Recent advances in the biotechnological production of erythritol and mannitol.

Dietary habits that include an excess of added sugars have been strongly associated with an increased risk of obesity, heart disease, diabetes, and tooth decay. With this association in view, modern food systems aim to replace added sugars with low calorie sweeteners, such as polyols. Polyols are generally not carcinogenic and do not trigger a glycemic response. Furthermore, owing to the absence of the carbonyl group, they are more stable compared to monosaccharides and do not participate in Maillard reactions. As such, since polyols are stable at high temperatures, and they do not brown or caramelize when heated. Therefore, polyols are widely used in the diets of hypocaloric and diabetic patients, as well as other specific cases where controlled caloric intake is required. In recent years, erythritol and mannitol have gained increased importance, especially in the food and pharmaceutical industries. In these areas, research efforts have been made to improve the productivity and yield of the two polyols, relying on biotechnological manufacturing methods. The present review highlights the recent advances in the biotechnological production of erythritol and mannitol and summarizes the benefits of using the two polyols in the food and pharmaceutical industries.

Analytical protocol for the sensitive determination of mannitol, sorbitol and glucose containing powders in pharmaceutical workplaces by ion chromatography using a pulsed amperometric detector.

Workers in the pharmaceutical industry can potentially be exposed to airborne dusts and powders that can contain potent active pharmaceutical ingredients (API). Occupational hygienists and health and safety professionals need to assess and ultimately minimise such inhalation and dermal exposure risks. Containment of dusts at source is the first line of defence but the performance of such technologies needs to be verified, for which purpose the good practice guide: assessing the particulate containment performance of pharmaceutical equipment, produced by the International Society for Pharmaceutical Engineering (ISPE), is a widely used reference document. This guide recommends the use of surrogate powders that can be used to challenge the performance of such containment systems. Materials such as lactose and mannitol are recommended as their physical properties (adhesion, compactability, dustiness, flow characteristics and particle sizes) mimic those of API-containing materials typically handled. Furthermore they are safe materials to use, are available in high purity and can be procured at a reasonable cost. The aim of this work was to develop and validate a sensitive ion-chromatography based analytical procedure for the determination of surrogate powders collected on filter samples so as to meet analytical requirements set out in this ISPE guide.

Acetone-butanol fermentation of marine macroalgae.

The objective of this study was to subject mannitol, either as a sole carbon source or in combination with glucose, and aqueous extracts of the kelp Saccharina spp., containing mannitol and laminarin, to acetone-butanol fermentation by Clostridium acetobutylicum (ATCC 824). Both mannitol and glucose were readily fermented. Mixed substrate fermentations with glucose and mannitol resulted in diauxic growth of C. acetobutylicum with glucose depletion preceding mannitol utilization. Fermentation of kelp extract exhibited triauxic growth, with an order of utilization of free glucose, mannitol, and bound glucose, presumably laminarin. The lag in laminarin utilization reflected the need for enzymatic hydrolysis of this polysaccharide into fermentable sugars. The butanol and total solvent yields were 0.12 g/g and 0.16 g/g, respectively, indicating that significant improvements are still needed to make industrial-scale acetone-butanol fermentations of seaweed economically feasible.

Assessment of transcapillary glucose exchange in human skeletal muscle and adipose tissue.

We studied the kinetics of glucose exchange between plasma and interstitial fluid (ISF) in human skeletal muscle and adipose tissue under fasting conditions. Five normal human subjects received an intravenous [6,6-2H2]glucose infusion in a prime-continuous fashion. During the tracer infusion, the open-flow microperfusion technique was employed to frequently sample ISF from quadriceps muscle and subcutaneous adipose tissue. The tracer glucose kinetics observed in muscle and adipose tissue ISF were found to be well described by a capillary-tissue exchange model. As a measure of transcapillary glucose exchange efficiency, the 95% equilibrium time was calculated from the identified model parameters. This time constant was similar for skeletal muscle and adipose tissue (28.6 +/- 3.2 vs. 26.8 +/- 3.6 min; P = 0.60). Furthermore, we found that the (total) interstitial glucose concentration was significantly lower (P < 0.01) in muscle (3.32 +/- 0.46 mmol/l) and adipose tissue (3.51 +/- 0.17 mmol/l) compared with arterialized plasma levels (5.56 +/- 0.13 mmol/l). Thus the observed gradients and dynamic relationships between plasma and ISF glucose in muscle and adipose tissue provide evidence that transcapillary exchange of glucose is limited in these two tissues under fasting conditions.

Analysis of multiple sugar probes in urine and plasma by high-performance anion-exchange chromatography with pulsed electrochemical detection. Application in the assessment of intestinal permeability in human immunodeficiency virus infection.

Mannitol, 3-O-methylglucose and lactulose administered orally are used to investigate small intestinal absorption pathways and mucosal integrity. Current methods of analysis include thin-layer chromatography, gas chromatography (GC) and enzymatic analysis, which require separate estimation of mono- and disaccharides and for GC, prior derivatization. We describe a high-pressure anion-exchange chromatographic method coupled with pulsed electrochemical detection allowing simultaneous measurement of all three sugars and its clinical application in monitoring intestinal damage in human immunodeficiency virus (HIV) infection. Sample preparation is simple and fast. All sugars are resolved within 10 min. Mean recovery is 93.3% for all sugars and the overall relative standard deviation is 4.2%. Intestinal permeability (lactulose/mannitol ratio) rises with disease progression to AIDS, indicating mucosal damage. The greatest increase in permeability is associated with chronic diarrhoea. The method is an ideal non-invasive test to assess gut mucosal damage in HIV infection.

[Study of chemical pattern recognition as applied to quality assessment of the traditional Chinese medicine "wei ling xian"].

Chemical pattern recognition was applied to the quality assessment of the traditional Chinese medicine "wei ling xian". The dried roots and rhizomes of Clematis chinensis Osbeck, Clematis hexapetalo Pall, and Clematis manshurica Rupr, 21 samples of "wei ling xian" of six different species which were collected from different regions of China, were extracted with methanol. The extracts were analyzed by gas chromatography and the GC data of "wei Ling xian" samples were correlated with their anti-inflammatory activity in pharmacologic experiments. Positive anti-inflammatory activity is regarded as the quality assurance of medicinal "wei ling xian". According to the results, the samples were classified as two groups, one having and the other not having distinct anti-inflammatory activity at the 5% significance level. Some samples were used as the training set, while some as the test set. The SIMCA program was used for the extraction of features and classification, whereas the PCA program for displaying the data in a two-dimensional space. The quality of unknown samples of "Wei Ling Xian" can be assessed as a result of the classification or the two-dimensional display.

[Pilot study on the Limulus test and apyrogenic injectable preparations]. / Limulus test e preparazioni iniettabili apirogene studio pilota

After some notices on the Limulus amebocyte lysate test the AA. expose the results of an investigation for in vitro pyrogen detection in parenteral preparations.