Query:  2,2',4,4'-Tetrahydroxybenzophenone

title: Action of 2,2',4,4' tetrahydroxybenzophenone in the biosynthesis pathway of melanin.
abstract: 2,2',4,4' tetrahydroxybenzophenone (Uvinul D50) a sunscreen used in cosmetics, has two effects in the melanin biosynthesis pathway. On the one hand, it acts a weak inhibitor of tyrosinase and on the other, it accelerates the conversion of dopachrome to melanin. Uvinul D50 was seen to behave as a weak competitive inhibitor: apparent constant inhibition=2.02+ 0.09mM and IC50=3.82+ 0.39mM established in this work. These values are higher than those in the bibliography, which tend to be undersetimated. This discrepancy could be explained by the reaction of Uvinul D50 with the dopachrome produced from l tyrosine or l dopa, which would interfere in the measurement. Based on studies of its docking to tyrosinase, it seems that Uvinul D50 interacts with the active site of the enzyme (oxytyrosinase) both in its protonated and deprotonated forms (pKa=7) However, it cannot be hydroxylated, meaning that it acts as a weak inhibitor, not as an alternative substrate, despite its resorcinol structure. Uvinul D50 can be used as sunscreen, in low concentrations without significant adverse effects on melanogenesis.

title: Effect of 2,2',4,4' tetrahydroxybenzophenone (BP2) on steroidogenesis in testicular Leydig cells.
abstract: Endocrine disruptors (EDs) affect the function of animal reproductive systems. Recently, 2,2',4,4' tetrahydroxybenzophenone (BP2) which is a component of UV protection products, was found to be an ED that interferes with the thyroid hormone (TH) axis. However, BP2 activity in the testis has not been well addressed. In this study, we have examined the effects of BP2 on steroidogenesis in testicular Leydig cells in connection with thyroid hormone signaling, which is known to play an important role in testicular development and function. Our study showed that BP2 affected the expression of steroidogenic enzyme genes in testicular Leydig cells, which is differentially regulated by thyroid hormone/thyroid hormone receptor (TR) signaling. In MA 10 Leydig cell line, TR/T3 signaling increased the expression of P450c17 and P450scc, while it decreased the expression of StAR and 3b HSD. Interestingly, BP2 affected the expression of steroidogenic enzyme genes in a manner opposite to that of T3 signaling. BP2 downregulated the TRa/T3 activation of P450c17 and P450scc expression while enhancing the TRa/T3 repression of StAR and 3b HSD expression. Transient transfection analyses with promoter reporter constructs revealed that BP2 altered the expression of steroidogenic enzyme genes by affecting the cAMP and Nur77 activated promoter activity of P450c17, StAR, and 3b HSD. Animal experiments with mice revealed that BP2 decreased the production of testosterone in the testis by affecting the expression of some steroidogenic enzyme genes in vivo. Together, these findings elucidate a molecular mechanism of BP2 action underlying testicular steroidogenesis and also suggest that BP2 acts, in part, as a thyroid antagonist that affects steroidogenesis in the testis.

title: Intramolecular hydrogen bonding in 2,2',4,4' tetrahydroxybenzophenone
abstract: 2,2',4,4' tetrahydroxybenzophenone, C~3HtoOs, is triclinic, P1, a 9.950(2) b 12.479 (2) c 9.334(1)/k, a 98.80(1) fl 93.22(1) 7 72.45 (1) deg, U 1091.9/ 3, Z 4, M r 246.1, D x 1 498(1) Mg m 3. The three dimensional X ray diffraction data were measured by the 0 20 scan technique with a scintillation detector. The structure was solved by direct methods and refined by full matrix least squares techniques to give R(Fo) 0.034 and Rw(Fo)=O.047 for the 2499 reflections above 20. There are two symmetry independent molecules, each of which has two relatively strong intramolecular hydrogen bonds between ortho hydroxyl groups and the keto O atom. Because of differences in crystallographic environment (intermolecular hydrogen bonding) the O O distances of the intramolecular hydrogen bonds are quite variable [2.516 (2) and 2.716 (2)A in one molecule and 2.584 (2) and 2.616 (2)A. in the other molecule] Each hydroxyl group is involved as either an intramolecular or intermolecular hydrogen bond donor to another hydroxyl O atom or to a carbonyl O atom. The ortho hydroxyl group with the longest intramolecular O O distance [2.716 (2)AI is the donor for a bifurcated hydrogen bond. Systematic deviations from an ideal benzene ring geometry are discussed.

