The PROTAC molecule consists of a ligand, which binds an E3 ubiquitin ligase, connected by a linker to another ligand that binds the target protein. The association between a protein and an E3 ligase, as induced by a PROTAC molecule, will lead to the transfer of ubiquitin and degradation of the targeted protein.


Anti-infection >
Arenavirus Bacterial CMV Enterovirus Filovirus Fungal HBV HCV HIV HSV Influenza Virus Parasite Reverse Transcriptase RSV SARS-CoV
Antibody-drug Conjugate >
ADC Cytotoxin ADC Linker Drug-Linker Conjugates for ADC PROTAC-linker Conjugate for PAC
Apoptosis >
Apoptosis Bcl-2 Family c-Myc Caspase DAPK Ferroptosis IAP MDM-2/p53 PKD RIP kinase Survivin Thymidylate Synthase TNF Receptor
Autophagy >
Autophagy LRRK2 ULK Mitophagy
Cell Cycle/DNA Damage >
Antifolate APC ATM/ATR Aurora Kinase Casein Kinase CDK Checkpoint Kinase (Chk) CRISPR/Cas9 Deubiquitinase DNA Alkylator/Crosslinker DNA-PK DNA/RNA Synthesis Eukaryotic Initiation Factor (eIF) G-quadruplex Haspin Kinase HDAC HSP IRE1 Kinesin LIM Kinase (LIMK) Microtubule/Tubulin Mps1 Nucleoside Antimetabolite/Analog p97 PAK PARP PERK Polo-like Kinase (PLK) PPAR RAD51 ROCK Sirtuin SRPK Telomerase TOPK Topoisomerase Wee1
Cytoskeleton >
Arp2/3 Complex Dynamin Gap Junction Protein Integrin Kinesin Microtubule/Tubulin Mps1 Myosin PAK
Epigenetics >
AMPK Aurora Kinase DNA Methyltransferase Epigenetic Reader Domain HDAC Histone Acetyltransferase Histone Demethylase Histone Methyltransferase JAK MicroRNA PARP PKC Sirtuin Protein Arginine Deiminase
GPCR/G Protein >
5-HT Receptor Adenosine Receptor Adenylate Cyclase Adiponectin Receptor Adrenergic Receptor Angiotensin Receptor Bombesin Receptor Bradykinin Receptor Cannabinoid Receptor CaSR CCR CGRP Receptor Cholecystokinin Receptor CRFR CXCR Dopamine Receptor EBI2/GPR183 Endothelin Receptor GHSR Glucagon Receptor Glucocorticoid Receptor GNRH Receptor GPCR19 GPR109A GPR119 GPR120 GPR139 GPR40 GPR55 GPR84 Guanylate Cyclase Histamine Receptor Imidazoline Receptor Leukotriene Receptor LPL Receptor mAChR MCHR1 (GPR24) Melatonin Receptor mGluR Motilin Receptor Neurokinin Receptor Neuropeptide Y Receptor Neurotensin Receptor Opioid Receptor Orexin Receptor (OX Receptor) Oxytocin Receptor P2Y Receptor Prostaglandin Receptor Protease-Activated Receptor (PAR) Ras RGS Protein Sigma Receptor Somatostatin Receptor TSH Receptor Urotensin Receptor Vasopressin Receptor Melanocortin Receptor
Immunology/Inflammation >
Aryl Hydrocarbon Receptor CCR Complement System COX CXCR FLAP Histamine Receptor IFNAR Interleukin Related IRAK MyD88 NO Synthase NOD-like Receptor (NLR) PD-1/PD-L1 PGE synthase Salt-inducible Kinase (SIK) SPHK STING Thrombopoietin Receptor Toll-like Receptor (TLR) Arginase
JAK/STAT Signaling >
