Recent progress in the biosynthesis of dicarboxylic acids, a monomer of biodegradable plastics / 生物工程学报

Plastics are one of the most important polymers with huge global demand. However, the downsides of this polymer are that it is difficult to degrade, which causes huge pollution. The environmental-friendly bio-degradable plastics therefore could be an alternative and eventually fulfill the ever-growing demand from every aspect of the society. One of the building blocks of bio-degradable plastics is dicarboxylic acids, which have excellent biodegradability and numerous industrial applications. More importantly, dicarboxylic acid can be biologically synthesized. Herein, this review discusses the recent advance on the biosynthesis routes and metabolic engineering strategies of some of the typical dicarboxylic acids, in hope that it will help to provide inspiration to further efforts on the biosynthesis of dicarboxylic acids.

Strain engineering and fermentation technology for production of long-chain dicarboxylic acid: a review / 生物工程学报

Long-chain dicarboxylic acid (DCA), a building block for synthesizing a variety of high value-added chemicals, has been widely used in agriculture, chemical, and pharmaceutical industries. The global demand for DCA is increasing in recent years. Compared with chemical synthesis which requires harsh conditions and complicated processes, fermentative production of DCA has many unparalleled advantages, such as low cost and mild reaction conditions. In this review, we summarized the chemical and microbial synthesis methods for DCA and the commercialization status of the fermentation process. Moreover, the advances of using molecular and metabolic engineering to create high-yielding strains for efficient production of DCA were highlighted. Furthermore, the challenges remaining in the microbial fermentation process were also discussed. Finally, the perspectives for developing high titer DCA producing strains by synthetic biology were proposed.

Improvement of tissue survival of skin flaps by 5 alpha-reductase inhibitors: possible involvement of nitric oxide and inducible nitric oxide synthase

Skin flap grafting is a popular approach for reconstruction of critical skin and underlying soft tissue injuries. In a previous study, we demonstrated the beneficial effects of two 5alpha-reductase inhibitors, azelaic acid and finasteride, on tissue survival in a rat model of skin flap grafting. In the current study, we investigated the involvement of nitric oxide and inducible nitric oxide synthase [iNOS] in graft survival mediated by these agents. A number of 42 male rats were randomly allocated into six groups: 1, normal saline topical application; 2, azelaic acid [100 mg/flap]; 3, finasteride [1 mg/flap]; 4, injection of L-N[G]-nitroarginine methyl ester [L-NAME] [i.p., 20 mg/kg]; 5, L-NAME [20 mg/kg, i.p.] + azelaic acid [100 mg/flap, topical]; 6, L-NAME [20 mg/kg, i.p.] + finasteride [1 mg/flap, topical]. Tissue survival, level of nitric oxide, and iNOS expression in groups were measured. Our data revealed that azelaic acid and finasteride significantly increased the expression of iNOS protein and nitric oxide [NO] levels in graft tissue [P < 0.05]. These increases in iNOS expression and NO level were associated with higher survival of the graft tissue. It appears that alterations of the NO metabolism are implicated in the azelaic acid- and finasteride-mediated survival of the skin flaps

Organic acids, sugars, vitamin C content and some pomological characteristics of eleven hawthorn species (Crataegus spp) from Turkey

BACKGROUND: The Hawthorn (Crateagus sp.) mostly occurs around the temperate region of the world with a high number of species, producing a fruit with numerous beneficial effects for human health. The aim of the study was to determine organic acid and sugar contents in the fruit of a number of hawthorn species grown in Erzincan province of Turkey. RESULTS: Citric acid was the predominant organic acid in all hawthorn species and C. pseudoheterophylla had the highest citric acid content (23.688 g/100 g). There were not statistically significant differences among hawthorn species (except C. atrosanguinea Pojark) in terms of fumaric acid content. C. pontica C.Koch had a higher content of vitamin C (9.418 mg/100 g) compared to other species. Fructose was the predominant sugar component in all species and C. monogyna subsp. monogyna Joiq had the highest fructose content (18.378 g/100 g). CONCLUSIONS: The high fruit quality of the studied species indicates the importance of this fruit in human nutrition as a natural source. The study revealed that there were differences in terms of fruit characteristics among hawthorn species and thus better quality hawthorn genotypes can be selected within the species. Hence, this study is considered to be a valuable reference for forthcoming studies. The high fruit quality of the studied species indicates the importance of this fruit in human nutrition as a natural source.

