The in vitro efficacy of neutral electrolysed water and povidone-iodine against CRS-associated biofilms

BACKGROUND

Despite best medical and surgical practice, some cases of chronic rhinosinusitis (CRS) can remain recalcitrant. Bacterial biofilms have been associated with the recalcitrance of sinonasal inflammation. Biofilms are highly resistant to commonly prescribed antibiotics. Accordingly, more effective antimicrobial treatment options are needed to treat refractory CRS. The aim of this study was to determine the in vitro efficacy of neutral electrolysed water (NEW) and povidone-iodine (PVI) against CRS-associated Staphylococcus aureus biofilms.

METHODS

Mature S. aureus biofilms were grown in a Centre for Disease Control (CDC) biofilm reactor. The antimicrobial activity of NEW, PVI and doxycycline was determined for both planktonic and biofilm cultures of a clinical S. aureus isolate using minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum biofilm eradication concentration (MBEC) assays.

RESULTS

MICs and MBCs were determined for all antimicrobials. MBC values were similar to MICs for both antiseptics, but doxycycline MBCs were significantly higher than the associated MICs. Biofilms were highly resistant to NEW and doxycycline. The MBEC for doxycycline was between 500 and 1000 µg/mL. NEW was ineffective against biofilms and no MBEC could be determined. In contrast, a concentration of 10% of the commercial PVI solution (10 mg/mL PVI) led to effective eradication of mature biofilms.

CONCLUSION

In this study, only PVI showed promising antibiofilm activity at physiological concentrations. The in vivo efficacy of PVI warrants further investigation of its potential as a treatment for recalcitrant CRS.

The sinonasal mycobiota in chronic rhinosinusitis and control patients

BACKGROUND

While bacterial associations with chronic rhinosinusitis (CRS) are increasingly well described, fewer studies have examined the fungal component of the sinonasal microbiota. Here we present a study of the sinonasal mycobiota in a cohort of 144 patients (106 patients with CRS and 38 controls).

METHODOLOGY

Fungal communities were characterised by analysis of mucosal swab samples of the left and right middle meatuses via ITS2 marker amplicon sequencing on the Illumina MiSeq platform. Fungal associations with previously published bacterial community and inflammatory cytokine and cell data for this cohort (collected at the same intra-operative time point) were also investigated.

RESULTS

Malassezia spp. were ubiquitous and often highly predominant. Season of sampling explained more of the variability in the data than any of the clinical parameters. The predominant Malassezia sp. was distinct in patients with cystic fibrosis compared to those without. However, distinctions in the mycobiota were not evident between any other patient groupings assessed, and few fungal-bacterial or fungal-inflammatory associations were observed.

CONCLUSIONS

This study confirms the prominent place of Malassezia spp. within the upper respiratory tract. Overall, few distinctions between patient groups were evident, and these data lend further support to the hypothesis that fungal community types may have no direct causative association with idiopathic CRS. Additional studies incorporating a broader array of inflammatory markers are required to assess whether these ubiquitous fungi nonetheless play an exacerbating role in some sensitive individuals.

Mechanical and Thermal Properties of Teak Wood Flour/Starch Filled High Density Polyethylene Composites

Teak wood flour (TWF) reinforced HDPE composites were prepared and characterized in terms of mechanical, morphological and thermal properties using 2% polyethylene grafted with maleic anhydride (PE-g-MAH) as compatibilizer. The composites were prepared by twin screw extrusion and samples were prepared by injection molding. Mechanical properties increased with the incorporation of TWF, Starch and PE-g-MAH. Tensile strength and Young's modulus increased by 96% and 207%, respectively for TWF (40%)-HDPE composite as compared to virgin matrix. Scanning electron microscopy revealed good interface between TWF and matrix. FT-IR spectra confirmed the esterification reaction and H-bond between anhydride group of PE-g-MAH and cellulose of TWF. The DSC results showed that the melting temperature increased from 129°C to 137°C while crystallization (%) decreased from 40.49% for HDPE to 34.77% for 40% TWF composites, respectively. The storage modulus increased for all the composites at low temperature. Glass transition temperature practically remained unaffected by filler loading.

