Cinnamic acid derivatives in cosmetics: current use and future prospects.

Cinnamic acid derivatives are widely used in cosmetics and possess various functions. This group of compounds includes both naturally occurring and synthetic substances. On the basis of the Cosmetic Ingredient Database (CosIng) and available literature, this review summarizes their functions in cosmetics, including their physicochemical and biological properties as well as reported adverse effects. A perfuming function is typical of many derivatives of cinnamaldehyde, cinnamyl alcohol, dihydrocinnamyl alcohol and cinnamic acid itself; these substances are commonly used in cosmetics all over the world. Some of them show allergic and photoallergic potential, resulting in restrictions in maximum concentrations and/or a requirement to indicate the presence of some substances in the list of ingredients when their concentrations exceed certain fixed values in a cosmetic product. Another important function of cinnamic acid derivatives in cosmetics is UV protection. Ester derivatives such as ethylhexyl methoxycinnamate (octinoxate), isoamyl p-methoxycinnamte (amiloxiate), octocrylene and cinoxate are used in cosmetics all over the world as UV filters. However, their maximum concentrations in cosmetic products are restricted due to their adverse effects, which include contact and a photocontact allergies, phototoxic contact dermatitis, contact dermatitis, estrogenic modulation and generation of reactive oxygen species. Other rarely utilized functions of cinnamic acid derivatives are as an antioxidant, in skin conditioning, hair conditioning, as a tonic and in antimicrobial activities. Moreover, some currently investigated natural and synthetic derivatives of cinnamic acid have shown skin lightening and anti-ageing properties. Some of them may become new cosmetic ingredients in the future. In particular, 4-hydroxycinnamic acid, which is currently indexed as a skin-conditioning cosmetics ingredient, has been widely tested in vitro and in vivo as a new drug candidate for the treatment of hyperpigmentation.

Design, physico-chemical properties and biological evaluation of some new N-[(phenoxy)alkyl]- and N-{2-[2-(phenoxy)ethoxy]ethyl}aminoalkanols as anticonvulsant agents.

A series of thirty N-(phenoxy)alkyl or N-{2-[2-(phenoxy)ethoxy]ethyl}aminoalkanols has been designed, synthesized and evaluated for anticonvulsant activity in MES, 6Hz test, and pilocarpine-induced status epilepticus. Among the title compounds, the most promising seems R-(-)-2N-{2-[2-(2,6-dimethylphenoxy)ethoxy]ethyl}aminopropan-1-ol hydrochloride (22a) with proved absolute configuration with X-ray analysis and enantiomeric purity. The compound is effective in MES test with ED50=12.92 mg/kg b.w. and its rotarod TD50=33.26 mg/kg b.w. The activity dose is also effective in a neurogenic pain model-the formalin test. Within high throughput profile assay, among eighty one targets, the strongest affinity of the compound is observed towards σ receptors and 5-HT transporter and the compound does not bind to hERG. It also does not exhibit mutagenic properties in the Vibrio harveyi test. Moreover, murine liver microsomal assay and pharmacokinetics profile (mice, iv, p.o., ip) indicate that the liver is the primary site of biotransformation of the compound, suggesting that both 22a and its metabolite(s) are active, compensating probably low bioavailability of the parent molecule.

RNAi in clinical studies.

RNA interference (RNAi) is an efficient process of posttranscriptional gene silencing. In recent years it has been developed into a new technology in biopharmaceutical fields of science. RNAi products include short interference RNA (siRNA) but also short hairpin RNA (shRNA), bifunctional short hairpin RNA (bi-shRNA) and microRNA (miRNA). They combine with homologous fragments of the mRNA and cause its degradation. It results in inhibition of protein synthesis, or in mutation in the gene encoding it. RNAi has been used in analysis of genomes and creation of new animal models to test drugs. From the pharmaceutical point of view, what is the most important is its therapeutic application. So far the basic and clinical research has been focused on the following targets: macular degeneration, cancer and antiviral therapy. But there are also reports on clinical trials in asthma, hypercholesterolemia and genetic diseases such as inherited skin disorders and amyloidosis. Among over 20 therapeutics that reached clinical trials, only few are still investigated. Another few are clinical candidates. The review focuses on RNAi products under clinical evaluation and their most promising new applications.

Evaluation of mutagenic and antimutagenic properties of some bioactive xanthone derivatives using Vibrio harveyi test.

