Bovine Metabolome Database: Showing metabocard for Ethanol (BMDB0000108)

Identification Taxonomy Physical properties Pathways Spectra Concentrations Links References enzymes (1) Show 1 protein XML

Record Information

Version

1.0

Creation Date

2016-09-30 22:19:41 UTC

Update Date

2020-06-04 20:55:28 UTC

BMDB ID

BMDB0000108

Secondary Accession Numbers

BMDB00108

Metabolite Identification

Common Name

Ethanol

Description

Ethanol, also known as alcohol or 1-hydroxyethane, belongs to the class of organic compounds known as primary alcohols. Primary alcohols are compounds comprising the primary alcohol functional group, with the general structure RCOH (R=alkyl, aryl). Ethanol is a drug which is used for therapeutic neurolysis of nerves or ganglia for the relief of intractable chronic pain in such conditions as inoperable cancer and trigeminal neuralgia (tic douloureux), in patients for whom neurosurgical procedures are contraindicated. Ethanol exists as a solid, possibly soluble (in water), and an extremely weak basic (essentially neutral) compound (based on its pKa) molecule. Ethanol exists in all living species, ranging from bacteria to humans. Ethanol participates in a number of enzymatic reactions, within cattle. In particular, Ethanol can be converted into acetaldehyde; which is catalyzed by the enzyme alcohol dehydrogenase 1B. In addition, Ethanol can be converted into acetaldehyde through the action of the enzyme cytochrome P450 2E1. In cattle, ethanol is involved in the metabolic pathway called the ethanol degradation pathway. Ethanol is a potentially toxic compound.

Structure

MOL SDF 3D-SDF PDB SMILES InChI View 3D Structure

Synonyms

Value	Source
1-Hydroxyethane	ChEBI
[CH2Me(OH)]	ChEBI
[OEtH]	ChEBI
Alcohol	ChEBI
Alcohol etilico	ChEBI
Alcool ethylique	ChEBI
Alkohol	ChEBI
Aethanol	ChEBI
Aethylalkohol	ChEBI
C2H5OH	ChEBI
Dehydrated ethanol	ChEBI
Etanol	ChEBI
Ethyl alcohol	ChEBI
EtOH	ChEBI
Hydroxyethane	ChEBI
Methylcarbinol	ChEBI
Spiritus vini	ChEBI
Anhydrous ethanol	Kegg
Absolute alcohol	HMDB
Absolute ethanol	HMDB
Absolute ethyl alcohol	HMDB
Alcare hand degermer	HMDB
Alcohols	HMDB
Alcool etilico	HMDB
Algrain	HMDB
Alkoholu etylowego	HMDB
Anhydrol	HMDB
Anhydrous alcohol	HMDB
Cologne spirit	HMDB
Cologne spirits	HMDB
Dehydrated alcohol	HMDB
Denatured alcohol	HMDB
Denatured ethanol	HMDB
Desinfektol el	HMDB
Diluted alcohol	HMDB
Distilled spirits	HMDB
Ethanol 200 proof	HMDB
Ethanol solution	HMDB
Ethicap	HMDB
Ethyl alc	HMDB
Ethyl alcohol anhydrous	HMDB
Ethyl alcohol in alcoholic beverages	HMDB
Ethyl alcohol usp	HMDB
Ethyl hydrate	HMDB
Ethyl hydroxide	HMDB
Fermentation alcohol	HMDB
Grain alcohol	HMDB
Hinetoless	HMDB
Infinity pure	HMDB
Jaysol	HMDB
Jaysol S	HMDB
Lux	HMDB
Molasses alcohol	HMDB
Potato alcohol	HMDB
Punctilious ethyl alcohol	HMDB
Pyro	HMDB
Silent spirit	HMDB
Spirit	HMDB
Spirits OF wine	HMDB
Spirt	HMDB
Synasol	HMDB
Tecsol	HMDB
Tecsol C	HMDB
Thanol	HMDB
Undenatured ethanol	HMDB
Alcohol, absolute	HMDB
Alcohol, ethyl	HMDB
Alcohol, grain	HMDB

Chemical Formula

C₂H₆O

Average Molecular Weight

46.0684

Monoisotopic Molecular Weight

46.041864814

IUPAC Name

ethanol

Traditional Name

ethyl alcohol

CAS Registry Number

64-17-5

SMILES

CCO

InChI Identifier

InChI=1S/C2H6O/c1-2-3/h3H,2H2,1H3

InChI Key

LFQSCWFLJHTTHZ-UHFFFAOYSA-N

Chemical Taxonomy

Description

belongs to the class of organic compounds known as primary alcohols. Primary alcohols are compounds comprising the primary alcohol functional group, with the general structure RCOH (R=alkyl, aryl).

