Zhang, Dongyang’s team published research in Journal of Materials Chemistry A: Materials for Energy and Sustainability in 2019 | CAS: 101-70-2

Bis(4-methoxyphenyl)amine(cas: 101-70-2) is a diphenylamine derivative used as a chemical additive for cured rubber.Bis(4-methoxyphenyl)amine is highly toxic and may potentially induce chromosome abberation.Recommanded Product: Bis(4-methoxyphenyl)amine

The author of 《Importance of terminated groups in 9,9-bis(4-methoxyphenyl)-substituted fluorene-based hole transport materials for highly efficient organic-inorganic hybrid and all-inorganic perovskite solar cells》 were Zhang, Dongyang; Tai, Wu‡; Xu, Peng; Ou, Yangmei; Sun, Anxin; Ma, Huili; Cui, Bo; Sun, Hanwen; Ding, Liming; Hua, Yong. And the article was published in Journal of Materials Chemistry A: Materials for Energy and Sustainability in 2019. Recommanded Product: Bis(4-methoxyphenyl)amine The author mentioned the following in the article:

Hole-transport materials (HTMs) play a crucial role in determining the photovoltaic performance and long-term stability of perovskite solar cells (PSCs), because they not only efficiently facilitate hole-extraction and transfer, but also act as a barrier to protect the perovskite from moisture and oxygen. So far, the power conversion efficiencies (PCEs) over 20% in PSCs have been mostly achieved by employing a Spiro-OMeTAD-based HTM. However, it suffers from some drawbacks such as relatively low hole-mobility, complicated synthesis and difficult purification, which hamper its potential com. applications. Here, for the first time, two new easily accessible 9,9-bis(4-methoxyphenyl)-substituted fluorene-based HTMs comprising H (YT1) and methoxyphenyl-fluorene (YT3) as the terminated groups have been synthesized for use in organic-inorganic hybrid and all-inorganic PSCs. The (FAPbI3)0.85(MAPbBr3)0.15 and CsPbI2Br PSCs based on YT3 yield very impressive PCEs of 20.23% and 13.36%, resp., both of which are higher than that of Spiro-OMeTAD (19.18% and 12.30%). More encouragingly, the YT3-based PSC displays good long-term stability for 600 h. These results confirm that different terminated groups in HTMs show a significant effect on the energy levels, hole extraction and transfer, thin-film surface morphol. and photovoltaic performance. Our findings could provide a useful insight for future rational design of HTMs for highly efficient and stable PSCs. In the part of experimental materials, we found many familiar compounds, such as Bis(4-methoxyphenyl)amine(cas: 101-70-2Recommanded Product: Bis(4-methoxyphenyl)amine)

Bis(4-methoxyphenyl)amine(cas: 101-70-2) is a diphenylamine derivative used as a chemical additive for cured rubber.Bis(4-methoxyphenyl)amine is highly toxic and may potentially induce chromosome abberation.Recommanded Product: Bis(4-methoxyphenyl)amine

Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem

Eglence-Bakir, Songul’s team published research in Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy in 2020 | CAS: 673-22-3

2-Hydroxy-4-methoxybenzaldehyde(cas: 673-22-3) is the main component of root bark essential oil of Periploca sepium Bunge. It is a potential tyrosinase inhibitor present in African medicinal plants. 2-Hydroxy-4-methoxybenzaldehyde was used in the synthesis of Schiff base ligand.Electric Literature of C8H8O3

《Palladium(II) complexes with thione and thioalkylated thiosemicarbazones: Electrochemical, antimicrobial and thermogravimetric investigations》 was written by Eglence-Bakir, Songul; Sahin, Musa; Salt, Betul Zehra; Tuzun, Elif; Kara, Emel Mataraci; Atun, Gulten; Cavus, Selva; Kizilcikli, Irfan. Electric Literature of C8H8O3 And the article was included in Spectrochimica Acta, Part A: Molecular and Biomolecular Spectroscopy in 2020. The article conveys some information:

Four methoxy substitute salicylidene thiosemicarbazones were synthesized. The reaction of both thione and thioalkylated thiosemicarbazones with PdCl2 in ethanol yields ONS-coordinated chelate complexes with general formula [Pd(L)Cl]. The structures of eight compounds were characterized by using anal. and spectroscopic methods. Electrochem. of the Pd(II) complexes was studied using cyclic voltammetric technique. The CVs of the complexes were quite complicate because of some oxidative responses of the ligands which proceed by forming conjugated -N:CH-, -HC:CH- and -N:CH-HC:CH- groups. Two cathodic responses attributed to one electron reduction of Pd(II)/(I) and Pd(I)/(0) were observed for the central ion coordinated with S atom of H3C-S- group whereas only one reduction peak appeared when the Pd(II) coordinated with S atom of >C:S group of thiosemicarbazone ligand. The latter also showed an addnl. anodic response assigned to Pd(II)/(III) oxidation Thermogravimetric anal. (TGA) technique was used to investigate and compare the thermal properties of the ligands and their metal complexes. In vitro antimicrobial activity of thiosemicarbazones and their complexes was evaluated against four Gram-neg. bacteria, three Gram-pos. bacteria, and antifungal activity against three fungi. After reading the article, we found that the author used 2-Hydroxy-4-methoxybenzaldehyde(cas: 673-22-3Electric Literature of C8H8O3)

2-Hydroxy-4-methoxybenzaldehyde(cas: 673-22-3) is the main component of root bark essential oil of Periploca sepium Bunge. It is a potential tyrosinase inhibitor present in African medicinal plants. 2-Hydroxy-4-methoxybenzaldehyde was used in the synthesis of Schiff base ligand.Electric Literature of C8H8O3

Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem

Mijbil, Zainelabideen Y.’s team published research in European Physical Journal B: Condensed Matter and Complex Systems in 2020 | CAS: 33100-27-5

1,4,7,10,13-Pentaoxacyclopentadecane(cas: 33100-27-5) is a member of crown ether Ligands. Crown-ethers are macrocyclic polyethers capable of forming host-guest complexes, especially with inorganic and organic cations. Crown-ethers can incorporate protonated primary amine compounds by formation of ion-dipole bonds with the oxygen atoms of the chiral selector. Crown-ethers have been widely used for the separation of several pharmaceuticals both in aqueous and non-aqueous media. Quality Control of 1,4,7,10,13-Pentaoxacyclopentadecane

《Destructive-quantum-interference suppression in crown ether single molecule junction》 was published in European Physical Journal B: Condensed Matter and Complex Systems in 2020. These research results belong to Mijbil, Zainelabideen Y.; Essa, Haider O.. Quality Control of 1,4,7,10,13-Pentaoxacyclopentadecane The article mentions the following:

The electronic transmission coefficient of X-crown ether-Y (X = 3Y ;Y = 4, 5, and 6) have been investigated using d. functional theory and Green’s function approximation incorporated with the Huckel method. The results illustrate unexpected role of the oxygen atoms to highly enhance charge transport in the crown ether mols. by moving the destructive quantum interferences (QI) close to the Fermi level. Such slight shifting creates a beneficial peak-valley pattern in the transmission spectra that facilitates the ON/OFF variation. Moreover, the length of the crown ether rings offers an insignificant impact on electronic transmission. Hence, we believe that these findings would deepen our understanding of QI patterns and exploit crown ether mols. more practically and efficiently in mol. devices. The results came from multiple reactions, including the reaction of 1,4,7,10,13-Pentaoxacyclopentadecane(cas: 33100-27-5Quality Control of 1,4,7,10,13-Pentaoxacyclopentadecane)

1,4,7,10,13-Pentaoxacyclopentadecane(cas: 33100-27-5) is a member of crown ether Ligands. Crown-ethers are macrocyclic polyethers capable of forming host-guest complexes, especially with inorganic and organic cations. Crown-ethers can incorporate protonated primary amine compounds by formation of ion-dipole bonds with the oxygen atoms of the chiral selector. Crown-ethers have been widely used for the separation of several pharmaceuticals both in aqueous and non-aqueous media. Quality Control of 1,4,7,10,13-Pentaoxacyclopentadecane

Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem

Ahsin, Atazaz’s team published research in Physica E: Low-Dimensional Systems & Nanostructures (Amsterdam, Netherlands) in 2022 | CAS: 33100-27-5

