A Comprehensive Multispectroscopic and Computational Analysis of the Interaction between Plant-Based Antiplasmodial Compounds and Bovine Serum Albumin.

This study was conducted to explore the interaction between two plant-based antiplasmodial compounds, gartanin and friedelin, and bovine serum albumin (BSA). The objectives aimed to elucidate the binding characteristics, structural changes, and thermodynamic parameters associated with the interaction. Various methods were used including UV-vis, fluorescence, and circular dichroism spectroscopy, supported by molecular docking and molecular dynamics simulation. The results showed a concentration-dependent interaction between the antiplasmodial compounds and BSA, revealing changes in protein conformation and stability. The obtained results showed that the plant products bound with BSA through static quenching with moderate binding affinity (104 M-1) with BSA. Thermodynamic parameters and structural transitions calculated from spectroscopic methods revealed that hydrogen bond and van der Waals forces caused the partial conformational alteration in the secondary structure of BSA as the α-helical content decreased with an increase in ß sheets, random coils, and other structures. Computational analysis provided insights into the binding sites and affinities. The study enhances our understanding of the molecular interactions between BSA protein and antiplamodial compounds obtained from plants, supporting the research of choosing, designing, and optimizing molecules for biomedical applications with a focus on selectively targeting their binding sites.

Synthesis, Characterization and Biological Activity of Benzimidazoleacrylonitrile Derivatives.

BACKGROUND: Benzimidazoles have a wide range of synthetic applications in medicinal chemistry and biological activities like anti-tumor/anti-proliferative activities etc. Moreover, different heterocyclic moieties attached to the benzimidazole ring improved anticancer activities. METHODS: All the chemicals were purchased from Aldrich Chemical Company, are of AR grade and used as received. Microanalytical data (C, H, and N) were analyzed on a Carlo Erba model 1108 analyzer. Melting points were measured by the Kofler apparatus and were uncorrected. Spectroscopic data were obtained using the following instruments: Fourier transform infrared spectra (KBr discs, 4000-400 cm-1) by Shimadzu IR-408 Perkin Elmer 1800 instrument; 1H NMR and 13C NMR spectra by JEOL Resonance Inc. Tokyo, Japan, JNM-ECZ400S/L1 using DMSO-d6 as a solvent containing TMS as the internal standard. Chemical shifts (δ) are reported in parts per million (ppm), and coupling constants (J) are reported in Hertz (Hz). RESULTS: We chose sulfosalicylic acid as a promoter for forming benzimidazole-acrylonitrile derivatives, which is an eco-friendly reaction, and we applied a series of synthesized compounds 3a-g in nematicidal activity. The results indicate that the concentrations of all treatments significantly kill M. incognita. CONCLUSION: This model reaction procedure provides a better method for preparing benzimidazoleacrylonitrile, which is superior to other methods. This protocol simplifies handling model reactions with mild reaction conditions, a short time period, a simple set-up, a fast reaction rate, and so on.

Reaction of 7α-bromo-6-nitrocholest-5-enes with hydrazine: Formation of steroidal pyrazolines and molecular docking against SARS-CoV-2 omicron protease.

The present work reports simple and effective protocol for preparing 6α-nitro-5α-cholestano[7α,5-cd] pyrazolines (4-7) by the reaction of 7α-bromo-6-nitrocholest-5-enes (1-3) with hydrazine hydrate under reflux [the substrate (2) gave products (5) and (6) and the later on acetylation with AC2O/Py gave (7)]. In the case of reaction of 3ß-hydroxy analogue (3) with hydrazine, however, 6α-nitro-5α-cholestano [3α,5-cd] pyrazoline (8) and 6α-nitro-3ß, 5-oxido-5ß-cholestane (9) were obtained. The probable mechanism of the formation of pyrazolines has also been outlined. In the current pandemic coronavirus disease 2019 scenario, the in-silico study was performed with reactants (1-3), their products (4-9) against SARS-CoV-2 omicron protease (PDB ID:7T9L) for knowing significant interactions between them. Docking results give information that both reactants and products have binding energies ranges from -5.7 to 7.7 kcal/mol and strong interactions with various hydrophilic and hydrophobic amino acids such as ASP, PRO, PHE, SER and LEU which are significant residues playing important role in SARS-CoV-2 Omicron main protease (Mpro).

