heterocyklické sloučeniny monocyklické [Heterocyclic Compounds, 1-Ring]

tematický
34
Termíny

Heterocyclic Cpds, 1-Ring

Perzistentní odkaz   https://www.medvik.cz/link/D006573
Definice

Organické sloučeniny, které obsahují kruhovou strukturu tvořenou uhlíkem a jedním nebo více dalšími prvky, jako je dusík a kyslík.

Organic compounds that contain a ring structure made up of carbon and one or more additional elements such as nitrogen and oxygen.

Anotace
general or unspecified; prefer specifics; used for mapping supplementary chemicals
obecné, dej přednost přesnějšímu deskriptoru; používá se pro mapování přídavných chemikálií
DUI
D006573 MeSH Prohlížeč
CUI
M0010292
Historická pozn.
98; use explode 1967-97
Veřejná pozn.
98

(1,4,7)triazecan-9-ol Chemical MeSH Prohlížeč

(1-(2-(5-(N,N-dimethylamino)naphthalenesulfonamido)ethyl)-1,4,7,10-tetraazacyclododecane)zinc(II) Chemical MeSH Prohlížeč

(2,2-diphenyl-(1,3)oxathiolan-5-ylmethyl)-(3-phenyl-propyl)amine Chemical MeSH Prohlížeč

(4,7-bis-carboxymethyl-10-(1-(2-(5-(2-oxohexahydrothieno(3,4-d)imidazol-6-yl)-pentanoylamino)ethyl)-1H-(1,2,3)triazol-4-ylmethyl)-1,4,7,10-tetraazacyclododec-1-yl)acetic acid Chemical MeSH Prohlížeč

(4-(((bis(phosphonopropyl))carbamoyl)methyl)-7,10-bis(carboxymethyl)-1,4,7,10-tetraazacyclododec-1-yl)acetic acid Chemical MeSH Prohlížeč

(4-((3,5-(2-(bis-carboxymethylamino)ethylcarbamoyl)phenylcarbamoyl)methyl)-7,10-bis-carboxymethyl-1,4,7,10-tetraazacyclododec-1-yl)acetic acid Chemical MeSH Prohlížeč

(4-(2-(bis(carboxymethyl)amino)-3-(4-nitrophenyl)propyl)-7-carboxymethyl(1,4,7)triazanonan-1-yl)acetic acid Chemical MeSH Prohlížeč

(4-(2-(biscarboxymethylamino)-3-(4-nitrophenyl)propyl)-7-carboxymethyl(1,4,7)triazonan-1-yl)acetic acid Chemical MeSH Prohlížeč

(4-carboxymethyl-7-(2-(carboxymethylamino)-3-(4-nitrophenyl)propyl)(1,4,7)triazonan-1-yl)acetic acid Chemical MeSH Prohlížeč

(4S,5S)-4,5-dihydroxy-1,2-dithiane Chemical MeSH Prohlížeč

(N,N'-di-2-picolyl-4,7-diaza-1-oxacyclononane)iron(II) Chemical MeSH Prohlížeč

1,1'-xylyl bis-1,4,8,11-tetraaza cyclotetradecane Chemical MeSH Prohlížeč

1,2,4,5-tetrathiane Chemical MeSH Prohlížeč

1,2,4-trithiolane Chemical MeSH Prohlížeč

1,2-dioxetane Chemical MeSH Prohlížeč

1,3,5-tris((1,5,9-triazacyclododecan-3-yl)oxymethyl)benzene Chemical MeSH Prohlížeč

1,3,5-trithiane Chemical MeSH Prohlížeč

1,3-bis((1,5,9-triazacyclododecan-3-yl)oxymethyl)benzene Chemical MeSH Prohlížeč

1,3-bis(1,4,7,10-tetraazacyclododecan-1-ylmethyl)benzene Chemical MeSH Prohlížeč

1,3-bis(1,4,7-triazacyclonon-1-yl)-2-hydroxypropane Chemical MeSH Prohlížeč

1,3-dithia-2-thioxocyclopent-4-ene Chemical MeSH Prohlížeč

1,3-dithiafulvene Chemical MeSH Prohlížeč

1,3-dithiolane-2-carboxaldehyde Chemical MeSH Prohlížeč

1,4,7,10,13,16-hexathiacyclooctadecane Chemical MeSH Prohlížeč

1,4,7,10-tetra(carboxyethyl)-1,4,7,10-tetraazacyclododecane Chemical MeSH Prohlížeč