title: Crystal Engineering Based on Polymeric Hydrogen Bonded Supramolecules by Self Assembling of 9, 10 Bis(3,5 dihydroxyphenyl)anthracene and 2,2',4,4' Tetrahydroxybenzophenone with Bipyridines
abstract: 9, 10 bis(3,5 dihydroxyphenyl)anthracene (BDHA) and 2,2',4,4' tetrahydroxybenzophenone (THB) are crystallized with bipyridine bases 4,4' bipyridyl (bipy) 1,2 bis(4 pyridyl)ethane (bipy eta) 1,2 di(4 pyridyl)ethylene (dipy ete) 1,3 di(4 pyridyl)propane (dipy pra) 4,4' dipyridyl sulfide (dipy sul) and 4,4' dipyridyl disulfide (dipy dis) to afford molecular complexes (BDHA)(bipy)21, (BDHA) (bipy eta)22, (BDHA)0.5* (dipy pra) *CH3CH2OH 3, (BDHA)0.5* (dipy sul) *H2O 4, (BDHA)0.5* (dipy dis) *CH3CH2OH 5 and (THB) (dipy ete)2*H2O 6. The crystal structures of 1 6 have been determined by single crystal X ray diffraction. All these molecular complexes exhibit polymeric supramolecular structures via O H* *N or O H* *O hydrogen bonding. 1 and 2 form infinitely rectangular macrocycles linked with one another, whose sizes are ca.12.477 a x 4.802 a and ca.14.575 a x 4.809 a, respectively. 3, 5 and 6 form the one dimensional zigzag chain structure. 4 forms a ladder structure, and two dipy sul molecules were included in a frame.

title: Crystal Structure Of Sea Bream Transthyretin in complex with 2,2',4,4' tetrahydroxybenzophenone (BP2)

title: Pseudopolymorphism in hydroxybenzophenones: the dihydrate of 2,2',4,4' tetrahydroxybenzophenone.
abstract: A dihydrate pseudopolymorph of bis(2,4 dihydroxyphenyl)methanone, C(13)H(10)O(5)*2H(2)O, (I) was obtained during polymorphism screening of hydroxybenzophenone derivatives. This structure, in which the molecule sits on a twofold axis, was compared with the known anhydrous form of (I) [Schlemper (1982)  The role of water in the crystal assembly was established on the basis of the known monohydrate pseudopolymorph of 3,4 dihydroxybenzophenone [Landre, Souza, Correa, Martins Doriguetto (2010)

title: Photometric analysis of complex of 2,2',4,4' tetrahydroxybenzophenone with copper
abstract: Absorption spectrum of 2,2',4,4 tetrahydroxybenzophenone(BP 2)was studied with spectrophotometric method.Under condition of pH=10.00,the lmax of BP 2 is determined as 377 nm.BP 2 can be complexed with cupric ion forming a stable yellow complex.Under pH=10.0,composition of the complex can be expressed as lmax of the complex compound is 431 nm,and e=1.1x104 L*mol 1*cm 1.The complexing ratio of BP 2 and copper is 2:1,and the complex formation stability constant is 4.02x109.Under optimum conditions,the linear regression equation is A=0.014 7c 0.014 with the correlation coefficient 0.999 7.The recovery with additional standard achieves 99%~103%.This method can be used for measuring content of BP 2 in sunscreen cosmetics.

title: Preparation of 2,2',4,4' tetrahydroxybenzophenone
abstract: The ultraviolet absorbent 2,2',4,4' tetrahydroxybenzophenone was prepared from 2,4 dihydroxy benzoic acid and resorcin in solvent medium sulfolane using anhydrous ZnCl_2 and POCl_3 as blend catalyst.The effects of catalyst,ratio of raw material,temperature,time and amount of solvent on this reaction were studied.The optimum conditions are as follows:n(phenol):n(acid)=1.4:1,m(POCl_3+ZnCl_2):m(material)=1.4:1,m(POCl_3):m(ZnCl_2)=1.33:1,m(solvent):m(reactants)=0.6:1,at 70 for 2.2 h.The yield of product was higher than 87.0

title: [2,2',4,4' tetrahydroxybenzophenone as a new aldose reductase inhibitor (author's transl)

title: Polarographic Behavior of Sunscreen 2,2'4,4' Tetrahydroxybenzophenone in B R Buffer Solution
abstract: The polarographic behavior of Benzophenone 2 was studied by linear sweep polarography.The results show that Benzophenone 2's first derivative peak potential is 1.12 V(vs SCE) at pH=2.25 B R buffer solution and its peak current is proportional to the logarithm in concentration of Benzophenone 2 over the range of 5.0x10 6~9.0x10 5 mol/L.The linear regression equation is ip'(nA/s) 11 457+2 133xlgc(mol/L) with correlation coefficient of 0.9998.The curve of cyclic voltammetry show that the polarographic wave is irreversible deoxidization wave.The mechanism of electrode reaction was also briefly discussed.