Studies on synthesis and evaluation of quantitative structure–activity relationship of 10-methyl-6-oxo-5-arylazo-6,7-dihydro-5H-[1,3]azaphospholo[1,5-d][1,4]benzodiazepin-2-phospha-3-ethoxycarbonyl-1-phosphorus dichlorides

Azobisisobutyronitrile-Initiated Oxidative C-H Functionalization of Simple Alcohols with Diaryl(arylethynyl)phosphine Oxides: A Metal-Free Approach toward Hydroxymethyl Benzo[b]phosphole Oxides and 6H-Indeno[2,1-b]phosphindole 5-Oxide Derivatives

The first metal-free and facile radical addition/cyclization of simple alcohols with diaryl(arylethynyl)phosphine oxides has been described with azobisisobutyronitrile as a radical initiator, affording an efficient and one-pot procedure to access a new class of hydroxymethyl benzo[b]phosphole oxides and 6H-indeno[2,1-b]phosphindole 5-oxides for potential application in organic materials via sequential C(sp³)-H/C(sp²)-H functionalization. The method employs easily accessible starting materials and is endowed with high regioselectivity and broad functional-group tolerance.

Electrooxidative CH/PH functionalization as a novel way to synthesize benzo[b]phosphole oxides mediated by catalytic amounts of silver acetate

Electrochemical oxidation synthesis of benzo[b]phosphole oxides has been performed at room temperature with catalytic amounts of AgOAc.

Palladium-Catalyzed Domino Addition and Cyclization of Arylboronic Acids with 3-Hydroxyprop-1-yn-1-yl Phosphonates Leading to 1,2-Oxaphospholenes

A novel and efficient palladium-catalyzed domino addition-cyclization of a wide range of arylboronic acids with various 3-hydroxyprop-1-yn-1-yl phosphonates has been developed, affording a convenient and powerful tool for the preparation of valuable 1,2-oxaphospholenes with mild reaction conditions, broad substrate applicability, and good to excellent yields. Mechanistic studies revealed that the reaction might involve Michael addition and nucleophilic substitution.

Ag-mediated cascade decarboxylative coupling and annulation: a convenient route to 2-phosphinobenzo[b]phosphole oxides

Structurally sophisticated 2-phosphinobenzo[b]phosphole oxide frameworks have been conveniently constructed by cascade decarboxylative coupling and annulation reactions.

Synthesis, antimicrobial, anticancer, antiviral evaluation and QSAR studies of 4-(1-aryl-2-oxo-1,2-dihydro-indol-3-ylideneamino)-N-substituted benzene sulfonamides

A series of 4-(1-aryl-2-oxo-1,2-dihydro-indol-3-ylideneamino)-N-substituted benzenesulfonamide derivatives (1-32) was synthesized and evaluated for its in vitro antimicrobial, antiviral and cytotoxic activities. Antimicrobial results indicated that compounds (11) and (18) were found to be the most effective ones. In general, the synthesized compounds were bacteriostatic and fungistatic in their action. The cytotoxic screening results indicated that the compounds were less active than the standard drug 5-fluorouracil (5-FU). None of the compounds inhibited viral replication at subtoxic concentrations. In general, the presence of a pyrimidine ring with electron releasing groups and an ortho- and para-substituted benzoyl moiety favored antimicrobial activities. The results of QSAR studies demonstrated the importance of topological parameters, valence zero order molecular connectivity index (0χv) and valence first order molecular connectivity index (1χv) in describing the antimicrobial activity of synthesized compounds.

Synthesis, characterization, antimicrobial activities and QSAR studies of some 10a-phenylbenzo[b]indeno[1,2-e][1,4]thiazin-11(10aH)-ones

A series of 10a-phenylbenzo[b]indeno[1,2-e][1,4]thiazin-11(10aH)-ones (3) has been synthesized and tested for their antimicrobial activity. The antimicrobial evaluation data indicated that compounds, 3b, 3d, 3k and 3m exhibited very promising antibacterial activity and the compounds 3b and 3k exhibited notable activity, almost comparable to penicillin for Staphylococcus aureus and Bacillus subtilis respectively. The derivatives 3g and 3l exhibited high antifungal activity. Moreover, antibacterial activities were more prolific than antifungal activity. The QSAR studies indicated the importance of topological parameters, Kiers second order molecular index (κα(2)) and molecular connectivity index (χ) in describing the antibacterial activity and electronic parameters, the energy of highest occupied molecular orbital (HOMO) and the dipole moment (μ) in describing the antifungal activity.

