Investigate and Compare Chemical Compositions in Ginkgo biloba Products

Xiaoting Zhang1,*, Xinyi Huang1, James T. Lyles1, Cassandra L. Quave1,2 1Center for the Study of Human Health, Emory University, Atlanta, GA; 2Department of Dermatology, Emory University School of Medicine, Atlanta, GA;

*E-mail: xiaoting.zhang@emory.edu Lab Website: http://etnobotanica.us/

I would like to acknowledge the Scholarly Inquiry Research Program at Emory (SIRE) for organizing undergraduate research. This work was supported by Dr. Quave’s research development funds. I would also like to thank Dr. Quave, Dr. Lyles, and my co-worker Xinyi Huang for all their support.

1.  Camag Laboratory. Application Notes. HPTLC Identification of Ginkgo: Ginkgolic Acids. F-16C.1

2.  Camag Laboratory. Application Notes. HPTLC Identification of Ginkgo: flavonoids. F-16B.1

3.  Camag Laboratory. Application Notes. HPTLC Identification of Ginkgo: Ginkgolides. F-16A.1

4.  Wang, Ruwei, Yuta Kobayashi, Yu Lin, Hans Rauwald, Jianbiao Yao, Ling Fang, Hongxiang Qiao, and Kenny Kuchta. "HPLC Quantification of All Five Ginkgolic Acid Derivatives in Ginkgo Biloba Extracts Using 13 : 0 Ginkgolic Acid as a Single Marker Compound." Planta Med Planta Medica 81.01 (2014): 71-78.

5.  Dubber, Mary Jean, and Isadore Kanfer. "High-Performance Liquid Chromatographic Determination of Selected Flavonols in Ginkgo Biloba Solid Oral Dosage Forms." Journal of Pharmaceutical Science 7(3) (2004): 303-09. Web.

INTRODUCTION AND BACKGROUND A. The story of Ginkgo biloba •  Ginkgo, sometimes called maidenhair tree, is the only living member of the botanical family Ginkgoaceae. •  Medicinal usage was recorded in Chinese Materia Medica Ben cao gang mu by Li Shizhen in 16th Century. •  Historical record: Most historical reference to the medicinal use of ginkgo refers to the seed. For example, in Ben Cao Gang Mu, ginkgo seed was cited for its use in the treatment of “ asthma, coughs, irritability of the bladder, blennorrhea, and uterine fluxes” (Read 1982). •  Modern usage: the highly concentrated extract of ginkgo leaf has been primarily used to enhance mental acuity and promote peripheral circulation in dementia such as Alzheimer’s disease. •  External usage: effective treatment for infectious skin diseases. •  A specifically characterized ginkgo leaf extract contains 24% flavonol glycosides; 6% terpene trilactones; < 5ppm ginkgolic acids.

B.  Primary Active Compounds in Ginkgo Terpenes (terpene trilactones) Ginkgotoxin Flavonoids Ginkgolides A,B,C,bilobalide

RESEARCH AIMS

•  Use Thin Layer Chromatography (TLC) and High-Performance Liquid Chromatography (HPLC) to compare the differences in chemical compositions for the variations of: 1. Leaves V.S. Seeds V.S. Seed Coats V.S. Branches 2. Female V.S. Male 3. Ethanol extracts V.S. Water extracts 4. Dry V.S. Fresh samples

 

RE

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METHODS

  RESULTS

A.   Mater collection and preparation

maceration decoc%on

B. Extraction: •  In the ration of 1:10 •  Solvent: ethanol or water

C. Course and Fine Filtration

D. Rotatory Evaporation

E. Freeze-Dryer

sonica%on

Standard Stationary phase Mobile phase Detection

Flavonoids HPTLC plates silica gel

Ethyl acetate, glacial acetic acid, formic

acid, water(100:11:11:27) a. UV 256nm

b.UV 365 nm c. Sprayed with 2% vanillin in sulfuric acid

and heated by hot plate

Ginkgolic acid

HPTLC plates silica gel

Toluene, ethyl acetate, glacial acetic acid

(40:10:1)

Ginkgolide A,B,C and bilobalide

HPTLC plates silica gel

Toluene, ethyl acetate, acetone, methanol

(20:10::10:1.2)

Chromatographic Condition Reference Substance

Column C18

(flavonoids) Quercetin,

Kaempferol, Isorhamnetin,

Flavonol glycosides

rutin, ginkgolide A,B, Bilobalide and

ginkgotoxin

Column Temperature 45°C

Mobile Phase A(acetonitrile)+B(0.3% formic acid) ratios

Gradient

one step linear gradient t=0-10mins: 2%B;

t=10-20mins: 2-15%B; t=20-30mins:15%B;

Detection Wavelength

Retention at:350nm Quantitation:350nm(rutin,and quercetin) 365nm

(isorhamnetin and kaempferol)

Extract# Part Solvent Gender Storage Rf Values

Indicated Compounds

661 leaves decoction female dry - -

662 leaves water female dry 0.3333 Ginkgolide A 0.1212 Ginkgolide C

664 seeds water female dry 0.2138 Ginkgolide B 668 leaves decoction male dry - - 669 leaves water male dry - -

Extract# Part Solvent Gender Storage Rf Values

Indicated Compounds

660 leaves EtOH female dry 0.3145 Ginkgolide A 0.4591 Bilobalide 0.5385 Ginkgolic acid

663 seeds EtOH female dry 0.4586 Ginkgolic acid 665 seedcoats EtOH female dry 0.4713 Ginkgolic acid

