Urease and Carbonic Anhydrase Inhibitory Effect of Xanthones from Aspergillus nidulans, an Endophytic Fungus of Nyctanthes arbor-tristis.

Urease plays a major role in the pathogenesis of peptic and gastric ulcer and also causes acute pyelonephritis and development of infection-induced reactive arthritis. Carbonic anhydrases (CA) cause pathological disorders such as epilepsy (CA I), glaucoma, gastritis, renal, pancreatic carcinomas, and malignant brain tumors (CA II). Although various synthetic urease and carbonic anhydrase inhibitors are known, these have many side effects. Hence, present studies were undertaken on ethyl acetate extract of Aspergillus nidulans, an endophytic fungus separated from the leaves of Nyctanthes arbor-tristis Linn. and led to the isolation of five furanoxanthones, sterigmatin (1: ), sterigmatocystin (3: ), dihydrosterigmatocystin (4: ), oxisterigmatocystin C (5: ), acyl-hemiacetal sterigmatocystin (6: ), and a pyranoxanthone (2: ). Acetylation of 3: gave compound O-acetyl sterigmatocystin (7: ). Their chemical structures were elucidated by 1H and 13C NMR and MS. The inhibitory effect of isolated compounds was evaluated on urease and carbonic anhydrase (bCA II) enzymes in vitro. Compounds 3: and 6: showed significant urease inhibition (IC50 19 and 21 µM), while other compounds exhibited varying degrees of urease inhibition (IC50 33 - 51 µM). Compounds 4, 6: and 7: exhibited significant inhibition of bCA II (IC50 values 21, 25 and 18 µM respectively), compounds 1: -3: displayed moderate inhibition (IC50 61, 76 and 31 µM respectively) while 5: showed no inhibition. A mechanistic study of the most active urease inhibitors was also performed using enzyme kinetics and molecular docking. All compounds were found non-toxic on the NIH-3T3 cell line.

Design, Synthesis, In Silico and POM Studies for the Identification of the Pharmacophore Sites of Benzylidene Derivatives.

Due to the uneven distribution of glycosidase enzyme expression across bacteria and fungi, glycoside derivatives of antimicrobial compounds provide prospective and promising antimicrobial materials. Therefore, herein, we report the synthesis and characterization of six novel methyl 4,6-O-benzylidene-α-d-glucopyranoside (MBG) derivatives (2-7). The structures were ascertained using spectroscopic techniques and elemental analyses. Antimicrobial tests (zone of inhibition, MIC and MBC) were carried out to determine their ability to inhibit the growth of different Gram-positive, Gram-negative bacteria and fungi. The highest antibacterial activity was recorded with compounds 4, 5, 6 and 7. The compounds with the most significant antifungal efficacy were 4, 5, 6 and 7. Based on the prediction of activity spectra for substances (PASS), compounds 4 and 7 have promising antimicrobial capacity. Molecular docking studies focused on fungal and bacterial proteins where derivatives 3 and 6 exhibited strong binding affinities. The molecular dynamics study revealed that the complexes formed by these derivatives with the proteins L,D-transpeptidase Ykud and endoglucanase from Aspergillus niger remained stable, both over time and in physiological conditions. Structure-activity relationships, including in vitro and in silico results, revealed that the acyl chains [lauroyl-(CH3(CH2)10CO-), cinnamoyl-(C6H5CH=CHCO-)], in combination with sugar, were found to have the most potential against human and fungal pathogens. Synthetic, antimicrobial and pharmacokinetic studies revealed that MBG derivatives have good potential for antimicrobial activity, developing a therapeutic target for bacteria and fungi. Furthermore, the Petra/Osiris/Molinspiration (POM) study clearly indicated the presence of an important (O1δ-----O2δ-) antifungal pharmacophore site. This site can also be explored as a potential antiviral moiety.

In vitro potential antiviral SARS-CoV-19- activity of natural product thymohydroquinone and dithymoquinone from Nigella sativa.