EGFR JAK Pim STAT
MAPK/ERK Pathway >
ERK JNK KLF MAP3K MAP4K MAPKAPK2 (MK2) MEK Mixed Lineage Kinase MNK p38 MAPK Raf Ribosomal S6 Kinase (RSK)
Membrane Transporter/Ion Channel >
ATP Synthase BCRP Calcium Channel CFTR Chloride Channel CRAC Channel CRM1 EAAT2 GABA Receptor GlyT HCN Channel iGluR Monoamine Transporter Monocarboxylate Transporter Na+/Ca2+ Exchanger Na+/HCO3- Cotransporter Na+/K+ ATPase nAChR NKCC P-glycoprotein P2X Receptor Potassium Channel Proton Pump SGLT Sodium Channel TRP Channel URAT1
Metabolic Enzyme/Protease >
15-PGDH 5 alpha Reductase 5-Lipoxygenase Acetyl-CoA Carboxylase Acyltransferase Adenosine Deaminase Adenosine Kinase Aldehyde Dehydrogenase (ALDH) Aldose Reductase Aminopeptidase Angiotensin-converting Enzyme (ACE) ATGL ATP Citrate Lyase Carbonic Anhydrase Carboxypeptidase Cathepsin CETP COMT Cytochrome P450 Dipeptidyl Peptidase Dopamine β-hydroxylase E1/E2/E3 Enzyme Elastase Enolase FAAH FABP Factor Xa Farnesyl Transferase Fatty Acid Synthase (FAS) FXR Glucokinase GSNOR Gutathione S-transferase HCV Protease Hexokinase HIF/HIF Prolyl-Hydroxylase HIV Integrase HIV Protease HMG-CoA Reductase (HMGCR) HSP Indoleamine 2,3-Dioxygenase (IDO) Isocitrate Dehydrogenase (IDH) Lactate Dehydrogenase LXR MAGL Mineralocorticoid Receptor Mitochondrial Metabolism MMP Nampt NEDD8-activating Enzyme Neprilysin PAI-1 PDHK PGC-1α Phosphatase Phosphodiesterase (PDE) Phospholipase Procollagen C Proteinase Proteasome Pyruvate Kinase RAR/RXR Renin ROR Ser/Thr Protease SGK Stearoyl-CoA Desaturase (SCD) Thrombin Tryptophan Hydroxylase Tyrosinase Xanthine Oxidase
Neuronal Signaling >
5-HT Receptor AChE Adenosine Kinase Amyloid-β Beta-secretase CaMK CGRP Receptor COMT Dopamine Receptor Dopamine Transporter FAAH GABA Receptor GlyT iGluR Imidazoline Receptor mAChR Melatonin Receptor Monoamine Oxidase nAChR Neurokinin Receptor Opioid Receptor Serotonin Transporter γ-secretase
NF-κB >
NF-κB IKK Keap1-Nrf2 MALT1
PI3K/Akt/mTOR >
Akt AMPK ATM/ATR DNA-PK GSK-3 MELK mTOR PDK-1 PI3K PI4K PIKfyve PTEN
PROTAC >
PROTAC E3 Ligase Ligand-Linker Conjugate Ligand for E3 Ligase PROTAC Linker PROTAC-linker Conjugate for PAC
Protein Tyrosine Kinase/RTK >
Ack1 ALK Bcr-Abl BMX Kinase Btk c-Fms c-Kit c-Met/HGFR Discoidin Domain Receptor DYRK EGFR Ephrin Receptor FAK FGFR FLT3 IGF-1R Insulin Receptor IRAK Itk PDGFR PKA Pyk2 ROS Src Syk TAM Receptor Trk Receptor VEGFR
Stem Cell/Wnt >
Casein Kinase ERK Gli GSK-3 Hedgehog Hippo (MST) JAK Notch Oct3/4 PKA Porcupine ROCK sFRP-1 Smo STAT TGF-beta/Smad Wnt YAP β-catenin γ-secretase
TGF-beta/Smad >
TGF-beta/Smad PKC ROCK TGF-β Receptor
Vitamin D Related >
VD/VDR
Others >
Androgen Receptor Aromatase Estrogen Receptor/ERR Progesterone Receptor Thyroid Hormone Receptor Others

