Apoptosi

<p>ZSH-512 is a potent inhibitor of RARγ with antiproliferative properties. It induces apoptosis and reduces the expression of CD133, NANOG, SOX2, and EPCAM proteins. ZSH-512 exhibits anticancer activity and shows potential for colorectal cancer research.</p>

XPO1-IN-1: an oral MM.1S cell inhibitor (IC50: 24 nM), induces apoptosis, stable metabolism, good pharmacokinetics.

HL001 is an orally active small molecule inhibitor of cyclophilin A (CypA) and a receptor antagonist of lysophosphatidic acid 1 (LPA1). It induces cell cycle arrest and apoptosis in tumor cells via p53. By downregulating G3BP1, HL001 promotes reactive oxygen species production and DNA damage to stabilize p53. It disrupts the interaction between MDM2 and p53-72R in a CypA-dependent manner. HL001 exhibits antitumor activity and can also be used in research on pulmonary fibrosis.

<p>NA-17 is a naphthalimide compound with antitumor activity and exhibits lower toxicity to normal cells such as HL-7702 and WI-38. It demonstrates p53-dependent inhibition selectivity in various NSCLC cells, inducing the accumulation of active p53 in the mitochondria and nuclei of these cells. NA-17 causes cell cycle arrest in the G1 phase and promotes apoptosis and cell death.</p>

Compound 2c is a potent p38α MAPK inhibitor with antitumor effects, enhancing apoptosis and ROS.

Sinulatumolin E, a terpenoid, inhibits TNF-α (IC 50: 3.6 μM); has anti-inflammatory properties.

Potent dual c-Met/HDAC inhibitor, IC50: HDAC1 5.4 nM, c-Met 18.49 nM; anti-cancer, induces apoptosis, G2/M arrest in HCT-116.

FHND5071 (1H) is a selective inhibitor of RET (rearranged during transfection) tyrosine kinase. It shows potential for research applications in RET-driven cancers, such as thyroid and lung cancer.

Dicycloplatin is an inducer of DNA damage. It activates doubly phosphorylated checkpoint kinase 2 (CHK2), breast cancer 1 (BRCA1), and triply phosphorylated p53 to induce DNA damage. Dicycloplatin can cause cell cycle arrest, inhibit proliferation, and trigger apoptosis in prostate cancer PC3 cells and lung cancer NCI/H446 cells. It is applicable for research in the field of cancer.

K20 selectively inhibits KRas G12C (IC50: 1.16 nM), shows anticancer activity in H358 cells (IC50: 0.78 μM), and induces apoptosis via Erk dephosphorylation.

HDAC-IN-37 inhibits HDACs 1, 3, 8, & 6, induces histone acetylation, halts G1 to S phase, and triggers early apoptosis.

HP590: potent oral STAT3 inhibitor, IC50=27.8 nM, blocks ATP, IC50=24.7 nM, hinders gastric cancer growth, triggers cell death.

Antitumor agent-72 (compound 6w) is a potent anticancer agent that exhibits its anticancer activity by inducing apoptosis via caspase-3 activation and PARP

<p>HC-7366 (GCN2 modulator-1) is an orally active GCN2 kinase activator with antitumor activity, inducing tumor growth inhibition.</p>

D18: Dual agonist for TLR7/8, boosts PD-L1, aids tumor sensitivity to PD-1/PD-L1 inhibitors, and is a cytotoxin for ADC HE-S2.

T0080 is an FPR-1 antagonist. It reduces apoptosis (Apoptosis) and inhibits the production of reactive oxygen species (ROS) and pro-inflammatory cytokines (TNF-α and IL-1β) in plaque macrophages within ApoE−/− mouse models, thereby slowing the progression of atherosclerosis.

Antitumor agent-51 targets osteosarcoma with 21.9 nM IC50, high selectivity, and low toxicity.

Bomedemstat (IMG-7289) hydrochloride, an oral LSD1 inhibitor, has anticancer properties, blocking cell growth and triggering apoptosis.