Kingdom

Organic compounds

Super Class

Organic oxygen compounds

Class

Organooxygen compounds

Sub Class

Alcohols and polyols

Direct Parent

Primary alcohols

Alternative Parents

Hydrocarbon derivatives

Substituents

Hydrocarbon derivative
Primary alcohol
Aliphatic acyclic compound

Molecular Framework

Aliphatic acyclic compounds

External Descriptors

primary alcohol (CHEBI:16236 )
alkyl alcohol (CHEBI:16236 )
ethanols (CHEBI:16236 )
a primary alcohol (ETOH )
a short-chain alcohol (ETOH )

Ontology

Status

Detected and Quantified

Origin

Exogenous

Biofunction

Not Available

Application

Not Available

Cellular locations

Cytoplasm
Myelin sheath
Peroxisome

Physical Properties

State

Liquid

Experimental Properties

Property	Value	Reference
Melting Point	-114.1 °C	Not Available
Boiling Point	Not Available	Not Available
Water Solubility	1000.0 mg/mL	Not Available
LogP	-0.31	HANSCH,C ET AL. (1995)

Predicted Properties

Property	Value	Source
logP	-0.4	ALOGPS
logP	-0.16	ChemAxon
logS	1.1	ALOGPS
pKa (Strongest Acidic)	16.47	ChemAxon
pKa (Strongest Basic)	-2.2	ChemAxon
Physiological Charge	0	ChemAxon
Hydrogen Acceptor Count	1	ChemAxon
Hydrogen Donor Count	1	ChemAxon
Polar Surface Area	20.23 Å²	ChemAxon
Rotatable Bond Count	0	ChemAxon
Refractivity	13.01 m³·mol⁻¹	ChemAxon
Polarizability	5.3 Å³	ChemAxon
Number of Rings	0	ChemAxon
Bioavailability	Yes	ChemAxon
Rule of Five	Yes	ChemAxon
Ghose Filter	Yes	ChemAxon
Veber's Rule	Yes	ChemAxon
MDDR-like Rule	Yes	ChemAxon