Thalidomide-5-O-C6-NH2 hydrochloride

Thalidomide-5-O-C6-NH2 hydrochloride is the Thalidomide (HY-10984)-based cereblon ligand used in the recruitment of CRBN protein.Thalidomide-5-O-C6-NH2 hydrochloride can be connected to the ligand for protein by a linker to form PROTACs[1].

  • CAS Number: 2761398-05-2
  • MF: C19H24ClN3O5
  • MW: 409.86
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Thalidomide, propargyl

Thalidomide-propargyl is the Thalidomide-based Cereblon ligand used in the recruitment of CRBN protein. Thalidomide-propargyl can be connected to the ligand for protein by a linker to form the IMiD containing PROTACs[1].

  • CAS Number: 2098487-39-7
  • MF: C16H12N2O5
  • MW: 312.27688
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Thalidomide-5-PEG2-NH2 hydrochloride

Thalidomide-5-PEG2-NH2 hydrochloride is the Thalidomide (HY-10984)-based cereblon ligand used in the recruitment of CRBN protein.Thalidomide-5-PEG2-NH2 hydrochloride can be connected to the ligand for protein by a linker to form PROTACs[1].

  • CAS Number: 2761406-70-4
  • MF: C17H20ClN3O6
  • MW: 397.81
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

E3 ubiquitin ligase binder-1

E3 ubiquitin ligase binder-1 (compound 11) is a potent E3 ubiquitin ligase binder. E3 ubiquitin ligase binder-1 is a ligand for E3 Ligase[1].

  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

CC-17369

CC-17369 (7-Hydroxy pomalidomide) is a metabolite of Pomalidomide. CC-17369 is the Pomalidomide -based cereblon (CRBN) ligand used in the recruitment of CRBN protein. CC-17369 can be connected to the ligand for protein by a linker to form PROTAC[1].

  • CAS Number: 1547162-46-8
  • MF: C13H11N3O5
  • MW: 289.24
  • Catalog: Ligand for E3 Ligase
  • Density: 1.7±0.1 g/cm3
  • Boiling Point: 649.7±55.0 °C at 760 mmHg
  • Melting Point: N/A
  • Flash Point: 346.7±31.5 °C

Cc-3060

CC-3060 is a Cereblon modulator that promotes ZBTB16 degradation. CC-3060 degrades ZBTB16 with a DC50 of 0.47 nM in HT-1080 cells. CC-3060 targets ZBTB16 for degradation by primarily engaging distinct structural degrons on different zinc finger domains[1].

  • CAS Number: 444288-86-2
  • MF: C22H17N3O5
  • MW: 403.39
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

VH032-C4-NH-Boc

VH032-C4-NH-Boc is a Boc-modified VH032 (HY-120217) that acts as a ligand for VHL to recruit von Hippel-Lindau (VHL) proteins. VH032-C4-NH-Boc will remove the protecting group under acidic conditions and be directly used in PROTAC molecule synthesis. VH032-C4-NH-Boc is a key intermediate in the synthesis of PROTAC based on VHL ligand.

  • CAS Number: 2412055-00-4
  • MF: C33H49N5O6S
  • MW: 643.84
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

DA-PROTAC

DA-PROTAC is a potent PROTAC degrader of copper ion-transport proteins Atox1 and CCS. DA-PROTAC can bind both Atox1 and CCS proteins, and the complex can be bound to E3 ligase, leading to increased levels of ubiquitination of Atox1 and CCS and degradation of Atox1 and CCS proteins via the proteasome pathway. DA-PROTAC can be used for triple negative breast cancer research[1].

  • CAS Number: 2488660-12-2
  • MF: C46H50BrF2N7O8S2
  • MW: 1010.96
  • Catalog: PROTAC
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Thalidomide-5,6-F

Thalidomide-5,6-F is the Thalidomide-based cereblon ligand used in the recruitment of CRBN protein. Thalidomide-5,6-F can be connected to the ligand for protein by a linker to form PROTACs[1].

  • CAS Number: 1496997-41-1
  • MF: C13H8F2N2O4
  • MW: 294.21
  • Catalog: Ligand for E3 Ligase
  • Density: 1.6±0.1 g/cm3
  • Boiling Point: 534.6±50.0 °C at 760 mmHg
  • Melting Point: N/A
  • Flash Point: 277.1±30.1 °C

Thalidomide-4-NH-PEG1-COO(t-Bu)

Thalidomide-4-NH-PEG1-COO(t-Bu) is a t-Bu modified Thalidomide (HY-14658), which acts as a Cereblon ligand to recruit CRBN protein. The t-Bu protecting group at the end of Thalidomide-4-NH-PEG1-COO(t-Bu) can be removed under acidic conditions to participate in the synthesis of PROTAC molecules. Thalidomide-4-NH-PEG1-COO(t-Bu) is a key intermediate in the synthesis of CRBN-based PROTAC molecules.

  • CAS Number: 2140807-19-6
  • MF: C22H27N3O7
  • MW: 445.47
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Thalidomide-5-NH-PEG1-NH2 hydrochloride

Thalidomide-5-NH-PEG1-NH2 hydrochloride is a Thalidomide (HY-14658)-based cereblon ligand that recruits CRBN proteins. Thalidomide-5-NH-PEG1-NH2 hydrochloride can be connected to the target protein ligand through a linker to form a PROTAC molecule. For example, THAL-SNS-032 (HY-123937).

