Hypocrellin A has gained much attention in recent years due to its light-induced antitumor, antifungal and antiviral activities. Here we report that hypocrellin A exerts immunomodulatory effects on MHC-restricted presentation of antigen. Hypocrellin A inhibited class II-MHC restricted presentation of exogenous antigen, but not class I MHC-restricted presentation of exogenous antigen, in dendritic cells. Hypocrellin A also inhibited the cytosolic pathway of endogenous antigen presentation. However, hypocrellin A did not inhibit the expression of class I and class II MHC molecules on dendritic cells (DCs), the phagocytic activity of DCs, or the H-2K(b)-restricted presentation of a synthetic peptide, SIINFEKL. These results show that hypocrellin A differentially modulates the MHC-restricted antigen presentation pathways.
Antigen Presentation ; Cytosol ; Dendritic Cells ; Perylene ; Quinones

Pheropsophus jessoensis, bombardier beetle, when physically assaulted, produces diverse toxicants, often at high concentrations, including acids, aldehydes, phenols, and quinones. They can eject these fluids forcibly, in the form of sprays, at 100degrees C. In this way, it induces a chemical burn to their enemies, including humans. We experienced a man who got a chemical burn by a biological pulse jet from Pheropsophus jessoensis, which has not been reported in the Korean literature.
Aldehydes ; Beetles ; Burns, Chemical* ; Humans ; Phenol ; Phenols ; Quinones

OBJECTIVETo establish an UPLC method for simultaneous determination of purpuroxanthine, purpurin, 1,3,6-trihydroxy-2-methylanthraquinone, rubimaillin in carbonized Rubiae Radix et Rhizoma.

METHODThe components were separated on acquity BEHC18 (2.1 mm x 50 mm, 1.7 microm) using methanol and 0.3% formic acid solution as the mobile phase; The flow rate was 0.2 mL x min(-1) and the volume of injection was 2 microL; the column temperature was maintained at 30 degrees C and the detective wavelength was set at 276 nm.

RESULTThere were good liner relationships between the peak area and concentration at ranges of 0.68-34.44 mg x L(-1) (r = 0.9999), 0.66-33.2 mg x L(-1) (r = 0.9997), 0.68-34.08 mg x L(-1) (r = 0.9999), 1.07-53.52 mg x L(-1) (r = 0.9999) for purpuroxanthine, purpurin, 1,3,6-trihydroxy-2-methylanthraquinone, rubimaillin, respectively; the average recovery rates of purpuroxanthine, purpurin, 1,3,6-trihydroxy-2-methylanthraquinone, rubimaillin were 96.95%, 95.75%, 102.5%, 96.15%, respectively, with RSD less than 3%.

CONCLUSIONThe established method was rapid and simple with good accuracy and reproducibility for the determination of carbonized Rubiae Radix et Rhizoma, the method was suitable for the quality control of carbonized Rubiae Radix et Rhizoma.

Four new sesquiterpene quinone meroterpenoids, dysideanones F-G (1-2) and dysiherbols D-E (3-4), were isolated from the marine sponge Dysidea avara collected from the South China Sea. The new structures were elucidated by extensive analysis of spectroscopic data including HR-MS and 1D and 2D NMR spectra, and their absolute configurations were assigned by single-crystal X-ray diffraction and ECD calculations. Anti-inflammatory evaluation showed that dysiherbols D-E (3-4) exhibited moderate inhibitory activity on TNF-α-induced NF-κB activation in human HEK-293T cells with IC₅₀ values of 10.2 and 8.6 μmol·L^-1, respectively.
Animals ; Dysidea/chemistry* ; Porifera ; Quinones/pharmacology* ; Sesquiterpenes/pharmacology* ; Skeleton