Spectra

Spectrum Type	Description	Splash Key
GC-MS	GC-MS Spectrum - EI-B (Non-derivatized)	splash10-001j-9000000000-a705823ce4aeba7f89e1	View in MoNA
GC-MS	GC-MS Spectrum - EI-B (Non-derivatized)	splash10-001j-9000000000-a705823ce4aeba7f89e1	View in MoNA
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	splash10-002b-9000000000-7fa80a491183c1cdd23e	View in MoNA
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (1 TMS) - 70eV, Positive	splash10-0fmi-9200000000-587cc3c48ab7fbf9cd3a	View in MoNA
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	Not Available	View in JSpectraViewer
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (Non-derivatized) - 70eV, Positive	Not Available	View in JSpectraViewer
Predicted GC-MS	Predicted GC-MS Spectrum - GC-MS (TBDMS_1_1) - 70eV, Positive	Not Available	View in JSpectraViewer
LC-MS/MS	LC-MS/MS Spectrum - EI-B (HITACHI RMU-7M) , Positive	splash10-001j-9000000000-a705823ce4aeba7f89e1	View in MoNA
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Positive	splash10-0002-9000000000-d75d9996bc68c673f090	View in MoNA
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Positive	splash10-0002-9000000000-893c2599624722912f25	View in MoNA
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Positive	splash10-004i-9000000000-8af4124822065023744f	View in MoNA
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Negative	splash10-0002-9000000000-22231ed69c5f28bfed79	View in MoNA
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Negative	splash10-0002-9000000000-d2881505c47bbef13f18	View in MoNA
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Negative	splash10-0002-9000000000-2ed988bb761ac20ba44a	View in MoNA
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Positive	splash10-0002-9000000000-5c5e98353b75870c1c55	View in MoNA
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Positive	splash10-0002-9000000000-326f4f38d260a85ea469	View in MoNA
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Positive	splash10-002b-9000000000-f850ab2a079485c4a276	View in MoNA
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 10V, Negative	splash10-0002-9000000000-b6602db69e5662ad67a9	View in MoNA
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 20V, Negative	splash10-0002-9000000000-b6602db69e5662ad67a9	View in MoNA
Predicted LC-MS/MS	Predicted LC-MS/MS Spectrum - 40V, Negative	splash10-0002-9000000000-4d0d1c69f8440a7fda18	View in MoNA
MS	Mass Spectrum (Electron Ionization)	splash10-003s-9000000000-dabf5a61c5a7da9fbe13	View in MoNA
1D NMR	¹H NMR Spectrum (1D, 600 MHz, H₂O, experimental)	Not Available	View in JSpectraViewer
1D NMR	¹³C NMR Spectrum (1D, 125 MHz, H₂O, experimental)	Not Available	View in JSpectraViewer
1D NMR	¹H NMR Spectrum (1D, 90 MHz, CDCl₃, experimental)	Not Available	View in JSpectraViewer
1D NMR	¹³C NMR Spectrum (1D, 25.16 MHz, CDCl₃, experimental)	Not Available	View in JSpectraViewer
1D NMR	¹H NMR Spectrum (1D, D₂O, experimental)	Not Available	View in JSpectraViewer
1D NMR	¹³C NMR Spectrum (1D, D₂O, experimental)	Not Available	View in JSpectraViewer
1D NMR	¹H NMR Spectrum (1D, 100 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹³C NMR Spectrum (1D, 100 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹H NMR Spectrum (1D, 1000 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹³C NMR Spectrum (1D, 1000 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹H NMR Spectrum (1D, 200 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹³C NMR Spectrum (1D, 200 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹H NMR Spectrum (1D, 300 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹³C NMR Spectrum (1D, 300 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹H NMR Spectrum (1D, 400 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹³C NMR Spectrum (1D, 400 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹H NMR Spectrum (1D, 500 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹³C NMR Spectrum (1D, 500 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹H NMR Spectrum (1D, 600 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹³C NMR Spectrum (1D, 600 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹H NMR Spectrum (1D, 700 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹³C NMR Spectrum (1D, 700 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹H NMR Spectrum (1D, 800 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹³C NMR Spectrum (1D, 800 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
1D NMR	¹H NMR Spectrum (1D, 900 MHz, D₂O, predicted)	Not Available	View in JSpectraViewer
2D NMR	[¹H, ¹H]-TOCSY. Unexported temporarily by An Chi on Oct 15, 2021 until json or nmrML file is generated. 2D NMR Spectrum (experimental)	Not Available	View in JSpectraViewer
2D NMR	[¹H, ¹³C]-HSQC NMR Spectrum (2D, 600 MHz, H₂O, experimental)	Not Available	View in JSpectraViewer

Biological Properties

Cellular Locations

Cytoplasm
Myelin sheath
Peroxisome

Biospecimen Locations

Adipose Tissue
Adrenal Cortex
Adrenal Gland
Adrenal Medulla
Bladder
Blood
Brain
Colostrum
Epidermis
Fibroblasts
Heart
Intestine
Kidney
Liver
Longissimus Thoracis Muscle
Lung
Milk
Muscle
Neuron
Ovary
Pancreas
Placenta
Platelet
Prostate Tissue
Ruminal Fluid
Semimembranosus Muscle
Testis