Inflammation, oxidation, and compromised immunity all increase the dangers of COVID-19, whereas many pharmaceutical protocols may lead to increased immunity such as ingesting from sources containing vitamin E and zinc. A global search for natural remedies to fight COVID-19 has emerged, to assist in the treatment of this infamous coronavirus. Nigella satvia is a world-renowned plant, an esteemed herbal remedy, which can be used as a liquid medicine to increase immunity while decreasing the dangers of acute respiratory distress syndrome. Thymoqinone (TQ), dithymoqinone (DTQ) and thymohydroquinone (THQ), are major compounds of the essential oil contained in N.sativa. A current study aims to discover the antiviral activity of two compounds, Thymohydroquinone and Dithymoquinone, which are synthesized through simple chemical procedures, deriving from thymoquinone, which happens to be a major compound of Nigella sativa. A half-maximal cytotoxic concentration, "CC50", was calculated by MTT assay for each individual drug, The sample showed anti-SARS-CoV-2 activity at non-cytotoxic nanomolar concentrations in vitro with a low selectivity index (CC50/IC50 = 31.74/23.15 = 1.4), whereby Dimthymoquinone shows high cytotoxicity.

Novel thiophene Chalcones-Coumarin as acetylcholinesterase inhibitors: Design, synthesis, biological evaluation, molecular docking, ADMET prediction and molecular dynamics simulation.

A series of around eight novel chalcone based coumarin derivatives (23a-h) was designed, subjected to in-silico ADMET prediction, synthesized, characterized by IR, NMR, Mass analytical techniques and evaluated as acetylcholinesterase (AChE) inhibitor for the treatment of Alzheimer's disease (AD). The results of predicted ADMET study demonstrated the drug-likeness properties of the titled compounds with developmental challenges in lipophilicity and solubility parameters. The in vitro assessment of the synthesized compounds revealed that all of them showed significant activity (IC50 ranging from 0.42 to 1.296 µM) towards AChE compared to the standard drug, galantamine (IC50 = 1.142 ±â€¯0.027 µM). Among these, compound 23e displayed the most potent inhibitory activity with IC50 value of 0.42 ±â€¯0.019 µM. Cytotoxicity of all compounds was tested on normal human hepatic (THLE-2) cell lines at three different concentrations using the MTT assay, in which none of the compound showed significant toxicity at the highest concentration of 1000 µg/ml compared to the control group. Based on the docking study against AChE, the most active derivative 23e was orientated towards the active site and occupied both catalytic anionic site (CAS) and peripheral anionic site (PAS) of the target enzyme. In-silico studies revealed tested showed better inhibition activity of AChE compared to Butyrylcholinesterase (BuChE). Molecular dynamics simulation explored the stability and dynamic behavior of 23e- AChE complex.

Crystallographic study, biological assessment and POM/Docking studies of pyrazoles-sulfonamide hybrids (PSH): Identification of a combined Antibacterial/Antiviral pharmacophore sites leading to in-silico screening the anti-Covid-19 activity.

