Discovery of Phenyl(pyridin-2-yl)methanone

Formula: C12H9NO. About Phenyl(pyridin-2-yl)methanone, If you have any questions, you can contact Dasgupta, S; Karim, S; Banerjee, S; Saha, M; Saha, KD; Das, D or concate me.

In 2020.0 DALTON T published article about NI-II COMPLEXES; MOLECULAR-STRUCTURE; HYDROLYSIS; MECHANISM; LIGANDS; ESTERS; DRUGS; COBALT(III); DERIVATIVES; KINETICS in [Dasgupta, Sanchari; Karim, Suhana; Das, Debasis] Univ Calcutta, Dept Chem, 92 APC Rd, Kolkata 700009, India; [Banerjee, Saswati; Saha, Moumita; Saha, Krishna Das] CSIR Indian Inst Chem Biol, Canc Biol & Inflammatory Disorder Div, 4 Raja SC Mullick Rd, Kolkata 700032, India in 2020.0, Cited 48.0. The Name is Phenyl(pyridin-2-yl)methanone. Through research, I have a further understanding and discovery of 91-02-1. Formula: C12H9NO

Three asymmetric tridentate acyl hydrazone Schiff base ligands namely L1, L2 and L3 were prepared via condensation of 4-methoxybenzohydrazide with picolinaldehyde, 1-(pyridin-2-yl)ethanone and phenyl(pyridin-2-yl)methanone respectively. Three bio-relevant mononuclear zinc(ii) complexes [Zn(L1)Cl-2]2H(2)O (1), [Zn(L2)Cl-2] (2) and [Zn(L3)Cl-2] (3) were synthesized by treatment of zinc(ii) chloride with the corresponding Schiff base ligands and characterised by the usual physicochemical techniques. The solid state structures of complexes 1 and 3 were evaluated by single crystal X-ray analysis. All complexes were able to hydrolyse the P-O bond of the phosphate monoester in 90% (v/v) DMSO-water medium using 4-nitrophenylphosphate (4-NPP) as the model substrate and the trend in their activity is 1 approximate to 2 > 3. On considering the highly efficient hydrolysis properties, complexes 1-3 were tested as potential therapeutic agents for cancer using HCT116 (human colorectal carcinoma), HepG2 (human hepatocellular carcinoma) and A549 (human non-small lung carcinoma) cells. Complex 2 showed the highest IC50 values for anti-cancer activity towards all three cell lines among the three complexes and complex 3 showed the least activity as observed in the phosphatase activity study. The internucleosomal degradation of DNA during apoptosis can be detected by cell death detection ELISA. DNA fragmentation that leads to cell death was examined and when induced by complex 2 in HepG2 cells a significant level of DNA fragmentation was observed at regular intervals of time.

Formula: C12H9NO. About Phenyl(pyridin-2-yl)methanone, If you have any questions, you can contact Dasgupta, S; Karim, S; Banerjee, S; Saha, M; Saha, KD; Das, D or concate me.

Reference:
Pyridine – Wikipedia,
,Pyridine | C5H5N – PubChem

The Best Chemistry compound:Phenyl(pyridin-2-yl)methanone

SDS of cas: 91-02-1. About Phenyl(pyridin-2-yl)methanone, If you have any questions, you can contact Yu, H; Zhao, QX; Wei, ZY; Wu, ZK; Li, Q; Han, S; Wei, YG or concate me.

An article Iron-catalyzed oxidative functionalization of C(sp(3))-H bonds under bromide-synergized mild conditions WOS:000474265200024 published article about C-H OXIDATION; AEROBIC OXIDATION; POLYOXOMETALATE; OXYGEN; ACTIVATION; REMOTE in [Yu, Han; Zhao, Qixin; Wei, Zheyu; Wu, Zhikang; Han, Sheng] Shanghai Inst Technol, Sch Chem & Environm Engn, Shanghai 201418, Peoples R China; [Yu, Han; Li, Qi; Wei, Yongge] Tsinghua Univ, Dept Chem, Minist Educ, Key Lab Organ Optoelect & Mol Engn, Beijing 100084, Peoples R China; [Yu, Han; Wei, Yongge] Peking Univ, State Key Lab Nat & Biomimet Drugs, Beijing 100191, Peoples R China in 2019.0, Cited 48.0. The Name is Phenyl(pyridin-2-yl)methanone. Through research, I have a further understanding and discovery of 91-02-1. SDS of cas: 91-02-1

An efficient oxidation and functionalization of C-H bonds with an inorganic-ligand supported iron catalyst and hydrogen peroxide to prepare the corresponding ketones was achieved using the bromide ion as a promoter. Preliminary mechanistic investigations indicated that the bromide ion can bind to FeMo6 to form a supramolecular species (FeMo6 center dot 2Br), which can effectively catalyze the reaction.

