Isolation and biological evaluation 7-hydroxy flavone from Avicennia officinalis L: insights from extensive in vitro, DFT, molecular docking and molecular dynamics simulation studies

The flavonoid based 7-hydroxy flavone (PubChem CID: 5281894; molecular formula: C₁₅H₁₀O₃) molecule has been isolated for the first time from the methanolic extract from the leaves of Avicennia officinalis L. in the tropical mangrove ecosystem of Andaman and Nicobar Islands (ANI), India. The molecular structure of bioactive compound was characterized by spectroscopic analysis, including FT-IR, ¹H, ¹³C NMR spectroscopy and ESI-HRMS and elucidated as 7-hydroxy flavone. An anticancer activity of isolated 7-hydroxy flavone was evaluated by in vitro study against two different human cancer cell lines namely, HeLa (cervical cells) and MDA-MB231 (breast cells) and they exhibited promising anticancer activity with IC₅₀ values are 22.5602 ± 0.21 µg/mL and 3.86474 ± 0.35 µg/mL, respectively. The antioxidant property of 7-hydroxy flavone at a standard concentration of 50 µg, was found to be (IC₅₀) 5.5486 ± 0.81 µg/mL. In summary, this investigation provides evidence that 7-hydroxy flavone exhibits both anticancer and antioxidant properties. Meanwhile, the antimicrobial activity ability of 7-hydroxy flavone were also evaluated using three Gram positive and two Gram negative strain exhibited no antimicrobial activities. Density-functional theory (DFT) studies confirm the structure is global minima in the PES, from the optimized geometry FMO and MESP map analyzed. Further, the molecular docking and molecular dynamics simulation studies result shows that 7-hydroxy flavone has the better binding ability with anti-apoptotic Bcl-2 protein with the estimated free energy of binding of -6.3 kcal/mol. This bioactive compound may be act as drug candidate for treating various kinds of cancers. HighlightsA 7-hydroxy flavone molecule has been isolated from Avicennia officinalis.The isolated pure compound was subjected to spectral analysis such as FT-IR, ¹H NMR, ¹³C NMR spectral data and HRMS analysis for skeleton of the molecule.The anticancer activity of 7-hydroxy flavone studied against Cervical (HeLa) cancer cell lines and breast (MDA-MB231) cancer cell lines with the IC₅₀ values of 22.5602 ± 0.21 µg/mL and 3.86474 ± 0.35 µg/mL), respectively.The antioxidant properties of 7-hydroxy flavone were found to be (IC₅₀) 5.5486 ± 0.81 µg/mL at a standard concentration of 50 µg.DFT, molecular docking and MD simulation results explained that 7-hydroxy flavone could be the most promising candidate to inhibit the function of anti-apoptotic Bcl-2 protein in cancerous cell.Communicated by Ramaswamy H. Sarma.

In vitro and in vivo biological characterization of the anti-proliferative potential of a cyclic trinuclear organotin(iv) complex

Identification of novel molecules that can selectively inhibit the growth of tumor cells, avoid causing side effects to patients and/or intrinsic or acquired resistance, usually associated with common chemotherapeutic agents, is of utmost importance. Organometallic compounds have gained importance in oncologic chemotherapy, such as organotin(iv) complexes. In this study, we assessed the anti-tumor activity of the cyclic trinuclear organotin(iv) complex with an aromatic oximehydroxamic acid group [nBu2Sn(L)]3(H2L = N,2-dihydroxy-5-[N-hydroxyethanimidoyl]benzamide) - MG85 - and provided further characterization of its biological targets. We have previously shown the high anti-proliferative activity of this complex against human colorectal and hepatocellular carcinoma cell lines and lower cytotoxicity in neonatal non-tumor fibroblasts. MG85 induces tumor cell apoptosis and down-regulation of proteins related to tubulin dynamics (TCTP and COF1). Further characterization included the: (i) evaluation of interference in the cell cycle progression, including the expression of critical genes; (ii) affinity to DNA and the corresponding mode of binding; (iii) genotoxic potential in cells with deficient DNA repair pathways; and (iv) in vivo tumor reduction efficiency using mouse colorectal carcinoma xenografts.