The discovery and development of new potent antimicrobial and antioxidant agents is an essential lever to protect living beings against pathogenic microorganisms and free radicals. In this regard, new functionalized pyrazoles have been synthesized using a simple and accessible approach. The synthesized aminobenzoylpyrazoles 3a-h and pyrazole-sulfonamides 4a-g were obtained in good yields and were evaluated in vitro for their antimicrobial and antioxidant activities. The structures of the synthesized compounds were determined using IR, NMR, and mass spectrometry. The structure of the compound 4b was further confirmed by single crystal X-ray diffraction. The results of the in vitro screening show that the synthesized pyrazoles 3 and 4 exhibit a promising antimicrobial and antioxidant activities. Among the tested compounds, pyrazoles 3a, 3f, 4e, 4f, and 4g have exhibited remarkable antimicrobial activity against some microorganisms. In addition, compounds 3a, 3c, 3e, 4a, 4d, 4f, and 4g have shown a significant antioxidant activity in comparison with the standard butylhydroxytoluene (BHT). Hence, compounds 3a, 4f, and 4g represent interesting dual acting antimicrobial and antioxidant agents. In fact, pyrazole derivatives bearing sulfonamide moiety (4a-g) have displayed an important antimicrobial activity compared to pyrazoles 3a-h, this finding could be attributed to the synergistic effect of the pyrazole and sulfonamide pharmacophores. Furthermore, Molecular docking results revealed a good interaction of the synthesized compounds with the target proteins and provided important information about their interaction modes with the target enzyme. The results of the POM bioinformatics investigations (Petra, Osiris, Molinspiration) show that the studied heterocycles present a very good non toxicity profile, an excellent bioavailability, and pharmacokinetics. Finally, an antiviral pharmacophore (O δ-, O δ-) was evaluated in the POM investigations and deserves all our attention to be tested against Covid-19 and its Omicron and Delta mutants.

Synthesis, biological activity and POM/DFT/docking analyses of annulated pyrano[2,3-d]pyrimidine derivatives: Identification of antibacterial and antitumor pharmacophore sites.

New annulated pyrano[2,3-d]pyrimidine derivatives were synthesized with hydroxyl, methoxy, bromine, nitrile and nitro substituents on its skeleton. The correlated electronic effect of substituents on the magnitude of antibacterial activity was noted. The electron donating substituents (namely; 4-OH, 4-OCH3, 4-Br) and electron withdrawing substituents (4-NO2) on phenyl ring in the pyrano[2,3-d]pyrimidine skeleton exerted different influence on its antimicrobial activity against some Gram-positive and Gram-negative bacteria such as Pseudomonas aureus, E. coli, Staphylococcus aureus, Klebsiella pneumonia and Bacillus cereus. All the pyrano[2,3-d]pyrimidines were characterized by spectroscopic analyses. Antibacterial screening revealed that the presence of heteroaryl, cyano and amino groups on pyrano[2,3-d]pyrimidine skeleton increases its penetrating power on the bacterial cell wall so that the product becomes more biologically active. So the the nature of electron withdrawing or electro-donnor Impact of substituents should be taken in consideration in drug design. Hydrolysis of -CRN to amide restored vital Intramolecular interaction like ortho-nitrophenyl and ONOδ-…NHδ+/amide link, offering a crucial template for antibacterial NH, HO-pharmacophore sites, which ultimately elevated innate antimicrobial profiles. POM combinatorial analysis of tangible electronic contributions due to armed annulated pyrano[2,3-d]pyrimidines concluded their broad antimicrobial activity and viable/prominent drug score index through perspective parameters particularly: inter atomic distance/linkers, steric, electronic, polar parameters, and with a different polarising effect of electron donating/withdrawing environments of substituents. Furthermore, an anti-Kinase pharmacophore site (OCNHCO) was evaluated in continuation of the POM investigations. All synthesized products verified fewer side effects than standard streptomycin, but facile implication in selective cancer media (viz. breast or leucemia still needs to be screened).

Multidrug resistance reversal activity of extract and a rare dimeric naphthoquinone from Diospyros lotus.

A dimeric naphthoquinone namely dihydrodyspyrole R (1) was purified once more from Diospyros lotus. Dihydrodyspyrole R and chloroform fractions were evaluated for their effects on the reversion of multidrug resistance (MDR). The compounds (1) and extract exhibited promising MDR reversing effect in a dose-dependent manner against mouse T-lymphoma cell line. Molecular docking of compound 1 revealed the correlation between in-silico with in-vitro results. The molecular docking results showed that compound 1 is bind closely where co-crystal ligand of P-gp is present. But usually, computational investigation predicts that, if a compound gives lesser score then compound will exhibit good activity. Hence, the docking scores of compound 1 are the near to the Rhodamine. It is conclude that there are certain important structural features of compound 1which are responsible for the inhibiting potency of P-gp from mice. The computational Petra/Osiris/Molinspiration (POM) analysis confirms the possibility of use of compound 1 without side effect or less toxicity risks.

