Synthesis and quantitative structure-activity relationship analysis of N-triiodoallyl- and N-iodopropargylazoles. New antifungal agents

New series of N-(2,3,3-triiodoallyl) and N-(3-iodopropargyl) azole derivatives (100 compounds) involving pyrrole, pyrazole, imidazole, triazole, and tetrazole nuclei were synthesized successively with the aid of quantitative structure-activity relationship (QSAR) analysis to obtain potent antifungal agents. Starting from the derivatives of nitropyrrole-containing antibiotics, the QSAR analysis of the pyrrole derivatives against Candida albicans and Trichophyton mentagrophytes strains indicated the positive contribution of the nitro group and negative effect of the size of molecule. Further application of the QSAR analysis on the multi-azole derivatives revealed the importance of hydrophobicity and electronegativity as well as steric effect to the activities and led to the synthesis of one of the most potent iodo compounds, 2-(2,3,3-triiodoallyl)tetrazole (67, ME1401).     

Micafungin sodium (FK-463)

FK-463 (micafungin) represents the latest development candidate in a novel chemical class of echinocandin lipopeptide antifungal compounds. This agent has potent in vitro and experimental in vivo activity against a variety of pathogenic Candida species (yeasts) and Aspergillus fumigatus (filamentous fungus). This compound has favorable pharmacokinetics and a unique mode of action that makes it active against fungal isolates resistant to established antifungal agents, particularly the triazole agent fluconazole. Single- and multiple-dose phase I studies in normal human volunteers and phase II clinical trials in patients have been completed, with the compound being generally well tolerated and efficacious against infections caused by Candida and Aspergillus species. Published information on the in vitro and experimental in vivo activity, experimental and human pharmacokinetics, and clinical trial data of this new antifungal, echinocandin-like lipopeptide are summarized in this monograph.     

The cytotoxicity of amine-cyanoboranes, amine-cyanoalkylboranes and aminomethyl-phosphonate cyanoborane adducts against the growth of murine and human tissue culture cells.

The amine-cyanoboranes, the amine-cyanoalkylboranes and the aminomethyl-phosphonate-N-cyanoborane adducts proved to be active antineoplastic agents. These compounds were more effective against single cell cultured cell growth rather than solid tumors. The following amine-cyanoboranes, (CH3)2(C18H37)NBH2CN (5), (CH3)2NHBH[CH(CH3)2]CN (7) and (CH3)3NB(CN)2.CH3 (10), were the most active in vivo and in vitro. A related phosphine-cyanoborane was also very active in both in vivo and in vitro model screens. Of the amino-methyl-phosphonate-N-cyanoborane adducts, (CH3O)2.P(O)CH2N(C2H5)2BH2CN (13) proved to be the most active. The amine-cyanoalkylboranes had the poorest in vivo activity; the in vitro cytotoxicity, however, was similar to that of other cyanoboranes.     

Design, synthesis, and biological evaluation of analogues of the antitumor agent, 2-(4-[(7-chloro-2-quinoxalinyl)oxy]phenoxy)propionic acid (XK469)

2-(4-[(7-Chloro-2-quinoxalinyl)oxy]phenoxy)propionic acid (XK469) is among the most highly and broadly active antitumor agents to have been evaluated in our laboratories and is currently scheduled to enter clinical trials in 2001. The mechanism or mechanisms of action of XK469 remain to be elaborated. Accordingly, an effort was initiated to establish a pharmacophore hypothesis to delineate the requirements of the active site, via a comprehensive program of synthesis of analogues of XK469 and evaluation of the effects of structural modification(s) on solid tumor activity. The strategy formulated chose to dissect the two-dimensional parent structure into three regions-I, ring A of quinoxaline; II, the hydroquinone connector linkage; and III, the lactic acid moiety-to determine the resultant in vitro and in vivo effects of chemical alterations in each region. Neither the A-ring unsubstituted nor the B-ring 3-chloro-regioisomer of XK469 showed antitumor activity. The modulating antitumor effect(s) of substituents of differing electronegativities, located at the several sites comprising the A-ring of region I, were next ascertained. Thus, a halogen substituent, located at the 7-position of a 2-(4-[(2-quinoxalinyl)oxy]phenoxy)propionic acid, generated the most highly and broadly active antitumor agents. A methyl, methoxy, or an azido substituent at this site generated a much less active structure, whereas 5-, 6-, 8-chloro-, 6-, 7-nitro, and 7-amino derivatives all proved to be essentially inactive. When the connector linkage (region II) of 1 was changed from that of a hydroquinone to either a resorcinol or a catechol derivative, all antitumor activity was lost. Of the carboxylic acid derivatives of XK469 (region III), i.e., CONH2, CONHCH3, CON(CH3)2, CONHOH, CONHNH2, CN, or CN4H (tetrazole), only the monomethyl- and N,N-dimethylamides proved to be active.     