BCL-2 and bax expression in skin flaps treated with finasteride or azelaic acid

Despite all modern surgical techniques, skin flap that is considered as the main method in most reconstructive surgeries puts the skin tissue at danger of necrosis and apoptosis derived from ischemia. Therefore, finding a treatment for decreasing the apoptosis derived from flap ischemia will be useful in clinic. In present study, we evaluated the effect of azelaic acid 20% and finasteride on expression of BCL-2 and bax proteins after the skin flap surgery. For this purpose, 21 rats were entered in three groups including control, azelaic acid 20% and finasteride, all experienced skin flap surgery and then flap tissue was assessed for determining the expression of proteins in 5 slices prepared from each rat that were graded between - to +++ scales. Both azelaic acid and finasteride increased the expression of BCL-2 protein [p < 0.05] and decrease the expression of bax protein [p < 0.05]. These results suggested an antiapoptotic role for finasteride and azelaic acid in preserving the flap after the ischemia reperfusion insult

On-column approach in the HPLC-UV analysis of non-chromophoric compounds using azelaic acid as a model

The manuscript introduces a detection solution of compounds lacking chromophoric properties [e.g. azelaic acid] by implementing a HPLC-UV analysis with on-column derivatisation of the analyte. Azelaic acid was used to test the feasibility of the method at Lamda [max] = 265 nm. Its chromatographic analysis shows linear [R = 0.999], precise [RSD < 2.0%] and accurate [97.0 - 103.5%] behavior. Furthermore, the method was found selective for azelaic acid in a prepared cream which contains other ingredients such as triethanolamine, vaseline and stearic acid. The limit of detection [LOD] and limit of quantification [LOQ] of azelaic acid were 9 and 30 micro g/ml, respectively

A Comparative Study on Mechanical and Biochemical Properties of Bovine Pericardium After Single or Double Crosslinking Treatment

BACKGROUND AND OBJECTIVES: Glutaraldehyde (GA) has been used as a representative method of tissue preservation in cardiovascular surgery. However, GA has showed limited durability including calcification, mechanical failure and toxicity. To overcome those unsolved problems, we analyzed the crosslinking differences of primary amines, GA and genipin in their mechanical and biochemical properties with a single or double crosslinking agent for clinical application. MATERIALS AND METHODS: Samples were divided into 3 groups; control, single crosslinking fixation and double crosslinking fixation after decellurarization using bovine pericardium. For analysis of the biochemical and mechanical properties of each crosslinking method, tensile strength, percentage strain, thermal stability, resistance to pronase, nynhydrin and cytotoxicity test were studied. RESULTS: Combined hexamethylene diamine and suberic acid in the carbodiimide hydrochloride/N-hydroxysucinimide solution (EDC/NHS) after decellurarization, tensile strength and strain percentage were not statistically significant compared to the single crosslinking treated groups (p>0.05). Tissue crosslinking stability was weak in single treatment of diphenylphosphoryl azide, suberic acid, low concentration of EDC, hexamethylene diamine and procyanidin groups, but thermal stability and resistance to the pronase and ninhydrin were markedly increased in concentrated EDC/NHS or after combined double treatment with low concentration of GA or genipin (p<0.001). CONCLUSION: Single or double crosslinking with low concentration of carbodiimide, diphenylphosphonyl azide, procyanidin, suberic acid and hexane diamine were not as effective in mechanical, biochemical, cytotoxic and crosslinking properties compared to GA or genipin fixation, but their mechanical and chemical properties were much improved when combined with low concentrations of GA or genipin in the double crosslinking process.