Synthesis and study of anti-HIV-1 RT activity of 5-benzoyl-4-methyl-1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-2-one derivatives.

In the present study, a series of fourteen 5-benzoyl-4-methyl-1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-2-one derivatives were designed, synthesized and characterized by appropriate spectral analysis. Further, titled compounds were in-vitro screened against wild HIV-1 RT enzyme using ELISA based colorimetric assay, in which four compounds significantly inhibited the RT activity with IC50≤25µM. Moreover, two significantly active compounds of the series, A10 and A11 exhibited IC50 values 8.62 and 6.87µM respectively, during the in-vitro assay. Structure Activity Relationship (SAR) studies were performed for the synthesized compounds in order to estimate the effect of substitution pattern on the RT inhibitory potency. The cytotoxicity of the synthesized compounds was evaluated against T lymphocytes. Further, putative binding modes of the significantly active (A11) and the least active (A4) compounds with wild HIV-1 RT were also investigated using docking studies.

Antimicrobial Activity of Some Novel Armed Thiophene Derivatives and Petra/Osiris/Molinspiration (POM) Analyses.

Tetrasubstituted 2-acetylthiophene derivative 5 was synthesized and then condensed with various nitrogen nucleophiles such as 5-amino-1,2,4-triazole, 2-aminobenzimidazole, aniline or p-chloroaniline to afford the corresponding iminothiophene derivatives 6-8a,b. Condensation of thiophene 5 with malononitrile as carbon nucleophile afforded compound 9, which underwent nucleophilic addition with DMF-DMA to afford compound 10. The newly synthesized products were characterized by elemental analysis, IR, MS, ¹H-(13)C-NMR and CHN analysis and then evaluated for their antimicrobial activity. Results of the in vitro antibacterial activity showed that thiophene derivative 7 was found to be more potent than the standard drug gentamicin against Pseudomonas aeruginosa. Some of these compounds showed potential antimicrobial activities. Molecular docking and Osiris/Molinspiration analyses show the crucial role and impact of substituents on bioactivity and indicate the unfavorable structural parameters in actual drug design: more substitution with electronic donor group doesn't guarantee more effective bioactivity. This study should greatly help in an intelligent and a controlled pharmacomodulation of antibiotics.

Design, Synthesis, in vitro Antiproliferative Activity, Binding Modeling of 1,2,4,-Triazoles as New Anti-Breast Cancer Agents.

This article demonstrates the synthesis of 1,2,4-triazole derivatives and their applications in medicine particularly as anti-breast cancer agents which is a major issue of the present. The synthesized compounds were characterized by elemental analysis, FT-IR and NMR. DFT was used to study the quantum chemical calculations of geometries and vibrational wave numbers of 3-hydroxynaphthyl and p-tolyl substituted 1,2,4-triazoles in the ground state. The scaled harmonic vibrational frequencies obtained from the DFT method were compared with those of the FT-IR spectra and found good agreement. The synthesized 1,2,4-triazole-naphthyl hybrids were screened for the anticancer activity against MCF-7 breast cancer lines. Among them compounds 3 and 7 showed broad spectrum anticancer activity with IC50 values 9.7 µM and 7.10 µM, respectively and their activity is comparable to that of the standard drugs. The molecular model for binding between the compounds (1-8) and the active site of BRCA2 was obtained on the basis of the computational docking results and the structure-activity relationship.

In vivo antinociceptive and muscle relaxant activity of leaf and bark of Buddleja asiatica L.