Combinatorial Characterization of Saliva for Oral Precancer Diagnostics

Background: Saliva based diagnostic can play an important role in the translational research related to cancer diagnostics and treatment. It is easily available, noninvasive, low storage cost, has less contamination chances with simple collection procedure. Cancers related to tobacco use, including oral cancer account for about 30% of all cancers in males and females. Five years' survival rate remains the same even after decades of advancement of detection, prevention, and treatment of OSCC (oral squamous cell carcinoma) mainly due to late diagnosis of oral potentially malignant disorders (OPMDs). Aim: Combinatorial characterization of saliva, endorsing multidimensional spectroscopic signatures using suitably designed biochamber. Methods: Eighteen saliva samples (6 normal, 6 OSF [oral submucous fibrosis, a type of OPMD] and 6 confirmed OSCC) were collected from GNIDSR (Guru Nanak Institute of Dental Science and Research) Kolkata. Ethical approval was obtained for the study and all the participants were explained the objectives of the study and a written informed consent was obtained from them. Participant's demographic detail and clinical characteristics were also recorded. The participants were asked not to consume food 1 hour before sample collection and were suggested to rinse their mouth 30 minutes prior to saliva expectoration to minimize the contamination of food in saliva. Empty, sterile, graded tubes were used for this purpose. The subjects were asked not to clear nose or throat during the process of saliva expectoration to avoid forced phlegm from other part of the respiratory tract. The saliva samples were then immediately transferred to −20 degrees and later in −80 degrees for long storage. The electrical impedance (EI) of saliva was measured in custom made biochambers with copper electrodes. The EI was measured for the frequency sweep from 20 Hz to 2 MHz using an impedance analyzer. Apart from EI measurement, the corresponding samples were subjected to FTIR (Fourier-transform IR spectroscopy) analysis. SPSS and OMNIC software were used for the data analysis of EI and FTIR respectively. Results: [Table: see text][Table: see text][Table: see text][ Table A , B & C represents descriptive statistics, correlation matrix and component matrix respectively. The multivariate analysis of the FTIR data indicates the significant differences ( P < 0.005) among the different study groups such as normal, OSF and OSCC. The eigen values (normal 0.917, OSF 0.962, OSCC 0.975) from component matrix analysis also indicate the same. Conclusion: The spectroscopic characterization (EI and FTIR) of saliva was effective in evaluating normal and OPMD condition. This noninvasive paradigm can serve as a complimentary technique to the existing gold standard methods for the early detection of oral cancer.

Moving beyond descriptions of diversity: clinical and research implications of bacterial imbalance in chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a debilitating disease which affects 5-16% of the general population and involves long-term inflammation of the sinonasal cavity. While microbial involvement in the pathogenesis of CRS has long been suspected, the exact role of microbes remains unclear. Recent application of cultivation-independent, molecular methods has provided much new information, taking advantage of developments in both laboratory- and bioinformatics-based analyses. The aim of this mini-review is to present a variety of available bioinformatics approaches, such as data classification techniques and network analyses, with proven applications in other aspects of human microbiome health and disease research. The uses of molecular techniques in the clinical setting are still in its infancy, but these tools can further our understanding of microbial imbalance during chronic disease and help guide effective patient treatment. The mini-review emphasises ways in which CRS bacterial gene-targeted sequencing data can progress beyond descriptive summaries and toward unlocking the mechanisms by which bacterial communities can be markers for sinus health.

Toll-like receptor activation by sino-nasal mucus in chronic rhinosinusitis

BACKGROUND

The sino-nasal disease chronic rhinosinusitis (CRS) is primarily an inflammatory condition that manifests in several ways. However, the aetiology of this complex disease is poorly understood. The aim of this study was to explore the association between toll-like receptor (TLR) activation, host immune response and sino-nasal mucus in healthy and diseased patients.

