3-(3-Chloro­phenyl­sulfin­yl)-2,4,6-trimethyl-1-benzofuran

In the title compound, C17H15ClO2S, the 3-chloro­phenyl ring makes a dihedral angle of 71.46 (4)° with the mean plane of the benzofuran fragment. In the crystal, mol­ecules are linked by weak C—H⋯O hydrogen bonds and a slipped π–π inter­action between the 3-chloro­phenyl rings of adjacent mol­ecules [centroid–centroid distance = 3.630 (2) Å, inter­planar distance = 3.375 (2) Å and slippage = 1.337 (2) Å]

2-(3-Fluoro­phen­yl)-5-iodo-7-methyl-3-methyl­sulfinyl-1-benzofuran

In the title compound, C16H12FIO2S, the 3-fluoro­phenyl ring makes a dihedral angle of 34.93 (7)° with the mean plane [r.m.s. deviation = 0.019 (1) Å] of the benzofuran fragment. In the crystal, mol­ecules are linked via pairs of I⋯O contacts [3.088 (2) Å] into inversion dimers. These dimers are connected by weak C—H⋯O hydrogen bonds

Sp1 up-regulates cAMP-response-element-binding protein expression during retinoic acid-induced mucous differentiation of normal human bronchial epithelial cells.

CREB [CRE (cAMP-response element)-binding protein] is an important transcription factor that is differentially regulated in cells of various types. We recently reported that RA (retinoic acid) rapidly activates CREB without using RARs (RA receptors) or RXRs (retinoid X receptors) in NHTBE cells (normal human tracheobronchial epithelial cells). However, little is known about the role of RA in the physiological regulation of CREB expression in the early mucous differentiation of NHTBE cells. In the present study, we report that RA up-regulates CREB gene expression and that, using 5\u27-serial deletion promoter analysis and mutagenesis analyses, two Sp1 (specificity protein 1)-binding sites located at nt -217 and -150, which flank the transcription initiation site, are essential for RA induction of CREB gene transcription. Furthermore, we found that CREs located at nt -119 and -98 contributed to basal promoter activity. Interestingly, RA also up-regulated Sp1 in a time- and dose-dependent manner. Knockdown of endogenous Sp1 using siRNA (small interfering RNA) decreased RA-induced CREB gene expression. However, the converse was not true: knockdown of CREB using CREB siRNA did not affect RA-induced Sp1 gene expression. We conclude that RA up-regulates CREB gene expression during the early stage of NHTBE cell differentiation and that RA-inducible Sp1 plays a major role in up-regulating human CREB gene expression. This result implies that co-operation of these two transcription factors plays a crucial role in mediating early events of normal mucous cell differentiation of bronchial epithelial cells

Methyl 2-(5-methyl-3-methyl­sulfinyl-1-benzofuran-2-yl)acetate

The title compound, C13H14O4S, was prepared by oxidation of methyl 2-(5-methyl-3-methyl­sulfanyl-1-benzofuran-2-yl)acetate with 3-chloro­peroxy­benzoic acid. The O atom and methyl group of the methyl­sulfinyl substituent lie on opposite sides of the plane of the benzofuran system. The crystal structure is stabilized by inter­molecular aromatic π–π inter­actions between the benzene rings of neighbouring mol­ecules, with a centroid–centroid separation of 3.841 (3) Å

5-Bromo-2-phenyl-3-phenyl­sulfinyl-1-benzofuran

In the title compound, C20H13BrO2S, the O atom and the phenyl group of the phenyl­sulfinyl substituent are located on opposite sides of the plane of the benzofuran system. The S-bound phenyl ring is almost perpendicular to this plane [80.35 (8)°]. The phenyl ring in the 2-position is twisted with respect to the benzofuran plane, making a dihedral angle of 16.0 (1)°

Isopropyl 2-(5-fluoro-3-methyl­sulfinyl-1-benzofuran-2-yl)acetate

In the title compound, C14H15FO4S, the O atom and the methyl group of the methyl­sulfinyl substituent are located on opposite sides of the plane of the benzofuran fragment which is essentially planar with a mean deviation of 0.008 (1) Å from its least-squares plane. The crystal structure stabilized by three different inter­molecular non-classical C—H⋯O hydrogen bonds. The crystal structure also exhibits aromatic π–π inter­actions between the benzene rings of adjacent benzofuran ring systems [centroid–centroid distance = 3.688 (2) Å

2,5,7-Trimethyl-3-phenyl­sulfinyl-1-benzo­furan

The title compound, C17H16O2S, was prepared by the oxidation of 2,5,7-trimethyl-3-phenyl­sulfanyl-1-benzofuran with 3-chloro­peroxy­benzoic acid. The O atom and the phenyl group of the phenyl­sulfinyl substituent lie on opposite sides of the plane of the benzofuran fragment. The phenyl ring is nearly perpendicular to the plane of the benzofuran unit [88.30 (9)°] and is tilted slightly towards it. No π–π or C—H⋯π inter­actions are observed between neighbouring mol­ecules in the crystal structure because of steric hindrance induced by the three methyl groups

2-(3-Ethyl­sulfanyl-5-phenyl-1-benzofuran-2-yl)acetic acid

The title compound, C18H16O3S, crystallizes with two symmetry-independent mol­ecules in the asymmetric unit. The phenyl rings are rotated out of the benzofuran planes, making dihedral angles of 43.38 (7) and 56.13 (6)° in the two mol­ecules. The carboxyl groups are involved in inversion-related inter­molecular O—H⋯O hydrogen bonds, which link the mol­ecules into centrosymmetric dimers. These dimers are further packed into stacks along the b axis by weak non-classical inter­molecular C—H⋯O hydrogen bonds. The crystal structure also exhibits inter­molecular C—H⋯π inter­actions, and two aromatic π–π inter­actions between the furan rings of neighbouring benzofuran systems; the centroid–centroid distances are 3.500 (3) and 3.605 (3) Å

Ethyl 2-(5-bromo-3-ethyl­sulfinyl-1-benzofuran-2-yl)acetate

The title compound, C14H15BrO4S, was prepared by the oxidation of ethyl 2-(5-bromo-3-ethyl­sulfanyl-1-benzofuran-2-yl)acetate with 3-chloro­peroxy­benzoic acid. The crystal structure is stabilized by aromatic π–π inter­actions between the benzene rings of neighbouring mol­ecules [centroid–centroid distance = 3.814 (9) Å], and possibly by weak C—H⋯π inter­actions. In addition, the crystal structure exhibits three inter­molecular C—H⋯O non-classical hydrogen bonds. The ethyl group bonded to carboxyl­ate O atom is disordered over two positions, with refined site-occupancy factors of 0.686 (18) and 0.314 (18)

2-(3-Fluoro­phen­yl)-3-methyl­sulfanyl-5-phenyl-1-benzofuran

In the title compound, C21H15FOS, the dihedral angles between the mean plane of the benzofuran fragment and the pendant 3-fluoro­phenyl and phenyl rings are 1.76 (5) and 32.29 (5)°, respectively. In the crystal, mol­ecules are linked by a slipped π–π inter­action between the furan and benzene rings of neighbouring mol­ecules [centroid–centroid distance = 3.665 (2) Å, inter­planar distance = 3.391 (2) Å and slippage = 1.390 (2) Å]