OBJECTIVE: To explore the proliferation inhibitory effect of quinones from Blaps rynchopetera defense secretion on colorectal tumor cell lines. METHODS: Human colorectal cancer cell HT-29, human colorectal adenocarcinoma cell Caco-2 and normal human colon epithelial cell CCD841 were chosen for the evaluation of inhibitory activity of the main quinones of B. rynchopetera defense secretion, including methyl p-benzoquinone (MBQ), ethyl p-benzoquinone (EBQ), and methyl hydroquinone (MHQ), through methyl thiazolyl tetrazolium assay. The tumor-related factors, cell cycles, related gene expressions and protein levels were detected by enzyme-linked immunosorbent assy, flow cytometry, RT-polymerase chain reaction and Western blot, respectively. RESULTS: MBQ, EBQ, and MHQ could significantly inhibit the proliferation of Caco-2, with half maximal inhibitory concentration (IC₅₀) values of 7.04 ± 0.88, 10.92 ± 0.32, 9.35 ± 0.83, HT-29, with IC₅₀ values of 14.90 ± 2.71, 20.50 ± 6.37, 13.90 ± 1.30, and CCD841, with IC₅₀ values of 11.40 ± 0.68, 7.02 ± 0.44 and 7.83 ± 0.05 µg/mL, respectively. Tested quinones can reduce the expression of tumor-related factors tumor necrosis factor α, interleukin (IL)-10, and IL-6 in HT-29 cells, selectively promote apoptosis, and regulate the cell cycle which can reduce the proportion of cells in the G₁ phase and increase the proportion of the S phase. Meanwhile, tested quinones could up-regulate mRNA and protein expression of GSK-3β and APC, while down-regulate that of β-catenin, Frizzled1, c-Myc, and CyclinD1 in the Wnt/β-catenin pathway of HT-29 cells. CONCLUSION Quinones from B. rynchopetera defense secretion could inhibit the proliferation of colorectal tumor cells and reduce the expression of related factors, which would be functioned by regulating cell cycle, selectively promoting apoptosis, and affecting Wnt/β-catenin pathway-related mRNA and protein expressions.
Humans ; beta Catenin/metabolism* ; Caco-2 Cells ; Quinones/pharmacology* ; Glycogen Synthase Kinase 3 beta/metabolism* ; Cell Proliferation ; Colorectal Neoplasms/metabolism* ; Cell Line, Tumor ; Apoptosis ; Benzoquinones/pharmacology* ; RNA, Messenger ; Wnt Signaling Pathway

Thioredoxin reductase (TrxR) is one class of the most important antioxidant selenoproteins and is involved in regulating tumor genesis and progression. It has been reported that naphthoquinones can target and inhibit TrxR1 activity therefore produce reactive oxygen species (ROS) mediated by TrxR1, resulting into cellular redox imbalance and making the naphthoquinone compounds to become potential antitumor chemotherapy drugs. The purpose of this work is to explore the interaction between TrxR1 and menadione using biochemical and mass-spectrometric (MS) analyses, to further reveal the detailed mechanisms of TrxR1-mediated naphthoquinone reduction and inhibition of TrxR1 by naphthoquinone compounds. Using the site-directed mutagenesis and recombinantly expressed TrxR1 variants, we measured the steady-state kinetic parameters of menadione reduction mediated by TrxR1 and its variants, performed the inhibition analysis of menadione on TrxR1 activity, and eventually identified the interaction between menadione and TrxR1 through MS analysis. We found that Sec-to-Cys mutation at residue of 498 significantly enhanced the efficiency of TrxR1-mediated menadione reduction, though the Sec⁴⁹⁸ is capable to catalyze the menadione reduction, indicating that TrxR1-mediated menadione reduction is dominantly in a Se-independent manner. Mutation experiments showed that Cys⁴⁹⁸ is mainly responsible for menadione catalysis in comparison to Cys⁴⁹⁷, while the N-terminal Cys⁶⁴ is slightly stronger than Cys⁵⁹ regarding the menadione reduction. LC-MS results detected that TrxR1 was arylated with one molecule of menadione, suggesting that menadione irreversibly modified the hyper-reactive Sec residue at the C-terminus of selenoprotein TrxR1. This study revealed that TrxR1 catalyzes the reduction of menadione in a Se-independent manner meanwhile its activity is irreversibly inhibited by menadione. Hereby it will be useful for the research and development of naphthoquinone anticancer drugs targeting TrxR1.
Catalysis ; Drug Development ; Oxidation-Reduction ; Thioredoxin Reductase 1/metabolism* ; Vitamin K 3/metabolism*