Comparative study of biogenically synthesized silver and gold nanoparticles of Acacia auriculiformis leaves and their efficacy against Alzheimer's and Parkinson's disease.

The present article reports the biogenic synthesis of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) from the extract of Acacia auriculiformis (AA) leaves using biogenic approach. Several spectral and morphological studies namely UV-vis, Fourier transform infrared (FT-IR), tunneling electron microscopy along with selected area electron diffraction (TEM/SAED), scanning electron microscopy along with energy dispersive X-ray (SEM-EDX) and X-ray diffraction (XRD) were carried out which ascertains the successful formation of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) starting from Silver nitrate and Chloroauric acid respectively. On the basis of TEM/SAED and SEM-EDX, AgNPs were found to be more regular with smaller particle size and hence they were selected for biological studies. Thermal techniques like thermo gravimetric analysis (TGA) and differential thermal analysis (DTA) were also performed to study the comparative thermal stability of AgNPs and AuNPs where AgNPs were found to be thermally more stable. Several biophysical techniques including Thioflavin T assay, ANS assay, Rayleigh scattering method and turbidity assay were also performed. These assays confirm that AgNPs possess better inhibitory property. Moreover, antioxidant activity of AgNPs was also carried out using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and AgNPs were found to be good antioxidant.

Green Synthesis of Fused Chromeno-pyrazolo-phthalazine Derivatives with Silicasupported Bismuth Nitrate under Solvent-free Conditions.

AIM: The study aimed to synthesize chromeno-pyrazolo[1,2-b]phthalazine-6,9,14(7H)-trione analogs with the help of silica-supported bismuth nitrate catalyst. BACKGROUND: Nitrogen-containing heterocyclic compounds are widespread, and their applications to pharmaceuticals, agrochemicals, and functional materials are becoming more and more important. Pyrazoles are an important class of compounds for new drug development, as they are the core structure of numerous biologically active compounds, including blockbuster drugs such as celecoxib, viagra, pyrazofurine, and many others. Similarly, heterocycles containing a phthalazine moiety are of current interest due to their pharmacological and biological activities; for example, pyrazolo[1,2-b]phthalazinedione is described as an anti-inflammatory, analgesic, antihypoxic, and antipyretic agent. OBJECTIVE: In continuation of our ongoing investigation for the synthesis of efficient and simple approaches for the preparation of heterogeneous catalysts, herein we wish to disclose a highly efficient, simple, and one-pot synthesis of chromeno-pyrazolo-phthalazine derivatives via a one-pot multi-component reaction between 4- hydroxycoumarin, aromatic/heterocyclic aldehydes and 2,3-dihydro-1,4-phthalazinedione using silica-supported bismuth nitrate as an inexpensive, environmentally friendly and reusable catalyst under solvent-free conditions. MATERIALS AND METHODS: Microanalytical data (C, H, and N) were collected on Carlo Erba analyzer model 1108. The microwave synthesis was performed in Anton Paar, Monowave 300 microwave synthesizer. Melting points were measured in open glass capillaries in the Kofler apparatus and are uncorrected. Spectroscopic data were obtained using the following instruments: Fourier transform infrared spectra (KBr discs, 4000-400 cm-1) by Shimadzu IR-408 Perkin-Elmer 1800 instrument; 1H NMR and 13C NMR spectra by Bruker Avance-II 400 MHz using DMSO-d6 as a solvent containing TMS as the internal standard. Mass spectra were set down on a JEOL D-300 mass spectrometer. RESULTS: In continuation of our ongoing studies to synthesize heterocyclic and pharmaceutical compounds by mild, facile, and efficient protocols, herein we wish to report our experimental results of the synthesis of chromeno- pyrazolo-phthalazine derivatives under solvent-free condition derivatives, using various aromatic/heterocyclic aldehydes in the presence of silica-supported bismuth nitrate catalyst. The prepared catalyst was characterized by various physical and chemical techniques. CONCLUSION: We have demonstrated an efficient reaction path for the synthesis of new aryl and heteroaryl chromeno-pyrazolo[1,2-b]phthalazine-6,9,14(7H)-trione by one-pot three-component condensation of aryl/ heteroaryl aldehydes, 2,3-dihydro-1,4-phthalazinedione and 4-hydroxy coumarin using silica-supported bismuth nitrate (SSBN) under microwave irradiation. The scheme not only offers the use of microwave at low temperatures and significant yield of products but also affords mild reaction conditions, without harmful solvent, shorter reaction times, high purity, operational simplicity, and easy workup.