Effect of sinapic acid on 1,2 dimethylhydrazine induced aberrant crypt foci, biotransforming bacterial enzymes and circulatory oxidative stress status in experimental rat colon carcinogenesis

AIM

This study was aimed to investigate the effect of sinapic acid (SA) on 1,2-dimethylhydrazine (DMH) induced experimental rat colon carcinogenesis.

MATERIALS AND METHODS

Rats were assorted into six groups, group 1 served as control, group 2 received SA (80 mg/kg b.w.) post orally every day until the end of the experimental period of 16 weeks, groups 3-6 rats were injected DMH (20 mg/kg b.w.) subcutaneously once a week for first four weeks. In addition, groups 4-6 rats received different doses of SA (20, 40 and 80 mg/kg b.w.).

RESULTS

Our results showed that DMH induced rats revealed significantly increased ACF development and multiplicity, which were significantly inhibited on supplementation with SA. Moreover, elevated levels/activities of circulatory oxidative stress markers, faecal and colonic mucosal bacterial enzymes were observed in DMH exposed rats, which were diminished on supplementation with SA.

CONCLUSION

Overall, our findings revealed that supplementation with SA offers significant protection against DMH induced rat colon carcinogenesis and the effect of SA at the dose of 40 mg/kg b.w. was more pronounced as compared to the other two doses. (Tab.5, Fig. 3, Ref. 46)

Synthesis, in vitro and in silico antimalarial activity of 7-chloroquinoline and 4H-chromene conjugates

A new series of chloroquinoline-4H-chromene conjugates incorporating piperizine or azipane tethers were synthesized and their anti-malarial activity were evaluated against two Plasmodium falciparum strains namely 3D7 chloroquine sensitive (CQS) and K1 chloroquine resistant (CQR). Chloroquine was used as the standard and also reference for comparison. The conjugates exhibit intense UV absorption with λmax located at 342 nm (log ε=4.0), 254 nm (log ε=4.2), 223 nm (log ε=4.4) which can be used to spectrometrically track the molecules even in trace amounts. Among all the synthetic compounds, two molecules namely 6-nitro and N-piperazine groups incorporated 7d and 6-chloro and N-azapane incorporated 15b chloroquinoline-4H-chromene conjugates showed significant anti-malarial activity against two strains (3D7 and K1) of P. falciparum. These values are lesser than the values of standard antimalarial compound. Molecular docking results suggested that these two compounds showing strong binding affinity with P. falciparum lactate dehydrogenase (PfLDH) and also they occupy the co-factor position which indicated that they could be the potent inhibitors for dreadful disease malaria and specifically attack the glycolytic pathway in parasite for energy production.

Estimation of magnesium in patients with functional hypoparathyroidism

CONTEXT

It is evident that about 30-50% of patients with Vitamin D deficiency (VDD) do not manifest develop secondary hyperparathyroidism (SHPT). A number of theories have been proposed to explain this lack of SHPT, including hypomagnesemia.

SETTINGS AND DESIGN

Retrospective review of laboratory database.

MATERIALS AND METHODS

We evaluated the differences in serum magnesium (Mg) levels among those with VDD with or without SHPT. A retrospective review of 6255 laboratory data of bone mineral profiles performed in the period of 2007-2013. After excluding patients with hypercalcemia, renal dysfunction/unknown kidney function and primary hypothyroidism, the remaining 1323 patient data were analyzed. SHPT was defined as serum parathyroid hormone >65 in those with VDD.

STATISTICAL ANALYSIS USED

ANOVA and Wilcoxon tests as appropriate to compare means. Multivariate logistic regression to analyze relation between variables and outcome of SHPT.