  • CAS Number: 2863634-98-2
  • MF: C17H21ClN4O5
  • MW: 396.83
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

VHL Ligand 3

A VHL ligand for PROTAC.

  • CAS Number: 1448189-98-7
  • MF: C27H38N4O5S
  • MW: 530.679
  • Catalog: Ligand for E3 Ligase
  • Density: 1.2±0.1 g/cm3
  • Boiling Point: 755.7±60.0 °C at 760 mmHg
  • Melting Point: N/A
  • Flash Point: 410.9±32.9 °C

Thalidomide-5-O-C2-NH2 hydrochloride

Thalidomide-5-O-C2-NH2 hydrochloride is the Thalidomide (HY-10984)-based cereblon ligand used in the recruitment of CRBN protein.Thalidomide-5-O-C2-NH2 hydrochloride can be connected to the ligand for protein by a linker to form PROTACs[1].

  • CAS Number: 2694727-89-2
  • MF: C15H16ClN3O5
  • MW: 353.76
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Pomalidomide-5-C9-NH2 hydrochloride

Pomalidomide-5-C9-NH2 hydrochloride is the Pomalidomide-based cereblon (CRBN) ligand used in the recruitment of CRBN protein.Pomalidomide-5-C9-NH2 hydrochloride can be connected to the ligand for protein by a linker to form PROTAC[1].

  • CAS Number: 2925306-22-3
  • MF: C22H31ClN4O4
  • MW: 450.96
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

CCR7 Ligand 1

CCR7 Ligand 1 (CCR7-Cmp2105) is an allosteric Ligand and antagonist for human CC chemokine receptor 7 (CCR7) with a Kd of 3 nM. CCR7 Ligand 1, thiadiazole-dioxide ligan, suppresses arrestin binding in response to activation by CCL19 with an IC50 of 7.3 μM[1].

  • CAS Number: 681514-83-0
  • MF: C22H29N5O5S
  • MW: 475.56
  • Catalog: CCR
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Lenalidomide-6-F

Lenalidomide-6-F is the Lenalidomide-based cereblon (CRBN) ligand used in the recruitment of CRBN protein. Lenalidomide-6-F can be connected to the ligand for protein by a linker to form PROTAC[1].

  • CAS Number: 2468780-87-0
  • MF: C13H11FN2O3
  • MW: 262.24
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Thalidomide-5-methyl

Thalidomide-5-methyl is the Thalidomide-based cereblon (CRBN) ligand used in the recruitment of CRBN protein[1].

  • CAS Number: 40313-92-6
  • MF: C14H12N2O4
  • MW: 272.26
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Thalidomide-5-OH

Thalidomide-5-OH is the Thalidomide-based cereblon ligand used in the recruitment of CRBN protein. Thalidomide-5-OH can be connected to the ligand for protein by a linker to form PROTACs[1].

  • CAS Number: 64567-60-8
  • MF: C13H10N2O5
  • MW: 274.22900
  • Catalog: Ligand for E3 Ligase
  • Density: 1.611g/cm3
  • Boiling Point: 600ºC at 760mmHg
  • Melting Point: N/A
  • Flash Point: 316.7ºC

VH 032, phenol

VH032-OH is the VH032-based VHL ligand. VH032-OH can be connected to the ligand for protein by a linker to form PROTACs[1].

  • CAS Number: 2244684-42-0
  • MF: C24H32N4O5S
  • MW: 488.60
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Thalidomide-NH-(CH2)2-NH2 TFA

Thalidomide-NH-(CH2)2-NH2 TFA is an alkyl-modified Thalidomide (HY-14658) that acts as a Cereblon ligand to recruit CRBN proteins. Thalidomide-NH-(CH2)2-NH2 TFA is a key intermediate in the synthesis of CRBN-based PROTAC molecules designed to synthesize small PROTAC molecules targeting SHP2 protein.

  • CAS Number: 1957235-67-4
  • MF: C17H17F3N4O6
  • MW: 430.34
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: >224°C (dec.)
  • Flash Point: N/A

Pomalidomide-C2-NH2(E3 ligase Ligand 17)

E3 ligase Ligand 17 is a ligand for E3 ubiquitin ligase. E3 ligase Ligand 17 can be connected to the ligand for protein by a linker to form PROTACs or SNIPERs. PROTACs are inducers of ubiquitination-mediated degradation of cancer-promoting proteins[1].