Silica bonded N-(propylcarbamoyl)sulfamic acid (SBPCSA) as a highly efficient and recyclable solid catalyst for the synthesis of Benzylidene Acrylate derivatives: Docking and reverse docking integrated approach of network pharmacology.

A green approach has been developed for the synthesis of a series of benzylidene acrylate 3(a-p) from differently substituted aromatic/heterocyclic aldehydes and ethyl cyanoacetate in excellent yields (90-98%), and employing silica bonded N-(Propylcarbamoyl)sulfamic acid as a recyclable catalyst under solvent-free condition. The molecular structure of compounds 3b, 3d and 3i were well supported by single-crystal X-ray crystallographic analysis. The present protocol bears wide substrate tolerance and is believed to be more practical, efficient, eco-friendly, and compatible as compared to existing methods. In-silico approaches were implemented to find the biochemical and physiological effects, toxicity, and biological profiles of the synthesized compounds to determine the expected biological nature and confirm a drug-like compound. A molecular docking study of the expected biologically active compound was performed to know the hypothetically binding mode with the receptor. Also, reverse docking is applied to recognize receptors from unknown protein targets for drug-like compounds to explain poly-pharmacology and binding postures with different receptors.

Z-Acrylonitrile Derivatives: Improved Synthesis, X-ray Structure, and Interaction with Human Serum Albumin.

AIMS AND OBJECTIVE: In the synthesis of heterocyclic compounds, acrylonitrile derivatives are the most important and appropriate precursors. These compounds are the most important intermediates and subunits for the enhancement of molecules having pharmaceutical or biological interests. Nitrogen-containing compounds have received extensive consideration in the literature over the years. MATERIALS AND METHODS: A facile, economic and efficient method has been developed for the synthesis of acrylonitrile derivatives using p-nitrophenylacetonitrile and aromatic/heterocyclic aldehydes in the presence of zinc chloride at room temperature. Spectroscopic data were obtained using the following instruments: Fourier transform infrared spectra (KBr discs, 4000-400 cm-1) by Shimadzu IR-408 Perkin-Elmer 1800 instrument; 1H NMR and 13C NMR spectra by Bruker Avance-II 400 MHz using DMSO-d6 as a solvent containing TMS as the internal standard. RESULTS: To continue our ongoing studies to synthesize heterocyclic and pharmaceutical compounds by mild, facile and efficient protocols, herein we wish to report our experimental results on the synthesis of acrylonitrile derivatives, using various aromatic/heterocyclic aldehydes and p-nitrophenylacetonitrile in the presence of zinc chloride in ethanolic media at room temperature. Some of the new compounds were tested for their human serum albumin activity (HSA) while a study of interaction with HSA protein was performed for compounds 3a and 3b. The results show that compound 3b binds tightly to HSA as compared to compound 3a. CONCLUSION: It can be concluded that acrylonitrile derivatives can be synthesized by an efficient method via the reaction of p-nitrophenylacetonitrile with aromatic/heterocyclic aldehydes by the use of zinc chloride as an effective solid catalyst. The remarkable features of this procedure include excellent yields (90-95%), short reaction period (30 min.), moderate reaction environment, easy workup procedure and managing of the catalyst. This method may find a wide significance in organic synthesis for the synthesis of the Z-acrylonitrile.