Chemical constituents of Halenia elliptica / 中国中药杂志

<p><b>OBJECTIVE</b>To study the chemical constituents of Halenia elliptica.</p><p><b>METHOD</b>The air-dried whole plants of Halenia elliptica were extracted with 90% EtOH. The EtOH extract was condensed to a small amount of volume and extracted with petroleum ether, EtOAc and n-BuOH, successively. The compounds were isolated and purified by column chromatography from the EtOAc fraction, and identified based on spectral analyses (MS, 1H-NMR, 13C-NMR).</p><p><b>RESULT</b>12 compounds were isolated from H. elliptica, and characterized as 8-hydroxy-2-methylchromone (1), 5-methoxy-2-methylchromone (2), 7-epi-vogeloside (3), coniferl aldehyde (4), sinapaldehyde (5), norbellidifolin (6), 1-hydroxyl-2,3,4,6-tetramethoxyxanthone (7), 1-hydroxyl-2,3,4,7-tetramethoxyxanthone (8), 1-hydroxyl-2,3,5-trimethoxyxanthone (9), together with azelaic acid, beta-sitosterol, and oleanolic acid.</p><p><b>CONCLUSION</b>Compounds 1, 2 were new natural compounds and compounds 3-6, 10 were obtained from H. elliptica for the first time and compound 6 showed inhibitory activities against HBsAg and HBeAg secretion with IC50 value of 0.77 and < 0.62 mmol x L(-1), respectively.</p>

efficacy of combination of 20% azelaic acid with 0.05% tretinoin cream in the treatment of melasma

Melasma is a common acquired macular hyperpigmentation which involves mostly the sun exposed areas of face and neck. To assess the efficacy of the combination of 20% azelaic acid with 0.05% tretinoin cream in the treatment of melasma. 30 patients of melasma were treated with daily night application of 20% azelaic acid and 0.05% tretinoin. Patients were assessed at 4, 8 and 12 weeks of treatment using melasma area severity index. Side effects during therapy were also noted. Majority i.e. 43% cases were between 26 to 30 years, 73.3% of patients were females and 56.7% were housewives, 70% were married and 86.7% were in middle class. Family history of melasma was positive in 66.7% cases. 93.3% patients had no history of systemic drug and 73.3% had no history of use of cosmetics. 93.3% of patients had malar area involvement and 6.7% had centrofacial area involvement. After treatment, the average MASI score decreased by 38.66% indicating moderate reduction of the severity of melasma. Burning sensation, itching and erythema developed in 50%, 30% and 16%, respectively. The combination of 20% azelaic acid and 0.05% tretinoin cream in the treatment of melasma has a moderate lightening effect with some remarkable side effects

A Study for Verification of Hair Growth Effect of Azelaic Acid and Vitamin B6

PURPOSE: Interest in the augmentation of hair growth for functional and aesthetic purpose has increased dramatically in recent years. Many hair growth products have been released, but most of these have not been proven scientifically. This study aims to measure the hair growth effect of azelaic acid and vitamin B6, which have been known as hair growth materials, in animal models. METHODS: Six weeks old C57BL/6 mice were used in this study and hair of mice were removed by topical treatment. The mice were divided into five experimental groups according to the testing material such as saline (negative control), propylene glycol(vehicle control), azelaic acid, vitamin B6 and azelaic acid plus vitamin B6 in combination. Hair growth was documented photographically and histologically, and then analysed by the high quality hair analysis program system. The quantity of endocrine factors, IGF-I and TGF-beta1 in the skin of mice was measured by PCR analysis. RESULTS: The topical treatment of azelaic acid and vitamin B6 in combination for 2 weeks to dorsal skin accelerated hair regrowth more than other groups. The azelaic acid and vitamin B6-combined treatment also promoted hair follicle elongation and thickness compared to the others. Histologic studies showed increased number of basal cells in azelaic acid and vitamin B6-combined treatment. Furthermore, the azelaic acid and vitamin B6-combined group significantly increased the expression of IGF-I but decreased the expression of TGF-beta1 in the skin of mice compared to other groups. CONCLUSION: These results suggest that azelaic acid and vitamin B6, when used together, have an additive effect and might be used as hair growth materials.

Efficacy of topical azelaic acid gel in the treatment of mild-moderate acne vulgaris.