1,4,7,10-tetraaza-1,4,10-tri(carboxymethyl)-7-(((4-phosphonomethylphenyl)aminocarbonyl)phenyl)dodecane Chemical MeSH Prohlížeč

1,4,7,10-tetraaza-4,7,10-tris(carboxymethyl)-1-cyclododecylacetyl-alpha-methylbenzylamine Chemical MeSH Prohlížeč

1,4,7,10-tetraaza-4,7,10-tris(carboxymethyl)-1-cyclododecylacetylbenzylamine Chemical MeSH Prohlížeč

1,4,7,10-tetraaza-7-(4-bromophenyl)-1,4,10-tri(carboxymethyl)dodecane Chemical MeSH Prohlížeč

1,4,7,10-tetraazacyclododecane- 1,4,7,10-tetraacetic acid Chemical MeSH Prohlížeč

1,4,7,10-tetraazacyclododecane-1,4,7,10-tetracetic acid Chemical MeSH Prohlížeč

1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid Chemical MeSH Prohlížeč

1,4,7,10-tetraazacyclododecane-1,7-diacetic acid Chemical MeSH Prohlížeč

1,4,7,10-tetraazacyclododecane-1-(4-((3-chloro-4-fluorophenyl)amino)quinazolin-6-yl)propionamide-4,7,10-triacetic acid Chemical MeSH Prohlížeč

1,4,7,10-tetraazacyclododecane-1-succinic acid-4,7,10-triacetic acid Chemical MeSH Prohlížeč

1,4,7,10-tetrakis(carbamoylmethyl)-1,4,7,10-tetraazacyclododecane Chemical MeSH Prohlížeč

1,4,7-triazacyclononane-1,4-diacetic acid-7-p-hydroxyphenylacetic acid Chemical MeSH Prohlížeč

1,4,7-triazacyclononane-1,4-diacetic acid-7-p-isothiocyanatophenylacetic acid Chemical MeSH Prohlížeč

1,4,7-triazacyclononane-1-acetic acid-4,7-di-p-isothiocyanatophenylacetic acid Chemical MeSH Prohlížeč

1,4,7-triazacyclononane-N,N',N''-triacetic acid Chemical MeSH Prohlížeč

1,4,7-triphenyl-1,4,7-triphosphacyclononane Chemical MeSH Prohlížeč

1,4,7-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecane Chemical MeSH Prohlížeč

1,4,7-tris(carboxymethyl)-10-(vinylsulfone)-1,4,7,10-tetraazacyclododecane Chemical MeSH Prohlížeč

1,4,7-tris(tert-butylacetate)-1,4,7,10-tetraazacyclododecane ester Chemical MeSH Prohlížeč

1,4,8,11-tetraazacyclotetradecyl-1,4,8,11-tetramethylenephosphonic acid Chemical MeSH Prohlížeč

1,4,8,11-tetrakis(carbamoylmethyl)-1,4,8,11-tetraazacyclotetradecane Chemical MeSH Prohlížeč

1,4-thioxane Chemical MeSH Prohlížeč

1,5,10,14-tetra(1-hydroxy-2-pyridon-6-oyl)-1,5,10,14-tetraazatetradecane Chemical MeSH Prohlížeč

1,5-diazacyclohenicosane Chemical MeSH Prohlížeč

1,5-diisopropyl-6-oxo-verdazyl Chemical MeSH Prohlížeč

1,6-anhydro-3,4,5-tri-O-benzyl-2-deoxyxylosept-1-enitol Chemical MeSH Prohlížeč

1,7-bis(N,N-bis(2-pyridylmethyl)aminoethylcarbamoylmethyl)4,10-bis(butylcarbamoylmethyl)1,4,7,10-tetraazacyclododecane Chemical MeSH Prohlížeč

