Chemistry:Bilobalide

Short description: Chemical compound

Bilobalide

Clinical data
Routes of administration	By mouth
Legal status
Legal status	In general: legal
Identifiers
IUPAC name (5aR-(3aS*,5aα,8b,8aS*,9a,10aα))-9-(1,1-dimethylethyl)-10,10a-dihydro-8,9-dihydroxy-4H,5aH,9H-furo[2,3-b]furo[3',2':2,3]cyclopenta[1,2-c]furan-2,4,7(3H,8H)-trione
CAS Number	33570-04-6 Y
PubChem CID	73581
IUPHAR/BPS	2366
ChemSpider	21106418 Y
UNII	M81D2O8H7U
ChEBI	CHEBI:3103
ChEMBL	ChEMBL133266 N
Chemical and physical data
Formula	C15H18O8
Molar mass	326.301 g·mol−1
3D model (JSmol)	Interactive image
SMILES CC(C)(C)[C@@]1(C[C@H]2[C@@]3([C@]14[C@H](C(=O)O[C@H]4OC3=O)O)CC(=O)O2)O
InChI InChI=1S/C15H18O8/c1-12(2,3)14(20)4-6-13(5-7(16)21-6)10(19)23-11-15(13,14)8(17)9(18)22-11/h6,8,11,17,20H,4-5H2,1-3H3/t6-,8-,11-,13-,14+,15?/m0/s1 Y Key:MOLPUWBMSBJXER-ISSLQHLCSA-N Y
NY (what is this?)  (verify)

Bilobalide is a biologically active terpenic trilactone present in Ginkgo biloba.

Chemistry

Bilobalide is a main constituent of the terpenoids found in Ginkgo leaves. It also exists in minor amounts in the roots. It is a sesquiterpenoid, i.e. it has a 15-carbon skeleton. Its exact synthesis pathway from farnesyl pyrophosphate is still unknown.

Biosynthesis

Bilobalide and ginkgolide have similar biosynthetic pathways. Bilobalide is formed by partially degraded ginkgolide. Bilobalide is derived from geranylgeranyl pyrophosphate (GGPP), which is formed by addition of farnesyl pyrophosphate (FPP) to an isopentenyl pyrophosphate (IPP) unit to form a C₁₅ sesquiterpene. Such formation went through the mevalonate pathway (MVA) and methylerythritol phosphate MEP pathway. In order to generate bilobalide, C₂₀ ginkgolide 13 must form first. To transform from GGPP to abietenyl cation 5, a single bifunctional enzyme abietadiene synthase E1 is required. However, due to the complexity of ginkgolide structures for rearrangement, ring cleavage, and formation of lactone rings, diterpene 8 is used to explain instead. Levopimaradiene 6 and abietatriene 7 are precursors for ginkgolide and bilobalide formation. The unusual tert-butyl substituent is formed from A ring cleavage in 9. Bilobalide 13 then formed in loss of carbons through degradation from ginkgolide 12, and lactones are formed from residual carboxyl and alcohol functions. The end product of bilobalide contains sesquiterpenes and three lactones units.

Pharmacology

Bilobalide is important for producing several of the effects of Ginkgo biloba extracts, and it has neuroprotective effects, as well as inducing the liver enzymes CYP3A1 and CYP1A2, which may be partially responsible for interactions between ginkgo and other herbal medicines or pharmaceutical drugs. Bilobalide has recently been found to be a negative allosteric modulator at the GABA_A and GABA_A-rho receptors. Of GABA_A, it may possibly be selective for the subunits predominantly implicated in cognitive and memory functioning such as α1.