DFT/TD-DFT calculations, spectroscopic characterizations (FTIR, NMR, UV-vis), molecular docking and enzyme inhibition study of 7-benzoyloxycoumarin.

The quantum chemical study, spectroscopic characterization and biological activity of the pharmaceutically active 7-benzoyloxycoumarin (2) molecule have been presented. Potential energy surface (PES) scanning has been performed to search for the most stable molecular geometry of the present compound. The stable geometry in the ground state, IR, UV-Vis absorption and NMR (13C, 1H) spectra of the title compound were theoretically obtained and compared with the experimental one. Various theoretical molecular parameters like molecular energy, atomic charges, dipole moment, thermodynamic parameters, donor-acceptor natural bond orbital (NBO) hyperconjugative interaction energies, frontier molecular orbitals energies, HOMO-LUMO gap, molecular electrostatic potential, chemical reactivity descriptors, molecular polarizability and non-linear optical (NLO) properties are presented. Moreover, the 3D Hirshfeld surfaces and the associated 2D fingerprint plots have been explored. The percentages of various non-covalent interactions are studied and pictorialized by fingerprint plots of Hirshfeld surface. 7-Benzoyloxycoumarin has shown promising inhibitory activity against butrylcholinesterase (BuChE) as compared to the reference drug, galantamine. Molecular docking is carried to introduce compound into the X-ray crystal structures of butrylcholinesterase at the active site to find out the probable binding mode. The results of molecular docking indicated that 7-benzoyloxy derivative of coumarin may show enzyme inhibitor activity.

Structure elucidation, DNA binding specificity and antiproliferative proficiency of isolated compounds from Garcinia nervosa.

Garcinia nervosa is an abundant source of bioactive phytochemicals. The present paper deals with the isolation of a novel isoflavone 5,7-dihydroxy-3-(3'-hydroxy-4',5'-dimethoxyphenyl)-6-methoxy-4H-chromen-4-one (1) along with a known compound DL-Allantoin (2) from the ethanolic extract of the leaves of Garcinia nervosa (Family: Guttiferae). Their structures were elucidated on the basis of chemical and physical evidences viz. elemental analysis, UV, FT-IR, 1H NMR, 13C NMR and mass spectral analysis. Single-crystal X-ray analysis was further used for the authentication of structure of both compounds (1 and 2). Interaction studies of compound (1) and (2) with ctDNA were studied by UV-Visible spectroscopy, fluorescence, KI quenching studies, competitive displacement assay and circular dichroism studies, which showed groove binding interaction (non-intercalation) of both the compounds 1 and 2 with ctDNA. However, compound 1 (K=3.9×104M-1) shows higher binding affinity to the ctDNA than compound 2 (K=1.44×104M-1). The molecular modeling results also illustrated that compound 1 strongly binds to groove of DNA by relative binding energy of docked structure -6.82kcal/mol. In addition the antiproliferative activity also showed high potential of compound 1 against MCF-7 and MDA-MB 231 cell line with IC50 value 8.44±3.5µM and 6.94±2.6µM, respectively.

Acetylcholinesterase and Cytotoxic Activity of Chemical Constituents of Clutia lanceolata Leaves and its Molecular Docking Study.