RESULTS

We noted that 55% patients (n = 727) had VDD, and among those who had VDD, 23% (n = 170) were hypocalcemic (corrected serum calcium <8.5). Patients with VDD who did not exhibit SHPT were 56% (n = 407). The mean (±standard deviation) serum Mg levels in the entire cohort (n = 1323) was 1.94 ± 0.26 mg/dl and 1.95 ± 0.26 mg/dl in VDD cohort and 2 ± 0.31 mg/dl in the VDD-hypocalcemic cohort. There was no statistical difference in the Mg levels among those with SHPT compared to those without SHPT (P = 0.14). Serum calcium and phosphorus were lower in those with SHPT (P = 0.06 and P < 0.001, respectively). In multivariate logistic regression, serum calcium (P = 0.043), phosphorus (P < 0.001) and severe VDD (P < 0.001) independently correlated with occurrence of SHPT in VDD.

CONCLUSIONS

Serum Mg levels did not explain the functional hypoparathyroidism seen in about half of the patients with VDD. A low normal serum calcium and phosphorus levels are more likely to be associated with VDD patients who develop SHPT.

Chemopreventive effect of sinapic acid on 1,2-dimethylhydrazine-induced experimental rat colon carcinogenesis

Sinapic acid (SA) is a naturally occurring phenolic acid found in various herbal plants which is attributed with numerous pharmacological properties. This study was aimed to investigate the chemopreventive effect of SA on 1,2-dimethylhydrazine (DMH)-induced rat colon carcinogenesis. Rats were treated with DMH injections (20 mg kg(-1) bodyweight (b.w.) subcutaneously once a week for the first 4 consecutive weeks and SA (20, 40 and 80 mg kg(-1) b.w.) post orally for 16 weeks. At the end of the 16-week experimental period, all the rats were killed, and the tissues were evaluated biochemically. Our results reveal that DMH alone treatment decreased the levels/activities of lipid peroxidation by-products such as thiobarbituric acid reactive substances, conjugated dienes and antioxidants such as superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase and reduced glutathione in the intestine and colonic tissues which were reversed on supplementation with SA. Moreover, the activities of drug-metabolizing enzymes of phase I (cytochrome P450 and P4502E1) were enhanced and those of phase II (glutathione-S-transferase, DT-diaphorase and uridine diphosphate glucuronosyl transferase) were diminished in the liver and colonic mucosa of DMH alone-treated rats and were reversed on supplementation with SA. All the above changes were supported by the histopathological observations of the rat liver and colon. These findings suggest that SA at the dose of 40 mg kg(-1) b.w. was the most effective dose against DMH-induced colon carcinogenesis, and thus, SA could be used as a potential chemopreventive agent.

Synthesis and in silico evaluation of 1N-methyl-1S-methyl-2-nitroethylene (NMSM) derivatives against Alzheimer disease: to understand their interacting mechanism with acetylcholinesterase

Anomalous action of human acetylcholinesterase (hAChE) in Alzheimer's disease (AD) was restrained by various AChE inhibitors, of which the specific and potent lead candidate Donepezil is used for treating the disease AD. Besides the specificity, the observed undesirable side effects caused by Donepezil invoked the quest for new lead molecules with the increased potency and specificity for AChE. The present study elucidates the potency of six 1N-methyl-1S-methyl-2-nitroethylene (NMSM) derivatives to form a specific interaction with the peripheral anionic site and catalytic anionic subsite residues of hAChE. The NMSMs were prepared in good yield from 1,1-di(methylsulfanyl)-2-nitroethylene and primary amine (or) amino acid esters. In silico interaction analysis reveals specific and potent interactions between hAChE and selected ligand molecules. The site-specific interactions formed between these molecules also results in a conformational change in the orientation of active site residues of hAChE, which prevents them from being accessed by beta-amyloid protein (Aβ), which is a causative agent for amyloid plaque formation and acetylcholine (ACh). In silico interaction analysis between the ligand-bounded hAChE with Aß and ACh confirms this observation. The variation in the conformation of hAChE associated with the decreased ability of Aβ and ACh to access the respective functional residues of hAChE induced by the novel NMSMs favors their selection for in vivo analysis to present themselves as new members of hAChE inhibitors.