1,4,7,10,13-Pentaoxacyclopentadecane(cas: 33100-27-5) is a member of crown ether Ligands. Crown-ethers are macrocyclic polyethers capable of forming host-guest complexes, especially with inorganic and organic cations. Crown-ethers can incorporate protonated primary amine compounds by formation of ion-dipole bonds with the oxygen atoms of the chiral selector. Crown-ethers have been widely used for the separation of several pharmaceuticals both in aqueous and non-aqueous media. Synthetic Route of C10H20O5

In 2022,Ahsin, Atazaz; Jadoon, Tabish; Ayub, Khurshid published an article in Physica E: Low-Dimensional Systems & Nanostructures (Amsterdam, Netherlands). The title of the article was 《M@[12-crown-4] and M@[15-crown-5] where (M=Li, Na, and K); the very first examples of non-conventional one alkali metal-containing alkalides with remarkable static and dynamic NLO response》.Synthetic Route of C10H20O5 The author mentioned the following in the article:

Excess electron compounds, such as alkalides, were shown to be promising nonlinear optical (NLO) materials with higher static and frequency-dependent nonlinearities. The intriguing alkalides are obtained after doping the alkali metals with crown ethers M@[12-crown-4] and M@[15-crown-5] (where M=Li, Na, and K). The studied complexes are thermodynamically stable and their interactions energies range from -66.51 to -3.51 kcal mol-1. The geometric, electronic, and nonlinear optical properties are validated through d. functional theory at the CAM-B3LYP/6-31+G(d,p) level of theory. The significant (neg.) NBO charge present on alkali metals reveals their alkalide characteristics. Furthermore, reduced HOMO-LUMO gaps for the designed complexes show their excellent electronic and conductive properties. Being excess electron candidate the significant static first hyperpolarizability value increased up to 1.2 x 107 au where the βvec response recorded up to 1.1 x 107 au. The total hyperpolarizability nicely correlates with hyperpolarizability (βtl) which suggests their excellent NLO properties. Besides, the dynamic hyperpolarizability response for electro-optical pockel’s effect β(-2ω;ω,0) increases up to 3.5 x 107 au at dispersion frequency of 1064 nm. The dynamic hyperpolarizability responses for SHG are much pronounced at the larger dispersion frequency. The dynamic second hyperpolarizability response for the dc-Kerr effect increases up to 6.4 x 109 au. The frequency-dependent NLO response of M@[12-crown-4] alkalides is slightly larger than those of M@[12-crown-4]. Moreover, the hyper Rayleigh scattering hyperpolarizability (βHRS) value is calculated up to 3.4 x 106 au. The experimental part of the paper was very detailed, including the reaction process of 1,4,7,10,13-Pentaoxacyclopentadecane(cas: 33100-27-5Synthetic Route of C10H20O5)

1,4,7,10,13-Pentaoxacyclopentadecane(cas: 33100-27-5) is a member of crown ether Ligands. Crown-ethers are macrocyclic polyethers capable of forming host-guest complexes, especially with inorganic and organic cations. Crown-ethers can incorporate protonated primary amine compounds by formation of ion-dipole bonds with the oxygen atoms of the chiral selector. Crown-ethers have been widely used for the separation of several pharmaceuticals both in aqueous and non-aqueous media. Synthetic Route of C10H20O5

Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem

Cho, Hong-Jun’s team published research in Proceedings of the National Academy of Sciences of the United States of America in 2020 | CAS: 139115-91-6

tert-Butyl (2-(2-hydroxyethoxy)ethyl)carbamate(cas: 139115-91-6) belongs to ethers.The C-O bonds that comprise simple ethers are strong. Product Details of 139115-91-6 They are unreactive toward all but the strongest bases. Although generally of low chemical reactivity, they are more reactive than alkanes.