LA-CB1 is a derivative of Abemaciclib that targets CDK4/6 and promotes their degradation via the ubiquitin-proteasome pathway, thereby blocking the CDK4/6-Cyclin D1-Rb-E2F axis and inducing G0/G1 cell cycle arrest and apoptosis (Apoptosis). It demonstrates antiproliferative activity against MDA-MB-231 cells with an IC50 of 0.27 µM and effectively inhibits epithelial-mesenchymal transition, cell migration, invasion, and angiogenesis. In highly invasive models like triple-negative breast cancer (TNBC), LA-CB1 significantly suppresses tumor growth, showing robust dose-dependent antitumor activity. This compound can be utilized in breast cancer research.

Antitumor agent-202 is a stabilizer of the p53Y220C mutant, selectively inhibiting the proliferation of tumor cells carrying the p53Y220C mutation. It is applicable for research focused on cancers associated with the p53 Y220C mutation.

Belotecan (CKD-602) inhibits DNA topoisomerase I, blocks cell cycle, induces apoptosis, and is a camptothecin-derived anticancer agent.

EGFR-IN-134 (compound 3f) is a triazolo[3,4-a]quinoline derivative and functions as a potent EGFR inhibitor with an IC50 of 0.023 µM. It induces apoptosis and necrosis in cells, and causes cell cycle arrest in the G2/M and pre-G1 phases. EGFR-IN-134 modulates the expression of apoptosis-regulating proteins by downregulating anti-apoptotic protein Bcl2 and upregulating pro-apoptotic proteins p53, Bax, and caspases 3, 8, and 9, demonstrating significant antiproliferative and anticancer activities.

3′-Hydroxyflavanone is a cyclized flavonoid with anti-tumor properties that induces apoptosis in HeLa cells.

CB-184 is a selective ligand for sigma-2 (σ2) receptors, with Ki values of 7436 nM for sigma-1 (σ1) and 13.4 nM for sigma-2 (σ2), and it promotes apoptosis with antitumor activity.

Fosizensertib is an inhibitor of RIP-1 kinase and is used in research related to ulcerative colitis.

MY-875 inhibits microtubule formation, binds like colchicine (IC50: 0.92 μM), activates Hippo pathway, and induces apoptosis with anticancer properties.

L-threo-Sphingosine C-18 is a protein kinase C inhibitor.

TAI-95 is an inhibitor of highly expressed cancer protein 1 (Hec1).

EGFR-IN-3 is an EGFR inhibitor with antitumor activity.EGFR-IN-3 inhibits EGFRwt-TK, induces apoptosis (cell death), and can block cells in the G2/M phase.

Compound 28 is a nonsteroidal VDR agonist with 690 nM potency, inducing cell cycle arrest and apoptosis in MCF-7 cells.

Akt/NF-κB/JNK-IN-1 (Compound 2i) is an inhibitor of Akt, NF-κB and JNK signalling pathways.Akt/NF-κB/JNK-IN-1 exhibits an inhibitory effect on nitric oxide

TAS-117 HCl: potent oral Akt inhibitor (Akt1 IC50: 4.8nM, Akt2: 1.6nM, Akt3: 44nM), boosts anti-myeloma effects, induces cell death.

Bim-IN-1 is a potent inhibitor of Bim expression with low toxicity, Bim-IN-1 reduces Bim expression levels with little inhibition of protein kinase A.

GGTI298 is a potent GGTase I inhibitor; IC50 3μM for Rap1A, >20μM for Ha-Ras.

hCAIX/XII-IN-1: potent CAIX inhibitor (KI=0.48μM), CAXII (KI=0.83μM), antiproliferative, induces apoptosis in MCF-7 cells.

<p>BMS-751324: p38α MAPK inhibitor with carbamyl-methyl, esters, phosphate from HPA. Reduces rat arthritis swelling and TNFα.</p>

Urease-IN-20 (compound XBP2) is an inhibitor of Helicobacter pylori (H. pylori), with an IC50 of 0.14 μM for H. pylori inhibition. It effectively decreases apoptosis in GES-1 cells infected with H. pylori and reduces levels of ROS and γH2AX. Urease-IN-20 also demonstrates significant gastric mucosal protective effects, making it suitable for H. pylori research.

Glyphosate isopropylammonium is a broad-spectrum, non-selective systemic biocide derived from the amino acid glycine. It inhibits the enzyme activity of 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) in the shikimate pathway, blocking the synthesis of aromatic amino acids tyrosine, phenylalanine, and tryptophan. Additionally, Glyphosate isopropylammonium induces oxidative stress, neuroinflammation, and mitochondrial dysfunction, leading to neuronal death through autophagy, necrosis, or apoptosis, resulting in behavioral and motor disturbances.