SDS of cas: 91-02-1. About Phenyl(pyridin-2-yl)methanone, If you have any questions, you can contact Yu, H; Zhao, QX; Wei, ZY; Wu, ZK; Li, Q; Han, S; Wei, YG or concate me.

Reference:
Pyridine – Wikipedia,
,Pyridine | C5H5N – PubChem

Get Up to Speed Quickly on Emerging Topics:3-Hydroxy-5-(hydroxymethyl)-2-methylisonicotinaldehyde hydrochloride

Quality Control of 3-Hydroxy-5-(hydroxymethyl)-2-methylisonicotinaldehyde hydrochloride. About 3-Hydroxy-5-(hydroxymethyl)-2-methylisonicotinaldehyde hydrochloride, If you have any questions, you can contact Yuwen, ZY; Mei, HX; Li, H; Pu, SZ or concate me.

Quality Control of 3-Hydroxy-5-(hydroxymethyl)-2-methylisonicotinaldehyde hydrochloride. In 2020.0 J PHOTOCH PHOTOBIO A published article about DUAL-CHANNEL RECOGNITION; MOLECULAR LOGIC GATES; TURN-ON SENSOR; FLUORESCENT SENSOR; AQUEOUS-MEDIA; COLORIMETRIC SENSOR; SCHIFF-BASE; CYANIDE; CHEMOSENSOR; MAGNESIUM in [Yuwen, Zhiyang; Li, Hui; Pu, Shouzhi] Jiangxi Sci & Technol Normal Univ, Jiangxi Key Lab Organ Chem, Nanchang 330013, Jiangxi, Peoples R China; [Mei, Hongxin] Nanchang Normal Univ, Dept Chem, Nanchang 330013, Jiangxi, Peoples R China in 2020.0, Cited 70.0. The Name is 3-Hydroxy-5-(hydroxymethyl)-2-methylisonicotinaldehyde hydrochloride. Through research, I have a further understanding and discovery of 65-22-5.

A chemical sensor composed of pyridoxal hydrochloride schiff base based on diarylethene (1O) was synthesized. Its photochemical properties and selectivity to ions were further studied. The chemosensor could detect cyanide effectively and is almost undisturbed by other ions. When titrating CN-, the reaction aroused a distinct change in the absorption spectrum with the color change from transparent to yellow, and the fluorescence intensity centered at 562 nm was increased 68 folds. It also exhibited a good fluorescence sensing of Mg(2+ )with high selectivity and sensitivity. Upon addition of Mg2+, its emission intensity enhanced 110 folds, with the color change from dark to bright blue. Its good spectral response could be applied to molecular logic circuit. Moreover, the chemosensor could be made into test paper strips for the qualitative and quantitative detection of CN- and Mg2+.

Quality Control of 3-Hydroxy-5-(hydroxymethyl)-2-methylisonicotinaldehyde hydrochloride. About 3-Hydroxy-5-(hydroxymethyl)-2-methylisonicotinaldehyde hydrochloride, If you have any questions, you can contact Yuwen, ZY; Mei, HX; Li, H; Pu, SZ or concate me.

Reference:
Pyridine – Wikipedia,
,Pyridine | C5H5N – PubChem

Search for chemical structures by a sketch :Phenyl(pyridin-2-yl)methanone

About Phenyl(pyridin-2-yl)methanone, If you have any questions, you can contact Kim, JH; Mertens, RT; Agarwal, A; Parkin, S; Berger, G; Awuah, SG or concate me.. COA of Formula: C12H9NO

