Mohd Fazli Mohammat

Synthesis of 2,3-Dioxo-5-(substituted)arylpyrroles and Their 2-Oxo-5-aryl-3-hydrazone Pyrrolidine Derivatives

Some novel 2,3-dioxo-5-(substituted)arylpyrroles have been synthesized. Among these, pyrrolidine compound 1b was converted to 2,3-dioxo-5-aryl pyrrolidine 2b. Finally a set of hydrazone derivatives was obtained from the reaction of 2b with various hydrazine salts. The structures of all the new synthesized compounds were confirmed by elemental analyses, IR and 1H-NMR spectra.

In Vitro Inhibitory and Cytotoxic Activity of MFM 501, a Novel Codonopsinine Derivative, against Methicillin-Resistant Staphylococcus aureus Clinical Isolates

28 new pyrrolidine types of compounds as analogues for natural polyhydroxy alkaloids of codonopsinine were evaluated for their anti-MRSA activity using MIC and MBC value determination assay against a panel of S. aureus isolates. One pyrrolidine compound, MFM 501, exhibited good inhibitory activity with MIC value of 15.6 to 31.3 μg/mL against 55 S. aureus isolates (43 MRSA and 12 MSSA isolates). The active compound also displayed MBC values between 250 and 500 μg/mL against 58 S. aureus isolates (45 MRSA and 13 MSSA isolates) implying that MFM 501 has a bacteriostatic rather than bactericidal effect against both MRSA and MSSA isolates. In addition, MFM 501 showed no apparent cytotoxicity activity towards three normal cell lines (WRL-68, Vero, and 3T3) with IC50 values of >625 µg/mL. Selectivity index (SI) of MFM 501 gave a value of >10 suggesting that MFM 501 is significant and suitable for further in vivo investigations. These results suggested that synthetically derived intermediate compounds based on natural products may play an important role in the discovery of new anti-infective agents against MRSA.

(5R)-Ethyl 6-benzyl-8,8-dimethyl-7,9-dioxo-1-oxa-2,6-diaza-spiro-[4.4]non-2-ene-3-carboxyl-ate.

In the title compound, C18H20N2O5, the pyrrolidine ring adopts an envelope conformation with the C atom bonded to the methyl groups as the flap. The dihydroisoxazole ring is essentially planar (r.m.s. deviation = 0.041 Å) and forms a dihedral angle of 65.19 (6)° with the phenyl ring. In the crystal, neighbouring molecules are linked into chains along [110] by intermolecular C—H⋯O hydrogen bonds and weak C—H⋯π interactions involving the phenyl ring.

tert-Butyl 5-(4-methoxy-phen-yl)-1-methyl-2-oxopyrrolidin-3-yl carbonate.

In the title compound, C17H23NO5, the pyrrolidinone ring is in an envelope conformation. The tert-butyl carbonate and 4-methoxyphenyl groups are arranged on the same side of the pyrrolidinone ring. The methoxy group is coplanar with the attached benzene ring. The molecules are linked into chains along the b axis via C—H⋯O hydrogen bonds.

4-Hydr­oxy-5-(4-methoxy­phen­yl)pyrrolidin-2-one

In the title compound, C11H13NO3, the pyrrolidin-2-one ring is in an envelope conformation with the hydroxyl and 4-methoxyphenyl substituents mutually cis. The methoxy group is slighty twisted away from the mean plane of the attached benzene ring. The molecules are arranged into screw chains along the c axis. These chains are interconnected via intermolecular O—H⋯O and N—H⋯O hydrogen bonds into sheets parallel to the ac plane. The crystal structure is further stabilized by weak intermolecular C—H⋯O and C—H⋯π interactions.

In Vitro Evaluations and In Vivo Toxicity and Efficacy Studies of MFM501 against MRSA

Previously we have discovered a synthetically derived pyrrolidone alkaloid, MFM501, exhibiting good inhibitory activity against 53 MRSA and MSSA isolates with low cytotoxicity against three normal cell-lines with IC50 values at >625 µg/ml. Time-kill assay, scanning electron microscopy (SEM) analysis, in vivo oral acute toxicity test, and mice peritonitis model were carried out in this study. In the time-kill study, MFM501 showed a less than 3 log10 decrease in bacterial colony concentration value (CFU/ml) which represented a bacteriostatic action while displaying a time-dependent inhibitory mechanism. Following that, SEM analysis suggested that MFM501 may exert its inhibitory activity via cytoplasmic membrane disruption. Moreover, MFM501 showed no toxicity effect on treated mice at an estimated median acute lethal dose (LD50) value of more than 300 mg/kg and less than 2000 mg/kg. For the efficacy test, a mean effective dose (ED50) of 87.16 mg/kg was obtained via a single dose oral administration. Our data demonstrated that MFM501 has the potential to be developed further as a new, safe, and effective oral-delivered antibacterial agent against MRSA isolates.

Ethyl 4-hy-droxy-1-methyl-5-oxo-2-phenyl-pyrrolidine-3-carboxyl-ate 1.25-hydrate.

The asymmetric unit of the title compound, C14H17NO4·1.25H2O, consists of four substituted pyrrolidone molecules (two pairs of enantiomers) and five water molecules. The five-membered rings each have an envelope conformation, with the C atom bonded to the ester group as the flap. The mean planes of the five-membered rings of the four pyrrolidone molecules make dihedral angles of 60.87 (5), 64.45 (5), 62.03 (5) and 65.79 (5)° with respect to the phenyl rings. In the crystal, the pyrrolidone and water molecules are connected through O—H⋯O hydrogen bonds, forming a layer parallel to the ab plane. The two-dimensional network is further stabilized by intermolecular C—H⋯O hydrogen bonds.

Methyl 2-{[(4-hydroxy­phen­yl)(methoxy­carbon­yl)meth­yl]amino­carbon­yl}ethano­ate hemihydrate

In the structure of the title compound, C13H15NO6·0.5H2O, the water O atom lies on a twofold rotation axis. The methoxycarbonylmethyl and amino groups are essentially coplanar and the methoxycarbonylmethyl group makes a dihedral angle of 79.73 (10)° with the mean plane of the hydroxyphenyl ring. The amino and methoxycarbonylmethyl groups are involved in an intramolecular N—H⋯O hydrogen bond which generates an S(5) ring motif. In the crystal structure, molecules are linked via N—H⋯O and O—H⋯O hydrogen bonds and weak C—H⋯O interactions into a two-dimensional network parallel to the (01) plane. The crystal structure is further stabilized by C—H⋯π interactions.