Ginkgolic acid

Satyan KS, Jaiswal AK, Ghosal S, Bhattacharya SK. (1998). Anxiolytic activity of ginkgolic acid conjugates from Indian Ginkgo biloba. Psychopharmacology (Berlin). 136(2) 148-52. 

Allergic reactions are a significant concern with unprocessed ginkgo leaf (ginkgolic acid) but are much less... 

Figure 1 Structures of (A) ginkgolide A, ginkgolide B, bilobalide, (B) flavonolgly-cosides (R=H kaempferol-3-O-rutinoside R=OH quercetin-3-O-rutinoside R=0CH3 isorhamnetin-3-O-rutinoside) and (C) ginkgolic acids (R=Ci3H27, C15H31, C15H29, C15H33).

Hausen BM. The sensitizing capacity of ginkgolic acids in guinea pigs. Am J Contact Derm 1998 9 146-148. 

Ginkgolic acids Ginkgo biloba (Ginkgoaceae) Quasi-apoptotic (cytotoxic but... 

Fuzzati N, Pace R, Villa F. A simple HPLC-UV method for the assay of ginkgolic acid in ginkgo biliba extract. Fitoterapia 2003 74 247-256. 

Alkylphenols with long alkyl groups have been identified from many plants [91]. Anacardic acids (Ginkgolic acids) are the most intensively... 

The isomer of Fig (2)-2, anacardic acid 8(E)-monoene has been synthesised by a Xrans elimination reaction as depicted in Scheme 2 [234], which also depicts the route used for the (Z)- isomer, ginkgolic acid. [235],... 

Anacardic 8(Z)-monoene (ginkgolic acid) has been synthesised from... 

Gymnospermae Gingo biloba Ginkgolic acid 2-Hydroxy-6-[(Z)-pentadec-8-enyl]- cf.2 16 China,Japan... 

Ginkgolic acid, (15 1)-anacardic acid has been synthesised by an aryne route... 

Alkylation routes have been used for the monoenes in this group. Thus, ethyl 2-methoxy-6-methylbenzoate as the carbanion (formed from lithium di-isopropylamide) has been alkylated with (Z) 1-bromotetradec-7-ene in the presence of hexamethylphosphoric triamide. Demethylation with lithium t-butytthiolate yielded (15 1)-anacardic acid (ref. 114). A more activated benzyl group having an adjacent sulphur atom was used for a synthesis of the 10(Z)-isomer of ginkgolic acid in the following way (ref. 8). 

In addition to the above substances, a large variety of polysaccharides, long-chain hydrocarbons, alcohols, and acids have been isolated, as well as (Z,Z)-4,4 -(1, 4-pentadiene-l, 5-diyl) diphenol and 6-hydroxykynurenic acid [1, 2]. The cytotoxic, mutagenic, and allergenic potential of some constituents, especially anacardic or ginkgolic acids, limits the use of a crude leaf extract for therapeutical... 

Ginkgo leaf contains ginkgolic acids (urushiol type alkylphenols), compounds that are related to those found in poison ivy Toxicodendron radicans) and associated with contact allergies, especially dermatitis. Ginkgolic acids are found in relatively high concentrations in ginkgo seed coats and in low concentrations in the leaf (Blumenthal 1997). 

Blumenthal, M. 1997. German government limits ginkgolic acid... 

Ginkgolic acid is a mixture of several 2-hydroxy-6-alkyIbenzoic acids, two of which (alkyl = 1-octene or 3-decene) were baseline resolved on a 45 C Cjg column (A = 308nm) with a 92/7/1 acetonitrile/water/acetic acid mobile phase [1053]. Elution was complete in 6 min and peaks of interest were well resolved from all extracted material. In a separate study, Pietta et al. [1054] isolated six metabolites (hippuric acid, 4-hydroxy- and 3-methoxy-4-hydroxyhippuric acid, 4-hydroxy-, 3,4-dihydroxy-, and 3-methoxy-4-hydroxybenzoic acid) of Ginkgo biloba leaf extracts from urine and blood samples and analyzed on a Cjg column (photodiode array detector). An 88/5/5/2 water/acetonitrile/methanol/acetic acid mobile phase generated good resolution and complete elution in 15 min. The standard used was at the 1 mg/mL level. 

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