Introduction

The leaves of Ginkgo biloba L. have been used in ancient and modern Chinese herbal pharmacopoeia as a treatment for dysfunctions of the heart and lung and as a promoter of longevity [1]. More than 60 different biologically active substances are present in G. biloba leaves (Fig. 17.1). Of these, terpenoids, flavonoids and organic acids are the most important. The standardized G. biloba leaf extract (EGb761, Tanakan) was developed in the early 1970s and contains 24% flavonol glycosides (the flavonoid fraction), 6% terpene lactones (terpenoid fraction), 70% other substances [such as rutin, proanthocyanidines (> 0.5%), organic acids (5 to 10%), glucose, rhamnose, etc.] and no more than 5ppm of ginkgolic acids. The flavonoid fraction is primarily composed of flavanals: quercetin, kaempferol, amentoflavon,

Comenius University, Jessenius Faculty of Medicine, Department of Medical Biochemistry, Mala Hora 4, 036 01 Martin, Slovak Republic, e-mail: [email protected]

K.G. Ramawat (ed.), Herbal Drugs: Ethnomedicine to Modern Medicine, DOI 10.1007/978-3-540-79116-4_17, © Springer-Verlag Berlin Heidelberg 2009

Non-flavonoid polyphenols

Anthocyanins

Flavans

^ Flavones

Flavanols —Catechins * Isoflavons

Flavonols

Anthocyanins

Flavans

Polyphenols

Flavonoids

^ Flavones

Flavanols —Catechins * Isoflavons

Flavonoids

Anthoxantins

Phenolic acid

Fig. 17.1 Classification of natural plyphenols found in EGb 761

Phenolic acid

Anthoxantins

Fig. 17.1 Classification of natural plyphenols found in EGb 761

bilobetin, ginkgetin, idoginkgetin, 5'-methoxybilobetin and isorhamnetin. The terpenoid fraction primarily contains ginkgolides A, B, C, J and M (2.8 to 3.4%), as well as seskviterpenoic polyketone bilobalide (2.6 to 3.4%) with unique chemical structures of polycyclic ethers containing a characteristic terc-butyl group, which is very rare in natural compounds [2].

Was this article helpful?

0 0
Traditional Chinese Medicine

Traditional Chinese Medicine

Ever wondered what Chinese medicine is all about and whether it works? Thinking about consulting a practitioner but want to know some facts first? Look no further! Here's your chance to purchase an in depth and fully comprehensive eBook on anything and everything to do with this ancient philosophy.

Get My Free Ebook


Post a comment