Pathways

Name	SMPDB/Pathwhiz	KEGG
Ethanol Degradation		Not Available

Normal Concentrations

Biospecimen	Status	Value	Age	Sex	Condition	Reference	Details
Adipose Tissue	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Adrenal Cortex	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Adrenal Gland	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Adrenal Medulla	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Bladder	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Blood	Detected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Jiyuan Li, Everes...	details
Blood	Detected and Quantified	8 +/- 1 uM	Not Specified	Not Specified	Normal	Aidin Foroutan, C...	details
Blood	Detected and Quantified	3-68 uM	Not Specified	Not Specified	Normal	PMID: 21524548	details
Blood	Detected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	PMID: 25372282	details
Brain	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Colostrum	Detected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	PMID: 25637742	details
Epidermis	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Fibroblasts	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Heart	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Intestine	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Kidney	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Liver	Detected and Quantified	2065 +/- 985 nmol/g of tissue	Not Specified	Not Specified	Normal	Aidin Foroutan, C...	details
Longissimus Thoracis Muscle	Detected and Quantified	299 +/- 182 nmol/g of tissue	Not Specified	Not Specified	Normal	Aidin Foroutan, C...	details
Lung	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Milk	Detected and Quantified	6.71 +/- 9.92 mg/100g dry matter content	Not Specified	Not Specified	Normal	Brigitta Gaspardo...	details
Milk	Detected and Quantified	5.94 +/- 5.8 mg/100g dry matter content	Not Specified	Not Specified	Normal	Brigitta Gaspardo...	details
Milk	Detected and Quantified	0.0418 +/- 0.0250 uM	Not Specified	Not Specified	Normal	PMID: 12463694	details
Milk	Detected and Quantified	0.406 +/- 0.449 uM	Not Specified	Not Specified	Normal	PMID: 12463694	details
Milk	Detected and Quantified	0.769 +/- 0.891 uM	Not Specified	Not Specified	Normal	PMID: 12463694	details
Milk	Detected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	PMID: 25087032	details
Muscle	Detected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	PMID: 25637742	details
Muscle	Detected and Quantified	160 nmol/g of tissue	Not Specified	Not Specified	Normal	PMID: 26437054	details
Muscle	Detected and Quantified	43-69 nmol/g of tissue	Not Specified	Not Specified	Normal	PMID: 28465593	details
Neuron	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Ovary	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Pancreas	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Placenta	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Platelet	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Prostate Tissue	Expected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	Not Applicable	details
Ruminal Fluid	Detected and Quantified	3-170 uM	Not Specified	Not Specified	Normal	PMID: 29642378	details
Ruminal Fluid	Detected and Quantified	176 uM	Not Specified	Not Specified	Normal	Burim NA, Qendrim...	details
Ruminal Fluid	Detected and Quantified	203 uM	Not Specified	Not Specified	Normal	Burim NA, Qendrim...	details
Ruminal Fluid	Detected and Quantified	341 uM	Not Specified	Not Specified	Normal	Burim NA, Qendrim...	details
Ruminal Fluid	Detected but not Quantified	Not Quantified	Not Specified	Not Specified	Normal	PMID: 24617926	details
Ruminal Fluid	Detected and Quantified	131 uM	Not Specified	Not Specified	Normal	Burim NA, Qendrim...	details
Ruminal Fluid	Detected and Quantified	600-3200 uM	Not Specified	Not Specified	Normal	PMID: 21524548	details
Ruminal Fluid	Detected and Quantified	556 +/- 450 uM	Not Specified	Not Specified	Normal	Aidin Foroutan, C...	details
Ruminal Fluid	Detected and Quantified	202.41 +/- 55.52 uM	Not Specified	Not Specified	Normal	Fozia Saleem, Sou...	details
Ruminal Fluid	Detected and Quantified	241.1 uM	Not Specified	Not Specified	Normal	PMID: 22959937	details
Ruminal Fluid	Detected and Quantified	355.2 uM	Not Specified	Not Specified	Normal	PMID: 22959937	details
Ruminal Fluid	Detected and Quantified	425.1 uM	Not Specified	Not Specified	Normal	PMID: 22959937	details
Ruminal Fluid	Detected and Quantified	202.4 uM	Not Specified	Not Specified	Normal	PMID: 22959937	details
Ruminal Fluid	Detected and Quantified	241 +/- 96 uM	Not Specified	Not Specified	Normal	Fozia Saleem, Sou...	details
Ruminal Fluid	Detected and Quantified	355 +/- 148 uM	Not Specified	Not Specified	Normal	Fozia Saleem, Sou...	details
Ruminal Fluid	Detected and Quantified	425 +/- 259 uM	Not Specified	Not Specified	Normal	Fozia Saleem, Sou...	details
Ruminal Fluid	Detected and Quantified	202 +/- 55 uM	Not Specified	Not Specified	Normal	Fozia Saleem, Sou...	details
Semimembranosus Muscle	Detected and Quantified	246 +/- 172 nmol/g of tissue	Not Specified	Not Specified	Normal	Aidin Foroutan, C...	details
Testis	Detected and Quantified	125 +/- 111 nmol/g of tissue	Not Specified	Not Specified	Normal	Aidin Foroutan, C...	details