An article Direct intramolecular carbon(sp(2))-nitrogen(sp(2)) reductive elimination from gold(III) WOS:000472449300036 published article about ORGANOGOLD COMPLEXES; CARBON-CARBON; BASIS-SETS; GOLD; MECHANISMS; CATALYSTS; IODIDE; ISOMERIZATION; DESIGN; AMINES in [Kim, Jong Hyun; Mertens, R. Tyler; Agarwal, Amal; Parkin, Sean; Awuah, Samuel G.] Univ Kentucky, Dept Chem, 505 Rose St, Lexington, KY 40506 USA; [Berger, Gilles] Univ Libre Bruxelles, Fac Pharm, Microbiol Bioorgan & Macromol Chem, Brussels, Belgium in 2019.0, Cited 54.0. The Name is Phenyl(pyridin-2-yl)methanone. Through research, I have a further understanding and discovery of 91-02-1. Recommanded Product: Phenyl(pyridin-2-yl)methanone

The reactivity of bidentate Au-III-Cl species, [(C<^>N)AuCl2], with a bisphosphine or carbon donor ligands results in reductive elimination. Combined experimental and computational investigations lead to the first evidence of a direct intramolecular C(sp(2))-N(sp(2)) bond formation from a monomeric [(C<^>N)AuCl2] gold(iii) complex. We show that bidentate ligated Au(iii) systems bypass transmetallation to form C(sp(2))-N(sp(2)) species and NHC-Au-Cl. Mechanistic investigations of the reported transformation reveal a ligand-induced reductive elimination via a key Au-III intermediate. Kinetic studies of the reaction support a second-order rate process.

About Phenyl(pyridin-2-yl)methanone, If you have any questions, you can contact Kim, JH; Mertens, RT; Agarwal, A; Parkin, S; Berger, G; Awuah, SG or concate me.. COA of Formula: C12H9NO

Reference:
Pyridine – Wikipedia,
,Pyridine | C5H5N – PubChem

You Should Know Something about C6H5NO

About 3-Pyridinecarboxaldehyde, If you have any questions, you can contact Lin, SS; Zhang, LY; Zhang, X; Yu, ZL; Huang, XW; Xu, JH; Liu, Y; Chen, LM; Wu, LX or concate me.. Formula: C6H5NO

An article Synthesis of novel dual target inhibitors of PARP and HSP90 and their antitumor activities WOS:000523307500017 published article about SERUM-ALBUMIN; CANCER; REPAIR; BINDING; CELLS in [Lin, Shanshan; Zhang, LingYu; Zhang, Xiao; Yu, Zelei; Huang, Xiuwang; Xu, Jianhua; Wu, Lixian] FMU, Sch Pharm, Dept Pharmacol, Fuzhou, Peoples R China; [Lin, Shanshan; Zhang, LingYu; Zhang, Xiao; Yu, Zelei; Xu, Jianhua; Liu, Yang; Chen, Limin; Wu, Lixian] FMU, Inst Mat Med, Fuzhou, Peoples R China; [Lin, Shanshan; Zhang, LingYu; Zhang, Xiao; Yu, Zelei; Huang, Xiuwang; Xu, Jianhua; Liu, Yang; Chen, Limin; Wu, Lixian] FMU, Fujian Key Lab Nat Med Pharmacol, Fuzhou, Peoples R China; [Huang, Xiuwang] FMU, Dept Publ Technol Serv Ctr, Fuzhou, Peoples R China; [Liu, Yang; Chen, Limin] FMU, Sch Pharm, Dept Pharmacochem, Fuzhou, Peoples R China in 2020.0, Cited 21.0. The Name is 3-Pyridinecarboxaldehyde. Through research, I have a further understanding and discovery of 500-22-1. Name: 3-Pyridinecarboxaldehyde

Poly (ADP-ribose) polymerase (PARP) inhibitors have achieved great success in clinical application, especially for the prolonged survival of cisplatin-sensitive ovarian cancer patients. However, there are still many patients who do not respond to PARP inhibitors. Novel PARP inhibitors with higher activity are urgently needed. Herein we report a series of compounds by molecular hybridization PARP-1 inhibitor Olaparib (Ola) with HSP90 inhibitor C0817 (one curcumin derivative). All synthesized compounds were evaluated for their antiproliferative activity in vitro, and some were further assessed for their inhibitory activities of the PARP enzyme and HSP90 affinity. Our results indicated that compound 4 could bind to HSP90 and cause static quenching, indicating that compound 4 was able to bind to HSP90, moreover, downstream molecular breast cancer 1 (BRAC-1) was reduced. In conclusion, dual target inhibitors of PARP and HSP90 exhibited stronger selective cytotoxicities against cancer.