Thalidomide-NH-C5-NH2 is a synthetic E3 ligase ligand-linker conjugate, consisting of a Thalidomide-based cereblon ligand and a linker, used in the synthesis of PROTACs.

Tuspetinib (HM43239) dihydrochloride is a selective FLT3 inhibitor with oral bioactivity, exhibiting IC50 values of 1.1 nM for FLT3 wild type, 1.8 nM for FLT3ITD mutant type, and 1.0 nM for FLT3D835Y mutant type. As a reversible type I inhibitor, it directly suppresses FLT3 kinase activity and modulates p-STAT5, p-ERK, SYK, JAK1/2, and TAK1. Tuspetinib dihydrochloride inhibits the proliferation of leukemia cells and induces apoptosis (apoptosis).

NLRP3-IN-28 (compound N77) serves as a potent inhibitor of NLRP3, effectively blocking Nigericin-induced pyroptosis with an EC50 of 0.07μM. Additionally, it mitigates inflammatory reactions in vivo [1].

ZIF-8 is an anticancer agent that can inherently trigger pyroptosis through a caspase-1/gasdermin D (GSDMD)-dependent pathway.

Tubulin inhibitor 14 blocks NQO2 and microtubule formation, disrupts blood vessels, and may target tumors; IC50 of 1.0 μM.

Compound 8a, a dual PARP10 & PARP15 inhibitor, has IC50s: PARP10 at 0.14μM & PARP15 at 0.40μM; it's cell-permeable & anti-apoptotic.

GLUT-1-IN-4 (Compound 13) is an inhibitor of the GLUT-1 glucose transporter that depends on the p53 protein. It suppresses the proliferation of various cancer cells at submicromolar IC50 levels. Additionally, GLUT-1-IN-4 can halt the cell cycle, induce oxidative stress, and promote apoptosis (cell death).

ASP9831 is an orally active PDE4 inhibitor. It suppresses LPS-induced TNF-α production and exhibits anti-inflammatory properties. ASP9831 is useful in the study of steatohepatitis.

XIAP degrader-1 is a small primary amine molecule that promotes the degradation of X-linked apoptosis inhibitory protein (XIAP).

TNF-α-IN-14, a potent TNFα inhibitor, exhibits a selective inhibition profile with an IC50 of 1.1 µM and demonstrates antiinflammatory properties (WO2001072735A2; compound 12) [1].

PD-1-IN-17 TFA is a potent PD-1 inhibitor, blocking 92% of splenocyte growth at 100 nM.

(2R,3S)-Emricasan ((2R,3S)-PF 03491390) is an isomer of Emricasan. This compound acts as an orally effective irreversible pan-caspase inhibitor. (2R,3S)-Emricasan inhibits the increase in caspase-3 activity induced by Zika virus (ZIKV) and protects human cortical neural progenitor cells.

<p>Casein kinase1δ-IN-29 (Compound 18) is an inhibitor that targets p38α and casein kinase 1 (CK1), exhibiting inhibitory effects on p38α, CK1δ, and CK1ε with IC50 values of 0.041 µM, 0.005 µM, and 0.447 µM, respectively. This compound causes cell cycle arrest at the subG1 phase and induces apoptosis in AC1-M88 cells.</p>

JR5-26B is an orally active apoptosis (apoptosis) inducer. It induces cell death via copper-mediated apoptosis and necroptosis (necroptosis). JR5-26B exhibits antiproliferative activity against MIA PaCa-2, PANC-1, PAN02, SU.86.86, and KPC-2 cells, with IC50 values of 0.6, 4.4, 8.0, 1.1, and 3.4 μM, respectively.

inhibitor of Akt, protein kinase C, PDK1 and cyclin-dependent kinases

Antitumor Agent-184 (compound 12aa) triggers apoptosis in various cell lines, exhibiting IC50 values of 2.35 μM in B16-F10 cells, 7.32 μM in 4T1 cells, and 10.31 μM in CT26 cells.

