimination complaint, complete the USDA Program Discrimination Complaint Form, AD-3027, found online at http://www.ascr.usda. gov/complaint_filing_cust.html and at any USDA office or write a letter addressed to USDA and provide in the letter all of the information requested in the form. To request a copy of the complaint form, call (866) 632–9992. Submit your completed form or letter to USDA by: (1) mail: U.S. Department of Agriculture, Office of the Assistant Secretary for Civil Rights, 1400 Independence Avenue, SW, Washington, D.C. 20250–9410; (2) fax: (202) 690–7442; or (3) email: [email protected]. USDA is an equal opportunity provider, employer, and lender. Two-Dimensional Gas Chromatography Characterization of Saw Palmetto Serenoa repens Chemical Composition Roderquita K. Moore, Research Chemist Doreen Mann, Physical Science Technician USDA Forest Service, Forest Products Laboratory, Madison, Wisconsin, USA Introduction Experimental Our ancestors used natural products and home remedies to Materials treat sickness and diseases. Saw palmetto (Serenoa repens) berry extracts are known for their alternative use for treating Live saw palmetto plants in moist soil were purchased urological disorders. Willetts and others (2003) tested the from a nursery. These plants were kept in a green house effects of Serenoa repens extracts in a double-blind placebo- and watered regularly. When the moisture content fell controlled random trial. In that study, it was concluded that below 30%, plants were considered to be dead. All solvents there was improvement in benign prostatic hypertrophy in were purchased from Thermo Fisher Scientific (Waltham, both groups, but there was no significant measurable effect Massachusetts, USA). Tetracosane 99%, purchased from between the group given paraffin oil and those given the Sigma-Aldrich (St. Louis, Missouri, USA), was the extract. This led to a study investigating the efficacy of calibration standard used for GC×GC. these extractives. By increasing dosage and using different solvent extractions, the next clinical trial improved quality Extraction Procedure of life for patients, with some side effects (Gerber and Saw palmetto leaves were extracted by acetone and water Fitzpatrick 2004). Bayne and others (2000) performed a (9:1) and hexane and isopropyl alcohol (50:50) solutions. selectivity and specificity test on the lipido-sterolic extract The leaves were cut and stored in a freezer. The leaves were of Serenoa repens on prostate epithelial and fibroblast removed from the freezer, slightly thawed, and weighed. cells and also investigated morphology changes in breast, The weight of leaves was calculated on the basis of dry kidney, skin, testes, and epididymis. In that study, changes mass (not shown). The leaves were placed in a 250-mL occurred within 24 hours, but not enough changes occurred Erlenmeyer flask with 100 mL of solvent solution. Each to conclude that lipido-sterolic chemicals from Serenoa extraction solution was filtered and filled with fresh solvent repens made significant changes in prostate cells. Lipido- every 24 hours and shaken (orbital shaker) for a total of sterolic chemicals were from a hexane fraction (Bayne and 48 hours. Extraction solutions were evaporated using a others 2000, Chua and others 2014). Other solvent fractions Rotavapor (Buchi Corporation, New Castle, Delaware, bring about different side effects and improvements. Gas USA), transferred to preweighed vials, sealed, and stored in chromatography coupled with mass spectrometry has a freezer. been used to identify complex mixtures. However, trace chemicals have not been detected (Moore and others 2015a, Instrumentation Operations 2015b, 2017a, 2017b, 2017c). An instrument with more The instrument parameters used for the analysis of saw resolution will identify these chemical mixtures. In this palmetto extracts are given in Table 1. The injection study, two-dimensional gas chromatography (GC×GC) split and the modulation varied for different samples. was used to qualitatively analyze chemical composition of The injection splits depended on the concentration of the saw palmetto extracts produced with two different solvent samples. The modulation time was less than 5 seconds for mixtures, acetone with water and hexane with isopropyl each run. The time changed based on chemicals retained on alcohol. The increase in peak capacity and resolving power the second-dimension column. from this analysis identified differences between the two extracts. GC×GC analysis was used to compare these fractions and identify their similarities and differences. Research Note FPL–RN–0387 Table 1. Two-dimensional gas chromatography-time of Table 2. Number of chemicals detected by flight mass spectroscopy (GC×GC-TOFMS) (Pegasus two-dimensional gas chromatography-time of BT 4D) instrument parameters flight mass spectrometry (GC×GC-TOFMS) and Gas chromatograph agilent 7890B with LECO dual stage quad jet identified by NIST and Wiley libraries (acetone modulator and LPAL 3 autosampler extract (spa) and hexane extract (sph)) Injection 1 uL, split 20–150:1 at 250 °C Total Peaks Peaks >800 >800 Extract >700 unknown known