See also

• Ginkgolide

External links

{{Navbox | name = GABA receptor modulators | title = GABA receptor modulators | state = collapsed | bodyclass = hlist | groupstyle = text-align:center;

 | group1 = Ionotropic
 |  list1 = {{Navbox|subgroup
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 | groupwidth = 5em

   | group1 = GABAA
   | list1  = 

• Agonists: (+)-Catechin
• Bamaluzole
• Barbiturates (e.g., phenobarbital)
• BL-1020
• DAVA
• Dihydromuscimol
• GABA
• Gabamide
• GABOB
• Gaboxadol (THIP)
• Homotaurine (tramiprosate, 3-APS)
• Ibotenic acid
• iso-THAZ
• iso-THIP
• Isoguvacine
• Isomuscimol
• Isonipecotic acid
• Kojic amine
• Lignans (e.g., honokiol)
• Methylglyoxal
• Monastrol
• Muscimol
• Nefiracetam
• Neuroactive steroids (e.g., allopregnanolone)
• Org 20599
• PF-6372865
• Phenibut
• Picamilon
• P4S
• Progabide
• Propofol
• Quisqualamine
• SL-75102
• TACA
• TAMP
• Terpenoids (e.g., borneol)
• Thiomuscimol
• Tolgabide
• ZAPA

• Positive modulators (abridged; see here for a full list): α-EMTBL
• Alcohols (e.g., ethanol)
• Anabolic steroids
• Avermectins (e.g., ivermectin)
• Barbiturates (e.g., phenobarbital)
• Benzodiazepines (e.g., diazepam)
• Bromide compounds (e.g., potassium bromide)
• Carbamates (e.g., meprobamate)
• Carbamazepine
• Chloralose
• Chlormezanone
• Clomethiazole
• Dihydroergolines (e.g., ergoloid (dihydroergotoxine))
• Etazepine
• Etifoxine
• Fenamates (e.g., mefenamic acid)
• Flavonoids (e.g., apigenin, hispidulin)
• Fluoxetine
• Flupirtine
• Imidazoles (e.g., etomidate)
• Kava constituents (e.g., kavain)<!--PMID: 9776662-->
• Lanthanum
• Loreclezole
• Monastrol
• Neuroactive steroids (e.g., allopregnanolone, [[Chemistry:Cholecholesterol]], THDOC)
• Niacin
• Nicotinamide (niacinamide)
• Nonbenzodiazepines (e.g., β-carbolines (e.g., [[abecarnil), cyclopyrrolones (e.g., zopiclone), imidazopyridines (e.g., zolpidem), pyrazolopyrimidines (e.g., zaleplon))
• Norfluoxetine
• Petrichloral
• Phenols (e.g., propofol)
• Phenytoin
• Piperidinediones (e.g., glutethimide)
• Propanidid
• Pyrazolopyridines (e.g., etazolate)
• Quinazolinones (e.g., methaqualone)
• Retigabine (ezogabine)
• ROD-188
• Skullcap constituents (e.g., baicalin)
• Stiripentol
• Sulfonylalkanes (e.g., sulfonmethane (sulfonal))
• Topiramate
• Valerian constituents (e.g., valerenic acid)
• Volatiles/gases (e.g., chloral hydrate, chloroform, [[Chemistry:Diethyl diethyl ether, Parparaldehyde]], sevoflurane)

• Antagonists: Bicuculline
• Coriamyrtin
• Dihydrosecurinine
• Gabazine (SR-95531)
• Hydrastine
• Hyenachin (mellitoxin)
• PHP-501
• Pitrazepin
• Securinine
• Sinomenine
• SR-42641
• SR-95103
• Thiocolchicoside
• Tutin