Phytochemical investigations of the ethanolic extract of leaves of Clutia lanceolata (Family: Euphorbiaceae) resulted in the isolation of four compounds viz. 3,4-dihydroxy-2-methylbenzoic acid (1), 2,2'-dihydroxy-1,1'-binaphthyl (2), 1,3,8-trihydroxy-6-methylanthracene-9,10-dione (3) and 5-hydroxy-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,4,6-trien-3-one (4). Although all the isolated compounds were known but this was the first report from this plant source. Their structures were established on the basis of chemical and physical evidences viz. elemental analysis, FT-IR, 1H-NMR, 13C-NMR and mass spectral analysis. Structure of compound 2 and 4 was further authenticated by single-crystal X-ray analysis and density functional theory calculations. The isolated compounds (1-4) were screened for AChE enzyme inhibition assay in which compound 3 and 4 were found to be more potent AChE inhibitor. Molecular docking study of potent AChE inhibitor was performed to find the probable binding mode of the compounds into the active site of receptor. Moreover, the isolated compounds were also screened for in vivo cytotoxicity by brine shrimp lethality assay.

Potent acetylcholinesterase inhibitors: Synthesis, biological assay and docking study of nitro acridone derivatives.

The reaction of o-halobenzoic acid with aniline derivatives and their subsequent cyclization reaction yielded the acridone derivatives. The series of nitro acridone derivatives were prepared by Ullmann condensation in presence of copper as catalyst and were characterized by FTIR, (1)H, (13)C NMR and mass spectra. The structure of 5-nitro-(2-phenyl amino) benzoic acid (4) was confirmed by X-ray crystallography and was found to crystallize in P21/c space group. The in vitro efficacy of the compounds for their acetylcholinesterase (AChE) and antimicrobial inhibitory activities have been evaluated against the standard drugs Ampicillin and Gentamicin against Gram positive and Gram negative bacteria. 1,7-Dinitroacridone was found to be the most potent AChE inhibitor (IC50=0.22µM). Moreover, the compounds have been screened for their antioxidant activity using the DPPH assay. Also, docking study results were found to be in good agreement with the results obtained through in vitro experiments. The docking study further predicted possible binding conformation.

Structure elucidation and DNA binding specificity of natural compounds from Cassia siamea leaves: A biophysical approach.

A novel isoflavone, 5,6,7-trimethoxy-3-(3',4',5'-trimethoxyphenyl)-4H-chromen-4-one (1) along with a known pyranocoumarin, Seselin (2) have been isolated from the ethanolic extract of the leaves of Cassia siamea (Family: Fabaceae). Compound 1 has been reported for the first time from any natural source and has not been synthesized so far. Their structures were elucidated on the basis of chemical and physical evidences viz. elemental analysis, UV, FT-IR, (1)H-NMR, (13)C-NMR and mass spectral analysis. Structure of compound (1) was further authenticated by single-crystal X-ray analysis and density functional theory (DFT) calculations. A multi-technique approach employing UV-Visible spectroscopy, fluorescence, KI quenching studies, competitive displacement assay, circular dichroism and viscosity studies have been utilized to probe the extent of interaction and possible binding modes of isolated compounds (1-2) with calf thymus DNA (CT-DNA). Both the compounds were found to interact with DNA via non-intercalative binding mode with moderate proficiencies. Groove binding was the major interaction mode in the case of compound 2 while compound 1 probably interacts with DNA through electrostatic interactions. These studies provide deeper insight in understanding of DNA-drug (natural products) interaction which could be helpful to improve their bioavailability for therapeutic purposes.

Antimicrobial agents from selected medicinal plants in Libya.

