Ketoconazole-p aminobenzoic cocrystal, an improved antimycotic drug formulation, does not induce skin sensitization on the skin of BALBc mice.

Fungal infections are a growing global health problem. Therefore, our group has synthetized and characterized an improved antimycotic by co-crystallization of ketoconazole and para-amino benzoic acid, named KET-PABA. The aim was to increase bioavailability, biocompatibility, and efficiency of the parent drug-ketoconazole. Based on our previous results showing the cocrystal improved physical properties, such as stability in suspension, solubility, as well as antimycotic efficiency compared to ketoconazole, the current study investigated the local possible side effects induced on the skin of BALBc mice by the application of KET-PABA cocrystal, in view of a further use as a topically applied antimycotic drug. A specific test (mouse ear-swelling test) was used, combined with the histopathological examination and the measurement of pro and anti-inflammatory cytokines and inflammation mediators. KET-PABA application was safe, without signs of skin sensitization shown by the mouse ear sensitization test, or histopathology. KET-PABA strongly inhibited proinflammatory cytokines such as IL1 α, IL1 ß, IL6 and TNF α, and other proinflammatory inducers such as NRF2, compared to vehicle. KET-PABA had no effect on the levels of the anti-inflammatory cytokine IL10, or proinflammatory enzyme COX2 and had minimal effects on the activation of the NF-κB pathway. Overall, KET-PABA application induced no sensitization, moreover, it decreased the skin levels of proinflammatory molecules. The lack of skin sensitization effects on BALBc mice skin along with the inhibition of the proinflammatory markers show a good safety profile for topical applications of KET-PABA and show promise for a further clinical use in the treatment of cutaneous mycosis.

Synthesis, morphology and antifungal activity of nano-particulated amphotericin-B, ketoconazole and thymoquinone against Candida albicans yeasts and Candida biofilm.

In the current study, nano-particulated drugs-Amphotericin-B, Ketoconazole and Thymoquinone (an active ingredient of Nigella sativa)-were prepared using the ball milling technique, and their particle sizes were examined by transmission electron microscopy (TEM) and using a particle size analyzer. The grain sizes of the prepared compounds were found in between 5 to 20 nm, and exhibited quasi-spherical morphology. The antifungal activity of each nano-particulated drug was investigated in vitro against Candida albicans yeasts and Candida biofilm, and compared with their micro-structured conventional forms. Nano-sized drugs were found to be two to four times more effective in disinfecting both the Candida yeasts and Candida biofilm. The study is a first of its kind as nano-forms of drugs have not been studied against Candida and Candida biofilm before. Further investigations are required for the determination of the clinical significance of the nano-formulation of antifungal substances.

Synthesis of novel brassinosteroid biosynthesis inhibitors based on the ketoconazole scaffold.

Brassinosteroids (BRs) are steroidal plant hormones that control several important agronomic traits such as plant architecture, seed yield, and stress tolerance. Inhibitors that target BR biosynthesis are candidate plant growth regulators. We synthesized novel triazole derivatives, based on the ketoconazole scaffold, that function as inhibitors of BR biosynthesis. The biological activity of the test compounds was evaluated by determining their ability to induce dwarfism in Arabidopsis seedlings grown in the dark. The chemically induced dwarfism of Arabidopsis seedlings was further evaluated by a rescue experiment using the co-application of brassinolide and/or gibberellins (GA). The structure-activity relationship studies revealed a potent BR biosynthesis inhibitor, 2RS, 4RS-1-{2-(4-chlorophenyl)-4-[2-(2-ethoxyphenyl)-ethyl]-1,3-dioxolan-2-ylmethyl}-1H-1,2,4-triazole (7m), with an IC(50) value of 0.10±0.03 µM for retardation of Arabidopsis seedling stem elongation. The compound-induced hypocotyl dwarfism was counteracted by the co-application of 10nM brassinolide, but not 1 µM GA(3), which produced seedlings that resembled BR-deficient mutants. This result suggests that 7m is a potent and specific inhibitor of BR biosynthesis.

NO-donors. Part 17: Synthesis and antimicrobial activity of novel ketoconazole-NO-donor hybrid compounds.

Novel hybrid compounds combining the antifungal drug ketoconazole with a diazen-1-ium-1,2-diolate or an organic nitrate moiety and the corresponding NO-donors without ketoconazole were synthesized and their activities against a broad variety of fungal strains were tested. Hybridization modifies the spectrum of antimicrobial activities and generally, the ketoconazole-NO-donor hybrids are more potent than ketoconazole. The NO-donors alone show insufficient effectiveness.