The current study was designed to assess the antinociceptive and skeleton muscle relaxant effect of leaves and barks of Buddleja asiatica in animal models. In acetic acid induced writhing test, pretreatment of ethanolic extract of leaves and barks evoked marked dose dependent antinociceptive effect with maximum of 70% and 67% pain relief at 300mg/kg i.p. respectively. In chimney test, the ethanolic extract of leaves and barks evoked maximum of 66.66% and 53.33% muscle relaxant effect after 90min of treatment at 300mg/kg i.p respectively. In traction test, the ethanolic extract of leaves and barks caused maximum of 60% and 73.33% muscle relaxant effect after 90min of treatment at 300mg/kg i.p respectively. In short, both leaves and barks demonstrated profound antinociceptive and skeleton muscle relaxant effects and thus the study provided natural healing agents for the treatment of said disorders.

Evaluation of phytochemical content, antimicrobial, cytotoxic and antitumor activities of extract from Rumex hastatus D. Don roots.

BACKGROUND: Being a part of Chinese as well as ayurdic herbal system, roots of Rumex hastatus D. Don (RH) is highly medicinal, used to regulated blood pressure. It is also reported that the plant is diuretic, laxative, tonic, used against microbial skin diseases, bilious complaints and jaundice. The present study is conducted to evaluate phytochemical, antimicrobial, antitumor and cytotoxic activities of extract obtained from R. hastatus roots. METHODS: RH roots were powdered and extracted with methanol to get crude extract. Crude extract was further fractioned on the basis of increasing polarity, with n-hexane (HRR), chloroform (CRR), ethyl acetate (ERR), n-butanol (BRR) and residual aqueous fraction (ARR). Methanol extract and its derived fractions were subjected to phytochemical screening and assayed for antibacterial activities via agar well diffusion method. Antifungal activities were checked through agar tube dilution method whereas potato disc assay was employed for the determination of antitumor activity. On the other hand cytotoxic activities were conducted using brine shrimps procedures. RESULTS: The results obtained from phytochemical analysis indicate the presence of alkaloids, anthraquinones, flavonoids and saponins in all the fractions. Most of the plant fractions showed substantial antimicrobial activities, which is in accordance with the spacious use of tested plant samples in primary healthcare center. Fractions of R. hastatus roots for cytotoxicity were tested as an effective cytotoxic was found as BRR > MRR > CRR > ARR > ERR > HRR. Ranking order of fractions of R. hastatus roots for effective antitumor screening was found as MRR > BRR > ARR > CRR > ERR > HRR. CONCLUSIONS: These results showed that R. hastatus appeared as an important source for the discovery of new antimicrobial drugs and antitumor agents; verify its traditional uses and its exploitation as therapeutic agent.

Synthesis, bioactivity, molecular docking and POM analyses of novel substituted thieno[2,3-b]thiophenes and related congeners.

Several series of novel substituted thienothiophene derivatives were synthesized by reacting the synthone 1 with different reagents. The newly synthesized compounds were characterized by means of different spectroscopic methods such as IR, NMR, mass spectrometry and by elemental analyses. The new compounds displayed significant activity against both Gram-positive and Gram negative bacteria, in addition to fungi. Molecular docking and POM analyses show the crucial role and impact of substituents on bioactivity and indicate the unfavorable structural parameters in actual drug design: more substitution doesn't guaranty more efficiency in bioactivity.

Report: antioxidant and nutraceutical value of wild medicinal Rubus berries.

Nutritional quality and antioxidant capacity of three edible wild berries (Rubus ellipticus Smith, Rubus niveus Thunb, Rubus ulmifolius L.) from Lesser Himalayan Range (LHR) were evaluated. Their edible portion was assayed for moisture, fats, ash, carbohydrates, proteins, fibers, essential minerals (Ca, P, Mg, K, Na, Cl, S, Mn, Zn, Fe, Cu, Se, Co, Ni) and DPPH free radical scavenging activity was applied to determine the antioxidant potential. The fruit of Rubus ulmifolius L. (blackberry) possessed the highest values of energy (403.29 Kcal), total protein (6.56g/100 g), Nitrogen (N) content (1500mg/100g), K (860.17mg/100g), Ca (620.56mg/100g), Zn (17.509mg/100g) and the strongest antioxidant activity (98.89% inhibition). While the raspberries (Rubus ellipticus Smith, Rubus niveus Thunb.) exhibited more significant contents of dietary fiber (5.90g/100g), carbohydrates (86.4 g/100 g) and Fe (4.249mg/100g). Significant variation was observed among the tested samples in all the investigated features. The combination of bio elements and active antioxidants clearly showed the applicability of these berries as a nutraceutical supplement.