About 3-Pyridinecarboxaldehyde, If you have any questions, you can contact Lin, SS; Zhang, LY; Zhang, X; Yu, ZL; Huang, XW; Xu, JH; Liu, Y; Chen, LM; Wu, LX or concate me.. Formula: C6H5NO

Reference:
Pyridine – Wikipedia,
,Pyridine | C5H5N – PubChem

You Should Know Something about 614-18-6

About Ethyl nicotinate, If you have any questions, you can contact Gu, YF; Zhang, Y; Yue, FL; Li, ST; Zhang, ZQ; Li, J; Bai, X or concate me.. Application In Synthesis of Ethyl nicotinate

Recently I am researching about SELECTIVE-INHIBITION; PROLYL 4-HYDROXYLASE; CYTOTOXIC ACTIVITIES; HEPATIC-FIBROSIS; IN-VITRO; DRUG, Saw an article supported by the National Natural Science Fund of ChinaNational Natural Science Foundation of China (NSFC) [81872741]; Innovation Project for College Students [202010183098]. Published in MDPI in BASEL ,Authors: Gu, YF; Zhang, Y; Yue, FL; Li, ST; Zhang, ZQ; Li, J; Bai, X. The CAS is 614-18-6. Through research, I have a further understanding and discovery of Ethyl nicotinate. Name: Ethyl nicotinate

A pyrimidine moiety exhibiting a wide range of pharmacological activities has been employed in the design of privileged structures in medicinal chemistry. To prepare libraries of novel heterocyclic compounds with potential biological activities, a series of novel 2-(pyridin-2-yl) pyrimidine derivatives were designed, synthesized and their biological activities were evaluated against immortalized rat hepatic stellate cells (HSC-T6). Fourteen compounds were found to present better anti-fibrotic activities than Pirfenidone and Bipy55 ‘ DC. Among them, compounds ethyl 6-(5-(p-tolylcarbamoyl)pyrimidin-2-yl)nicotinate (12m) and ethyl 6-(5-((3,4-difluorophenyl)carbamoyl)pyrimidin-2-yl)nicotinate (12q) show the best activities with IC50 values of 45.69 mu M and 45.81 mu M, respectively. Furthermore, the study of anti-fibrosis activity was evaluated by Picro-Sirius red staining, hydroxyproline assay and ELISA detection of Collagen type I alpha 1 (COL1A1) protein expression. Our study showed that compounds 12m and 12q effectively inhibited the expression of collagen, and the content of hydroxyproline in cell culture medium in vitro, indicating that compounds 12m and 12q might be developed the novel anti-fibrotic drugs.

About Ethyl nicotinate, If you have any questions, you can contact Gu, YF; Zhang, Y; Yue, FL; Li, ST; Zhang, ZQ; Li, J; Bai, X or concate me.. Application In Synthesis of Ethyl nicotinate

Reference:
Pyridine – Wikipedia,
,Pyridine | C5H5N – PubChem

What kind of challenge would you like to see in a future of compound:C6H5NO

Recommanded Product: 3-Pyridinecarboxaldehyde. About 3-Pyridinecarboxaldehyde, If you have any questions, you can contact Kalashnik, IN; Dyachenko, VD or concate me.

I found the field of Chemistry very interesting. Saw the article New Multicomponent Synthesis of Functionalized Nitriles and Esters of 6-Alkylsulfanyl-1,4-dihydronicotinic Acids published in 2020.0. Recommanded Product: 3-Pyridinecarboxaldehyde, Reprint Addresses Dyachenko, VD (corresponding author), T Shevchenko Lugansk Natl Univ, UA-91011 Lugansk, Ukraine.. The CAS is 500-22-1. Through research, I have a further understanding and discovery of 3-Pyridinecarboxaldehyde

The multicomponent condensation of malononitrile, hydrogen sulfide, aryl or hetaryl aldehydes, 1,3-dicarbonyl compounds and alkylating reagents afforded functionalized nitriles and esters of 6-alkylsulfanyl-1,4-dihydronicotinic acids, their aromatic analogues and 1,4-dihydrothieno[2,3-b]pyridines.