AIMS: Drug safety evaluation plays an important role in the early phase of drug development, especially in the preclinical identification of compounds' biological activity. The Vibrio harveyi assay was used to assess mutagenic and antimutagenic activity of some aminoalkanolic derivatives of xanthone (1-5), which were synthesized and evaluated for their anticonvulsant and hemodynamic activities. METHODS AND RESULTS: A novel V. harveyi assay was used to assess mutagenic and antimutagenic activity of derivatives of xanthone 1-5. Two V. harveyi strains were used: BB7 (natural isolate) and BB7M (BB7 derivative containing mucA and mucB genes on a plasmid pAB91273, products of these genes enhance error-prone DNA repair). According to the results obtained, the most beneficial mutagenic and antimutagenic profiles were observed for compounds 2 and 3. A modification of the chemical structure of compound 2 by the replacement of the hydroxy group by a chloride improved considerably the antimutagenic activity of the compound. Thus, antimutagenic potency reached a maximum with the presence of tertiary amine and chloride atom in the side chain. CONCLUSIONS: Among the newly synthesized aminoalkanolic derivatives of xanthone with potential anticonvulsant properties, there are some compounds exhibiting in vitro antimutagenic activity. In addition, it appears that the V. harveyi assay can be applied for primary mutagenicity and antimutagenicity assessment of compounds. SIGNIFICANCE AND IMPACT OF THE STUDY: The obtained preliminary mutagenicity and antimutagenicity results encourage further search in the group of amino derivatives of xanthone as the potential antiepileptic drugs also presenting some antimutagenic potential. Furthermore, V. harveyi test may be a useful tool for compounds safety evaluation.

Microbial transformation of hydroxy metabolites of 1-oxohexyl derivatives of theobromine by Cunninghamella echinulata NRRL 1384.

AIM: The biotransformation of pentoxifylline (PTX), propentofylline (PPT) and their racemic hydroxy metabolites ((+/-)-OHPTX and (+/-)-OHPPT) by using the fungus Cunninghamella echinulata NRRL 1384. METHODS AND RESULTS: A fungus Cunninghamella echinulata NRRL 1384 was used to catalyse the (S)-selective oxidation of the racemic hydroxy metabolites: (+/-)-OHPTX and (+/-)-OHPPT and for reduction of PTX and PPT. The first oxidation step appears to be selective and relatively fast while the second reduction step is slower and more selective with PTX. Modifications involving supplementing the bioconversion with glucose give yields and enantiomeric excess (ee) values similar to those obtained without glucose. CONCLUSIONS: The bioconversion of (+/-)-OHPTX gave an (R)-enantiomer (LSF-lisofylline) with a higher enantiopurity (maximum approximately 93% ee) compared to the bioconversion of (+/-)-OHPPT, when the maximum ee value for (R)-OHPPT was recorded at 83%. SIGNIFICANCE AND IMPACT OF THE STUDY: The conversion of (+/-)-OHPTX and (+/-)-OHPPT using Cunninghamella echinulata can be recognized as a process, which may be recommended as an alternative to the methods used to obtain (R)-OHPTX and (R)-OHPPT.

Pharmacological properties of some aminoalkanolic derivatives of xanthone.

A series of appropriate aminoisopropanoloxy derivatives of 2-, 3- or 6-xanthone was synthesized and evaluated for anticonvulsant activity in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole seizure threshold (ScMet) assays and for neurotoxicity (TOX). The most interesting result was the anticonvulsant activity of (+/-)-3-(2-propylamino)-1- [(2-methyl)-6-xanthonoxy]-2-propanol hydrochloride (10), which displayed anti-MES activity with a protective index (TD50/ED50) of 0.80. Some of the obtained compounds were also tested for their effect on the circulatory system (influence on the non-working heart perfusion, protection against adrenaline induced-arrhythmia) and acute toxicity.

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.

1-substituted 4-[chloropyrazolyl][1,2,4]triazolo[4,3-a]quinoxalines: synthesis and structure-activity relationships of a new class of benzodiazepine and adenosine receptor ligands.

Starting from 3-(3-chloro-1H-pyrazol-5-yl)-1H-quinoxalin-2-one (2) a series of substituted [1,2,4]triazolo[4,3-a]quinoxalines (3a-f) was prepared via a multistep reaction sequence. Affinities of the novel derivatives 3a-f for benzodiazepine as well as for adenosine A1- and A2A-receptors of rat brain were determined by radioligand binding assays. 1-Methyl-4-(3-chloro-1H-pyrazol-5-yl) derivative 3a exhibited submicromolar affinity for the benzodiazepine binding site of GABAA receptors (Ki = 340 nM) and was less potent at A1-(Ki = 7.85 microM) and A2A-(Ki = 1.43 microM) adenosine receptors (AR). Derivatives with larger substituents in the 1-position showed reduced binding to benzodiazepine and A2A-AR, but increased A1-AR affinity, the 2-thienylmethyl derivative 3f being the most potent and selective A1-AR ligand of the present series (Ki = 200 nM).