4-[1-(Substituted aryl/alkyl carbonyl)-benzoimidazol-2-yl]-benzenesulfonic acids: synthesis, antimicrobial activity, QSAR studies, and antiviral evaluation

A series of 4-[1-(substituted aryl/alkyl carbonyl)-benzoimidazol-2-yl]-benzene sulphonic acids (1-20) was synthesized and evaluated, in vitro, for their antimicrobial activity and the results indicated that compounds 4-[1-(4-Nitrobenzoyl)-1H-benzoimidazol-2-yl]-benzenesulfonic acid (9) and 4-(1-octadec-9-enoyl-1H-benzoimidazol-2-yl)-benzenesulfonic acid (18) were found to be the most active ones. QSAR investigations indicated that the multi-target QSAR model was effective in describing the antimicrobial activity over the one-target QSAR models. Further the mt-QSAR model indicated the importance of the topological parameter, Balaban index (J) followed by the electronic parameter, LUMO and topological parameter, valence second order molecular connectivity index (2χv) in describing the antimicrobial activity of synthesized compounds (1-20).

QSAR studies of a number of triazole antifungal alcohols

The activity of fungicide agents containing a quinazolinone ring was described using the quantitative structure-activity relationship (QSAR) model by applying it to data taken from literature. The title compounds exhibit two important types of activity against certain fungal pathogens, i.e. activity against yeast and activity against filamentous fungi. A correlation between both antifungal activities (e.g. FA(yst) and FA(ff)) and physicochemical parameters such as the logarithm of the n-octanol/water partition coefficient (log P), the polarizability (P), the global minimum energy (TE), the energy difference between the frontier molecular orbital (DELH) and the molar refractivity (MR), was established using multiple linear regression. The molecular descriptors of the antifungal agents were obtained by quantum chemical calculations combined with molecular modeling calculations. Statistical analysis shows that the antifungal activity depends mainly on the calculated partition coefficients, log P, of the compounds. Bi-parametric models reveal that antifungal activity relates linearly to log P and P.

Benzylidene/2-chlorobenzylidene hydrazides: synthesis, antimicrobial activity, QSAR studies and antiviral evaluation

A series of benzylidene hydrazides (1–20) was synthesized and tested, in vitro, for antibacterial, antifungal and antiviral activities. The microbial screening results indicated that compounds having chloro and nitro substituents were the most active ones. The antiviral evaluation depicted that compounds 9 and 19 were active against Vesicular stomatitis virus (VSV) in HeLa cell cultures. QSAR investigations indicated that the multi-target QSAR model was effective in describing the antimicrobial (antibacterial and antifungal) activity over the one-target QSAR models. Further the mt-QSAR model indicated that the topological parameters, second order molecular connectivity index (²χ) and third order Kier's alpha shape index (κα₃) are effective in describing the antimicrobial activity of synthesized hydrazides.

Quantitative structure–activity relationship studies for prediction of antimicrobial activity of synthesized 2,4-hexadienoic acid derivatives

A new series of 2,4-hexadienoic acid derivatives (S(1)-S(42)) has been synthesized and evaluated as antimicrobial agents against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Candida albicans, and Aspergillus niger. Quantitative structure-activity relationship (QSAR) investigation using Hansch analysis was applied to find out correlation between antimicrobial activities with physicochemical properties of the synthesized compounds. Various physicochemical descriptors and experimentally determined minimum inhibitory concentration values for different microorganisms were used as independent and dependent variables, respectively. The QSAR revealed that topological parameters especially molecular connectivity indices (chi(2), (0)chi(v), (2)chi(v)) were found to have overall significant correlation with antimicrobial activity of 2,4-hexadienoic acid derivatives. The statistical results of training set, cross-validated r(2) and conventional r values gave reliability to the prediction of molecules with activity using QSAR models.

Synthesis and Evaluation of Antimicrobial Activity of Novel Hydrazino andN-Benzylidinehydrazino-Substituted 4,8-Dihydro-1H,3H-pyrimido[4,5-d]pyrimidin-2,7-dithiones

A number of novel pyrimido[4,5-d]pyrimidine-2,7-dithone derivatives bearing hydrazino and N-benzylidinehydrazino substitution were efficiently synthesized and screened for in vitro antibacterial activities against the representative panel of three Gram-positive and two Gram-negative bacteria. All the synthesized compounds showed the potent inhibitory action against Gram-positive bacteria. Particularly, N-benzylidinehydrazino-substituted compounds imparted profound effect. Furthermore, the Connolly-accessible surface area values were also calculated for the target compounds and correlated with the expressed biological activity.