APD-94 is a dual inhibitor targeting tubulin and Bmi-1. It disrupts the normal polymerization of tubulin and suppresses the expression of Bmi-1. This compound induces cell cycle arrest at the G2/M phase and triggers apoptosis, thereby inhibiting cancer cell proliferation. Additionally, APD-94 inhibits the growth of HT29 cell xenograft tumors in NOD/SCID mice and is applicable to colorectal cancer research.

17-Demethoxy-reblastatin (17-DR) acts as an inhibitor of heat shock protein 90 (Hsp90). It suppresses the proliferation of HepG2 and SMMC7721 cancer cells, diminishes colony formation, and triggers apoptosis via a mitochondria and caspase-mediated pathway.

NiCur is an effective and selective inhibitor of CBP histone acetyltransferase (HAT), with an IC50 of 0.35 μM.

Apoptosisinducer 25 (Compound 4H) demonstrates potent anticancer capabilities by inhibiting the proliferation of BGC-823 cancer cells with an IC50 of 0.37 μM. It induces apoptosis in BGC-823 cells, causes mitochondrial dysfunction, and arrests the cell cycle at the G2/M phase. Additionally, Apoptosisinducer 25 exhibits favorable pharmacokinetic properties in rats.

<p>BMI-135, a selective estrogen mimic, demonstrates agonist activity for the estrogen receptor and induces a rapid endoplasmic reticulum stress response (UPR) alongside apoptosis in breast cancer cells.</p>

MC3629, an inhibitor of the histone methyltransferase (EZH2), exhibits antitumor activity. This compound effectively inhibits the proliferation and self-renewal of SHH MB cancer cells while inducing cell apoptosis (apoptosis). MC3629 is also useful in research on tumor aggressiveness and resistance.

Ran-IN-1 (Compound M36) is an orally active and selective inhibitor of Ran GTPase. It binds allosterically with high specificity to the switch II pocket of GDP-bound Ran (RanGDP), stabilizing its inactive state and reducing the formation of active Ran-GTP. Ran-IN-1 induces apoptosis in epithelial ovarian cancer (EOC) cells and inhibits DNA repair pathways such as homologous recombination (HR) and non-homologous end joining (NHEJ). This compound shows potential for research in epithelial ovarian cancer, particularly in high-grade serous carcinoma.

PF-7006, an Mps1 kinase inhibitor, exhibits a Ki value of 0.27 nM and an IC50 value of 2.5 nM. It disrupts cell cycle checkpoints by inhibiting the catalytic activity of Mps1, reduces histone H3 levels, and shortens the duration of mitosis, thereby inducing apoptosis (Apoptosis) in cancer cells. When used in combination with Palbociclib, the tolerance of cancer cells to PF-7006 is enhanced. PF-7006 is applicable for research on breast cancer.

<p>Pan-KRAS-IN-5 (compound 15a) is a pan-KRAS translation inhibitor targeting 5′-UTR RNA G-quadruplexes (rG4s). It induces cell cycle arrest and promotes apoptosis in KRAS-driven cancer cells [1].</p>

Topo II/HDAC-IN-1 (7d) demonstrates potent dual inhibitory effects on Topo II and HDAC, while Topo II/HDAC-IN-1 (8d) effectively induces apoptosis [1].

GPX4 Activator 2 (Compound C3) serves as an activator of GPX4 and exhibits cardioprotective effects by inhibiting cellular iron death (ferroptosis) with an efficacy concentration (EC50) of 7.8 μM. It is used in the study of myocardial damage.

Antiproliferative agent-63 (compound 4d) is a cyclic analog of cannabidiol that acts as an anticancer agent. It demonstrates favorable activity against breast and colorectal cancer. Moreover, this compound can arrest the cell cycle in the G1 phase and induce apoptosis through the mitochondrial pathway in breast cancer cell lines.

NSD2-IN-1: potent, selective NSD2-PWWP1 inhibitor, IC50 0.11 μM, induces gene expression changes, apoptosis, cell cycle arrest.

06:0 PE (PE(6:0/6:0)) is a water-soluble phospholipid characterized by its short acyl chains. It possesses notable antitumor activity and can inhibit tumor progression in the body. Additionally, it exhibits antiproliferative and pro-apoptotic properties, and serves as a precursor for phosphatidylcholine and phosphatidylethanolamine.

MA242 is a nuclear factor of activated T cells 1 (NFAT1) for Pancreatic Cancer Therapy and dual inhibitor of murine double minute 2 (MDM2).