METHODS

The activation of TLR2/1 and TLR4 by sino-nasal mucus from 26 CRS patients and 10 healthy controls was measured. In addition, 7 inflammatory cytokines, bacterial community composition and bacterial abundance within the sino-nasal mucus were measured using molecular and diagnostic tools.

RESULTS

TLR activity was observed in 9/36 samples, including 2 healthy controls. There was a strong, positive correlation between members of the Gammaproteobacteria (Haemophilus, Enterobacter, Pseudomonas) and TLR2/1 and TLR4 activity. Bacterial abundance and cytokine (tumour necrosis factor) abundance were also positively correlated with TLR activity.

CONCLUSIONS

These findings suggest that a small proportion (20-30%) of individuals in each sub-group are more predisposed to TLR activity, which may be related to bacterial composition, diversity and abundance in the sinuses.

The in vitro effect of xylitol on chronic rhinosinusitis biofilms

INTRODUCTION

Biofilms have been implicated in chronic rhinosinusitis (CRS) and may explain the limited efficacy of antibiotics. There is a need to find more effective, non-antibiotic based therapies for CRS. This study examines the effects of xylitol on CRS biofilms and planktonic bacteria.

METHODS

Crystal violet assay and spectrophotometry were used to quantify the effects of xylitol (5% and 10% solutions) against Staphylococcus epidermidis, Pseudomonas aeruginosa, and Staphylococcus aureus. The disruption of established biofilms, inhibition of biofilm formation and effects on planktonic bacteria growth were investigated and compared to saline and no treatment.

RESULTS

Xylitol 5% and 10% significantly reduced biofilm biomass (S. epidermidis), inhibited biofilm formation (S. aureus and P. aeruginosa) and reduced growth of planktonic bacteria (S. epidermidis, S. aureus, and P. aeruginosa). Xylitol 5% inhibited formation of S. epidermidis biofilms more effectively than xylitol 10%. Xylitol 10% reduced S. epidermidis planktonic bacteria more effectively than xylitol 5%. Saline, xylitol 5% and 10% disrupted established biofilms of S. aureus when compared with no treatment. No solution was effective against established P. aeruginosa biofilm.

CONCLUSIONS

Xylitol has variable activity against biofilms and planktonic bacteria in vitro and may have therapeutic efficacy in the management of CRS.

Al2O3 influence on structural, elastic, thermal properties of Yb(3+) doped Ba-La-tellurite glass: evidence of reduction in self-radiation trapping at 1μm emission

Ba-La-tellurite glasses doped with Yb(3+) ions have been prepared through melt quenching technique by modifying their composition with the inclusion of varied concentration of Al2O3 to elucidate its effects on glass structural, elastic, thermal properties and Yb(3+) ion NIR luminescence performance. The FTIR spectral analysis indicates Al2O3 addition is promoting the conversion of BOs from NBOs which have been generated during the process of depolymerisation of main glass forming TeO4 units. The elastic properties of the glass revealed an improved rigidity of the glass network on addition of Al2O3. In concurrence to this, differential thermal analysis showed an increase in glass transition temperature with improved thermal stability factor. Also, Yb(3+) fluorescence dynamics demonstrated that, Al2O3 inclusion helps in restraining the detrimental radiation trapping of ∼1μm emission.

A study of tubular potassium secretory capacity in older patients with hyperkalaemia

OBJECTIVES

Sustained hyperkalaemia usually indicates a defect in renal potassium (K+) excretion and can be due to severe impairment of glomerular filtration rate (GFR). The major determinants of renal K+ secretion were studied in hyperkalaemic and normokalaemic elderly subjects to probe the major determinants of hyperkalaemia in this setting.

