Isolation of four new pterocarpans from Zygophyllum eurypterum (Syn. Z. atriplicoides) with enzyme-inhibition properties

Four new pterocarpans, atricarpan A (=(-)-1,2-dihydroxy-4-(hydroxymethyl)-3,9-dimethoxypterocarpan; 1), atricarpan B (=(-)-2,3-ethylenedioxy)-1,4-dihydroxy-9-methoxypterocarpan; 2), atricarpan C (=(-)-1,9-dimethoxypterocarpan-3-carboxylic acid; 3), and atricarpan D (=(-)-2,9-dimethoxy-4-(5-oxohexyl)pterocarpan; 4) were isolated from the BuOH extract of the whole plant of Zygophyllum eurypterum. The structure elucidations of those compounds were based primarily on 1D- and 2D-NMR analysis, including COSY, HMBC, and HMQC correlations. Compounds 1-4 also inhibited butyrylcholinesterase (BChE; EC 3.1.1.8) enzyme in a concentration-dependent manner with IC(50) values between 12.5-65.0 microM. Similarly, compounds 1 and 4 inhibited lipoxygenase (LOX; EC 1.13.11.12) and acetylcholinesterase (AChE; EC 3.1.1.7) enzymes with IC50 values of 13.5 and 20.5 muM, respectively.     

Blood-based lung cancer biomarkers identified through proteomic discovery in cancer tissues,cell lines and conditioned medium

Background

Support for early detection of lung cancer has emerged from the National Lung Screening Trial (NLST), in which low-dose computed tomography (LDCT) screening reduced lung cancer mortality by 20 % relative to chest x-ray. The US Preventive Services Task Force (USPSTF) recently recommended annual screening for the high-risk population, concluding that the benefits (life years gained) outweighed harms (false positive findings, abortive biopsy/surgery, radiation exposure). In making their recommendation, the USPSTF noted that the moderate net benefit of screening was dependent on the resolution of most false-positive results without invasive procedures. Circulating biomarkers may serve as a valuable adjunctive tool to imaging.

Results

We developed a broad-based proteomics discovery program, integrating liquid chromatography/mass spectrometry (LC/MS) analyses of freshly resected lung tumor specimens (n = 13), lung cancer cell lines (n = 17), and conditioned media collected from tumor cell lines (n = 7). To enrich for biomarkers likely to be found at elevated levels in the peripheral circulation of lung cancer patients, proteins were prioritized based on predicted subcellular localization (secreted, cell-membrane associated) and differential expression in disease samples. 179 candidate biomarkers were identified. Several markers selected for further validation showed elevated levels in serum collected from subjects with stage I NSCLC (n = 94), relative to healthy smoker controls (n = 189). An 8-marker model was developed (TFPI, MDK, OPN, MMP2, TIMP1, CEA, CYFRA 21–1, SCC) which accurately distinguished subjects with lung cancer (n = 50) from high risk smokers (n = 50) in an independent validation study (AUC = 0.775).

Conclusions

Integrating biomarker discovery from multiple sample types (fresh tissue, cell lines and conditioned medium) has resulted in a diverse repertoire of candidate biomarkers. This unique collection of biomarkers may have clinical utility in lung cancer detection and diagnoses.

Electronic supplementary material

The online version of this article (doi:10.1186/s12014-015-9090-9) contains supplementary material, which is available to authorized users.     

Molecular interaction analysis of cigarette smoke carcinogens NNK and NNAL with enzymes involved in DNA repair pathways: An in silico approach

DNA damage occurs almost all the times in cells, but is repaired also continuously. Occurrence of all these mutations and their accumulation in one cell which finally becomes tumorigenic/carcinogenic appears possible if the DNA repair mechanism is hampered. We hypothesize that alterations in DNA repair pathways, either all or at least at one i.e. genetic, translational or posttranslational level, becomes quite imperative for the initiation and progression of Cancer. Therefore, we investigated the interaction capability of some carcinogens with the enzymes involved in the DNA repair mechanisms. Cigarette smoke''s derivatives like NNK and NNAL are well established carcinogens. Hence, we analyzed 72 enzymes involved in the DNA repair Mechanisms for their interactions with ligands (NNK and NNAL). The binding efficiencies with enzymes ranging from +36.96 to -7.47 Kcal/Mol. Crystal Structure of Human Carbonmonoxy-Haemoglobin at 1.25 Å Resolution, PDB ID-1IRD as a +Ve control, showed binding energy -6.31 to -6.68 Kcal/Mol. and Human heat shock factor-binding protein 1, PDB ID- 3CI9 as a -Ve control, showed - 3.91 to +2.09 Kcal/Mol. Binding was characterized for the enzymes sharing equivalent or better interaction as compared to +Ve control. Study indicated the loss of functions of these enzymes, which probably could be a reason for fettering of DNA repair pathways resulting in damage accumulation and finally cancer formation.     