6-Ethyl-N-methyl-3-nitro-4-nitro-methyl-4H-chromen-2-amine

In the title compound, C₁₃H₁₅N₃O₅, the O and N atoms of the nitro­methyl group and the methyl C atom of the ethyl group are disordered over two sets of sites with refined occupancies of 0.629 (7):0.371 (7) and 0.533 (8):0.467 (8), respectively. The dihydro­pyran ring has an extremely flattened conformation. An intra­molecular N—H⋯O hydrogen bond occurs. In the crystal, pairs of N—H⋯O hydrogen bonds link mol­ecules, forming inversion dimers. In addition, weak inter­molecular C—H⋯O hydrogen bonds are also present.

1-(2-Naphth-yl)-3-phenyl-3-(4,5,6,7-tetra-hydro-1,2,3-benzoselenadiazol-4-yl)propan-1-one

In the title compound, C(25)H(22)N(2)OSe, the fused six-membered cyclo-hexene ring of the 4,5,6,7-tetra-hydro-1,2,3-benzoselenadiazole group adopts a near half-chair conformation and the five-membered 1,2,3-selenadiazole ring is essentially planar (r.m.s. deviation = 0.004 Å). There are weak inter-molecular C-H⋯O and C-H⋯π inter-actions in the crystal structure. Inter-molecular π-π stacking is also observed between the naphthyl units, with a centroid-centroid distance of 3.529 (15) Å.

Butane-1,4-diyl bis(pyridine-4-carboxylate)

The mol­ecule of the title compound, C₁₆H₁₆N₂O₄, lies about an inversion centre; the butane chain adopts an extended zigzag conformation. The dihedral angle between the pyridine ring and the adjacent COO group is 3.52 (s14)°.

3-(4-Methyl-phen-yl)-1-phenyl-3-(4,5,6,7-tetra-hydro-1,2,3-benzoselenadiazol-4-yl)propan-1-one

In the title compound, C(22)H(22)N(2)OSe, the fused six-membered ring of the 4,5,6,7-tetra-hydro-benzo[d][1,2,3] selenadiazole group adopts a near to envelope (E form) conformation and the five-membered 1,2,3-selenadiazole ring is essentially planar (r.m.s. deviation = 0.0059 Å). In the crystal, adjacent mol-ecules are inter-linked through weak inter-molecular C-H⋯π inter-actions.

2,2'-[Naphthalene-1,5-diylbis(nitrilo-methanylyl-idene)]diphenol

The title compound, C₂₄H₁₈N₂O₂, lies about an inversion centre and the asymmetric unit contains one half-mol­ecule. An intra­molecular O—H⋯N hydrogen bond generates a six-membered ring, producing an S(6) ring motif. The crystal packing exhibits inter­molecular π–π stacking inter­actions between the aromatic rings with a centroid–centroid distance of 3.851 (2) Å.

4-[4-(Diethylamino)phenyl]-N-methyl-3-nitro-4H-chromen-2-amine

In the title compound, C₂₀H₂₃N₃O₃, the dihydro­pyran ring adopts half-chair conformation. The chromene system makes a dihedral angle of 87.35 (5)° with the adjacent benzene ring. An intra­molecular N—H⋯O hydrogen bond generates an S(6) motif, which stabilizes the mol­ecular conformation. In the crystal, weak inter­molecular C—H⋯O hydrogen bonds contribute to the stabilization of the packing.