Recommanded Product: 3-Pyridinecarboxaldehyde. About 3-Pyridinecarboxaldehyde, If you have any questions, you can contact Kalashnik, IN; Dyachenko, VD or concate me.

Reference:
Pyridine – Wikipedia,
,Pyridine | C5H5N – PubChem

Discovery of 91-02-1

HPLC of Formula: C12H9NO. About Phenyl(pyridin-2-yl)methanone, If you have any questions, you can contact Waldchen, F; Mohr, F; Wagner, AH; Heiles, S or concate me.

HPLC of Formula: C12H9NO. Recently I am researching about STRUCTURAL-ANALYSIS; STRESS; BONDS, Saw an article supported by the Fonds der chemischen IndustrieFonds der Chemischen IndustrieEuropean Commission; Deutsche ForschungsgemeinschaftGerman Research Foundation (DFG) [HE 8521/1-1]. Published in AMER CHEMICAL SOC in WASHINGTON ,Authors: Waldchen, F; Mohr, F; Wagner, AH; Heiles, S. The CAS is 91-02-1. Through research, I have a further understanding and discovery of Phenyl(pyridin-2-yl)methanone

Local lipid variations in tissues are readily revealed with mass spectrometry imaging (MSI) methods, and the resulting lipid distributions serve as bioanalytical signatures to reveal cell- or tissue-specific lipids. Comprehensive MSI lipid mapping requires measurements in both ion polarities. Additionally, structural lipid characterization is necessary to link the lipid structure to lipid function. Whereas some structural elements of lipids are readily derived from high-resolution mass spectrometry (MS) and tandem-MS (MSn), the localization of C=C double bonds (DBs) requires specialized fragmentation and/or functionalization methods. In this work, we identify a multifunctional matrix-assisted laser desorption/ionization (MALDI) matrix for spatially resolved lipidomics investigations that reacts with lipids in Paterno-Biichi (PB) reactions during laser irradiation facilitating DB-position assignment and allows dual-polarity high-resolution MALDI-MSI and MALDI (MSI)-I-2 studies. By screening 12 compounds for improved ionization efficiency in positive-/negative-ion mode and the functionalization yield compared to the previously introduced reactive MALDI matrix benzophenone, 2-benzoylpyridine (BzPy) is identified as the best candidate. The new matrix enables DB localization of authentic standards belonging to 12 lipid classes and helps to assign 133/58 lipid features in positive-/negative-ion mode from mouse cerebellum tissue. The analytical capabilities of BzPy as a multifunctional MALDI-MSI matrix are demonstrated by imaging endogenous and PB-functionalized lipids in mouse kidney sections with 7 mu m lateral resolution in both ion modes. Tracking diagnostic lipid DB-position fragment ions in mouse pancreatic tissue with down to 10 mu m pixel size allows us to identify the islets of Langerhans associated with lipid isomer upregulation and depletion.

HPLC of Formula: C12H9NO. About Phenyl(pyridin-2-yl)methanone, If you have any questions, you can contact Waldchen, F; Mohr, F; Wagner, AH; Heiles, S or concate me.

Reference:
Pyridine – Wikipedia,
,Pyridine | C5H5N – PubChem

Why Are Children Getting Addicted To C6H5NO

COA of Formula: C6H5NO. About 3-Pyridinecarboxaldehyde, If you have any questions, you can contact Fernandes, FS; Santos, H; Lima, SR; Conti, C; Rodrigues, MT; Zeoly, LA; Ferreira, LLG; Krogh, R; Andricopulo, AD; Coelho, F or concate me.

Fernandes, FS; Santos, H; Lima, SR; Conti, C; Rodrigues, MT; Zeoly, LA; Ferreira, LLG; Krogh, R; Andricopulo, AD; Coelho, F in [Fernandes, Fabio S.; Santos, Hugo; Lima, Samia R.; Conti, Caroline; Rodrigues Jr, Manoel T.; Zeoly, Lucas A.; Coelho, Fernando] Univ Estadual Campinas, Inst Chem, Lab Synth Nat Prod & Drugs, POB 6154, BR-13083970 Campinas, SP, Brazil; [Ferreira, Leonardo L. G.; Krogh, Renata; Andricopulo, Adriano D.] Univ Sao Paulo, Inst Phys Sao Carlos, Lab Med & Computat Chem, Ave Joao Dagnone 1100, BR-13563120 Sao Carlos, SP, Brazil published Discovery of highly potent and selective antiparasitic new oxadiazole and hydroxy-oxindole small molecule hybrids in 2020.0, Cited 68.0. COA of Formula: C6H5NO. The Name is 3-Pyridinecarboxaldehyde. Through research, I have a further understanding and discovery of 500-22-1.

