Structural Characterization and In Vitro Antioxidant Activity of Metallothionein from Oratosquilla oratoria.

We report here the purification of a novel metal-binding protein from Oratosquilla oratoria (O. oratoria MT-1) by gel and ion-exchange chromatography. SDS-PAGE and MALDI-TOF analyses demonstrated that isolated O. oratoria MT-1 was of high purity with a molecular weight of 12.4 kDa. The fluorescence response to SBD-F derivatives revealed that O. oratoria MT-1 contained a large number of sulfhydryl groups, which is a general property of metallothioneins. Zn and Cu metal stoichiometries for O. oratoria MT-1 were 3.97:1 and 0.55:1, respectively. The proportion of cysteine (Cys) residues in the amino acid composition was 32.69%, and aromatic amino acids were absent. The peptide sequence coverage with Macrobrachium rosenbergii calmodulin (accession AOA3S8FSK5) was 60%. Infrared spectroscopy of O. oratoria MT-1 revealed two obvious peaks at absorption frequencies for the amide I band and the amide II band. CD spectra revealed that the secondary structure was mainly composed of random coil (57.6%) and ß-sheet (39.9%). An evaluation of in vitro antioxidant activity revealed that isolated O. oratoria MT-1 has strong reducing activities, exhibiting scavenging rates for DPPH and OH of 77.8% and 75.8%, respectively (IC50 values 0.57 mg/mL and 1.1 mg/mL). O. oratoria MT-1 may be used as a functional additive in cosmetics, health foods, and medical products, as well as a reference material for quantitative analysis of metallothionein in such products.

Docosahexaenoic acid monoglyceride induces apoptosis and autophagy in breast cancer cells via lipid peroxidation-mediated endoplasmic reticulum stress.

Epidemiologic and preclinical studieshave shown that marine n-3 polyunsaturated fatty acids (n-3 PUFAs) elicit promising chemoprevention against breast cancer. Docosahexaenoic acid monoglyceride (MAG-DHA), a docosahexaenoic acid sn-1-monoacylglycerol does not required pancreatic lipase to be absorbed, eliciting a better bioavailability when compared with other formulations such as DHA-free fatty acid, DHA-triglycerol, or DHA-ethyl ester. However, the anticancer actions and underlying mechanisms of MAG-DHA on breast cancer remain to be assessed. In this study, MAG-DHA induced significant growth inhibition in MCF-7 and MDA-MB-231 breast cancer cells in a dose-dependent manner. MAG-DHA treatment (80 µM) led to 83.8 and 94.3% growth inhibition between MCF-7 and MDA-MB-231 cells, respectively. MAG-DHA-induced growth inhibition was tightly associated with apoptosis, as evidenced by increased active forms of caspase-3, poly (ADP-ribose) polymerase (PARP) and caspase-12. In particular, MAG-DHA-induced apoptosis was triggered by oxidative stress-mediated endoplasmic reticulum (ER) stress, as evidenced by activation of the PERK-eIF2α pathway in ER. MAG-DHA treatment also strongly suppressed the growth of E0771 murine breast cancer xenografts, significant differences of tumor volume were found between MAG-DHA group (0.271 cm3 ) and control group (0.875 cm3 ) after 15 daily MAG-DHA treatments. The in vitro antibreast cancer mechanism of MAG-DHA was supported by the in vivo xenograft model. In addition, MAG-DHA-induced ER stress concomitantly triggered autophagy in these cancer cells, and the induction of autophagy suppressed its ability to induce apoptotic cell death. Our data suggested that MAG-DHA as dietary supplement, in combination with autophagy inhibitors may be a useful therapeutic strategy in treating breast cancer.

1-{(Z)-1-(2,4-Dichloro-phen-yl)-1-[2-(4-methyl-phen-oxy)eth-oxy]prop-1-en-2-yl}-1H-imidazol-3-ium nitrate.

In the title salt, C21H21Cl2N2O2(+)·NO3(-), the imidazole ring makes dihedral angles of 43.39 (14) and 10.9 (2)° with the 4-methyl-phenyl and 2,4-dichloro-phenyl rings, respectively. The mol-ecule adopts a Z conformation about the C=C double bond, which links the imidazole ring to the 4-methyl-phen-oxy unit via an eth-oxy chain. In the crystal, cations and anions are linked into chains by N-H⋯O and C-H⋯O hydrogen bonds.

1-{(1Z)-1-[3-(2,4-Dichloro-phen-oxy)prop-oxy]-1-(2,4-difluoro-phen-yl)prop-1-en-2-yl}-1H-1,2,4-triazole.

In the title compound, C(20)H(17)Cl(2)F(2)N(3)O(2), the triazole ring makes dihedral angles of 28.0 (3) and 72.5 (2)° with the 2,4-dichloro-pheny and 2,4-difluoro-phenyl rings, respectively, and the mol-ecule adopts a Z-conformation about the C=C double bond. In the crystal, C-H⋯O and C-H⋯N hydrogen bonds link the mol-ecules.

1-{(1Z)-1-[6-(4-Chloro-phen-oxy)hex-y-l-oxy]-1-(2,4-difluoro-phen-yl)prop-1-en-2-yl}-1H-1,2,4-triazol-4-ium nitrate.

In the title compound, C(23)H(25)ClF(2)N(3)O(2) (+)·NO(3) (-), the triazole ring makes dihedral angles of 60.9 (4) and 25.0 (3)° with the 6-chloro-phenyl and 2,4-difluoro-phenyl rings, respectively. The mol-ecule adopts a Z configuration about the C=C double bond. In the crystal, the cations and anions are linked by N-H⋯O hydrogen bonds and weak C-H⋯O inter-actions.

3,4-Dihy-droxy-phenethyl acetate.

In the title compound, C(10)H(12)O(4), the dihedral angle between the acetate group and the aromatic ring is 20.47 (10)°. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds, forming [001] chains. Weak C-H⋯O inter-actions consolidate the packing.

Bis[2-bromo-4-(2-hy-droxy-eth-yl)phenol] monohydrate.

In the title compound, 2C(8)H(9)BrO(2)·H(2)O, the O-C-C-C torsion angles for the hy-droxy-ethyl group and the Br-C-C-O torsion angles involving bromo and phenol groups are 61.7 (11) and 0.7 (12)°, respectively, in one independent mol-ecule and 61.5 (11) and 0.2 (11)°, respectively, in the other. In the crystal, mol-ecules are linked through O-H⋯O and O-H⋯Br hydrogen bonds, forming a polymeric chain.

1-Bromo-2-(4-methoxy-phen-oxy)ethane.

In the crystal structure of the title compound, C(9)H(11)BrO(2), mol-ecules are stacked parallel to the b-axis direction, forming double layers in which the molecules are arranged head-to-head, with the bromo-methyl groups pointing towards each other.

7'-Methyl-5'-oxo-2',3'-dihydro-spiro-[1,3-dioxolane-2,1'(5'H)-indolizine]-6'-carbonitrile.

In the title compound, C(12)H(12)N(2)O(3), the five-membered ring attached to the aromatic ring adopts an envelope conformation with a C atom in the flap position. The spiro-linked five-membered ring adopts a twisted conformation. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules into C(5) chains propagating in [001].

1,2-Bis(4-methyl-phen-oxy)ethane.

In the title compound, C(16)H(18)O(2), the two aromatic rings are almost orthogonal, making a dihedral angle of 89.41 (2)°. There is a C-H⋯π contact between the methyl-ene group and the 4-methyl-phenyl ring. The molecule exhibits twofold symmetry..

2-(2,4,6-Trichloro-phen-oxy)ethyl bromide.

In the title compound, C(8)H(6)BrCl(3)O, there is a weak intra-molecular C-H⋯Cl hydrogen bond involving the O bound methylene group. Intermolecular Cl⋯Cl contacts [3.482 (2) Å] are present in the crystal structure.

1,5-Dimethyl-2-nitro-imino-1,3,5-tri-azinane.

The asymmetric unit of the title compound, C(5)H(11)N(5)O(2), contains two independent mol-ecules. The two triazine rings adopt envelope conformations. Intra-molecular C-H⋯N and N-H⋯O hydrogen bonds result in the formation of two five- and two six-membered rings which are nearly planar; in addition, they are also nearly coplanar. In the crystal structure, inter-molecular N-H⋯N, C-H⋯N and C-H⋯O hydrogen bonds link the mol-ecules.

1-(4-Methyl-1-naphth-yl)ethanone.

In the mol-ecule of the title compound, C(13)H(12)O, the two aromatic rings are oriented at a dihedral angle of 2.90 (3)°. An intra-molecular C-H⋯O hydrogen bond results in the formation of a non-planar six-membered ring, which adopts an envelope conformation. In the crystal structure, inter-molecular C-H⋯O hydrogen bonds link the mol-ecules.

1-(3-Bromopropoxy)-4-chlorobenzene.

In the mol-ecule of the title compound, C(8)H(8)BrClO, the Cl atom lies slightly out of the aromatic ring plane [displacement = 0.072 (3) Å]. In the crystal structure, a π-π contact between the phenyl rings [centroid-centroid distance = 3.699 (3) Å] may stabilize the structure. There also exists a C-H⋯π contact between the methyl-ene group and the chloro-phenyl ring.