DESIGN

The transtubular potassium gradient (TTKG) provides an index of tubular K+ secretion and normally rises in patients with significant hyperkalaemia. Both GFR(glomerular filtration rate) and TTKG were assessed at baseline and repeated after 3 hours following ingestion of 0.1mg of fludrocortisone in three groups.

SETTING

An acute general hospital in the West of Ireland.

PARTICIPANTS

23 subjects in total; 8 older patients with unexplained hyperkalaemia (OHK), 8 older patients with normokalaemia (ONK) and 9 young normokalaemic controls (YNK).

MEASUREMENTS

The GFR was either measured by 24 hour creatinine clearance estimation or calculated using the Cockroft and Gault formula.TTKG was calculated using a specific formula.

RESULTS

Mean baseline TTKG was similar in all three groups and consequently inappropriately low in hyperkalaemic subjects. Three hours post fludrocortisone, the TTKG had risen significantly from baseline levels in the young subjects only (from 7.5+/-0.09 to 11.6+/-1.1, p<0.05). No significant increase was noted in either older group at this timepoint.

CONCLUSIONS

The inappropriately low baseline TTKG in the OHK group as well as the absence of a response to fludrocortisone indicate tubular insensitivity to aldosterone. GFR values in both OHK (40.06+/-2.31) and ONK (55.58+/-6.1) groups were significantly lower than those in the YNK group (101.66+/-6.9). In aggregate, these findings indicate that older hyperkalaemic patients typically have both impairment of glomerular filtration and renal tubular K+ secretion and highlights the requirement for vigilance in elderly patients when using medications which interfere with tubular function.

Recurrent lymphocytic hypophysitis in a woman 27 years after subtotal adrenalectomy for hypercortisolism possibly of autoimmune origin

Lymphocytic hypophysitis commonly occurs in females in peripartum period but several unusual presentations have been reported. Here we report a rare case of recurrent lymphocytic hypophysitis in a woman who had subtotal adrenalectomy for hypercortisolism 27 years back. Polyglandular autoimmune endocrinopathy with an uncommon combination of Cushing's syndrome and recurrent hypophysitis is a strong possibility in this case. Treatment with steroids has been found to have beneficial effect.

A proteomic approach to understanding the development of multidrug-resistant Candida albicans strains

Resistance of the pathogenic yeast Candida albicans to the antifungal agent fluconazole is often caused by the overexpression of genes that encode multidrug efflux pumps ( CDR1, CDR2, or MDR1). We have undertaken a proteomic approach to gain further insight into the regulatory network controlling efflux pump expression and drug resistance in C. albicans. Three pairs of matched fluconazole-susceptible and resistant clinical C. albicans isolates, in which drug resistance correlated with stable activation of MDR1 or CDR1/2, were analyzed for differences in their protein expression profiles. In two independent, MDR1-overexpressing, strains, additional up-regulated proteins were identified, which are encoded by the YPR127 gene and several members of the IFD ( YPL088) gene family. All are putative aldo-keto reductases of unknown function. These proteins were not up-regulated in a fluconazole-resistant strain that overexpressed CDR1 and CDR2 but not MDR1, indicating that expression of the various efflux pumps of C. albicans is controlled by different regulatory networks. To investigate the possible role of YPR127 in the resistance phenotype of the clinical isolates, we constitutively overexpressed the gene in a C. albicans laboratory strain. In addition, the gene was deleted in a C. albicans laboratory strain and in one of the drug-resistant clinical isolates in which it was overexpressed. Neither forced overexpression nor deletion of YPR127 affected the susceptibility of the strains to drugs and other toxic substances, suggesting that the regulatory networks which control the expression of efflux pumps in C. albicans also control genes involved in cellular functions not related to drug resistance.