Pradimicins A, B and C: new antifungal antibiotics. II. In vitro and in vivo biological activities

Pradimicins A, B and C specify novel antibiotics produced by Actinomadura hibisca No. P157-2 (ATCC 53557) possessing potent and broad antifungal activity in vivo. They showed moderate in vitro antifungal activity against a wide variety of fungi and yeasts including clinically important pathogens, and were highly effective in systemic infection with Candida albicans in mice after iv and im administrations. Pradimicin A showed in vivo therapeutic activity against C. albicans, Cryptococcus neoformans and Aspergillus fumigatus in both normal and immunocompromized mice. 5-Fluorocytosine- and azole-resistant C. albicans strains were susceptible to pradimicin A. This antibiotic also demonstrated therapeutic efficacy against lung candidiasis and aspergillosis, vaginal candidiasis and skin Trichophyton mentagrophytes infection in mice with iv or topical treatment. The LD50 values after a single iv or im administration were 120 mg/kg and more than 400 mg/kg, respectively. Against various cultured mammalian cells, pradimicin A was noncytotoxic at 100 or 500 micrograms/ml, and showed potent anti-influenza virus activity with an IC50 value of 6.8 micrograms/ml.     

Fungicidal activity of human lactoferrin-derived peptides based on the antimicrobial αβ region

Owing to the increasing number of infections in hospitalised patients caused by resistant strains of fungi, there is a need to develop new therapeutic agents for these infections. Naturally occurring antimicrobial peptides may constitute models for developing such agents. A modified peptide sequence (CFQWKRAMRKVR; HLopt2) based on amino acid residues 20-31 of the N-terminal end of human lactoferrin (hLF) as well as a double-sized human lactoferricin-like peptide (amino acid residues 16-40; HLBD1) were investigated for their antifungal activities in vitro and in vivo. By in vitro assay, HLopt2 was fungicidal at concentrations of 12.5-25 μg/mL against Cryptococcus neoformans, Candida albicans, Candida krusei, Candida kefyr and Candida parapsilosis, but not against Candida glabrata. HLopt2 was demonstrated to have ≥ 16-fold greater killing activity than HLBD1. By inducing some helical formation caused by lactam bridges or by extending the assay time (from 2h to 20 h), HLBD1 became almost comparable with HLopt2 in its fungicidal activity. Killing of C. albicans yeast cells by HLopt2 was rapid and was accompanied by cytoplasmic and mitochondrial membrane permeabilisation as well as formation of deep pits on the yeast cell surface. In a murine C. albicans skin infection model, atopic treatment with the peptides resulted in significantly reduced yields of Candida from the infected skin areas. The antifungal activities of HLopt2 in vitro and in vivo suggest possible potential as a therapeutic agent against most Candida spp. and C. neoformans. The greatly improved antifungal effect of the lactam-modified HLBD1 indicates the importance of amphipathic helix formation for lethal activity.     

Water-soluble pradimicin derivatives, synthesis and antifungal evaluation of N,N-dimethyl pradimicins

Three N,N-dimethyl pradimicins were synthesized by reductive alkylation of pradimicins A, E and FA-2 and evaluated for antifungal activity, water solubility and acute toxicity in mice. They showed in vitro antifungal activity superior to pradimicin A. N,N-Dimethylpradimicins E and FA-2 showed great improvement in water solubility and animal tolerance. N,N-Dimethylpradimicin FA-2 was effective in 3 experimental in vivo fungal infection models.     