OBJECTIVE: To test the in vitro antimicrobial efficacy of water and methanol extracts of 23 plant species that are commonly used in Libyan folk medicine. METHODS: The antimicrobial activity was determined using the well-diffusion method. Four test microorganisms were used namely, Escherichia coli, Salmonella species, Staphylococcus aureus and Bacillus subtilis. The minimum inhibitory concentration (MIC) was determined for the high biologically active crude plant extracts. RESULTS: Among 23 medicinal plants used in the study, only 5 methanolic extracts [Rosmarinus offcinalis L., Carduus marianium L., Lantana camara L., Rhus tripartite (ueria) Grande, and Thymus capitatus (L.) Hoffm (link)] showed the highest antimicrobial activity against Staphylococcus aureus, Bacillus subtilis and Salmonella species, while 22 methanolic and aqueous extracts showed moderate to weak antimicrobial activity on all tested organisms. However 19 of the extracts showed no activity at all against Gram-ve and Gram +ve microorganisms. MIC was found to be 1.25 mg/mL (Thymus capitatus), 3 mg/mL (Rhus tripartite), 4 mg/mL (Carduus marianium), 5 mg/mL (Rosamarinus officinalis) and 5 mg/mL (Lantana camara), respectively. CONCLUSIONS: The present results revealed that, crude methanolic extracts of the investigated Libyan folk medicinal plants exhibited mild to high in vitro antibacterial activities against Gram-positive and Gram-negative microorganisms.

Two new phenolic compounds from Ficus rumphii and their antiproliferative activity.

Two new compounds 2 and 4, along with two known compounds 1 and 3, were isolated for the first time from 95% ethanolic extract of the leaves of Ficus rumphii. Their structures were elucidated on the basis of chemical and physical evidences (elemental analysis, UV, IR, (1)H NMR, (13)C NMR and mass spectra) and comparison with the literature compounds. Structural authentication of compound 4 was further validated by single-crystal X-ray analysis and DFT calculations. The compounds 1-4 were screened for in vitro cytotoxicity against cancer and non-cancer cells and also tested for genotoxicity (comet assay). Compounds 2 and 4 displayed significant activity against HL-60 with IC50 values of 3.3 and 2.3 µM, respectively. The results revealed that compound 4 has better prospectus to act as cancer chemotherapeutic candidate which warrants further in vivo anticancer investigations.

A novel 6-hydroxy-8,11,11-trimethyl-bicyclo[7.2.0]undec-4-ene-4-carboxylic acid: a potent antioxidant agent from Iphiona scabra.

A novel 6-hydroxy-8,11,11-trimethyl-bicyclo[7.2.0]undec-4-ene-4-carboxylic acid 1 has been isolated from leaves of Iphiona scabra DC. Its structure has been established on the basis of chemical and physical evidence (IR, ¹H NMR, ¹³C NMR, and MS) and further confirmed by single-crystal X-ray diffraction study. The in vitro antioxidant activities of isolated compound 1 and extracts were evaluated by 1,1-diphenyl-2-picrylhydrazyl method.

Synthesis, characterization, DNA-binding studies and acetylcholinesterase inhibition activity of new 3-formyl chromone derivatives.

A series of new substituted 3-formyl chromone derivatives (4-6) were synthesized by one step reaction methodology by knoevenagel condensation, structurally similar to known bisintercalators. The new compounds were characterized by IR, (1)H NMR, (13)C NMR, MS and analytical data. The in vitro DNA binding profile of compounds (4-6) was carried out by absorption, fluorescence and viscosity measurements. It was found that synthesized compounds, especially compound 6 (evident from binding constant value) bind strongly with calf thymus DNA, presumably via an intercalation mode. Additionally, molecular docking studies of compounds (4-6) were carried out with B-DNA (PDBID: 1BNA) which revealed that partial intercalative mode of mechanism is operational in synthesized compounds (4-6) with CT-DNA. The binding constants evaluated from fluorescence spectroscopy of compounds with CT-DNA follows the order compound 6>compound 5>compound 4. All the compounds (4-6) were screened for acetylcholinesterase inhibition assay. It can be inferred from data, that compound (6) showed potent AChE inhibition having IC50=0.27µM, almost in vicinity to reference drug Tacrine (IC50=0.19µM).

Synthesis, bioassay, crystal structure and ab initio studies of Erlenmeyer azlactones.