Tanshinone II A, which was known unique to the salvia, was separated and purified by silica gel column chromatography and recrystallisation from an ethyl acetate-soluble portion (the anti-inflammatory active portion) of ethanol extract of Periploca forrestii. The diterpenoid quinone was obtained from the Periploca for the first time.
Diterpenes ; analysis ; isolation & purification ; Drugs, Chinese Herbal ; analysis ; isolation & purification ; Periploca ; chemistry ; Quinones ; analysis ; isolation & purification

Lichen-forming fungal proteins have been seldom searched due to many difficulties in their extraction. Phenols, quinones, proteases, and other components released during cell disruption have been known to be the greatest challenges related to protein extraction from lichens. To overcome these problems and maintain good electrophoretic resolution and high protein concentration, an extraction buffer containing polyvinylpolypyrrolidone, ascorbic acid, Triton X-100, polyethylene glycol, proteinase, and oxidase inhibitors in sodium phosphate buffer was developed. This extraction buffer showed high efficiency for all lichen species tested in the study.
Ascorbic Acid ; Electrophoresis ; Fungal Proteins ; Lichens* ; Octoxynol ; Oxidoreductases ; Peptide Hydrolases ; Phenol ; Phenols ; Polyethylene Glycols ; Quinones ; Sodium

Danshen, the dried roots and rhizomes of Salvia miltiorrhiza Bunge (S. miltiorrhiza), is widely used in the treatment of cardiovascular and cerebrovascular diseases. Tanshinones, the bioactive compounds from Danshen, exhibit a wide spectrum of pharmacological properties, suggesting their potential for future therapeutic applications. Tanshinone biosynthesis is a complex process involving at least six P450 enzymes that have been identified and characterized, most of which belong to the CYP76 and CYP71 families. In this study, CYP81C16, a member of the CYP71 clan, was identified in S. miltiorrhiza. An in vitro assay revealed that it could catalyze the hydroxylation of four para-quinone-type tanshinones, namely neocryptotanshinone, deoxyneocryptotanshinone, and danshenxinkuns A and B. SmCYP81C16 emerged as a potential broad-spectrum oxidase targeting the C-18 position of para-quinone-type tanshinones with an impressive relative conversion rate exceeding 90%. Kinetic evaluations andin vivo assays underscored its highest affinity towards neocryptotanshinone among the tested substrates. The overexpression of SmCYP81C16 promoted the accumulation of (iso)tanshinone in hairy root lines. The characterization of SmCYP81C16 in this study accentuates its potential as a pivotal tool in the biotechnological production of tanshinones, either through microbial or plant metabolic engineering.
Humans ; Salvia miltiorrhiza/metabolism* ; Biosynthetic Pathways ; Quinones/metabolism* ; Plant Roots/metabolism* ; Gene Expression Regulation, Plant

This study sought to clarify the molecular location and the interaction between mitoxantrone and mitoxantrone transforsomes. The anthraquinone of mitoxantrone, a heterocyclic ring that intercalates in the lipid of bilayer, was determined by UV-spectrophotometry and electron probes scan microscopy. Two aminoethylamino side-chains of the drugs fit to the phosphates of lecithin were determined by 8-value, thus the interaction with lecithin was substantiated. Differential scanning calorimetry confirmed that mitoxantrone has remarkable stabilizing effect on the mitoxantrone transforsomes membrane. The mitoxantrone binds tightly to lecithin. So a high degree of encapsulation efficiency and the sustained-release character of mitoxantrone transforsomes are verified.
Anthraquinones ; chemistry ; Calorimetry, Differential Scanning ; Delayed-Action Preparations ; chemistry ; Lecithins ; chemistry ; Mitoxantrone ; chemistry ; Spectrophotometry