The epothilones, eleutherobins, and related types of molecules

Taxol is currently one of the most effective anticancer agents available. However, limitations due to multidrug-resistance (MDR) susceptibility and lack of aqueous solubility render it less than an ideal drug. These limitations, coupled with taxol's unique mechanism of tumor inhibition, involving the stabilization of microtubule assembly, have spurred the search for more effective chemotherapeutic agents. This review will discuss the chemistry and biology of some of the most promising new molecules with "taxol-like" activity. The extended family of microtubule-stabilizing agents now includes the epothilones, eleutherobins, discodermolide, laulimalide and WS9885B. The epothilones have emerged as one of the most exciting new candidates for detailed structure-activity-related studies. A review of our efforts in the synthetic and biological aspects of this research is presented, as are the latest developments reported from other laboratories in academia and the pharmaceutical industry. The synthesis and structure-activity studies of eleutherobins, as well as recent progress with discodermolide, laulimalide and WS9885B are also reviewed. An abundance of exciting advances in chemistry and biology have emerged from these studies, and it is hoped that it will ultimately result in the development of new and more effective chemotherapeutic agents in the fight against cancer.

Gastric toxicity and mucosal ulceration induced by oxygen-derived reactive species: protection by melatonin

Uncontrolled hydrochloric acid secretion and ulceration of the stomach mucosa due to various factors are serious global problems. Although the mechanism of acid secretion from the parietal cell is now well understood, the processes involved in gastric ulceration are still not clear. Among various causes of gastric ulceration, lesions caused by stress, alcohol consumption, Helicobacter pylori infection and due to use of nonsteroidal antiinflammatory drugs have been shown to be mediated largely through the generation of reactive oxygen species, especially the hydroxyl radical. A number of excellent drugs have proven useful in controlling hyperacidity and ulceration but their long-term use is associated with disturbing side-effects. Hence, the search is still on to find a compound possessing antisecretory, antiulcer and antioxidant properties which will serve as a therapeutic agent to reduce gastric hyperacidity and ulcers. This article describes the role of reactive oxygen species in gastric ulceration, drugs controlling them with their merits and demerits and, the role of melatonin, a pineal secretory product, in protecting against gastric lesions. In experimental studies, melatonin has been shown to be effective in reducing mucosal breakdown and ulcer formation in a wide variety of situations. Additionally, the low toxicity of melatonin supports further investigation of this molecule as a gastroprotective agent. Finally, we include a commentary on how melatonin research with respect to gastric pathophysiology can move forward with a view of eventually using this indole as a therapeutic agent to control gastric ulceration in humans.

Melatonin protects against stress-induced gastric lesions by scavenging the hydroxyl radical

The antiulcer effect of melatonin on gastric lesions caused by restraint-cold stress or by indomethacin (IMN) was studied with the intent of determining the mechanism of action of the indole. Melatonin dose-dependently prevents both stress and IMN-induced gastric damage with around 90% inhibition at a dose of 60 mg per kg BW. When compared with already-marketed antiulcer drugs, such as ranitidine and omeprazole, melatonin was found to be more effective than ranitidine but less effective than omeprazole in preventing stress ulcer. When compared with other antioxidants, melatonin was more potent than glutathione and essentially equipotent to alpha-tocopherol in blocking stress-induced ulcer. As stress-induced gastric lesions are mainly caused by oxidative damage due to hydroxyl radicals (*OH), the effect of melatonin in scavenging the *OH generated during stress conditions, as well as in an in vitro model system, was studied. The results indicate that melatonin at the dose of 60 mg per kg BW caused an 88% reduction of endogenous *OH during stress. Melatonin was also highly effective in scavenging *OH generated in vitro by a Cu2+-ascorbate system. In this case, melatonin at 100 microM reduced *OH by 80%. Melatonin was also found to be a more potent radical scavenger than benzoate, a known *OH scavenger. The results indicate that melatonin prevents stress-induced gastric lesions by scavenging the endogenous *OH. As it also protects against IMN-induced gastric damage, it probably also offers gastroprotection by maintaining endogenous prostaglandin levels.