666 branches EtOH female dry

0.1946 Ginkgolide C 0.3356 Ginkgolide A 0.4832 Bilobalide 0.4459 Ginkgolic acid

667 leaves EtOH male dry 0.4161 Bilobalide 0.5315 Ginkgolic acid

670 branches EtOH male dry

0.1678 Ginkgolide C 0.3221 Ginkgolide A 0.4698 Bilobalide 0.4586 Ginkgolic acid

 Quercetin

 Isorhamnetin

 Kaempferol

 Rutin

distance from the starting point to the center of the spot Rf Value = distance from the starting point to the solvent front

A. Thin Layer Chromatography Ethanol Extracts V.S. Water Extracts

Figure 3. TLC data for dry ethanol extracts from both genders and all tree parts

Figure 2. HPLC machine conditions for ginkgo samples Figure 1. Methods of TLC tests for ginkgo samples targeting different compounds

Figure 4. TLC data for fresh ethanol extracts from both genders and all tree parts

Extract# Part Solvent Gender Storage Rf Values

Indicated Compounds

671 leaves EtOH female fresh-frozen

0.1667 Ginkgolide C 0.2756 Ginkgolide B

674 seeds EtOH female fresh-frozen 0.5000 Ginkgolic acid

677 seedcoats EtOH female fresh-frozen

0.3121 Ginkgolide A 0.5079 Ginkgolic acid

678 immature seed EtOH female fresh-

frozen 0.3006 Ginkgolide A 0.4921 Ginkgolic acid

679 branches EtOH female fresh-frozen

0.1677 Ginkgolide C 0.2050 Ginkgolide B 0.5000 Ginkgolic acid

680 leaves EtOH male fresh-frozen

0.1923 Ginkgolide C 0.3013 Ginkgolide A 0.4803 Ginkgolic acid

683 branches EtOH male fresh-frozen

0.1988 Ginkgolide C 0.2857 Ginkgolide B 0.4658 Bilobalide 0.5159 Ginkgolic acid

Dry Samples

V.S.

Fresh Samples

Extract# Part Solvent Gender Storage Rf Values Indicated Compounds

672 leaves decoction female fresh-frozen - -

673 leaves water female fresh-frozen

0.1667 Ginkgolide C 0.2692 Ginkgolide B

675 seeds water female fresh-frozen - -

681 leaves decoction male fresh-frozen 0.3205 Ginkgolide A

682 leaves water male fresh-frozen - -

687 branches water female fresh-frozen

0.1677 Ginkgolide C 0.2050 Ginkgolide B

688 branches water male fresh-frozen 0.1801 Ginkgolide C

689 seeds water female fresh-frozen 0.3006 Ginkgolide A

Figure 5. TLC data for dry water extracts from both genders and all tree parts

Figure 6. TLC data for fresh water extracts from both genders and all tree parts

CONCLUSIONS

B. High Liquid Performance Chromatography 　 Female Leaves EtOH Seed EtOH Female Branch EtOH Male Leaves EtOH

Standards Retention Time

Closest Retention time

Peak height

% of Abundance

Closest Retention

time

Peak height

% of Abundance

Closest Retention

time

Peak height

% of Abundance

Closest Retention

time

Peak height

% of Abundance

Ginkgolide A 2.6805 2.6857 3257.0547 11.00% − − − 2.6869 892.3681 3.93% − − − Ginkgolide B 2.6799 − − − 2.6762 853.6333 20.72% − − − − − −

Biloblide 2.61 − − − − − − − − − − − − Ginkgotoxin 4.68 − − − − − − − − − − − −

Rutin 32.93 − − − − − − − − − 32.9356 1908.894 2.47% Quercetin 38.1/38.3 − − − − − − − − − − − −

Isohamnetin 39.2/39.3 − − − − − − − − − − − − Kaempferol 39.04/39.14 − − − − − − − − − − − −

F. Thin Layer Chromatography (TLC) G. High Liquid Performance Chromatography (HPLC)

Variation of solvent methods

•  Based on both HPLC and TLC results, ethanol is a more effective extraction solvent than water for ginkgo products.

Variation of material storage methods •  Based on the TLC data, difference in storage methods does not significantly affect

the number of results of ethanol extracts. However, the fresh-frozen water extracts showed more compounds than the dry fresh-frozen water extracts.

•  Keep other factors constant, different compounds were found between dry and fresh samples, while there were some overlap.

Variation of genders •  HPLC test found more compounds in female extracts than male extracts. However,

there is no significant difference in the number of compounds we found in TLC tests.

•  Keep other factors constant, different compounds were found between female and male samples, while there were some overlap.

Variation of tree parts •  For both male and female ginkgo extracts, branches showed most diversity in

chemical composition from the TLC data.

Future Directions •  Finish HPLC test for fresh samples and compare the data with dry samples •  Incorporate the results from biology assays

Figure 7. Table of matching up standards with ginkgo samples using HPLC.

Rutin

Ginkgolide A

Ginkgolide A

Ginkgolide A

Female Leaves EtOH

Female Branches EtOH

Ginkgolide B

Seeds EtOH

Ginkgolide B

Male Branches EtOH

Rutin

distance from the starting point to solvent front

Under UV 256 nm Under UV 365 nm

After sprayer

FUN

DIN

G &

T

HA

NK

S  

References Standards Rf Values

Ginkgolide A 0.3226 Ginkgolide B 0.25806 Ginkgolide C 0.1129

Bilobalide 0.4032 Ginkgolic acid 0.5000

Ginkgolic Acids

Figure 8. TLC data for targeted chemical compounds.