Anti-hepatitis B activity of isoquinoline alkaloids of plant origin.

Hepatitis B virus (HBV) is the causative agent of B-type hepatitis in humans, a vaccine-preventable disease. Despite the availability of effective vaccines, globally, 2 billion people show evidence of past or current HBV infection, of which 350 million people are persistently infected, with an estimated annual increase of 1 million. There is no cure for chronic HBV infections, which are associated with cirrhotic liver failure and with an increased risk of developing hepatocellular carcinoma. Hepatitis antiviral research has focused primarily on the development of inhibitors of viral polymerase through the use of nucleoside analogues. Therefore, there is an urgent need for the development of non-nucleoside compounds to be used as an alternative or to complement the current therapy. To address this need, 18 isoquinoline alkaloids were evaluated for their potential antiviral activity against HBV in vitro.

Design, synthesis, characterization of novel ruthenium(II) catalysts: highly efficient and selective hydrogenation of cinnamaldehyde to (E)-3-phenylprop-2-en-1-ol.

In this contribution, two novel supported and non-supported ruthenium(II) complexes of type [RuCl2(dppme)(NN)] where [dppme is H2C=C(CH2PPh2)2 and NN is N1-(3-(trimethoxysilyl)propyl)ethane-1,2-diamine] were prepared. The NN co-ligand caused release of one of the dppme ligands from [RuCl2(dppme)2] precursor to yield complex 1. The process of substitution of dppme by NN was monitored by 31P{1H}-NMR. Taking advantage of the presence of trimethoxysilane group in the backbone of complex 1, polysiloxane xerogel counterpart, X1, was prepared via sol-gel immobilization using tetraethoxysilane as cross-linker. Both complexes 1 and X1 have been characterized via elemental analysis, CV and a number of spectroscopic techniques including FT-IR, 1H-, 13C-, and 31P-NMR, and mass spectrometry. Importantly, carbonyl selective hydrogenation was successfully accomplished under mild conditions using complex 1 as a homogenous catalyst and X1 as a heterogeneous catalyst, respectively.

In vitro and in vivo evaluation of the antimicrobial, antioxidant, cytotoxic, hemolytic activities and in silico POM/DFT/DNA-binding and pharmacokinetic analyses of new sulfonamide bearing thiazolidin-4-ones.

In this work, Schiff bases and Thiazolidin-4-ones, were synthesized using Sonication and Microwave techniques, respectively. The Schiff base derivatives (3a-b) were synthesized via the reaction of Sulfathiazole (1) with benzaldehyde derivatives (2a-b), followed by the synthesis of 4-thiazoledinone (4a-b) derivatives by cyclizing the synthesized Schiff bases through thioglycholic acid. All the synthesized compounds were characterized by spectroscopic techniques such as FT IR, NMR and HRMS. The synthesized compounds were tested for their in vitro antimicrobial and antioxidant and in vivo cytotoxicity and hemolysis ability. The synthesized compounds displayed better antimicrobial and antioxidant activity and low toxicity in comparison to reference drugs and negative controls, respectively. The hemolysis test revealed the compounds exhibit lower hemolytic effects and hemolytic values are comparatively low and the safety of compounds is in comparison with standard drugs. Theoretical calculations were carried out by using the molecular operating environment (MOE) and Gaussian computing software and observations were in good agreement with the in vitro and in vivo biological activities. Petra/Osiris/Molinspiration (POM) results indicate the presence of three combined antibacterial, antiviral and antitumor pharmacophore sites. The molecular docking revealed the significant binding affinities and non-bonding interactions between the compounds and Erwinia Chrysanthemi (PDB ID: 1SHK). The molecular dynamics simulation under in silico physiological conditions revealed a stable conformation and binding pattern in a stimulating environment. HighlightsNew series of Thaiazolidin-4-one derivatives have been synthesized.Sonication and microwave techniques are used.Antimicrobial, Antioxidant, cytotoxicity, and hemolysis activities were observed for all synthesized compounds.Molecular Docking and DFT/POM analyses have been predicted.Communicated by Ramaswamy H. Sarma.

