Design, green synthesis, molecular docking and anticancer evaluations of diazepam bearing sulfonamide moieties as VEGFR-2 inhibitors.

Novel series of diazepam bearing sulfonamide moieties 5a-f and 7a-c were designed, synthesized and evaluated for anticancer activity against HepG2, HCT-116 and MCF-7 cell lines. MCF-7 was the most sensitive cell line to the influence of the new derivatives. In particular, compound 5d was found to be the most potent derivative overall the tested compounds against the three HepG2, HCT116 and MCF-7 cancer cell lines with IC50 = 8.98 ± 0.1, 7.77 ± 0.1 and 6.99 ± 0.1 µM respectively. Compound 5d exhibited higher activity than sorafenib, (IC50 = 9.18 ± 0.6, 5.47 ± 0.3 and 7.26 ± 0.3 µM respectively), against HepG2 and MCF-7 but exhibited lower activity against HCT116 cancer cell lines respectively. Also, this compound displayed lower activity than doxorubicin, (IC50 = 7.94 ± 0.6, 8.07 ± 0.8 and 6.75 ± 0.4 µM respectively), against HepG2 and MCF-7 but higher activity against HCT116 cell lines respectively. Compounds 5b, 5c, 5d, 5e, 5f and 7c are respectively, 5.77, 8.58, 9.54, 5.71, 4.68 and 2.31 fold times more toxic in breast cancer cell lines (MCF-7, the most sensitive cells) than in VERO normal cells. All the synthesized compounds 5a-f and 7a-c were evaluated for their inhibitory activities against VEGFR-2. Among them, compound 5d was found to be the most potent derivative that inhibited VEGFR-2 at IC50 value of 0.10 ± 0.01 µM, which is equipotent to sorafenib IC50 value (0.10 ± 0.02 µM). Compound 5c exhibited excellent activity with IC50 value of 0.12 ± 0.01 µM which nearly equipotent to that of sorafenib. Compounds 5b, 5e and 5f exhibited very good activity with the same IC50 value of 0.14 ± 0.02 µM. Also, compounds 7c and 7b possessed good VEGFR-2 inhibition with IC50 values of 0.16 ± 0.06 and 0.17 ± 0.06 µM respectively which are more than the half activity of that of sorafenib. The data obtained from docking studies were highly correlated with that obtained from the biological screening.

Brain targeting of chitosan-based diazepam mucoadhesive microemulsions via nasal route: formulation optimization, characterization, pharmacokinetic and pharmacodynamic evaluation.

OBJECTIVE: The aim of present investigation was to develop microemulsions (MEs) and mucoadhesive microemulsions (MME) of diazepam for brain uptake through nasal administration for the treatment of seizure emergency. SIGNIFICANCE: Status epilepticus (SE) is a medical emergency, requires intravenous administration of diazepam which requires hospitalization of patient. Initiation of therapy at home via nasal administration of diazepam could prevent the damage of brain due to delay of therapy initiation. METHODS: Diazepam MEs were prepared by phase titration method, optimized by using Box-Behnken design. The influence of independent variables oleic acid, surfactant mixture (tween 80:propylene glycol), and water on dependent variables size, flux, and zeta potential was investigated. Optimized MEs, MMEs, and Calmpose (i.v route) were evaluated for pharmacokinetic and pharmacodynamic studies on rats. RESULTS: MME2 composed of oleic acid (5), surfactant mixture (50), water (45), and chitosan (0.5) showed size of 96.45 nm, PDI 0.21 and zeta potential 13.52 mV. MME2 showed significantly high flux of 846.96 ± 34 µg/cm2/h and AUCbrain 1206.49 ± 145.8. The drug targeting efficiency (314%) and direct nose-to-brain transport (68.1%) of MME2 were significantly high compared to Calmpose (i.v) and ME. The latency periods of minimal clonal seizures and generalized tonic-clonic seizures of MME2 was significantly increased (p < 0.0001) compared to drug solution and Calmpose (i.v). CONCLUSION: The brain uptake of diazepam from chitosan-based MMEs via nasal route is significantly high compared to i.v route.