Synergetic skin targeting effect of hydroxypropyl-β-cyclodextrin combined with microemulsion for ketoconazole

The objective was to develop a ternary skin targeting system for ketoconazole (KET) using a combined strategy of microemulsion (ME) and cyclodextrin (HP-β-CD), i.e., KET-CD-ME, which exploits both virtues of cyclodextrin complex and ME to obtain the synergetic effect. KET-CD-ME was formulated using Labrafil M 1944 CS as oil phase, Solutol HS 15 as surfactant, Transcutol P as cosurfactant, and HP-β-CD solution as aqueous phase. The formulation of KET-CD-ME was optimized and the optimal formulation was characterized in terms of particle size, size distribution, pH value, and viscosity. Long term stability experiment showed that HP-β-CD could increase the physical stability of ternary system and KET chemical stability. Percutaneous permeation of KET from KET-CD-ME in vitro through rat skin was investigated in comparison with KET microemulsion (KET-ME), KET HP-β-CD inclusion solution (KET-CD), KET aqueous suspension, and commercial KET cream; the results showed that the combination of ME with HP-β-CD exhibited significantly synergistic effect on KET deposition within the skin (29.38 ± 1.79 μg/cm²) and a slightly synergistic effect on KET penetration through the skin (11.3 μg/cm²/h). The enhancement of the combination on skin deposition was further visualized by confocal laser scanning microscope (CLSM). In vitro sensitivity against Candida parapsilosis test indicated that KET-CD-ME enhanced KET antifungal activity mainly owing to the solubilization of HP-β-CD on KET in the ternary system. Moreover, the interactions between HP-β-CD and KET in the ternary system were elucidated through microScale thermophoresis (MST) and 2D ¹H NMR spectroscopy. The profiles from MST confirmed the host–guest interactions of HP-β-CD with KET in the ternary system and a deep insight into the interactions between KET and HP-β-CD were obtained by means of 2D ¹H NMR spectroscopy. The results indicate that the ternary system of ME combination with HP-β-CD may be a promising approach for skin targeting delivery of KET.     

In vitro and in vivo antifungal activities of the eight steroid saponins from Tribulus terrestris L. with potent activity against fluconazole-resistant fungal pathogens

Antifungal activity of natural products is being studied widely. Saponins are known to be antifungal and antibacterial. We have isolated eight steroid saponins from Tribulus terrestris L., namely TTS-8, TTS-9, TTS-10, TTS-11, TTS-12, TTS-13, TTS-14 and TTS-15. TTS-12 and TTS-15 were identified as tigogenin-3-O-beta-D-xylopyranosyl(1-->2)-[beta-D-xylopyranosyl(1-->3)]-beta-D-glucopyranosyl(1-->4)-[alpha-L-rhamnopyranosyl(1-->2)]-beta-D-galactopyranoside and tigogenin-3-O-beta-D-glucopyranosyl(1-->2)-[beta-D-xylopyranosyl(1-->3)]-beta-D-glucopyranosyl(1-->4)-beta-D-galactopyranoside, respectively. The in vitro antifungal activities of the eight saponins against six fluconazole-resistant yeasts, Candida albicans, Candida glabrata, Candida parapsilosis, Candida tropicalis, Candida krusei, and Cryptococcus neoformans were studied using microbroth dilution assay. The results showed that TTS-12 and TTS-15 were very effective against several pathogenic candidal species and C. neoformans in vitro. It is noteworthy that TTS-12 and TTS-15 were very active against fluconazole-resistant C. albicans (MIC(80)=4.4, 9.4 microg/ml), C. neoformans (MIC(80)=10.7, 18.7 microg/ml) and inherently resistant C. krusei (MIC(80)=8.8, 18.4 microg/ml). So in vivo activity of TTS-12 in a vaginal infection model with fluconazole-resistant C. albicans was studied in particular. Our studies revealed TTS-12 also showed in vivo activities against fluconazole-resistant yeasts. In conclusion, steroid saponins TTS-12 and TTS-15 from Tribulus terrestris L. have significant in vitro antifungal activity against fluconazole-resistant fungi, especially TTS-12 also showed in vivo activity against fluconazole-resistant C. albicans.     