《Design of a multivalent bifunctional chelator for diagnostic 64Cu PET imaging in Alzheimer′s disease》 was published in Proceedings of the National Academy of Sciences of the United States of America in 2020. These research results belong to Cho, Hong-Jun; Huynh, Truc T.; Rogers, Buck E.; Mirica, Liviu M.. Product Details of 139115-91-6 The article mentions the following:

Herein, we report a 64Cu positron emission tomog. (PET) imaging agent that shows appreciable in vivo brain uptake and exhibits high specific affinity for beta-amyloid (Aβ) aggregates, leading to the successful PET imaging of amyloid plaques in the brains of 5xFAD mice vs. those of wild-type mice. The employed approach uses a bifunctional chelator with two Aβ-interacting fragments that dramatically improves the Aβ-binding affinity and lipophilicity for favorable blood-brain barrier penetration, while the use of optimized-length spacers between the Cu-chelating group and the Aβ-interacting fragments further improves the in vivo Aβ-binding specificity and brain uptake of the corresponding 64Cu PET imaging agent. The results came from multiple reactions, including the reaction of tert-Butyl (2-(2-hydroxyethoxy)ethyl)carbamate(cas: 139115-91-6Product Details of 139115-91-6)

tert-Butyl (2-(2-hydroxyethoxy)ethyl)carbamate(cas: 139115-91-6) belongs to ethers.The C-O bonds that comprise simple ethers are strong. Product Details of 139115-91-6 They are unreactive toward all but the strongest bases. Although generally of low chemical reactivity, they are more reactive than alkanes.

Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem

Cruz-Migoni, Abimael’s team published research in Proceedings of the National Academy of Sciences of the United States of America in 2019 | CAS: 2398-37-0

1-Bromo-3-methoxybenzene(cas: 2398-37-0) can be used in chemical reaction as intermediates to obtain target materials such as dyes, pharmaceuticals, perfumes, photoinitiators and agrochemicals.Recommanded Product: 1-Bromo-3-methoxybenzene

Recommanded Product: 1-Bromo-3-methoxybenzeneIn 2019 ,《Structure-based development of new RAS-effector inhibitors from a combination of active and inactive RAS-binding compounds》 appeared in Proceedings of the National Academy of Sciences of the United States of America. The author of the article were Cruz-Migoni, Abimael; Canning, Peter; Quevedo, Camilo E.; Bataille, Carole J. R.; Bery, Nicolas; Miller, Ami; Russell, Angela J.; Phillips, Simon E. V.; Carr, Stephen B.; Rabbitts, Terence H.. The article conveys some information:

The RAS gene family is frequently mutated in human cancers, and the quest for compounds that bind to mutant RAS remains a major goal, as it also does for inhibitors of protein-protein interactions. We have refined crystallization conditions for KRAS169Q61H-yielding crystals suitable for soaking with compounds and exploited this to assess new RAS-binding compounds selected by screening a protein-protein interaction-focused compound library using surface plasmon resonance. Two compounds, referred to as PPIN-1 and PPIN-2, with related structures from 30 initial RAS binders showed binding to a pocket where compounds had been previously developed, including RAS effector protein-protein interaction inhibitors selected using an intracellular antibody fragment (called Abd compounds). Unlike the Abd series of RAS binders, PPIN-1 and PPIN-2 compounds were not competed by the inhibitory anti-RAS intracellular antibody fragment and did not show any RAS-effector inhibition properties. By fusing the common, anchoring part from the two new compounds with the inhibitory substituents of the Abd series, we have created a set of compounds that inhibit RAS-effector interactions with increased potency. These fused compounds add to the growing catalog of RAS protein-protein inhibitors and show that building a chem. series by crossing over two chem. series is a strategy to create RAS-binding small mols. After reading the article, we found that the author used 1-Bromo-3-methoxybenzene(cas: 2398-37-0Recommanded Product: 1-Bromo-3-methoxybenzene)

1-Bromo-3-methoxybenzene(cas: 2398-37-0) can be used in chemical reaction as intermediates to obtain target materials such as dyes, pharmaceuticals, perfumes, photoinitiators and agrochemicals.Recommanded Product: 1-Bromo-3-methoxybenzene

Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem

Almenar, S’s team published research in Annals of anatomy = Anatomischer Anzeiger : official organ of the Anatomische Gesellschaft in 2019 | CAS: 106685-40-9