1,7-dioxa-4,10-diazacyclododecane Chemical MeSH Prohlížeč

1,8-(2,6-pyridinedimethylene)-1,4,8,11-tetraazacyclotetradecane-2,4-diacetic acid Chemical MeSH Prohlížeč

1,8-N,N'-bis-(carboxymethyl)-4-N''-(4'-isothiocyanatophenethyl)-1,4,8,11-tetraazacyclotetradecane Chemical MeSH Prohlížeč

1-(1,3-carboxypropyl)-4,7-carboxymethyl-1,4,7-triazacyclononane Chemical MeSH Prohlížeč

1-(2-(beta,D-galactopyranosyloxy)ethyl)-7-(1-carboxy-3-(4-aminophenyl)propyl)-4,10-bis(carboxymethyl)-1,4,7,10-tetraazacyclododecane Chemical MeSH Prohlížeč

1-(2-fluorenyl)ethenylspiro(1,2,4-trioxane-3,2'-adamantane) Chemical MeSH Prohlížeč

1-(azocan-1-yl)dec-3-en-1one Chemical MeSH Prohlížeč

1-(dansylamidopropyl)-1-aza-4,7,10-trithiacyclododecane Chemical MeSH Prohlížeč

1-(ferrocenemethyl)-1,4,7,10-tetraazacyclododecane Chemical MeSH Prohlížeč

1-carboxymethyl-4,7-dimethyl-1,4,7-triazacyclononane Chemical MeSH Prohlížeč

1-ethyl-3-(4-(4-((thiiran-2-ylmethyl)sulfonyl)phenoxy)phenyl)urea Chemical MeSH Prohlížeč

1-oxa-4,7,10-triazacyclododecane-N,N'',N'''-triacetic acid Chemical MeSH Prohlížeč

10-(2-aminoethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-tris(methylenephosphonic acid) Chemical MeSH Prohlížeč

10-(2-hydroxypropyl)-1,4,7-tetraazacyclododecane-1,4,7-triacetic acid Chemical MeSH Prohlížeč

10-(2-sulfanylethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid Chemical MeSH Prohlížeč

13-epilaurencienyne Chemical MeSH Prohlížeč

177Lu-DOTA-lanreotide Chemical MeSH Prohlížeč

2,11-diaza--4-(2-(trifluoromethyl)phenyl)-5-(hydroxyaminocarbonyl)-1-((((piperazin-1-yl)carbonyl)methyl)aminocarbonyl)-9-oxa-3,10-dioxocyclopentadecane Chemical MeSH Prohlížeč

2,11-diaza-4-(2-(trifluoromethyl)phenyl)-5-(hydroxyaminocarbonyl)-1-((((morpholin-4-yl)carbonyl)methyl)aminocarbonyl)-9-oxa-3,10-dioxocyclopentadecane Chemical MeSH Prohlížeč

2,2',2''-(10-(2-(2-mercaptoethylamino)-2-oxoethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl)triacetic acid Chemical MeSH Prohlížeč

2,2',2''-(10-(2-(9,10-dioxo-9,10-dihydroanthracen-1-ylamino)-2-oxoethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl)triacetic acid Chemical MeSH Prohlížeč

2,2-diphenyl-(1,3)dioxan-5-ylmethyl)-(2-(2-methoxyphenoxy)ethyl)amine Chemical MeSH Prohlížeč

2,3,8,9-tetraphenyl-1,4,7,10-tetraazacyclododeca-1,3,7,9-tetraene Chemical MeSH Prohlížeč

2,4,6,8-tetranitro-1,3,5,7-tetraaza cyclooctatetraene Chemical MeSH Prohlížeč

2,5-dideoxy-2,5-imino-altritol 1,6- bisphosphate Chemical MeSH Prohlížeč

2,5-dihydroxy-1,4-dithiane-2,5-dicarboxylic acid Chemical MeSH Prohlížeč

2-amino-3-(1-(1,4,7-triazacyclononyl))propanoic acid Chemical MeSH Prohlížeč

2-anilino-4-thioxo-4-chloromethyl-1,3,4-thiazaphosphol-2-ine Chemical MeSH Prohlížeč

2-chloro-1,3-dithiane Chemical MeSH Prohlížeč

2-tert-butylamino-4-thioxo-4-chloromethyl-1,3,4-thiazaphosphol-2-ine Chemical MeSH Prohlížeč