Optimization of culture conditions and characterization of a new lectin from <Emphasis Type="Italic">Aspergillus niger</Emphasis>

Lectin activity was determined on solidified medium containing agar and in broth cultures of Aspergillus niger. The fungus was found to express 16 times higher activity in broth cultures, when grown in a medium adjusted to pH 5.5 at 30°C under stationary condition. Lectin activity was found to be expressed by 6-day-old mycelial cultures with maximum activity being expressed on 9th day of incubation. The crude lectin (total titer 1280) was found to be precipitated at 50% saturation of ammonium sulphate with 2.4-fold purifi cation and 83% yield in the precipitate. The partially purifi ed lectin was found to agglutinate all human, rat, mice and pig erythrocytes. It was found to have a strong binding affinity to mucin, asialofetuin and inulin.     

Phonon and thermoelectric properties of single- and double-walled carbon nanotubes from first principles

The phonon and thermal properties of different single- ((n,0) (n = 7,8,9,10,14,15)) and double-walled carbon nanotubes ((7, 0) @ (14, 0), (8, 0) @ (14, 0), (9, 0) @ (15, 0) and (10, 0) @ (15, 0),) were calculated using the combination of density functional theory and non-equilibrium Green’s function methods. It was found that the Seebeck and Peltier coefficients for some of the single- and multi-walled carbon nanotubes have negative values. Moreover, in sharp contrast to low ?T, the higher thermoelectric figure of merit is anticipated at the higher temperature. The effect of the atoms number per unit cell on the phonons energies outweighs the effect of the vacuum and the size of the tubes for DWCNTs. All in all, the electron–phonon coupling generates the roughly plethora of thermoelectric coefficients and thermal conductance.     

Antiviral potential of 4-hydroxypanduratin A,secondary metabolite of Fingerroot,Boesenbergia pandurata (Schult.), towards Japanese Encephalitis virus NS2B/NS3 protease

4-hydroxypanduratin A is a secondary metabolite of Boesenbergia pandurata Schult. (Fingerroot) plant with various pharmacological activities such as neuroprotective, potent antioxidant, antibacterial and antifungal. Flaviviral NS2B/NS3 protease activity is essential for polyprotein processing and viral replication for Japanese Encephalitis Virus (JEV), a major cause of Acute Encephaltis in Asia. Inhibition of formation of this complex by arresting the binding of NS2B with NS3 would reduce the enzyme''s activity to meager proportions and hence would prevent further viral proliferation. The automated 3D structure of NS2B protein of the JEV GP78 was predicted based on the sequence-to-structure-to-function paradigm using I-TASSER and the function of NS2B protein was inferred by matching to other known proteins. The stereochemical quality of predicted structure was checked by PROCHECK. The antiviral activity of 4-hydroxypanduratin A against NS2B protein as a potential drug has been elucidated in this paper. Docking simulation analysis showed 4-hydroxypanduratin A as potential inhibitor of NS2B protein/cofactor which is necessary for NS3 protease activity. 220 derivatives of 4-hydroxypanduratin A were virtually screened with rigid criteria of Lipinski''s rule of 5 using Autodock4.2. 4-hydroxypanduratin A was found interacting with target hydrophilic domain in NS2B protein by two Hbonds (Gly80 and Asp81) with active residues, several hydrophobic interactions, Log P value of 5.6, inhibition constant (Ki) of 51.07nM and lowest binding energy of -9.95Kcal/Mol. Hence, 4-hydroxypanduratin A targeted to Site 2 will have sufficient profound effect to inhibit protease activity to abrogate viral replication. It could be a promising potential drug candidate for JEV infections using NS2B Site 2 as a Drug target.