Sayed Hasan Mehdi

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-β-D-glucuropyranoside named as peltophorumyl-β-D-glucuropyranoside (5), along with four known phytoconstituents, 1-pentatriacontanol (1), friedelin (2), β-sitosterol (3) and β-sitosterol-β-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.

A new triterpenoid from the leaves of Ficus benjamina (var. comosa)

The benzene extract of the leaves of Ficus benjamina (variety comosa) afforded a new triterpene, named serrat-3-one (Fc-2), along with the known phytoconstituents pentacontanyl decanoate (Fc-1), friedelin and β-sitosterol. Their structures were established on the basis of chemical and physical evidence (IR, 1H NMR, 13C NMR and MS). The aqueous and alcoholic extracts of leaves of F. bejamina showed significant antinociceptive activity in an analgesiometer test.

9-(3,4-Dimeth­oxy­phen­yl)-3,3,6,6-tetra­methyl-4,5,6,9-tetra­hydro-3H-xanthene-1,8(2H,7H)-dione

The asymmetric unit of the title xanthene compound, C25H30O5, contains two molecules in which the pyran ring and the dimethoxyphenyl ring are nearly perpendicular to one another [dihedral angles = 86.81 (8) and 84.45 (9)°]. One of the methoxy groups in one molecule is twisted away from the phenyl ring [C—O—C—C torsion angle = −103.40 (16)°]. The pyran ring adopts a boat conformation whereas the two fused cyclohexane rings adopt envelope conformations in both molecules. In the crystal, molecules are linked into a three-dimensional network by C—H⋯O hydrogen bonds.

Synthesis, Antimicrobial and Cholinesterase Enzymes Inhibitory Activities of Indeno Imidazoles and X-Ray Crystal Structure of 3a,8a-Dihydroxy-1,3-diphenyl-1,3,3a,8a-tetrahydro-indeno[1,2-d]imidazole-2,8-dione

Two indeno imidazoles have been synthesized by the reaction of ninhydrin with diphenylurea and diphenylthiourea. The structures have been determined by spectral analysis. The supramolecular behavior of 3a,8a-Dihydroxy-1,3-diphenyl-1,3,3a,8a-tetrahydro-indeno[1,2-d]imidazole-2,8-dione (1) was thoroughly analyzed and reported using X-ray single crystal technique and concepts. The presence of oxygen and nitrogen atoms led to very interesting supramolecular motifs interactions such as nitrogen–oxygen, nitrogen–nitrogen, oxygen–oxygen, nitrogen–hydrogen, and oxygen–hydrogen. 3a,8a-dihydroxy-1,3-diphenyl-2-thioxo-2,3,3a,8a-tetrahydro-1H-indeno[1,2-d]imidazol-8-one 2 showed good antibacterial activity against B. subtilis and P. aeruginosa, while 3a,8a-dihydroxy-1,3-diphenyl-1,3,3a,8a-tetrahydro-indeno[1,2-d]imidazole-2,8-dione 1 only showed antibacterial activity against P. aeruginosa. Both of 1 and 2 were inactive against C. albicans. Derivative 2 demonstrated good cholinesterase enzyme activity unlike derivative 1 which has weak inhibitory activity against these enzymes. Furthermore, 2 was found to be a selective butyrylcholinesterase enzyme inhibitor that has potential use for prevention of further neurodegeneration as well for symptomatic treatment of Alzheimer patients.Graphical AbstractThe non-covalent interactions involved in the crystal structure of 3a,8a-Dihydroxy-1,3-diphenyl-1,3,3a,8a-tetrahydro-indeno[1,2-d]imidazole-2,8-dione (1) were investigated and reported in terms of crystal engineering and supramolecular chemistry. Different motifs of N···H and O···H interactions as well as N···O, N···N, and O···O are adopted by the crystal structure and led to a strong crystal packing.

9-(3,4-Dimeth­oxy­phen­yl)-3,4,5,6,7,9-hexa­hydroxanthene-1,8(2H)-dione

In the title compound, C21H22O5, the mean planes of the pyran and dimethoxyphenyl rings are nearly perpendicular to one another, with the dihedral angle between them being 88.21 (8)°. The pyran ring adopts a boat conformation whereas the two fused cyclohexane rings adopt envelope conformations. In the crystal, molecules are linked into a three-dimensional network by intermolecular C—H⋯O hydrogen bonds.

Phytochemical analysis, cytotoxic activity and constituents–activity relationships of the leaves of Cinnamomum iners (Reinw. ex Blume-Lauraceae)

The leaves of Cinnamomum iners (Reinw. ex Blume-Lauraceae) have been refluxed successively with chloroform and alcohol to get chloroform extract and alcoholic extract. Both the extracts have been assayed for cytotoxicity against human colorectal tumour cells. The chloroform extract exhibited significant cytotoxicity with IC50 31 µg mL−1 (p < 0.01). However, ethanol extract was found to be much less cytotoxic with IC50 > 200 µg mL−1. The chloroform extract has been further proceeded for chemical analysis by GC-TOFMS and 178 components were identified including acids, amines, amides, aldehydes, alcohols, esters, benzene derivatives, bicyclic compounds, terpenes, hydrocarbons, naphthalene derivatives, furan derivatives, azulenes, etc. Nine components representing 51.73% of the total chloroform extract were detected as major components. Caryophyllene (14.41%) and Eicosanoic acid ethyl ester (12.17%) are the most prominent components of the chloroform extract. β-Caryophyllene (14.41%) as most abundant compound supports potent cytotoxicity as shown by chloroform extract.

2-Acetonyl-2-hydroxy­indan-1,3-dione

In the title compound, C12H10O4, the five-membered ring adopts an envelope conformation, with the Csp 3 atom at the flap [deviation = 0.145 (2) Å]. In the crystal structure, molecules are linked by intermolecular O—H⋯O and C—H⋯O hydrogen bonds, forming a three-dimensional network.

3a,8a-Dihy-droxy-1,3,3a,8a-tetra-hydro-indeno-[1,2-d]imidazole-2,8-dione.

In the title molecule, C10H8N2O4, the imidazolidine ring adopts a twisted conformation. In the crystal, the molecules are linked via a pair of bifurcated intermolecular O—H⋯O hydrogen bonds, forming an inversion dimer. The dimers are further linked via N—H⋯O hydrogen bonds into a tape along the b axis.

2,3-Dimethyl-6-nitro­quinoxaline

The asymmetric unit of the title quinoxaline compound, C10H9N3O2, contains two crystallographically independent molecules (A and B). The quinoxaline ring systems are essentially planar, with maximum deviations of 0.006 (1) and 0.017 (1) Å, respectively, for molecules A and B. In molecule A, the dihedral angle formed between the quinoxaline ring system and nitro group is 10.94 (3)° [6.31 (13)° for molecule B]. In the crystal, molecules are linked into chains propagating along [001]: one forms zigzag chains linked by C—H⋯O hydrogen bonds, whilst the other forms ladder-like chains by way of C—H⋯N and C—H⋯O hydrogen bonds. The packing is further consolidated by weak π–π interactions [range of centroid–centroid distances = 3.5895 (7)–3.6324 (7) Å].

2-Hy­droxy-2-(3-oxobutan-2-yl)indan-1,3-dione

In the indane ring system of the title molecule, C13H12O4, the hydroxy-bearing C atom is 0.134 (1) Å out of the plane of the remaining essentially planar atoms (r.m.s. deviation = 0.010 Å). In the crystal, molecules are linked into chains along the b axis by intermolecular O—H⋯O hydrogen bonds. Additional stabilization is provided by weak intermolecular C—H⋯O hydrogen bonds.