3,4-dihydroxy-1-selenolane Chemical MeSH Prohlížeč

3,4-dihydroxy-1-selenolane oxide Chemical MeSH Prohlížeč

3,6-bis(3,4-dimethoxybenzoyl)-1,2,4,5-tetrazine Chemical MeSH Prohlížeč

3,6-dimethyl-1,2,4,5-tetrazine Chemical MeSH Prohlížeč

3-(4-benzylamino)-1,2,4,5-tetrazine Chemical MeSH Prohlížeč

3-(4-bromoacetamidobenzyl)-2-(1,4,7,10-tetraazacyclodecane-1,4,7-triacetic acid-(10-acetamido))propanamide Chemical MeSH Prohlížeč

4,5-epithiopentyl methacrylate Chemical MeSH Prohlížeč

4-(4,6-diphenyl-1,3-dioxan-2-yl)-N,N-dimethylaniline Chemical MeSH Prohlížeč

4-(4-((thiiran-2-ylmethyl)sulfonyl)phenoxy)phenyl ethylcarbamate Chemical MeSH Prohlížeč

4-(4-ethylamino-(4-(N-ethylamino)-4'-(dimethylamino)stilbene))-1,4,7,10-tetraazacyclotridecane-11,13-dione Chemical MeSH Prohlížeč

4-(4-fluorophenyl)-1,3-dithia-2-thioxocyclopent-4-ene Chemical MeSH Prohlížeč

4-phenyl-1,3-dithia-2-thioxocyclopent-4-ene Chemical MeSH Prohlížeč

5-(3-hydroxy-4-methoxyphenyl)-4-(3,4,5-trimethoxyphenyl)-3H-1,2-dithiol-3-one Chemical MeSH Prohlížeč

5-(4-(3-phenyl-2-propenoyloxy)phenyl)-3H-(1,2)dithiole-3-thione Chemical MeSH Prohlížeč

5-(4-methoxyphenyl)-3H-1,2-dithiole-3-thione Chemical MeSH Prohlížeč

5-tert-butyl-3H-1,2-dithiole-3-thione Chemical MeSH Prohlížeč

6,19-bis(2-hydroxypropyl)-3,6,9,16,19,22-hexaazatricyclo(22.2.2.2(11,14))triaconta-11,13,24,26,27,29-hexaene Chemical MeSH Prohlížeč

6,7-dihydroxy-9-propylnon-4-eno-9-lactone Chemical MeSH Prohlížeč

6,7-dimethoxyazacyclooct-4-yne Chemical MeSH Prohlížeč

6-(4-nitrobenzyl)-1-oxa-4,7,10-triazacyclododecane-N,N'',N'''-triacetic acid Chemical MeSH Prohlížeč

64Cu-1,4,7-triazacyclononane-1,4,7-triacetic acid-8-aminooctanoic acid-bombesin(7-14)amide Chemical MeSH Prohlížeč

68Ga-DOTA-Arg-Gly-Asp Chemical MeSH Prohlížeč

68Ga-NODAGA-glycine Chemical MeSH Prohlížeč

7,13-bis(4-nitrobenzyl)-1,4,10-trioxa-7,13-diazacyclopentadecane Chemical MeSH Prohlížeč

7,8-16,17-dibenzo-6,9,15,18-tetraoxo-1,5,10,14-tetrathiacyclooctadeca-7,16-diene Chemical MeSH Prohlížeč

7-(2-(bis-carboxymethyl-amino)ethyl)-4,10-bis-carboxymethyl-1,4,7,10-tetraazacyclododec-1-yl-acetic acid Chemical MeSH Prohlížeč

7-phenyl-1,4-diazepin-5-one Chemical MeSH Prohlížeč

8,17-dimethyl-1,7,10,16-tetraaza-4,13-dithiacyclooctadeca-2,6,11,15-tetraone Chemical MeSH Prohlížeč

8,8'-(1,4,10,13-tetraoxa-7,16-diazacyclooctadecane-7,16-diyl)-bis(methylene)diquinolin-7-ol Chemical MeSH Prohlížeč