Stereoselective synthesis and in vitro antifungal evaluation of (E)- and (Z)-imidazolylchromanone oxime ethers

A series of (E)- and (Z)-2, 3-dihydro-3-(1H-imidazol-1-yl)-4H-1-benzopyran-4-one oxime ethers have been synthesized and tested for antifungal activity. Most compounds showed moderate to potent in vitro antifungal activity. Among the tested compounds, compound (E)-3d was the most active agent against Candida albicans and Aspergillus niger, and compounds (Z)-(3a) and (E)-3a were the most potent compounds against Microsporum gypseum. Detailed stereoselective synthesis, spectroscopic, and biological data are reported.     

Synthesis and pharmacological properties of benzisothiazole/benzimidazole derivatives with acidic groups

The synthesis and the pharmacological evaluation of benzisothiazole and benzimidazole tetrazolyl- and carboxyl- derivatives 1-6 are described. Structural modification was aimed at investigating the influence of two isosteric substituents (tetrazolyl- and carboxyl-) on the title benzofused heterocycles. The antiphlogistic, antipyretic and analgesic activities have been investigated in in vivo experimental models. Additional investigations have been performed in vitro to study the antiplatelet and spasmolytic activity of the compounds synthetized. All the compounds produced peripheral analgesic effects, but were less effective in hot plate test. The tetrazole and the carboxylic benzisothiazole derivatives 2 and 3 proved to be the most effective drugs within the series, exhibiting maximal inhibition of writhes with a potency 3-fold higher than that of acetaminophen. Only compound 5 provided indication for a central analgesic activity since it was active in hot plate test although with a low potency. The findings obtained in these in vivo and in vitro studies indicate that these compounds do not share the same mechanism of action of acetaminophen. All of the compounds under study present lower acute toxicity than acetaminophen when orally administered in mice.     

Synthesis and antifungal activity of a novel series of alkyldimethylamine cyanoboranes and their derivatives

A series of new amine cyanoborane derivatives were synthesized and exhibited antifungal activity. A long alkyl chain attached to the nitrogen of the amine cyanoboranes and carboxyboranes enhances antifungal activity. An enhanced activity was also obtained upon the halogenation of the amine cyanoboranes as well as in the presence of C=C double bond at the end of the N-alkyl group. The lead compounds were dimethylundecylamine cyanoborane (C11H23N(CH3)2BH2CN), 9, and its dibromo derivative dimethylundecylamine dibromocyanoborane (C11H23N(CH3)2BBr2CN), 11. The MIC values for the lead compounds against the most important human pathogenic fungi ranged from 16.25 to 32.5 micromol/L and from 10.05 to 79 micromol/L, respectively. Both compounds were found to be relatively safe in intravenous injections to mice, (MTD = 121.9 and 73.1 micromol/kg, respectively) and active against strains that are resistant to fluconazole (a conventional antifungal medicine). These data indicate their potential to become antifungal agents.     

Pharmacological investigations of 4-ethoxy-2-methyl-5-morpholino-3(2H)-pyridazinone (M 73101), a new analgesic and anti-inflammatory drug

Analgesic, anti-inflammatory and other related actions of 4-ethoxy-2-methyl-5-morpholino-3(2H)-pyridazinone (M73101) were investigated in experimental animals, and the following results were obtained: Analgesic activity of M73101 was more potent than that of other anti-inflammatory drugs except for aminopyrine in phenylquinone test in mice. M73101 showed the most potent analgesic activity among the drugs tested in Randall-Selitto test in rats. The mode of analgesic action of M73101 resembled that of aminopyrine. M73101 possessed potent inhibitory activities on acute inflammatory edema and suppressed the permeability of capillary vessels. M73101 inhibited histamine release from isolated rat mast cells (in vitro) and rat skin (in vivo) by the condensation product of N-methyl-homoanisylamine formaldehyde (compound 48/80), and leucocyte emigration in carrageenin rat pleurisy. M73101 was much less active than phenylbutazone and other anti-inflammatory drugs in causing gastric lesion. Considering from therapeutic index, M73101 was found to be much superior to mepirizole, tiaramide, benzydamine, phenylbutazone and acetylsalicylic acid.     