Minimizing E-factor in the continuous-flow synthesis of diazepam and atropine.

Minimizing the waste stream associated with the synthesis of active pharmaceutical ingredients (APIs) and commodity chemicals is of high interest within the chemical industry from an economic and environmental perspective. In exploring solutions to this area, we herein report a highly optimized and environmentally conscious continuous-flow synthesis of two APIs identified as essential medicines by the World Health Organization, namely diazepam and atropine. Notably, these approaches significantly reduced the E-factor of previously published routes through the combination of continuous-flow chemistry techniques, computational calculations and solvent minimization. The E-factor associated with the synthesis of atropine was reduced by 94-fold (about two orders of magnitude), from 2245 to 24, while the E-factor for the synthesis of diazepam was reduced by 4-fold, from 36 to 9.

On-demand continuous-flow production of pharmaceuticals in a compact, reconfigurable system.

Pharmaceutical manufacturing typically uses batch processing at multiple locations. Disadvantages of this approach include long production times and the potential for supply chain disruptions. As a preliminary demonstration of an alternative approach, we report here the continuous-flow synthesis and formulation of active pharmaceutical ingredients in a compact, reconfigurable manufacturing platform. Continuous end-to-end synthesis in the refrigerator-sized [1.0 meter (width) × 0.7 meter (length) × 1.8 meter (height)] system produces sufficient quantities per day to supply hundreds to thousands of oral or topical liquid doses of diphenhydramine hydrochloride, lidocaine hydrochloride, diazepam, and fluoxetine hydrochloride that meet U.S. Pharmacopeia standards. Underlying this flexible plug-and-play approach are substantial enabling advances in continuous-flow synthesis, complex multistep sequence telescoping, reaction engineering equipment, and real-time formulation.

Cytogenetic activity of newly synthesized 1,5-benzodiazepines in normal human lymphocyte cultures.

INTRODUCTION: Many different types of benzodiazepine medications exist to treat a wide array of psychological and physical diseases based on dosage and implications. Benzodiazepines are generally considered as safe and effective drugs in short term; however, cognitive impairments and paradoxical effects occasionally occur. Our recent studies have shown that some 1,4-benzodiazepines exhibit cytogenetic activity (alprazolam, diazepam, and lorazepam) in normal human lymphocyte cultures. 1,5-Benzodiazepine derivatives are used in the synthesis of fused ring compounds, to study the chemical structure-pharmacological activity correlation. We synthesized four compounds of this category with small structural differences. AIM: The aim of this study was to investigate their cytogenetic activity in vitro at doses equivalent to the per os doses of the used 1,4-benzodiazepines. Sister chromatid exchanges (SCEs), proliferation rate index, and mitotic index were evaluated in lymphocytes of peripheral blood cultures from two healthy donors. RESULTS: Three of the newly synthesized compounds exhibited positive cytogenetic activity (statistically significant reduction of SCEs, p < 0.01, t-test), without showing cytostatic properties. CONCLUSION: The observed reduction of the lymphocytes' SCEs because of 1,5-benzodiazepines' activity is remarkable and requires further investigation to improve pharmacological effects.

Imidazo[2,1-b]thiazepines: synthesis, structure and evaluation of benzodiazepine receptor binding.

As a continuation of our search for new ligands acting on benzodiazepine receptors among the fused 2-thiohydantoin derivatives, a series of 5-substituted imidazo[2,1-b]thiazepines was synthesized and investigated in radioligand binding studies at the benzodiazepine binding site of GABA(A) receptors in rat brain cortical membranes. Among ortho-substituted 5-arylidene-imidazo[2,1-b]thiazepines compounds could be identified which exhibit affinity for the benzodiazepine binding site at low micromolar concentrations. X-ray structure analyses for two compounds (6ae and 6ag) have been performed. In order to analyze the structure-activity relationships, 3D models of all compounds have been completed (using X-ray data). Physicochemical properties calculated (log P and log D) as well as experimental thin layer chromatography data were examined.