• Negative modulators: 1,3M1B
• 3M2B
• 11-Ketoprogesterone
• 17-Phenylandrostenol
• α5IA (LS-193,268)
• β-CCB
• β-CCE
• β-CCM
• β-CCP
• β-EMGBL
• Anabolic steroids
• Amiloride
• Anisatin
• β-Lactams (e.g., penicillins, cephalosporins, carbapenems)
• Basmisanil
• Bemegride
• Bicyclic phosphates (TBPS, TBPO, IPTBO)
• BIDN
• Bilobalide
• Bupropion
• CHEB
• Chlorophenylsilatrane
• Cicutoxin
• Cloflubicyne
• Cyclothiazide
• DHEA
• DHEA-S
• Dieldrin
• (+)-DMBB
• DMCM
• DMPC
• EBOB
• Etbicyphat
• FG-7142 (ZK-31906)
• Fiproles (e.g., fipronil)
• Flavonoids (e.g., amentoflavone, oroxylin A)
• Flumazenil
• Fluoroquinolones (e.g., ciprofloxacin)
• Flurothyl
• Furosemide
• Golexanolone
• Iomazenil (¹²³I)
• IPTBO
• Isopregnanolone (sepranolone)
• L-655,708
• Laudanosine
• Leptazol
• Lindane
• MaxiPost
• Morphine
• Morphine-3-glucuronide
• MRK-016
• Naloxone
• Naltrexone
• Nicardipine
• Nonsteroidal antiandrogens (e.g., [[apalutamide, [[Chemistry:Bicalutbicalutamide, Enzalutenzalutamide, Chemistry:Flutamide|flut]]amide]], nilutamide)
• Oenanthotoxin
• Pentylenetetrazol (pentetrazol)
• Phenylsilatrane
• Picrotoxin (i.e., picrotin, picrotoxinin and dihydropicrotoxinin)
• Pregnenolone sulfate
• Propybicyphat
• PWZ-029
• Radequinil
• Ro 15-4513
• Ro 19-4603
• RO4882224
• RO4938581
• Sarmazenil
• SCS
• Suritozole
• TB-21007
• TBOB
• TBPS
• TCS-1105
• Terbequinil
• TETS
• Thujone
• U-93631
• Zinc
• ZK-93426

   | group2 = GABAA-ρ
   | list2  = 

• Agonists: BL-1020
• CACA
• CAMP
• Homohypotaurine
• GABA
• GABOB
• Ibotenic acid
• Isoguvacine
• Muscimol
• N⁴-Chloroacetylcytosine arabinoside
• Picamilon
• Progabide
• TACA
• TAMP
• Thiomuscimol
• Tolgabide

• Positive modulators: Allopregnanolone
• Alphaxolone
• ATHDOC
• Lanthanides

• Antagonists: (S)-2-MeGABA
• (S)-4-ACPBPA
• (S)-4-ACPCA
• 2-MeTACA
• 3-APMPA
• 4-ACPAM
• 4-GBA
• cis-3-ACPBPA
• CGP-36742 (SGS-742)
• DAVA
• Gabazine (SR-95531)
• Gaboxadol (THIP)
• I4AA
• Isonipecotic acid
• Loreclezole
• P4MPA
• P4S
• SKF-97541
• SR-95318
• SR-95813
• TPMPA
• trans-3-ACPBPA
• ZAPA

• Negative modulators: 5α-Dihydroprogesterone
• Bilobalide
• Loreclezole
• Picrotoxin (picrotin, picrotoxinin)
• Pregnanolone
• ROD-188
• THDOC
• Zinc

 }}

 | group2 = Metabotropic

| list2 =

GABAB

Agonists: 1,4-Butanediol 4-Fluorophenibut Aceburic acid Arbaclofen Arbaclofen placarbil Baclofen BL-1020 GABA Gabamide GABOB GBL GHB GHBAL GHV GVL Isovaline Lesogaberan Phenibut Picamilon Progabide Sodium oxybate SKF-97,541 SL 75102 Tolgabide Tolibut Positive modulators: ADX-71441 BHF-177 BHFF BSPP CGP-7930 CGP-13501 GS-39783 rac-BHFF KK-92A Antagonists: 2-Hydroxysaclofen CGP-35348 CGP-46381 CGP-52432 CGP-54626 CGP-55845 CGP-64213 DAVA Homotaurine (tramiprosate, 3-APS) Phaclofen Saclofen SCH-50911 SKF-97541 Negative modulators: Compound 14

 | below = 

See also

Receptor/signaling modulators

GABA_A receptor positive modulators

GABA metabolism/transport modulators

}}