6-(3-(Adamantan-1-yl)-4-methoxyphenyl)-2-naphthoic acid(cas:106685-40-9) is a third-generation synthetic retinoid and a highly lipophilic compound derived from naphthoic acid. It is widely used in the treatment of acne.Application of 106685-40-9

The author of 《Anatomy, immunohistochemistry, and numerical distribution of human splenic microvessels.》 were Almenar, S; Rios-Navarro, C; Ortega, M; Molina, P; Ferrandez-Izquierdo, A; Ruiz-Sauri, A. And the article was published in Annals of anatomy = Anatomischer Anzeiger : official organ of the Anatomische Gesellschaft in 2019. Application of 106685-40-9 The author mentioned the following in the article:

The microvascular architecture of the spleen plays an important role in the immunological function of this organ. The different types of vessels are related to different reticular cells each with their own immunomodulatory functions. The present study describes an immunohistochemical and morphometric analysis of the various types of vessels in 21 human autopsy non-pathological splenic samples. On an area of 785,656.37 μm2 for each sample, we classified and quantified the type and number of vascular structures, each according to their morphology and immunohistochemical profile, and obtained the ratios between them. The distribution of trabecular vessels and the characteristics of the venules are reviewed. In our material the so-called “”cavernous perimarginal sinus”” (anatomical structure previously described by Schmidt et al., 1988) was observed and interpreted as a curvilinear venule shaped by the follicle in contact with the trabecular vein. Our material comprised 261 trabeculae (containing 269 arterial sections and 508 venous sections), 30,621 CD34+ capillaries, 7739 CD271+ sheathed capillaries, 2588 CD169+ sheathed capillaries, and 31,124 CD8+ sinusoids. The total area (TA) (14,765,714.88 μm2) occupied by the sinusoidal sections of the 21 cases was much higher than the TA of the capillary sections (1,700,269.83 μm2). Similarly, the TA (651,985 μm2) occupied by the sections of the trabecular veins was much higher than the TA of the trabecular arteries (88,594 μm2). The total number of CD34+ capillaries and of sinusoids CD8+ was similar for the sum of the 21 cases, nevertheless there were large differences in each case. Statistically the hypothesis that the number of capillaries and sinusoids are present with the same frequency is discarded. In view of the absence of a numerical correlation between capillaries and sinusoids, we postulate that very possibly the arterial and the venous vascular trees are two anatomically independent structures separated by the splenic cords. We believe that this is the first work where splenic microvascularization is simultaneously approached from a morphometric and immunohistochemical point of view. The experimental part of the paper was very detailed, including the reaction process of 6-(3-(Adamantan-1-yl)-4-methoxyphenyl)-2-naphthoic acid(cas: 106685-40-9Application of 106685-40-9)

6-(3-(Adamantan-1-yl)-4-methoxyphenyl)-2-naphthoic acid(cas:106685-40-9) is a third-generation synthetic retinoid and a highly lipophilic compound derived from naphthoic acid. It is widely used in the treatment of acne.Application of 106685-40-9

Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem

More, Vijaykumar’s team published research in Indian Journal of Chemistry, Section B: Organic Chemistry Including Medicinal Chemistry in 2020 | CAS: 882-33-7

1,2-Diphenyldisulfane(cas: 882-33-7) belongs to ethers.Ethers do have nonbonding electron pairs on their oxygen atoms, and they can form hydrogen bonds with other molecules (alcohols, amines, etc.) that have O―H or N―H bonds. Recommanded Product: 882-33-7 The ability to form hydrogen bonds with other compounds makes ethers particularly good solvents for a wide variety of organic compounds and a surprisingly large number of inorganic compounds.

《KF-Al2O3 catalyzed mild and efficient preparation of symmetrical disulfides from thiols》 was published in Indian Journal of Chemistry, Section B: Organic Chemistry Including Medicinal Chemistry in 2020. These research results belong to More, Vijaykumar; Malba, Chandrashekhar; Panchgalle, Sharad. Recommanded Product: 882-33-7 The article mentions the following:

A facile, efficient, convenient and environmentally friendly method for the oxidation of various thiols RCH2SH (R = n-Pr, Ph, 2-furyl, etc.) to their corresponding disulfides (RCH2S)2 catalyzed by KF-Al2O3 in very short reaction times in acetonitrile and at room temperature has been reported. In addition to this study using 1,2-Diphenyldisulfane, there are many other studies that have used 1,2-Diphenyldisulfane(cas: 882-33-7Recommanded Product: 882-33-7) was used in this study.