A pair of carbazate derivatives as novel Schiff base ligands: DFT and POM theory supported spectroscopic and biological evaluation.

Schiff bases are mentioned as strongly important molecular scaffolds of industrial and medicinal purposes. Due to wide range applications of carbazate derivatives herein synthesis and characterization of a new Schiff base ligand, (E)-ethyl 2-(4-methoxybenzylidene)hydrazinecarboxylate and 4-(nitrobenzaldehyde)ethylcarbazate are reported. The compound was characterized on the basis of experimental and density functional theory calculations (using the B3LYP and 6-31 G(d,p)formalism combination). Among characterization techniques elemental analysis, FT-IR, UV-Vis and NMR spectroscopic evaluations were mainly employed to carry out the formulation of the compound. In addition to computational validation of characterization other significant molecular parameters were also evaluated including geometry optimization, frontier molecular orbital analysis (FMO) and Columbic interaction of different constituent atoms of the title compound. A good agreement has been found between DFT and experimental outcomes confined to prove the structure of the compound. Moreover, molecular docking and antimicrobial studies have proven the Schiff base as an effective bioactive compound.Communicated by Ramaswamy H. Sarma.

Synthesis and characterization of hybrid materials consisting of n-octadecyltriethoxysilane by using n-hexadecylamine as surfactant and Q(0) and T(0) cross-linkers.

Novel hybrid xerogel materials were synthesized by a sol-gel procedure. n-octadecyltriethoxysilane was co-condensed with and without different cross-linkers using Q(0) and T(0) mono-functionalized organosilanes in the presence of n-hexadecylamine with different hydroxyl silica functional groups at the surface. These polymer networks have shown new properties, for example, a high degree of cross-linking and hydrolysis. Two different synthesis steps were carried out: simple self-assembly followed by sol-gel transition and precipitation of homogenous sols. Due to the lack of solubility of these materials, the compositions of the new materials were determined by infrared spectroscopy, (13)C and (29)Si CP/MAS NMR spectroscopy and scanning electron microscopy.

(2,9-Dimethyl-1,10-phenanthroline-κ(2)N,N')bis-(thio-cyanato-κS)mercury(II).

The asymmetric unit of the title compound, [Hg(SCN)(2)(C(14)H(12)N(2))], contains two complex mol-ecules in which the Hg(II) atoms are both four-coordinated in a distorted tetra-hedral configuration by two N atoms from a chelating 2,9-dimethyl-1,10-phenanthroline ligand and by two S atoms from two thio-cyanate anions. The 1,10-phenanthroline ligand is slightly folded for one complex, the dihedral angle between the pyridine planes being 5.3 (1)°. In contrast it is nearly planar [0.5 (1)°] as it complexes with the other Hg(II) atom. The thio-cyanate ligands are virtually linear and the S atom is bonded to Hg(II) with N⋯S-Hg angles ranging from 99.3 (1) to 103.5 (1)°. Despite the presence of six aromatic rings in the asymmetric unit, there are no significant inter-molecular π-π contacts between phenanthroline ligands as the centroid-centroid distance of the closest contact between six-membered rings is 4.11 (1) A°.