Novel ketoconazole analogues based on the replacement of 2,4-dichlorophenyl group with 1,4-benzothiazine moiety: design, synthesis, and microbiological evaluation.

As a part of a program to develop novel antifungal agents, new compounds which incorporate the 1,4-benzothiazine moiety into the structure of ketoconazole (KTZ) were prepared. These compounds were computationally investigated to assess whether the 1,4-benzothiazine moiety was a suitable bioisosteric replacement for the 2,4-dichlorophenyl group of KTZ in order to obtain a more potent inhibition of CYP51 enzyme of Candida albicans. Results of preliminary microbiological studies show that the racemic cis-7 analogue has a good in vivo activity, comparable to that of KTZ, but the best activity was observed in the racemic trans-7 analogue.

Partial structures of ketoconazole as modulators of the large conductance calcium-activated potassium channel (BK(Ca)).

A series of partial structures of ketoconazole has been synthesized and tested for activity on the large conductance calcium-activated potassium channel (BK) in bovine smooth muscle cells. This has provided openers and blockers of the channel. The results suggest that the phenyl and phenoxy moieties are important for interaction with BK, whereas the imidazole group is unimportant. The properties of the phenoxy moiety seem to determine whether the compounds act to open or block the channel.

Antibacterial and antifungal agents. XV. Synthesis and antifungal activity of structural analogues of bifonazole and ketoconazole.

The synthesis and antifungal activities of the cis- and trans-1-acetyl-4-[4-[[2-(1,1'-biphenyl-4-yl)-2-(1H-imidazol-1-ylmethy l)- 1,3-dioxolan-4-yl]-methoxy]phenyl)piperazines 3 and 4 are reported. Stereochemical assignments to diastereomeric pairs of cis/trans isomers were made on the basis of 1H- and 13C-NMR data. Among test derivatives the best activity was shown by the benzoyl esters of the cis- and trans-[2-(1,1'-biphenyl-4-yl)-2-(1H-imidazol-1-ylmethyl)-1,3-di oxolan-4- yl]methanols 9 and 10.

Stereoisomers of ketoconazole: preparation and biological activity.

The four stereoisomers of the antifungal agent ketoconazole (1) were prepared and evaluated for their selectivity in inhibiting a number of cytochrome P-450 enzymes. Large differences in selectivity among the isomers were observed for inhibition of the cytochromes P-450 involved in steroid biosynthesis, whereas little differences was observed for inhibition of those associated with hepatic drug metabolism. The cis-(2S,4R) isomer 2 was the most effective against rat lanosterol 14 alpha-demethylase, (2S,4R)-2 greater than (2R,4S)-4 much greater than (2R,4R)-3 = (2S,4S)-5, and progesterone 17 alpha,20-lyase, (2S,4R)-2 much greater than (2S,4S)-5 greater than (2R,4R)-3 = (2R,4S)-4, whereas the cis-(2R,4S) isomer 4 was more effective against cholesterol 7 alpha-hydroxylase, (2R,4S)-4 greater than (2S,4S)-5 greater than (2R,4R)-3, greater than (2S,4R)-2, and the trans-(2S,4S) isomer 5 was the most effective against aromatase, (2S,4R)-5 much greater than (2R,4R)-3 = (2R,4S)-4 greater than (2S,4R)-2. The cis-(2S,4R) and trans-(2R,4R) isomers 2 and 3 are equipotent in inhibiting corticoid 11 beta-hydroxylase and much more effective than their antipodes. Little selectivity was observed for inhibition of cholesterol side chain cleavage or xenobiotic hydroxylase. These data indicate that the affinity of azoles for cytochrome P-450 enzymes involved in steroid synthesis is highly dependent on the stereochemistry of the entire molecule, whereas binding to drug metabolizing enzymes is a less selective process.

Antimycotic azoles. 7. Synthesis and antifungal properties of a series of novel triazol-3-ones.

A series of novel triazol-3-ones have been synthesized, and their in vitro and in vivo antifungal properties are reported. Compound 68 (itraconazole), which displays a pronounced oral activity against vaginal candidosis in rats and against microsporosis in guinea pigs, has been selected for clinical evaluation.