<p>PD-1/PD-L1-IN-17 (Compound P20) is a potent PD-1/PD-L1 inhibitor (IC50: 26.8 nM).</p>

TLBC, a borane-chalcone derivative, exhibits dose-dependent inhibitory effects across various glioma cell lines with IC50 values ranging from 5.5 to 25.5 μM. TLBC induces apoptosis independently of alterations in the tumor suppressor factor p53.

Tubulin polymerization-IN-4: inhibits tubulin (IC50=4.6 μM), blocks G2/M phase, induces apoptosis, hinders cell cloning/migration, damages vasculature.

HER2-IN-10 is a psoralen derivative that induces apoptosis. HER2-IN-10 shows anti-breast cancer activity and light-activated cytotoxicity [1].

DC-U4106: USP8 inhibitor, Kd 4.7μM, IC50 1.2μM, degrades Erα, low-toxicity tumor suppressor for breast cancer research.

Ferroptosis-IN-15 (compound 12) serves as an effective inhibitor of ferroptosis, exhibiting EC50 values of 0.76 μM and 0.67 μM in A375 cells and 786-O cells, respectively. It acts as a potential iron chelator and radical-scavenging antioxidant.

Antitumor agent-76 is a water-soluble, orally active, rapid-release prodrug of Triptolide that exhibits anticancer effects.

KMUP-1 is a xanthine derivative known for its vasodilatory properties. It functions as a phosphodiesterase (PDE) inhibitor and an activator of soluble guanylate cyclase (sGC), engaging the NO/sGC/cyclic guanosine monophosphate pathway. Additionally, KMUP-1 can open K+ channels and has the potential to alleviate ischemia-induced cardiac myocyte apoptosis (apoptosis). This compound is useful in cardiovascular and anti-inflammatory research.

Soquelitinib (CPI-818) is a selective ITK inhibitor， inhibits tumor growth,T-cell, up-regulatCXCR3, IFNγ, TNFα, and CD107a expression in normal CD8 cells.

Mcl-1 Inhibitor 9 (Example 2) is a potent inhibitor of myeloid cell leukemia 1 (Mcl-1), demonstrating anti-tumor activity with an IC50 value of 0.21889 nM.

INNO-220 is an orally active, CRBN-dependent molecular glue degrader that targets CK1α. By degrading CK1α, INNO-220 induces cell cycle arrest at the G0/G1 phase and triggers apoptosis (Apoptosis). It disrupts the assembly and function of the CARD11/BCL10/MALT1 complex, inhibiting the NF-κB signaling pathway in T cells and lymphoma cells with activating mutations in CARD11. INNO-220 offers a novel direction for lymphoma research.

Z-3578 is a small molecule antagonist targeting the MrgX2 (Mas-related G protein-coupled receptor X2) with notable anti-pseudoallergic properties, exhibiting a KD value of 729 nM. It effectively inhibits mast cell degranulation induced by substance P (SP) and C48/80, with IC50 values of 4.90 µM and 6.18 µM, respectively, suppresses the release of β-hexosaminidase, and significantly reduces the release of histamine and TNF-α, as well as intracellular calcium flux. Additionally, in a mouse pseudoallergy model, Z-3578 significantly alleviates foot swelling, dye leakage, and reduces serum histamine levels, indicating a strong in vivo anti-allergic effect. Z-3578 presents as a promising lead compound in the field of anti-allergic treatments, particularly for pseudoallergic reactions.

SF-9-2 is a PD-L1/PD-1 binding inhibitor with an IC50 of 24.9 nM. It suppresses epithelial-mesenchymal transition, migration, invasion, and proliferation of SK-N-SH cells, while also inducing apoptosis and causing cell cycle arrest. SF-9-2 blocks PD-L1-induced growth of SK-N-SH cells via the MAPK signaling pathway. It restores GSK-3β activity and enhances PD-L1 degradation through the ubiquitin-proteasome pathway. In the SK-N-SH NOG mouse model, SF-9-2 inhibits tumor growth without notable toxicity. Additionally, SF-9-2 acts as an immune checkpoint inhibitor, blocking PD-L1 to restore T cell function and is applicable to neuroblastoma research.