A series of highly active hybrids were discovered as novel antiparasitic agents. Two heterocyclic scaffolds (1,2,4-oxadiazole and 3-hydroxy-2-oxindole) were linked, and the resulting compounds showed in vitro activities against intracellular amastigotes of two protozoan parasites, Tiypanosoma cruzi and Leishmania infantum. Their cytotoxicity was assessed using HFF-1 fibroblasts and HepG2 hepatocytes. Compounds 5b, 5d, 8h and 8o showed selectivity against L. infantum (IC50 values of 3.89, 2.38, 2.50 and 2.85 mu M, respectively). Compounds 4c, 4q, 8a and 8k were the most potent against T. cruzi, exhibiting IC50 values of 6.20, 2.20, 2.30 and 2.20 mu M, respectively. Additionally, the most potent anti-T. cruzi compounds showed in vitro efficacies comparable or superior to that of benznidazole. These easy-to-synthesize molecules represent novel chemotypes for the design of potent and selective lead compounds for Chagas disease and leishmaniasis drug discovery. (C) 2020 Elsevier Masson SAS. All rights reserved.

COA of Formula: C6H5NO. About 3-Pyridinecarboxaldehyde, If you have any questions, you can contact Fernandes, FS; Santos, H; Lima, SR; Conti, C; Rodrigues, MT; Zeoly, LA; Ferreira, LLG; Krogh, R; Andricopulo, AD; Coelho, F or concate me.

Reference:
Pyridine – Wikipedia,
,Pyridine | C5H5N – PubChem

More research is needed about 91-02-1

About Phenyl(pyridin-2-yl)methanone, If you have any questions, you can contact Gao, XY; Han, SJ; Zheng, ML; Liang, A; Li, JY; Zou, DP; Wu, YS; Wu, YJ or concate me.. HPLC of Formula: C12H9NO

An article Transition-Metal-Free Oxidation of Benzylic C-H Bonds of Six Membered N-Heteroaromatic Compounds WOS:000464250800029 published article about SELECTIVE OXIDATION; AEROBIC OXIDATION; DIRECT AMIDATION; BRONSTED ACID; METHYL-GROUP; COPPER; PYRIDINE; FUNCTIONALIZATION; OXYGENATION; KETONES in [Gao, Xianying; Han, Shuaijun; Zheng, Maolin; Liang, Apeng; Zou, Dapeng; Wu, Yusheng; Wu, Yangjie] Zhengzhou Univ, Henan Key Lab Chem Biol & Organ Chem, Coll Chem & Mol Engn, Zhengzhou 450052, Henan, Peoples R China; [Li, Jingya; Wu, Yusheng] Tetranov Biopharm LLC, Zhengzhou 450052, Henan, Peoples R China; [Li, Jingya; Wu, Yusheng] Collaborat Innovat Ctr New Drug Res & Safety Eval, Zhengzhou 450052, Henan, Peoples R China; [Wu, Yusheng] Tetranov Int Inc, 100 Jersey Ave,Suite A340, New Brunswick, NJ 08901 USA in 2019.0, Cited 77.0. The Name is Phenyl(pyridin-2-yl)methanone. Through research, I have a further understanding and discovery of 91-02-1. Application In Synthesis of Phenyl(pyridin-2-yl)methanone

A novel oxidation of benzylic C H bonds for the synthesis of diverse six-membered N-heteroaromatic aldehydes and ketones has been developed. The obvious advantages of this approach are the simple operation, mild reaction conditions, and without use of toxic reagent and transition metal. The present method should provide a useful access for the synthesis and modification of N-heterocycles.

About Phenyl(pyridin-2-yl)methanone, If you have any questions, you can contact Gao, XY; Han, SJ; Zheng, ML; Liang, A; Li, JY; Zou, DP; Wu, YS; Wu, YJ or concate me.. HPLC of Formula: C12H9NO

Reference:
Pyridine – Wikipedia,
,Pyridine | C5H5N – PubChem