Anticancer activity of new (tetrazol-5-yl)methylindole derivatives and their acyclic c-nucleoside analogs

New (tetrazol-5-yl)methylindole derivatives were synthesized from 2-phenylindole. Furthermore, the sugar acetyl hydrazones of the tetrazole derivatives as well as their derived acyclic C-nucleoside analogs were prepared. The synthesized compounds were studied for their anticancer activity against human liver carcinoma cell line (HepG2) and the results showed that arylidine substituted tetrazole derivatives 7c and 7d were the most active.     

Microemulsion and poloxamer microemulsion-based gel for sustained transdermal delivery of diclofenac epolamine using in-skin drug depot: In vitro/in vivo evaluation

Microemulsion (ME) and poloxamer microemulsion-based gel (PMBG) were developed and optimized to enhance transport of diclofenac epolamine (DE) into the skin forming in-skin drug depot for sustained transdermal delivery of drug. D-optimal mixture experimental design was applied to optimize ME that contains maximum amount of oil, minimum globule size and optimum drug solubility. Three formulation variables; the oil phase X₁ (Capryol^®), Smix X₂ (a mixture of Labrasol^®/Transcutol^®, 1:2 w/w) and water X₃ were included in the design. The systems were assessed for drug solubility, globule size and light absorbance. Following optimization, the values of formulation components (X₁, X₂, and X₃) were 30%, 50% and 20%, respectively. The optimized ME and PMBG were assessed for pH, drug content, skin irritation, stability studies and ex vivo transport in rat skin. Contrary to PMBG and Flector^® gel, the optimized ME showed the highest cumulative amount of DE permeated after 8 h and the in vivo anti-inflammatory efficacy in rat paw edema was sustained to 12 h after removal of ME applied to the skin confirming the formation of in-skin drug depot. Our results proposed that topical ME formulation, containing higher fraction of oil solubilized drug, could be promising for sustained transdermal delivery of drug.     

重组干扰素α-2b栓的抗疱疹病毒作用

目的探讨重组干扰素α-2b栓(IFNα-2b栓)的体外、体内抗单纯疱疹病毒Ⅰ型和Ⅱ型作用。方法应用细胞病变抑制法,观察IFNα-2b栓的体外抗病毒作用。建立HSV-2豚鼠阴道炎模型和HSV-1型豚鼠皮肤感染模型,分别用0.75、2.25、6.75 mg.kg-1的IFNα-2b栓治疗,进行豚鼠阴道分泌物的病毒毒力检测及阴道组织的病理组织学等检查,每天记录豚鼠皮肤损伤病变分值情况,观察IFNα-2b栓的体内抗病毒作用。结果体外实验,IFNα-2b栓、重组人干扰素α-2b注射液和阿昔洛韦对单纯疱疹病毒Ⅱ型的IC50分别是(0.59±0.11)、(0.56±0.08)、(21.20±1.90)mg.L-1。体内实验,各给药组中,IFNα-2b栓6.75 mg.kg-1剂量抗病毒作用最强,豚鼠阴道分泌物中病毒毒力显著低于模型组(P<0.01)。阴道组织切片病理结果也表明IFNα-2b栓对豚鼠阴道损伤具有较好的治疗作用。IFNα-2b栓能显著的减轻单纯疱疹I型病毒感染豚鼠的皮肤损伤程度(P<0.01),在相同剂量下,干扰素α-2b栓剂与干扰素α-2b注射液的抗单纯疱疹病毒活性相比较,2.25 mg.kg-1的干扰素α-2b栓剂组与其注射液组的治疗作用相当。结论 IFNα-2b栓在体外及体内均有一定的病毒抑制作用。     