RIPK2-IN-6 (Compound 15a) is an inhibitor of RIPK that specifically targets the phosphorylation of RIPK2, thereby suppressing the NF-κB and MAPK signaling pathways. It has demonstrated anti-inflammatory and anti-fibrotic activities in a mouse model of colitis induced by Dextran sodium sulfate.

FAK-IN-4 (Compound 7d) has anticancer activities that can induce cell apoptosis. FAK-IN-4 is potential inhibitor of FAK [1].

<p>MLKL-IN-6 (compound P28) is a mixed lineage kinase inhibitor that specifically targets the Mixed Lineage Kinase domain-like (MLKL) protein.</p>

BMS 310705, an Epothilone B analog, targets ovarian/renal/bladder/lung cancer, inducing apoptosis via mitochondria.

Samuraciclib (CT7001) is a potent oral CDK7 inhibitor (IC50: 41 nM) with anti-breast cancer properties.

Anticancer agent 17 was effective against HeLa cells (IC50: 0.19 μM) and A2780 cells (IC50: 0.09 μM).

CDK2-IN-9: potent CDK2 inhibitor (IC50: 0.63 μM), anti-proliferative, arrests S/G2M cell cycle, induces apoptosis, promising for melanoma study.

Apoptosis inducer42 is an apoptosis inducer that triggers late-stage apoptosis and inhibits the secretion of IL-6. It exhibits high cytotoxicity toward cancer cells and is applicable in cancer research, including studies on colon cancer.

UR-AK49 (compound 11) is an agonist for the human histamine H1 and H2 receptors. It exhibits an EC50 of 23 nM in the GTPase assay involving hH2R-Gsalpha fusion protein expressed in Sf9 insect cells. UR-AK49 is applicable in neurologically related research.

MAO-B-IN-45 is a dual inhibitor of ferroptosis and MAO-B. It selectively inhibits MAO-B with an IC50 of 87.47 nM, demonstrating a selectivity over MAO-A by more than 229 times. In vitro, MAO-B-IN-45 exhibits significant anti-ferroptosis activity by modulating iron metabolism pathways and the GSH-GPX4 axis. Additionally, it improves cognitive and behavioral deficits in 3×Tg (APP/Tau/Ps1) Alzheimer's disease mice and significantly reduces levels of ferritin heavy chain 1 (FTH1), β-amyloid protein (APP), and Tau protein phosphorylation (p-Tau) in their brains.

WEHI-9625 is a tricyclic sulfone small molecule apoptosis inhibitor (EC50: 69 nM).

Compound 3 (DOR agonist 2) acts as a Delta Opioid Receptor agonist. It inhibits the expression of TNF-α, obstructs NF-κB transportation to the nucleus, and activates the G protein-mediated ERK1/2 pathway. This compound is useful for research into neurodegenerative diseases.

ER covalent antagonist-1 (Compound 39D) acts as an antagonist of the estrogen receptor α (ERα). This compound inhibits the proliferation of ERα-positive MCF-7 cells with an IC50 of 0.98 μM, induces cell cycle arrest at the G0/G1 phase, and triggers apoptosis. Additionally, ER covalent antagonist-1 demonstrates antitumor activity in mouse models.

MI-888 (TFA) is an orally active inhibitor of the MDM2-p53 interaction with a Ki of 0.44 nM. It can induce rapid, complete, and durable tumor regression in xenograft mouse models.

DDO-8958 is an orally active and selective BET BD1 inhibitor, exhibiting a KD of 5.6 nM for BRD4 BD1. It shows low nanomolar inhibitory activity across all BET BD1 bromodomains except for BRDT BD1. DDO-8958 inhibits tumor cell proliferation and migration, induces apoptosis and cell cycle arrest, and demonstrates antitumor activity.

Anticancer agent 64 (5m) induces apoptosis, has IC50 2.4μM in CCRF-CEM, activates caspases, cleaves PARP, affects mitochondria.

RIPK1-IN-14 inhibits RIPK1 with 92 nM IC50 and reduces necrotic apoptosis in U937 cells.

Topoisomerase IIα-IN-4 (F2) is a non-intercalative ATP-competitive inhibitor of human DNA topoisomerase II, specifically inhibiting TopoIIα with an IC50 value

Ferroptosis-IN-6 is an efficient ferroptosis inhibitor, protecting cells from cell death induced by ferroptosis inducers, and inhibiting STY-BODIPY oxidation.