Several 4-arylidene-2-phenyl-5(4H)-azlactones have been synthesized via Erlenmeyer method. The synthesized compounds have been characterized on the basis of systematic spectral studies (IR, (1)H NMR, (13)C NMR, and MS). The compound (4Z)-4-(3,5-dimethoxybenzylidene)-2-phenyl-1,3-oxazol-5(4H)-one, C(18)H(15)NO(4), (5), crystallizes in the orthorhombic system, space group P2(1)2(1)2(1), with a=5.6793(3) Å, b=15.2038(7) Å, c=17.6919(10) Å, Mr=309.31, V=1527.64(14) Å(3), Z=4 and R=0.0547. The compound (4Z)-2-phenyl-4-(3,4,5-trimethoxybenzylidene)-1,3-oxazol-5(4H)-one, C(19)H(17)NO(5), (6) crystallizes in triclinic geometry with space group P-1, having unit cell parameters a=7.3814(3) Å, b=8.1446(3) Å, c=13.9845(5) Å, α=86.918(3), ß=83.314(2), γ=82.462(3), Mr=339.34, V=827.16(5) Å(3), Z=2 and R=0.0433. The DFT calculations of compounds (5) and (6) have been carried out to ascertain the stability of Z-conformer. The in vitro antimicrobial activity of all the compounds (1-6) was evaluated by the disk diffusion method against gram +ve and gram -ve microorganism and fungal strains. The MIC of the synthesized compounds was determined by agar well diffusion method in 96-well microtiter plate. All the synthesized compounds were also screened for their free radical scavenging activity by DPPH method.

Synthesis, characterization, thermal and antioxidant studies of potassium dihydrobisphenothiazinyl borate and its transition metal complexes.

The bidentate borate anion H(2)B(ptz)(2)(-) and its transition metal complexes have been synthesized and characterized by elemental analyses, magnetic susceptibility, electronic, IR, (1)H and (13)C NMR data. The molar conductance of 10(-3) M solution for all the complexes supports their non-ionic nature. The TGA profile of borate anion shows a single stage unlike that of two stage decomposition plot of the metal complexes. On the basis of spectroscopic studies the geometry of all the complexes have been proposed to be distorted-tetrahedral. The in vitro antioxidant and lipid oxidation inhibition of the ligand and its complexes have also been studied. The Cu[B(ptz)(2)](2) complex was found to be most effective in all the studies.

8-Iodo-5,7-dimeth-oxy-4-methyl-2H-chromen-2-one.

In the title compound, C(12)H(11)IO(4), the C and O atoms of both meth-oxy groups lie very close to the mean plane of the six C atoms of the benzene ring. The O and C atoms of the group lying closest to the I atom are 0.012 (3) and 0.022 (4) Å, respectively, out of the mean plane. For the other meth-oxy group, the corresponding distances are 0.020 (3) and 0.078 (4) Å. In the crystal, there are only very weak inter-molecular C-H⋯O hydrogen bonds and O⋯I contacts [3.080 (2) Å]. The mol-ecules are approximately parallel to (100), forming a layered structure.

A novel antimicrobial agent from the leaves of Peltophorum vogelianum (Benth.).

The methanolic extract of the leaves of Peltophorum vogelianum (Caesalpiniaceae) afforded a new phytoconstituent, 2-methoxy-4,5-dihydroxy-1(7,8-dihydroxyethylene)-8-beta-D-glucuropyranoside named as peltophorumyl-beta-D-glucuropyranoside (5), along with four known phytoconstituents, 1-pentatriacontanol (1), friedelin (2), beta-sitosterol (3) and beta-sitosterol-beta-D-glucopyranoside (4), which have not been isolated previously from this plant. Their structures were established on the basis of chemical and physical evidence (IR, 1H-NMR, 13C-NMR, DEPT, HSQC, HMBC and MS). Moreover, compound 5 showed significant antimicrobial activity.