BACKGROUND: Twenty percent azelaic acid gel is recommended as a topical treatment for acne due to its favorable profile. AIM: Our objective in this study was to evaluate the efficacy of 20% azelaic acid gel in the treatment of mild to moderate acne vulgaris. METHODS: This was a double blind, randomized clinical trial. Sixty patients with mild to moderate acne vulgaris were selected randomly to receive either azelaic acid gel or the vehicle gel alone. Patients were followed up every 15 days for a period of 45 days. The number of lesions and the acne severity index (ASI) were recorded and compared using Student's t-test. RESULTS: Total lesion count was reduced by 60.6% and 19.9% by azelaic acid gel and the placebo respectively (P = 0.002). ASI was reduced by 65.2% and 21.3% by azelaic acid gel and the placebo respectively (P = 0.001), i.e, azelaic acid gel was 3.06 times more effective than the placebo in reducing ASI. CONCLUSION: Azelaic acid gel can be used as an effective treatment in mild to moderate acne vulgaris.

Preparation of gentamicin sulfate-polyanhydride sustained-release beads and in vitro bacteriostatic activity studies / 生物医学工程学杂志

Drug slow release in osteomyelitis treatment is an important biomedical problem, to prepare the high effect drug sustained-release bead is the sticking point. A sustained-release bead system consisting of gentamicin sulfate in biodegradable poly(dimer acid-tetradecandioic acid) copolymer [P(DA-TA), WDA: WTA= 50: 50] is prepared by melt casting which may be useful in osteomyelitis treatment. The stability at room temperature and the in vitro release profile in distilling water, in 0.9% saline buffer and in 0.1 mol/LpH7.4 PBS at 37 degrees C of the bead are determined, the drug release behavior in vitro follows the first order release kinetics and Peppas release kinetics equation. In vitro bacteriostatic activity studies demonstrated that the beads possessed desired bacteriostatic activity and lasted for 50 days for Staphylococcus aureus and Escherichia coli, which are common bacteria for infections in bone. All the above suggest that the biodegradable sustained-release beads may be a new treatment device for osteomyelitis treatment.

Isolation and structure identification of chemical constituents from the skin of Bufo bufo gargarizans / 药学学报

The skin of Bufo bufo gargarizans, originated from Bufo bufo gargarizans Cantor (Bufonidae), is widely used in traditional Chinese medicine for the treatment of hepatoma, lung cancer and etc. The preparation of the aqueous components has significant therapeutic effect against the digestive tract cancer. The water-soluble chemical constituents in the skin of Bufo bufo gargarizans were then investigated to make clear the active compounds. Six compounds were isolated and purified by recrystallization and column chromatography on silica gel and ODS, their structures were elucidated as 4-amido-3-hydroxymethyl-cyclooctylamidezotetra-alpha-furanone (I), bufogargarizanine C (II), bufothionine (III), dehydrobufotenine hydrobromide (IV), suberic acid (V) and succinic acid (VI) on the basis of physicochemical properties and spectral data (UV, IR, 1H NMR, 13C NMR and MS). Of the above compounds, compounds I and II are new compounds and named bufogargarizanine B and C, respectively.

Studies on chemical constituents in root tuber of Cynanchum auriculatum / 中国中药杂志

<p><b>OBJECTIVE</b>To study chemical constituents from Cynanchum auriculatum.</p><p><b>METHOD</b>The chemical components were isolated and purified by silca gel, sephedex-LH-20 and ODS column chromatography. The chemical structures were elucidated on the basis of physicochemical properties and spectral data.</p><p><b>RESULT</b>Thirteen compounds were isolated and identified as: caudatin (1), metaplexigenin (2), cynauricuoside A (3), succinic acid (4), azelaic acid (5), wilforibiose (6), sucrose (7), 1-O-hexadecanolenin (8), beta-amyrin acetate (9), cynanchone A (10), acetylquinol (11), beta-sitosterol (12), daucosterol (13).</p><p><b>CONCLUSION</b>Compounds 4-9 were obtained from this plant for the first time.</p>

Measurement of intracellular pH in long-chain dicarboxylic acid-producing yeast Candida tropicalis and its growth activity / 生物工程学报