4-{(4-Chloro-phen-yl)[4-(4-methyl-phen-yl)-1,2,3-selenadiazol-5-yl]meth-yl}-4,5,6,7-tetra-hydro-1,2,3-benzoselenadiazole

In the title compound, C(22)H(19)ClN(4)Se(2), the mean plane of the non-fused selenadiazole ring forms dihedral angles of 54.20 (16)° and 70.48 (11)°, respectively, with the essentially planar [maximum deviations of 0.025 (5) and 0.009 (2) Å, respectively] methyl-phenyl and chloro-phenyl substituents. The tetra-hydro-1,2,3-benzoselenadiazole group is disordered over two sets of sites with a refined occupancy ratio of 0.802 (5):0.198 (5). In the crystal, weak inter-molecular C-H⋯N inter-actions are observed.

6-Meth-oxy-N-methyl-3-nitro-4-nitro-methyl-4H-chromen-2-amine

In the title compound, C₁₂H₁₃N₃O₆, the dihydro­pyran ring adopts a near screw-boat conformation. The dihedral angle between the mean planes of the benzene and dihydro­pyran rings is 6.35 (5)°. An intra­molecular N—H⋯O hydrogen bond generates an S(6) motif, which stabilizes the mol­ecular conformation. In the crystal, weak inter­molecular C—H⋯O, N—H⋯O and C—H⋯π hydrogen bonds contribute to the stabilization of the packing.

6,8-Dichloro-N-methyl-3-nitro-4-nitro-methyl-4H-chromen-2-amine

In the title compound, C(11)H(9)Cl(2)N(3)O(5), the dihydro-pyran ring adopts a near-half-chair conformation. The benzene ring makes a torsion angle of 5.02 (5)° with the dihydro-pyran ring. Adjacent mol-ecules are inter-linked through inter-molecular C-H⋯O, N-H⋯O and C-Cl⋯π [3.4743 (9) Å] inter-actions. The inter-molecular N-H⋯O hydrogen bond generates an R(2) (2)(12) motif, which is observed to contribute to the crystal packing stability. Moreover, the mol-ecular structure displays an S(6) motif formed by intra-molecular N-H⋯O hydrogen bonding.

Bis(μ-phenyl-tellurido-κTe:Te)bis-[tetra-carbonyl-rhenium(I)]

The title compound, [Re(2)(C(6)H(5)Te)(2)(CO)(8)], crystallizes with two mol-ecules in the asymmetric unit, in which two Re atoms are coordinated in a slightly distorted octa-hedral environment and are bridged by two Te atoms, which show a distorted trigonal-pyramidal geometry. The torsion angles for the Te-Re-Te-Re sequence of atoms are 19.29 (18) and 16.54 (16)° in the two mol-ecules. Thus, the Re-Te four-membered rings in the two mol-ecules deviate significantly from planarity. Two intra-molecular C-H⋯O inter-actions occur in one of the mol-ecules. Te-Te [4.0551 (10) Å] inter-actions between the two mol-ecules and weak inter-molecular C-H⋯O inter-actions stabilize the crystal packing.

Heptacarbonyl-1κC,2κC-(4-phenyl-pyridine-1κN)di-μ-phenyltellurido-1:2κTe:Te-dirhenium(I)

In the title complex, [Re(2)(C(6)H(5)Te)(2)(C(11)H(9)N)(CO)(7)], two Re atoms are coordinated in slightly distorted octa-hedral coordination environments and are bridged by two Te atoms, which are coordinated in trigonal-pyramidal environments. The torsion angle for the Te-Re-Te-Re sequence of atoms is 17.06 (3)°. The crystal structure is stabilized by weak C-H⋯O and C-H⋯π inter-actions. In addition, there are Te⋯Te distances [4.0392 (12) Å] and O⋯O distances [2.902 (19) Å] which are shorter than the sum of the van der Waals radii for these atoms. A short inter-molecular lone pair⋯π distance [C O⋯Cg = 3.31 (2) Å] is also observed.