  • CAS Number: 1957235-66-3
  • MF: C15H16N4O4
  • MW: 316.31
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

VL-285

VL285 is a potent VHL ligand.

  • CAS Number: 1448188-57-5
  • MF: C29H32N4O4S
  • MW: 532.65
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

AR antagonist 1 hydrochloride

AR antagonist 1 (compound 29) hydrochloride is a potent androgen receptor (AR) antagonist and binds to E3 ligase ligands with weak binding affinities to VHL protein in the synthesis of PROTAC ARD-266 (HY-133020)[1].

  • CAS Number: 1818885-55-0
  • MF: C15H20Cl2N2O
  • MW: 315.24
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

2-chloro-4-[trans-3-amino-2,2,4,4-tetramethylcyclobutoxy]benzonitrile

AR antagonist 1 (compound 29) is a potent androgen receptor (AR) antagonist and binds to E3 ligase ligands with weak binding affinities to VHL protein in the synthesis of PROTAC ARD-266 (HY-133020).

  • CAS Number: 1818885-54-9
  • MF: C15H19ClN2O
  • MW: 278.78
  • Catalog: Ligand for E3 Ligase
  • Density: 1.18±0.1 g/cm3(Predicted)
  • Boiling Point: 394.9±42.0 °C(Predicted)
  • Melting Point: N/A
  • Flash Point: N/A

E3 ligase Ligand 1

E3 ligase Ligand 1 is a Ligand for E3 Ligase extracted from patent WO/2017/030814A1 compound example 202, used in PROTAC technology.

  • CAS Number: 1948273-03-7
  • MF: C23H33ClN4O3S
  • MW: 481.05
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

CC-99282

CC-99282 is a potent and orally active cereblon (CRBN) E3 ligase modulator (CELMoD). CC-99282 co-opts CRBN to induce potent and targeted degradation of Ikaros and Aiolos. CC-99282 can be used for researching non-Hodgkin lymphomas[1].

  • CAS Number: 2379572-34-4
  • MF: C28H30FN5O5
  • MW: 535.57
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

Pomalidomide-PEG5-C2-NH2 hydrochloride

Pomalidomide-PEG5-C2-NH2 hydrochloride is the Pomalidomide-based cereblon (CRBN) ligand used in the recruitment of CRBN protein.Pomalidomide-PEG5-C2-NH2 hydrochloride can be connected to the ligand for protein by a linker to form PROTAC[1].

  • CAS Number: 2357117-23-6
  • MF: C25H37ClN4O9
  • MW: 573.04
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

E3 ligase Ligand 1A

E3 ligase Ligand 1A is a ligand of E3 ligase, used in PROTAC technology; E3 ligase Ligand 1A can be used in the research of cancer.

  • CAS Number: 1948273-02-6
  • MF: C23H32N4O3S
  • MW: 444.59
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

VH032-PEG2-NH-BOC

VH032-PEG2-NH-BOC is a Boc-modified VH032 (HY-120217) that serves as a ligand for VHL and recruits von Hippel-Lindau (VHL) proteins. VH032-PEG2-NH-BOC will remove the protecting group under acidic conditions and be directly used for PROTAC molecule synthesis. VH032-PEG2-NH-BOC is a key intermediate in the synthesis of PROTAC based on VHL ligand.

  • CAS Number: 2162120-75-2
  • MF: C33H49N5O8S
  • MW: 675.84
  • Catalog: Ligand for E3 Ligase
  • Density: N/A
  • Boiling Point: N/A
  • Melting Point: N/A
  • Flash Point: N/A

BC-1215

BC-1215 is an inhibitor of F-box protein 3 (FBXO3, a ubiquitin E3 ligase component, IC50=0.9 μg/mL for IL-1β release). BC-1215 decreases Fbxo3-Fbxl2 interaction and prevents SCFFbxo3 catalyzed Fbxl2 ubiquitination. BC-1215 inhibits the Fbxo3-TRAF activation pathway by destabilizing TRAF1–TRAF6. BC-1215, interacts with ApaG to profoundly inhibit secretion of a broad spectrum of TH1 panel cytokines from human PBMC[1].

  • CAS Number: 1507370-20-8
  • MF: C26H26N4
  • MW: 394.511
  • Catalog: Ligand for E3 Ligase
  • Density: 1.1±0.1 g/cm3
  • Boiling Point: 589.9±50.0 °C at 760 mmHg
  • Melting Point: N/A
  • Flash Point: 310.6±30.1 °C