8-benzenesulfonyloxy-5-N,N-dimethylaminosulfonylquinolin-2-ylmethyl-pendant 1,4,7,10-tetraazacyclododecane Chemical MeSH Prohlížeč

9,10-epithiodecyl methacrylate Chemical MeSH Prohlížeč

9-(1',4',7',10',13'-pentaazacyclopentadecyl)methylanthracene Chemical MeSH Prohlížeč

9-chloro-13-bromo-6,12-epoxy-7,10-diacetoxypentadec-3-en-1-yne Chemical MeSH Prohlížeč

97-63 compound Chemical MeSH Prohlížeč

97-78 compound Chemical MeSH Prohlížeč

99-408 compound Chemical MeSH Prohlížeč

ATB 337 Chemical MeSH Prohlížeč

BEMP phosphazene Chemical MeSH Prohlížeč

BODIPY-TZ Chemical MeSH Prohlížeč

CK147 compound Chemical MeSH Prohlížeč

DOTA tris(phenylmethyl)ester Chemical MeSH Prohlížeč

DOTA-PEG(4)-bombesin (7-14) Chemical MeSH Prohlížeč

DOTA-Tyr(1)-octreotate Chemical MeSH Prohlížeč

DOTA-tyrosyl-lysyl(histaminyl-succinyl-glycyl)-glutamyl-lysyl(histaminyl-succinyl-glycyl)amide Chemical MeSH Prohlížeč

DOTA4 compound Chemical MeSH Prohlížeč

DOTAGA-anhydride Chemical MeSH Prohlížeč

DOTALAN Chemical MeSH Prohlížeč

FROPDOTA compound Chemical MeSH Prohlížeč

Gd-DOTA-4amP Chemical MeSH Prohlížeč

GdDOTA-diBPEN diamide Chemical MeSH Prohlížeč

HTE1PA compound Chemical MeSH Prohlížeč

In-DOTA-NSC-ST Chemical MeSH Prohlížeč

KKD023 Chemical MeSH Prohlížeč

LY2183240 Chemical MeSH Prohlížeč

MOTU-N44 compound Chemical MeSH Prohlížeč

Met-ac-TE3A Chemical MeSH Prohlížeč

N,N',N''-tris(dihydroxyphosphorylmethyl)-1,4,7-triazacyclononane Chemical MeSH Prohlížeč

N,N',N',N-tetrakis((N-(arginyl-arginyl-prolyl-tyrosyl-isoleucyl-leucine)aminocarbonyl)ethyl)-1,4,8,11-tetraazacyclotetradecane Chemical MeSH Prohlížeč

N,N'-dibenzyl-1,4,10,13-tetraoxa-7,16-diazacyclooctadecane Chemical MeSH Prohlížeč

N,N-di-(m-methylphenyl)-3,6-dimethyl-1,4-dihydro-1,2,4,5-tetrazine-1,4-dicarboxamide Chemical MeSH Prohlížeč

N,N-dimethyl-1,2,3-trithian-5-yl amine Chemical MeSH Prohlížeč

N-(5,7-dimethyl-1,8-naphthyridin-2-yl)-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid-10-acetamide Chemical MeSH Prohlížeč

N-(triethylammonium)-3-propyl(15)ane-N5 Chemical MeSH Prohlížeč

N-formyl-1-((3-hexyl-4-methylene-2-oxetanyl)methyl)dodecyl 2-amino-4-methylpentanoate Chemical MeSH Prohlížeč