Convergent synthesis and antibacterial activity of pyrazole and pyrazoline derivatives of diazepam.

Polysubstituted pyrazoles (5)(a-l), pyrazolines (7)(a-c), (8)(a-c) and pyrazolotriazine (10) derivatives of diazepam were synthesized. The structures of hitherto unknown compounds were established by analytical and spectral methods. Some of these compounds were screened to test their antibacterial activity against gram-positive (B. subtilis) and gram-negative (P. aeruginosa). All compounds showed potent activity against these bacteria.

Facile synthesis and biological evaluation of heterocyclic compounds containing diazepam.

Diazepamoxadiazoles 4, 5, 6, 12, 14 and 22 were prepared with the binary form system. Diazepamthiadiazoles 15, 20 and Diazepamtriazoles 7, 8, 9, 17, 18, 19 and 21 were also shapely synthesized. Some of these compounds were screened to test their antibacterial activity against E. coli and B. subtilis compounds 15 and 20 show potent activity against these bacteria.

Imidazo-thiazine, -diazinone and -diazepinone derivatives. Synthesis, structure and benzodiazepine receptor binding.

In our search for new compounds acting on benzodiazepine receptors among the fused 2-thiohydantoin derivatives, a series of arylidene imidazo[2,1-b]thiazines was synthesized. The 1,2- and 2,3- cyclized derivatives of mono- and di-substituted Z-5-arylidene-2-thiohydantoins were examined (the X-ray crystal structure of Z-2-cinnamylidene-6,7-dihydro-5H-imidazo[2,1-b][1,3]thiazin-3(2H)-one was determined) and compared with the diphenyl derivatives. To investigate the influence of the type of annelated ring on the biological activity, imidazo[2,1-b]pyrimidinone and imidazo[2,1-b]diazepinone derivatives were obtained. The method used in annelation (1,2- and 2,3-cyclized isomers with the exception of fused arylidene imidazothiazines), the substitution pattern (arylidene towards diphenyl) as well as the character of the annelated ring had minor influence on the benzodiazepine receptor affinity of the investigated compounds. It appears that the greatest influence on the biological activity has the character and position of the substituents on the arylidene ring.

[A novel pyridazino-fused ring system: synthesis of pyridazino[3,4-b]diazepam]. / Egy új piridazin-gyúrúrendszer, piridazino[3,4-b]diazepin elóállítása.

As an analogue of pyridazino-fused ring systems with pharmacological activities, the novel pyridazinol[3,4-b][1,5]diazepine ring system was prepared. The synthetic pathway includes three steps from 4 5-(N-benzyl-N-3-hydroxypropyl)amino derivative which is easily available through nucleophilic substitution reaction of the known 4,5-dichloro-2-methyl-6-nitro-3(2H)-pyridazinone (2) with N-benzyl-N-(3-hydroxypropyl)amine. In the first step, compound 4 was treated with thionyl chloride to give the chloropropyl derivative 5. In the second step, a Bechamp reduction was carried out with Fe in acetic acid to obtain the amino compound 6, and finally the ring closure reaction of 6 was performed in N,N-dimethylformamide in the presence of potassium carbonate at 110 degrees C for 40 hours. In this way the bicyclic compound 7 could be isolated in 48% yield.

11C-labeled 2'-iododiazepam for PET studies of benzodiazepine receptors: synthesis and comparison of biodistribution with its radioiodinated compound.