1,2-Diphenyldisulfane(cas: 882-33-7) belongs to ethers.Ethers do have nonbonding electron pairs on their oxygen atoms, and they can form hydrogen bonds with other molecules (alcohols, amines, etc.) that have O―H or N―H bonds. Recommanded Product: 882-33-7 The ability to form hydrogen bonds with other compounds makes ethers particularly good solvents for a wide variety of organic compounds and a surprisingly large number of inorganic compounds.

Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem

Manuri, Brahmayya’s team published research in Proceedings of the National Academy of Sciences, India, Section A: Physical Sciences in 2018 | CAS: 33797-34-1

(3-Methoxy-2-methylphenyl)methanol(cas: 33797-34-1) belongs to ethers.SDS of cas: 33797-34-1Although ethers resist hydrolysis, they are cleaved by hydrobromic acid and hydroiodic acid. Hydrogen chloride cleaves ethers only slowly.

SDS of cas: 33797-34-1On March 31, 2018, Manuri, Brahmayya; Dasi, Samsonu; Korla, Praveen Kumar published an article in Proceedings of the National Academy of Sciences, India, Section A: Physical Sciences. The article was 《Neat Synthesis of Substituted Benzoic Acids Employing TBHP/Oxone Catalyst and Study of Their Anti-oxidant Activity》. The article mentions the following:

In the present study, a variety of benzyl alcs. are synthesized from corresponding benzoic acids employing TBHP/oxone and FeCl3 as an effective and selective catalyst under solvent free conditions. The conversion rate and yields of the products are significant. The advantages of the selected catalyst are: cheaply available and more selectivity of the product formations rather than the formation of any undesired byproducts. The synthesized compounds were tested for anti-oxidant activities. In the experiment, the researchers used (3-Methoxy-2-methylphenyl)methanol(cas: 33797-34-1SDS of cas: 33797-34-1)

(3-Methoxy-2-methylphenyl)methanol(cas: 33797-34-1) belongs to ethers.SDS of cas: 33797-34-1Although ethers resist hydrolysis, they are cleaved by hydrobromic acid and hydroiodic acid. Hydrogen chloride cleaves ethers only slowly.

Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem

Zhao, Xin’s team published research in ACS Catalysis in 2022-02-04 | 10541-78-3

ACS Catalysis published new progress about Amination catalysts (stereoselective, regioselective). 10541-78-3 belongs to class ethers-buliding-blocks, and the molecular formula is C8H11NO, Formula: C8H11NO.

Zhao, Xin; Yang, Fang; Zou, Shao-Yu; Zhou, Qian-Qian; Chen, Zi-Sheng; Ji, Kegong published the artcile< Cu-Catalyzed Intermolecular γ-Site C-H Amination of Cyclohexenone Derivatives: The Benefit of Bifunctional Ligands>, Formula: C8H11NO, the main research area is aniline cyclohexenone copper catalyst regioselective amination green chem; amino alc preparation antibacterial antioxidant; cyclohexadienyl oxy silyl ether aniline copper regioselective diastereoselective amination; aminocyclohexenone preparation green chem.

Utilizing 1,10-phenanthroline-type bifunctional ligands, an efficient Cu-catalyzed intermol. site-selective remote C-H amination using cyclohexenone derivatives and anilines was realized. The amide group installed on the bifunctional ligand played a key role in stabilizing the N-centered radical generated in-situ to realize C-N-directed formation. Meanwhile, a useful catalytic system for site-selective intermol. remote γ-C-H amination to p-aminophenols and γ-aminated enones was established. This economical and practical approach using oxygen as the terminal oxidant was mild and environmentally friendly.

ACS Catalysis published new progress about Amination catalysts (stereoselective, regioselective). 10541-78-3 belongs to class ethers-buliding-blocks, and the molecular formula is C8H11NO, Formula: C8H11NO.

Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem