OBJECTIVETo analysis chemical components of volatile oil from the seed of Nigella glandulifera (NG), comparing them with those from the seed of foreign N. sativa (NS) and N. damascene (ND), and to quantify thymoquinone in the volatile oil extracted by hydrodistillation (HD) from the seed of NG.

METHODThe volatile oil was extracted by supercritical CO2 extraction (SFE-CO2 ) and HD from the seed of NG and its chemical components was analysed by GC-MS, the relative percentage of components were determined by peak aera normalization method and compare with those of the seed of NS and ND. The content of the thymoquinone in the volatile oil was determined by one point external standard method.

RESULTIn terms of the volatile compounds, p-cymene is the major component of NG and NS, their relative percentage contents are 33.75% and 61.48%, respectively. beta-Elemene is the major component of ND, its relative percentage content is 73.24%. The relative percentage contents of thymoquinone are 3.73% (HD), 3.80% and 0.08% in NG, NS and ND, respectively. Linoleic acid is a major component of volatile oil by SFE-CO2 in NG, but its content of p-cymene is lower. The absolute percentage content of thymoquinone is 1.58% by HD in volatile oil of NG.

CONCLUSIONThere are comparatively large differences of volatile components in NG, NS and ND.

Benzoquinones ; analysis ; Nigella ; chemistry ; Oils, Volatile ; analysis ; Plant Oils ; analysis ; Seeds ; chemistry

Ansamycins, such as rifamycin and ansamitocin, usually consist of a group of structural similar components. Geldanamycin, a benzenic ansamycin, has been found to consist of four structural similar components. We analyzed the geldanamycin (GDM) preparation from Streptomyces hygroscopicus 17997 by LC-ESI(+)-MS/MS, and discovered five novel and one known GDM analogues in trace amounts. Based on the ESI(+)-MS/MS spectra of these GDM analogues, and the present understanding of GDM biosynthesis, we proposed the possible chemical structures of these GDM analogues. Three novel GDM analogues, all having the same molecular formula of C29H42N2O10, were GDM biosynthetic derivatives with one of the three C-C double bonds between C2-C3, C4-C5 and C8-C9 in GDM changed to mono-hydroxylated C-C single bond. The other two novel GDM analogues, having the same molecular formula of C28H38N2O8, were 17(or 12, or 4)-desmethoxylgeldanamycin and 4,5-dihydro-10,11-dehydrate-17-desmethyl-17-hydroxylgeldanamycin, respectively. The known GDM analogue, having the molecular formula of C29H42N2O9, was 4, 5-dihydrogeldanamycin, an intermediate in GDM biosynthesis. The discovery of novel GDM analogues provided us new insights in understanding the biosynthetic details of GDM, and clues of obtaining GDM derivatives by gene-disruption and combinatorial biosynthesis.
Anti-Bacterial Agents ; chemistry ; Benzoquinones ; analysis ; chemistry ; Chromatography, Liquid ; methods ; Lactams, Macrocyclic ; analysis ; chemistry ; Tandem Mass Spectrometry ; methods

OBJECTIVETo evaluate the effects of Embelin on HL-60 cells by the impact of oxidative stress on DNA double-strain breaks (DSBs).

METHODSHL-60 cells were treated with Embelin in different concentration (3, 10, 30, 100, and 300 μg/ml) for 24 h, and inhibitory effects was examined by CCK-8 assay. Reactive oxygen species (ROS) levels were evaluated by flow cytometry using DCFH-DA. Comet assay was used to detect the extent of DSBs.

RESULTSEmbelin inhibited proliferation of HL-60 cells in a dose-dependent manner. At the concentration of 10, 30, 100, and 300 μg/ml, the inhibition rate was (12.74 ± 2.27)%, (23.49 ± 1.96)%, (30.30±1.89)%, and (57.55 ± 3.59)% (P<0.05). Embelin also lead to high level of intracellular ROS and deterioration of DNA damage (P<0.05). When HL-60 cells were pretreated with ROS scavenger N-acetyl-l-cysteine (NAC) for 2 h and then treated with 300 μg/ml Embelin for 24 h, the intracellular ROS level declined and DSBs relieved (P<0.05). Meanwhile, embelin-induced cell viability significantly declined to (32.75 ± 2.70)% (P<0.05).

CONCLUSIONEmbelin induced the death of HL-60 cells by increasing the generation of intracellular oxidation and the oxidative stress, which drived the damage of DNA double-strand.

Acetylcysteine ; Apoptosis ; Benzoquinones ; Cell Survival ; Comet Assay ; DNA Damage ; Fluoresceins ; HL-60 Cells ; Humans ; Oxidative Stress ; Reactive Oxygen Species

To study the chemical constituents of Ardisia punctata, compounds were isolated with a combination of multi-chromatography. Their structures were determined on the basis of spectral analysis and comparison to those of the known compounds. A 1,4-benzoquinone derivative and a alkylphenol were isolated from the petroleum ether extract of the roots of Ardisia punctata. Their structures were elucidated as 2-tridecyl-3-[(2-tridecyl-4-acetoxy-6-methoxy)-phenoxyl] -6-methoxy-1,4-benzoquinone (1) and 2-methoxy-4-hydroxy-6-tridecyl-phenyl acetate (2). The two compounds are both new.
Ardisia ; chemistry ; Benzoquinones ; chemistry ; isolation & purification ; Molecular Structure ; Phenylacetates ; chemistry ; isolation & purification ; Plant Roots ; chemistry ; Plants, Medicinal ; chemistry

OBJECTIVETo detect the structure and chemical characteristics of the adduct from the reaction of p-benzoquinone (BQ) with deoxyguanoside (dGMP).

METHODSdGMP and calf thymus DNA were reacted with BQ in buffered solutions with neutral pH, the reaction products were separated and purified by high performance liquid chromatograph (HPLC), and then characterized by UV spectroscopy and mass spectrometry.

RESULTSThe reaction of BQ with dGMP yielded two adduct products (Ad(1) and Ad(2) respectively). The characterized results of Ad(1) suggested that BQ reacted at the N-1 and N(2) position of dGMP by losing one H(2)O molecule, the molecular weight of Ad(1) was 437, and the molecular formula was C(16)H(16)O(8)N(5)P. Ad(1) could also be detected from calf thymus DNA reacted with BQ in vitro, which possessed the same elution profile by HPLC analysis. Meanwhile, Ad(2) was detected in the experimental condition. It was proposed that Ad(2) was formed by BQ reacted at the N-9 position of dGMP by losing one molecule of deoxyribose, the molecular weight was 241, and the molecular formula was C(11)H(7)O(2)N(5).

CONCLUSIONThe structure of one major adduct from reaction of BQ with DNA is (3'-OH)-1, N(2)-C(6)H(5)CH-2'-deoxyguanosine-5'-monophosphate.

Benzoquinones ; metabolism ; DNA Adducts ; chemistry ; Deoxyguanine Nucleotides ; metabolism ; Hydrogen-Ion Concentration ; Mass Spectrometry ; Molecular Weight ; Spectrophotometry, Ultraviolet

OBJECTIVETo explore the effect of heat shock protein 90 (HSP90) inhibitor (17-DMAG) and oxaliplatin on the proliferation and invasion of colorectal cancer.

METHODSAfter 17-DMAG, oxaliplatin and half-dose combination of 2 drugs processing colorectal cancer SW480 and HCT116 cell lines, CCK8 assay was applied to detect cell viability. RT-PCR and Western blot were used to detect the expression level of the apoptosis-related molecules. Transwell chemokine axis experiment and Western blot were employed to detect cell invasion ability and the expression level of tumor metastasis-associated protein.

RESULTSThe growth of SW480 and HCT116 cells was inhibited after the administration of 17-DMAG and oxaliplatin(P<0.05) in dose- and time-dependent manner. Processed by 17-DMAG 100 nmol/L, oxaliplatin 50 mg/L and half-dose combination of 2 drugs, transcription level of the apoptosis inhibitory gene (Bcl-2) in SW480 and HCT116 cells was decreased, the level of apoptosis promoting gene (Bax) transcription and protein PARP-1 spliceosome expression was increased, and the above trend was more obvious when using half-dose combination of 2 drugs. Transwell chemokine axis experiments showed the penetrating relative percentage and expression level of MMP9 and integrin β3 decreased, especially for half-dose combination of 2 drugs.

CONCLUSION17-DMAG and oxaliplatin can co-inhibit the proliferation and invasion of colorectal cancer.

Antineoplastic Agents ; Apoptosis ; Benzoquinones ; Cell Proliferation ; Cell Survival ; Colorectal Neoplasms ; HCT116 Cells ; Humans ; Lactams, Macrocyclic ; Neoplasm Invasiveness ; Organoplatinum Compounds

Geldanamycin (Gdm), an inhibitor of heat shock protein 90 (Hsp90), shows antitumor and antivirus bioactivity. Most Geldanamycin biosynthetic genes have been cloned from the genome library of Streptomyces hygroscopicus 17997. In this report, polyketide synthase (pks) gene, mono-oxygenase (gdmM) gene and carbamoyltransferase gene (gdmN) were subjected to inactivation. Three gene disrupted mutants (deltapks, deltagdmM and deltagdmN) were obtained by double crossover. No Geldanamycin production was detected in three mutant strains cultured in fermentation broth. Gene complementation experiments excluded the possible polar effect of gene disruption on other genes. These results confirmed that pks, gdmM and gdmN genes were essential for Geldanamycin biosynthesis.
Benzoquinones ; metabolism ; Carboxyl and Carbamoyl Transferases ; genetics ; Lactams, Macrocyclic ; metabolism ; Mixed Function Oxygenases ; genetics ; Polyketide Synthases ; genetics ; Streptomyces ; genetics ; metabolism

OBJECTIVETo study the effect of reactive oxygen species (ROS) during the leukemogenic process associated with exposure to benzene.

METHODSHL-60 was treated with 3 micromol/L benzoquinone (BQ). Generation of ROS in cells was measured by DCFH-DA method. For proliferation assays,cells were stained with alamar blue dye and counted.

RESULTSROS production and the proliferation of cell were all increased in BQ-treated cells (13.10 +/- 0.15, 185% +/- 30.00%) as compared with control cells (11.32 +/- 0.09, 100% +/- 0.00%) (P < 0.05); The addition of catalase just before BQ addition reduced ROS generation to basal levels and decreased the growth of cell (P < 0.05).

CONCLUSIONROS may play an important role in the process of proliferation of HL-60 cells induced by BQ.

Benzoquinones ; toxicity ; Cell Proliferation ; drug effects ; HL-60 Cells ; drug effects ; metabolism ; pathology ; Humans ; Reactive Oxygen Species ; metabolism

BACKGROUND: NAD(P)H: quinone oxidoreductase 1 (NQO1), which is an obligate two-electron reductase that utilizes NAD(P)H as an electron donor and is involved in the protection against oxidative stress, is likely involved in beta-cell destruction. We evaluated the frequency of the NQO1 polymorphism and its association with blood glucose levels. METHODS: Genotypes were determined using a polymerase chain reaction restriction fragment length polymorphism-based assay in 56 patients and 48 healthy subjects. Fasting blood glucose, insulin, and lipid profiles were measured and homeostasis model assessment (HOMA)-insulin resistance (IR) was calculated from fasting glucose and insulin levels in the healthy subjects. RESULTS: The genotype frequencies of NQO1 polymorphism were C/C (56.7%), C/T (42.3%), and T/T (1.0%). There were no associations between the NQO1 polymorphism and body mass index, blood pressure, lipid profile, HbA1c, postprandial glucose, and HOMA-IR. However, NQO1 mutants (C/T and T/T) showed weak but significantly higher fasting blood glucose levels compared with wild type (C/C). CONCLUSION: Our data suggest that NQO1 609 C --> T polymorphism may be associated with glucose metabolism.
Benzoquinones ; Blood Glucose ; Blood Pressure ; Body Mass Index ; Electrons ; Fasting ; Genotype ; Glucose ; Homeostasis ; Humans ; Insulin ; Oxidative Stress ; Oxidoreductases ; Polymerase Chain Reaction ; Polymorphism, Single Nucleotide ; Tissue Donors

Beta-lapachone (beta-Lap; 3,4-dihydro-2, 2-dimethyl-2H-naphthol[1, 2-b]pyran-5,6-dione) is a novel anti-cancer drug under phase I/II clinical trials. beta-Lap has been demonstrated to cause apoptotic and necrotic death in a variety of human cancer cells in vitro and in vivo. The mechanisms underlying the beta-Lap toxicity against cancer cells has been controversial. The most recent view is that beta-Lap, which is a quinone compound, undergoes two-electron reduction to hydroquinone form utilizing NAD(P)H or NADH as electron source. This two-electron reduction of beta-Lap is mediated by NAD(P)H:quinone oxidoreductase (NQO1), which is known to mediate the reduction of many quinone compounds. The hydroquinone forms of beta-Lap then spontaneously oxidizes back to the original oxidized beta-Lap, creating futile cycling between the oxidized and reduced forms of beta-Lap. It is proposed that the futile recycling between oxidized and reduced forms of beta-Lap leads to two distinct cell death pathways. First one is that the two-electron reduced beta-Lap is converted first to one-electron reduced beta-Lap, i.e., semiquinone beta-Lap (SQ).- causing production of reactive oxygen species (ROS), which then causes apoptotic cell death. The second mechanism is that severe depletion of NAD(P)H and NADH as a result of futile cycling between the quinone and hydroquinone forms of beta-Lap causes severe disturbance in cellular metabolism leading to apoptosis and necrosis. The relative importance of the aforementioned two mechanisms, i.e., generation of ROS or depletion of NAD(P)H/NADH, may vary depending on cell type and environment. Importantly, the NQO1 level in cancer cells has been found to be higher than that in normal cells indicating that beta-Lap may be preferentially toxic to cancer cells relative to non-cancer cells. The cellular level of NQO1 has been found to be significantly increased by divergent physical and chemical stresses including ionizing radiation. Recent reports clearly demonstrated that beta-Lap and ionizing radiation kill cancer cells in a synergistic manner. Indications are that irradiation of cancer cells causes long-lasting elevation of NQO1, thereby sensitizing the cells to beta-Lap. In addition, beta-Lap has been shown to inhibit the repair of sublethal radiation damage. Treating experimental tumors growing in the legs of mice with irradiation and intraperitoneal injection of beta-Lap suppressed the growth of the tumors in a manner more than additive. Collectively, beta-Lap is a potentially useful anti-cancer drug, particularly in combination with radiotherapy.
Animals ; Apoptosis ; Benzoquinones ; Cell Death ; Electrons ; Humans ; Hydroquinones ; Injections, Intraperitoneal ; Leg ; Mice ; NAD ; Naphthoquinones ; Necrosis ; Radiation Tolerance ; Radiation, Ionizing ; Reactive Oxygen Species ; Recycling ; Substrate Cycling