For PET studies of benzodiazepine receptors, N-11C-methyl-2'-iododiazepam (2'-IDZ) was synthesized by N-methylation of its desmethyl derivative with 11C-methyl iodide, and was subsequently purified by HPLC. The labeling and purification procedures were completed within 45 min after 11C-methyl iodide trapping, and the radiochemical yield (corrected for decay) was approximately 40% based on the initial trapped radioactivity of 11C-methyl iodide. Biodistribution studies in mice demonstrated that 11C-2'-IDZ was rapidly and noticeably accumulated in the brain, and subsequently decreased with time. Accumulation was greater in the cortex than in other brain regions. When compared with 125I-2'-IDZ, the distribution was almost the same until 5 min after injection, but levels were low after 20 min. Metabolic studies indicated that the difference between these two compounds in the time course of brain radioactivity distribution may be due to N-demethylation in vivo.

An approach for assaying benzodiazepine receptor binding with radioiodinated ligand: 125I-labeled diazepam derivative.

[125I]2'-Iododiazepam (IDZ) was prepared and its application in a benzodiazepine receptor binding assay was studied. [125I]2'-IDZ binds to the rat cortical membrane with a high affinity (Kd, 0.66 nM). Various benzodiazepines showed competition with [125I]2'-IDZ for the binding sites in the rat cortical membrane, and the specificity of its binding correlated well with that of [3H]diazepam (r = 0.992, p < 0.001). These findings suggested that [125I]2'-IDZ binds to the same sites as [3H]diazepam and indicated that [125I]2'-IDZ can be used in a benzodiazepine receptor assay.

Synthesis and biodistribution of [11C]fludiazepam for imaging benzodiazepine receptors.

As a tracer for in vivo studies on benzodiazepine receptors, 7-chloro-1,3-dihydro-5-(2-fluorophenyl)-1-[11C]methyl-2H-1,4- benzodiazepin-2-one, [11C]fludiazepam, was synthesized by the methylation of nor-derivative with [11C]CH3I, and purified by high-performance liquid chromatography. Within 60 min [11C]fludiazepam was obtained for injection in high radiochemical yields and in high radiochemical purity with a specific activity of up to 230 mCi/mumol. After i.v. injection of [11C]fludiazepam in rats the radioactivity was rapidly incorporated into many tissues and the blood clearance of the radioactivity was very rapid. The brain uptake was high and decreased gradually. The adrenal uptake was the highest and decreased with high loading doses. The effect of the loading dose on the uptake was also found in the heart and lungs. By autoradiography using [11C]fludiazepam, a higher accumulation was visualized in the cortex and thalamus than in other regions.

Pharmacology of some metabolites of triazolam, alprazolam, and diazepam prepared by a simple, one-step oxidation of benzodiazepines.

A simple, one-step chemical oxidation of triazolam (7) to its 4-hydroxy analogue, 7a, has been developed and applied to other triazolo- and imidazobenzodiazepines. The reaction may be used to convert diazepam to temazepam. 4-Hydroxytriazolo[4,3-a][1,4]benzodiazepines have low central nervous system sedative and anticonvulsant activity in sharp contrast to metabolites of diazepam which remain active. While 10, an alpha-hydroxy metabolite of triazolam, retains much of the activity of 7, 10a, and alpha,4-dihydroxy metabolite of triazolam, is 250 times less potent than 7 on the nicotine-antagonism assay and over 300 times less potent on the traction assay.

[Determination of the origin of drugs by measuring natural isotope contents: D/H and 13C/12C ratios of some diazepam samples (author's transl)]. / Herkunftsbestimmung von Arzneimitteln durch Messung von natürlichen Isotopenverhältnissen: D/H und 13C/12C Verhältnisse einiger Proben von Diazepam

The precise determination of the natural isotopic abundance ratios of carbon and hydrogen in several production batches of the commercial product 7-chlor-1,3-dihydro-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-on (diazepam) gave results which allowed certain batches to be differentiated. The differences in the ratios appear to be mainly due to differences in the isotopic composition of the (fossile) starting materials of the synthesis. The measurement of the natural isotopic ratios may therefore offer another possibility to determine the origin of a drug.