2—（2，4—二氟苯基）—3—（N—甲基—N—取代磺酰胺基）—1—（1H—1，2，4—三唑—1—基）—2—丙醇的合成和抗真菌活性的研究

本文设计合成了10个新的具有3－取代磺酰胺基－2－芳基－1－三唑基结构特征的三氮唑类化合物作为真菌细菌色素P450 14α－去甲基化酶的抑制剂。体外抗真菌活性试验表明化合物1b,1c,和1g对白色念珠菌,近平滑念珠菌和裴氏着色菌具有较强的抑菌活性,但总体来说活性不如酮康唑。与标准对照品氟康唑相比,化合物1b,1c和1g对近平滑念珠菌的作用分别比氟康唑强32倍,16倍和4倍;对裴氏着色菌的抑制作用分别双氟康唑强4倍,8倍和8倍。     

DNA-directed alkylating agents. 5. Acridinecarboxamide derivatives of (1,2-diaminoethane)dichloroplatinum(II).

A series of acridine-2- and -4-carboxamide-linked analogues of PtenCl2 has been prepared and evaluated for biological activity against several tumor cell lines in vitro and in vivo. The platinum complexes were generally more cytotoxic than the corresponding ligands against wild-type P388 leukemia cells in vitro, with acridine-4-carboxamide complexes being the more effective. In contrast to cisplatin and PtenCl2, the complexes were equally active in vitro against both wild-type and cisplatin-resistant P388 lines. The 4-carboxamide complexes showed high levels of in vivo activity (ILS greater than 100%) against wild-type P388 using a single-dose protocol, and one compound was also significantly active in vivo in a cisplatin-resistant line, against which cisplatin and PtenCl2 are inactive.     

In vitro activity of Phytolacca dodecandra (Endod) against dermatophytes

There is a need for better and less costly treatment of superficial mycotic infections, and one approach might be testing of'traditionally used plants for their antifungal activities as potentials for drug development. The aim of the present study was to determine the in vitro activity of Phytolacca dodecandra (Endod) on various species of dermatophytes and yeasts of medical importance. The aqueous extract from the plant P. dodecandra was tested for its antifungal activity against 33 dermatophyte and yeast strains. The minimum inhibitory concentration (MIC) was determined by adopting the broth microdilution method for testing of conidium forming filamentous fungi according to the NCCLS M38-P proposed standard with some modifications. The MIC of P. dodecandra against the dermatophytes tested ranged from 19.5 mg/l to 156.0 mg/l, while for all the yeasts the MIC was >500 mg/l. The minimum inhibitory concentration for 50% (MIC50) of the dermatophyte strains was 62.5 mg/l. The extract showed fungicidal activity against the dermatophytes that ranged from 19.5 to 312.5 mg/l. No activity was observed against the yeasts. From our preliminary results antifungal activity of P. dodecandra has been shown. This should he strengthened with more extensive studies which address both the antifungal activity and the active principle that is responsible for its fungicidal activity.     

Transdermal delivery of tea catechins and theophylline enhanced by terpenes: a mechanistic study

Using in vitro and in vivo techniques, terpenes were evaluated as enhancers to improve the skin permeation of therapeutically active agents derived from tea, including tea catechins and theophylline. The in vitro permeation was determined by Franz cells. The skin deposition and subcutaneous amounts of drugs sampled by microdialysis were evaluated in vivo. Terpenes varied in their activities of enhancing drug permeation. The oxygen-containing terpenes were effective enhancers of drug permeation, whereas the hydrocarbon terpenes were much less efficient. Oxygen-containing terpenes with a bicyclic structure had reduced enhancing activity. Terpenes enhanced tea catechin permeation to a much greater degree than they did theophylline. The isomers of (+)-catechin and (-)-epicatechin showed different permeation behaviors when incorporated with terpenes. In the in vivo status, terpenes promoted the skin uptake but not the subsequent subcutaneous concentration of (-)-epigallocatechin gallate (EGCG). Both increased skin/vehicle partitioning and lipid bilayer disruption of the stratum corneum (SC) contributed the enhancing mechanisms of terpenes for topically applied tea catechins and theophylline based on the experimental results from the partition coefficient and transepidermal water loss (TEWL). alpha-Terpineol was found to be the best enhancer for catechins and theophylline. The high enhancement by alpha-terpineol was due to macroscopic perturbation of the SC and the biological reaction in viable skin as evaluated by TEWL and colorimetry.