Abnormal Concentrations

Biospecimen	Status	Value	Age	Sex	Condition	Reference	Details
Blood	Detected but not Quantified	Not Quantified	Not Specified	Not Specified	All Mycobacterium avium subsp. paratuberculosis-infected	PMID: 25372282	details
Blood	Detected but not Quantified	Not Quantified	Not Specified	Not Specified	High dose Mycobacterium avium subsp. paratuberculosis-infected	PMID: 25372282	details
Blood	Detected but not Quantified	Not Quantified	Not Specified	Not Specified	Low dose Mycobacterium avium subsp. paratuberculosis-infected	PMID: 25372282	details
Colostrum	Detected but not Quantified	Not Quantified	Not Specified	Not Specified	Commercial Product/bacterial growth on ground beef	PMID: 22417363	details
Muscle	Detected but not Quantified	Not Quantified	Not Specified	Not Specified	Commercial Product/bacterial growth on ground beef	PMID: 22417363	details
Ruminal Fluid	Detected and Quantified	425.13 +/- 251.3 uM	Not Specified	Not Specified	Rumen acidosis	Fozia Saleem, Sou...	details

External Links

HMDB ID

HMDB0000108

DrugBank ID

DB00898

Phenol Explorer Compound ID

Not Available

FooDB ID

KNApSAcK ID

Chemspider ID

KEGG Compound ID

BioCyc ID

BiGG ID

Wikipedia Link

METLIN ID

PubChem Compound

PDB ID

Not Available

ChEBI ID

16236

References

Synthesis Reference

Lashley, David. Process for producing an alcoholic sugar cane juice beverage. U.S. (1988), 3 pp. CODEN: USXXAM US 4784859 A 19881115 CAN 110:113222 AN 1989:113222

Material Safety Data Sheet (MSDS)

Not Available

General References

Toso B, Procida G, Stefanon B: Determination of volatile compounds in cows' milk using headspace GC-MS. J Dairy Res. 2002 Nov;69(4):569-77. [PubMed:12463694 ]
Sundekilde UK, Gustavsson F, Poulsen NA, Glantz M, Paulsson M, Larsen LB, Bertram HC: Association between the bovine milk metabolome and rennet-induced coagulation properties of milk. J Dairy Sci. 2014 Oct;97(10):6076-84. doi: 10.3168/jds.2014-8304. Epub 2014 Jul 30. [PubMed:25087032 ]
Brigitta Gaspardo, Giuseppe Procida, Saša Volarič, Sandy Sgorlon & Bruno Stefanon (2009). Brigitta Gaspardo et al. Determination of volatile fractions in raw milk and ripened cheese by means of GC-MS. Results of a survey performed in the marginal area between Italy and Slovenia. Italian Jounal of Animal Science Vol 8, 377-390, 2009. Italian Journal of Animal Science .

Enzymes

Enzyme Details

1. Catalase

General function:: Inorganic ion transport and metabolism
Specific function:: Occurs in almost all aerobically respiring organisms and serves to protect cells from the toxic effects of hydrogen peroxide. Promotes growth of cells.
Gene Name:: CAT
Uniprot ID:: P00432
Molecular weight:: 59915.0

Reactions

Ethanol + Hydrogen peroxide → Acetaldehyde +2 Water	details

Showing metabocard for Ethanol (BMDB0000108)

Structure for BMDB0000108 (Ethanol)

Enzymes

Reactions