N-triethylammonium-propyl-cyclam Chemical MeSH Prohlížeč

OZ418 compound Chemical MeSH Prohlížeč

PC-g(6)-Cs-g(2)-Cyclen Chemical MeSH Prohlížeč

PSMA-617 Chemical MeSH Prohlížeč

RP 697 Chemical MeSH Prohlížeč

RP 748 Chemical MeSH Prohlížeč

RP688 Chemical MeSH Prohlížeč

RPX7009 Chemical MeSH Prohlížeč

SB 3CT compound Chemical MeSH Prohlížeč

TA 138 Chemical MeSH Prohlížeč

TA 145 Chemical MeSH Prohlížeč

Tat-DOTA Chemical MeSH Prohlížeč

XP 620 Chemical MeSH Prohlížeč

andavadoic acid Chemical MeSH Prohlížeč

arterolane Chemical MeSH Prohlížeč

bombesin (7-14)amide, DO3A-amide- Chemical MeSH Prohlížeč

bombesin (7-14)amide, DO3A-amide-beta-alanyl- Chemical MeSH Prohlížeč

cis-2-methyl-4-propyl-1,3-oxathiane Chemical MeSH Prohlížeč

cis-DO2A2P Chemical MeSH Prohlížeč

cyclic phosphatidic acid 16:0 Chemical MeSH Prohlížeč

diazinane-2-thione Chemical MeSH Prohlížeč

dihydromotuporamine C Chemical MeSH Prohlížeč

dioxetanone Chemical MeSH Prohlížeč

gadolinium 1,4,7,10-tetra-(2-glutaryl)-1,4,7,10-tetraazacyclododecane Chemical MeSH Prohlížeč

gadolinium 1,4,7-tris(carboxymethyl)-10-(2-hydroxyhexadecyl)-1,4,7,10-tetraazacyclododecane Chemical MeSH Prohlížeč

gadolinium 2,2',2'-(10-(2-(1-carboxy-3-(methylthio)propylamino)-2-oxoethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl)triacetic acid Chemical MeSH Prohlížeč

gallium 2,2',2'-(10-(2-(1-carboxy-3-(methylthio)propylamino)-2-oxoethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl)triacetic acid Chemical MeSH Prohlížeč

gallium 68-DOTA-lanreotide Chemical MeSH Prohlížeč

gallium(67)-2,2'-(4,10-bis(2-((2-(2-methyl-5-nitro-1H-imidazol-1-yl)ethyl)amino)-2-oxoethyl)-1,4,7,10-tetraazacyclododecane-1,7-diyl)diacetic acid Chemical MeSH Prohlížeč

heptatriacontakis(O-(aminopropyl)inulin-(10-(2-ethoxy-3,4-dioxo-1-cyclobutenyl)-1,4,7,10-tetraazacyclododecan-1,4,7-triacetic acid))heptatriacontagadolinium Chemical MeSH Prohlížeč

hexafluorocyclophosphazene Chemical MeSH Prohlížeč

hexahydro-5,6-dihydroxy-1,3,4,7-tetrakis(phenylmethyl)-2H-1,3-diazapin-2-one Chemical MeSH Prohlížeč

indium-111-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid Chemical MeSH Prohlížeč

isohaliclorensin Chemical MeSH Prohlížeč

lachabnormic acid Chemical MeSH Prohlížeč

laurenyne Chemical MeSH Prohlížeč

mercury green 1 Chemical MeSH Prohlížeč

meropenem and vaborbactam Chemical MeSH Prohlížeč

methylaminotriazacyclononane trimethylphosphinate Chemical MeSH Prohlížeč

microcarpalide Chemical MeSH Prohlížeč

octreotide, DOTA-Phe(1)- Chemical MeSH Prohlížeč

oxathiane Chemical MeSH Prohlížeč

oxazaborolidinone Chemical MeSH Prohlížeč

penaresidin Chemical MeSH Prohlížeč

stagonolide Chemical MeSH Prohlížeč

stagonolide E Chemical MeSH Prohlížeč

substance P, 1,4,7,10-tetraazacyclododecane-1-glutaric acid-4,7,10-triacetic acid-arginyl(1)- Chemical MeSH Prohlížeč

technetium Tc 99m cyclam Chemical MeSH Prohlížeč

tetrathiafulvalene-2-carboxylic acid Chemical MeSH Prohlížeč

tetrazine dye 10 Chemical MeSH Prohlížeč

thiopalmyrone Chemical MeSH Prohlížeč

trans-DO2A2P Chemical MeSH Prohlížeč

triacetone triperoxide Chemical MeSH Prohlížeč

trigoxazonane Chemical MeSH Prohlížeč

tris(2-methoxyphenyl)phosphadioxirane Chemical MeSH Prohlížeč

verdazyl radical Chemical MeSH Prohlížeč

zinc(II) ((9-acridinyl)methyl)cyclen Chemical MeSH Prohlížeč