Intracellular pH (pHi) has an important influence on the metabolic activity of cells or cellular processes. The intracellular pH (pHi) of long-chain alpha,omega-dicarboxylic acid-producing Candida tropicalis was determined by fluorescence technique using a pH-sensitive fluorescent probe 5(6)-carboxyfluorescein diacetate. Optimal loading conditions of the fluorescent probe into the cells were experimentally determined. Effects of extracellular pH and carbon sources for growth on pHi in the cell grown in a flask were studied; the results indicated that extracellular pH has a slight influence on pHi, whereas carbon sources such as sucrose, glucose, acetic acid, and n-tridecane showed moderate influences. Further work on the relationship between the cell growth activity and pHi was carried out in a 5 L bioreactor. The time course of specific rates of the cell growth, glucose consumption, CO2 production, and pH gradients across cell plasma membrane were plotted, where the cell growth was improved by the higher pHi at 8 - 12 h. The measured pHi values were varied from 5.72 to 6.15 at medium pH 6.0 in which glucose and sodium acetate were used together as carbon source. The investigation of pHi can be helpful for understanding its effects on the kinetics of the metabolic steps involved in the synthesis rate of alpha,omega-dicarboxylic acid and alpha,omega-dicarboxylic acid transport across plasma membranes.

Studies on chemical constituents of root of Cichorium intybus / 中国中药杂志

<p><b>OBJECTIVE</b>To study the chemical constituents in the root of Cichorium intybus.</p><p><b>METHOD</b>The compounds were isolated and identified by column chromatography and NMR, IR, MS data.</p><p><b>RESULT</b>Twelve compounds were isolated and identified.</p><p><b>CONCLUSION</b>2,3,4,9-tetrahydro-1H-pyrido-(3,4-b)indole-3-carboxylic acid was isolated from the Cichorium genus for the first time, azelaic acid and daucosterol were isolated from the the plant for the first time.</p>

Antimicrobianos tópicos en acné: novedades / Topical antimicrobials in acne: news

Los antimicrobianos y principalmente los antibióticos tópicos son un arma terapéutica eficaz y segura en el tratamiento del acné. Antiobióticos tópicos tales como Eritromicina, Clidamicina o Tetraciclina son eficaces en el acné inflamatorio leve a moderado. Su mecanismo de acción es por inhibición de la inflamación más que por un efecto bactericida. Su uso combinado con Peróxido de Benzoílo, Tretinoina o Zinc aumentan su eficacia. Los efectos adversos son leves siendo el de mayor relevancia el desarrollo de cepas resistentes de Propionibacterium Acnes. Nuevos antibióticos tópicos están en investigación siendo una promesa al futuro del tratamiento tópico del acné

Melanins and lens pigments: a comparative study

Based on previous findings that lens pigments and melanins share many physicochemical properties, human lens pigments and natural (hair) and synthetic melanins were submitted to oxidation with permanganate under strong acidic conditions. This procedure has been utilized for the characterization of melanins and results in the well defined products, thiazole-4,5-dicarboxylic acid (TDCA) and pyrrole-2,3,5-tricarboxylic acid (PTCA), which can be quantitated by high performance liquid chromatography (HPLC). PTCA is regarded as a marker of black eumelanins and was therefore a main component of synthetic DOPA-eumelanin and dark hair. Its identity was established by synthesis from 5-hydroxyindole-2-carboxylic acid. TDCA derives from pheomelanins and was therefore an important component of red hair and synthetic GSH-pheomelanin. TDCA was identified by its retention time relative to PTCA. The analysis of a series of cataract digests of increasing pigmentation (type I < type IV < type V) and a purified fraction of lens pigments (DE52 pigment) revealed the presence in these preparations of both PTCA and TDCA. The concentration of TDCA significantly increased with the degree of pigmentation of the digests and reached a maximum in the DE52 pigment. The TDCA/PTCA ratio was high in the lens preparations and comparable to that given by hair pheomelanin. These findings support that pheomelanin is an integral part of lens pigments. By comparing the yields of TDCA in GSH-pheomelanin and in the purified lens pigment, a 9 per cent contribution of pheomelanin to the lens pigment was estimated