Hypothalamic hamartoma as a cause of precocious puberty in neurofibromatosis type 1: patient report

Precocious puberty resulting from hypothalamic hamartoma is well known. Neurofibromatosis type 1 can also present with precocious puberty. However, hypothalamic hamartoma as the cause of precocious puberty in patients with neurofibromatosis type 1 has never been described in the literature. This rare occurrence of these two together in a patient with precocious puberty is reported.

Dexamethasone makes the gastric mucosa susceptible to ulceration by inhibiting prostaglandin synthetase and peroxidase--two important gastroprotective enzymes

The plausible mechanism by which dexamethasone makes the gastric mucosa susceptible to ulceration has been studied. As acid aggravates ulcer, the role of dexamethasone on acid secretion was first investigated. Dexamethasone stimulates both basal and drug (mercaptomethylimidazole)-induced gastric acid secretion by 100 and 50% respectively in male Wister rats 24 h after intramuscular administration at the dose of 1 mg/kg body wt. This stimulated acid secretion is 93% blocked by cimetidine indicating increased liberation of histamine in the process. Pretreatment of dexamethasone before 24 h produces ulcer in 30% of the pylorus- ligated rats and aggravates the ulcer index by 82% in both pylorus and esophagus ligated rats. The incidence of ulceration in the latter cases is also increased by 25%. As mucosal prostaglandin synthetase and peroxidase play an important role in gastroprotection through biosynthesis of prostaglandin and by scavenging endogenous H2O2 respectively, the effect of dexamethasone on the activities of these gastroprotective enzymes were studied. Prostaglandin synthetase and peroxidase activities of the mucosa are significantly inhibited by 87 and 83% respectively by 24-h pretreatment with dexamethasone. The results indicate that dexamethasone makes the mucosa prone to ulceration by inhibiting the activity of prostaglandin synthetase to block the gastroprotective action of prostaglandin and also by inhibiting the peroxidase, thereby elevating the endogenous H2O2 level to generate more reactive hydroxyl radical responsible for the mucosal damage.

Study of portal hypertension in children with special reference to sclerotherapy

Portal Hypertension (PH) is the commonest cause of upper gastrointestinal bleeding in children. Most Indian studies have highlighted extrahepatic portal venous obstruction (EHPVO) as the major cause of PH in children. As there is paucity of data from the eastern part of the country we decided to study the major causes of PH in children in this region and to ascertain the efficacy of sclerotherapy for its management. Fifty children aged 14 months to 10 years with PH were studied from April 1990 to April 1995. Thorough examination and relevant investigations showed non-cirrhotic portal fibrosis (NCPF) in 24 (48%), EHPVO in 18 (36%) and cirrhosis of liver in 8 (16%) children. Forty six children had hematemesis and melaena of whom endoscopic sclerotherapy (EST) was done in 45 cases. One child having type 2 gastric varices was referred for surgery. Following eradication of varices the patients were followed-up at 3 monthly intervals. Number of sittings of sclerotherapy required for obliteration of varices was 5.9 +/- 1.6. A variceal state was achieved in 35 (78%) cases and varices were reduced to Grade I in 6 cases (13%). Two cases underwent surgery for EST failure. One patient of cirrhosis died within two weeks of bleeding episode due to hepatic encephalpathy. Rebleeding (13%) and recurrences (13%) were noted during the follow-up period. Retrosternal discomfort (22%), dysphagia (22%), stricture (13%), oesophageal ulceration (13%) and fever (11%) were the complications noted but these could be managed conservatively. The present study highlights that NCPF is an important cause of PH in eastern India. EST is useful in controlling variceal bleeding in children irrespective of their aetiology.

Parallel synthesis and screening of a solid phase carbohydrate library

A solid phase carbohydrate library was synthesized and screened against Bauhinia purpurea lectin. The library, which contains approximately 1300 di- and trisaccharides, was synthesized with chemical encoding on TentaGel resin so that each bead contained a single carbohydrate. Two ligands that bind more tightly to the lectin than Gal-beta-1,3-GalNAc (the known ligand) have been identified. The strategy outlined can be used to identify carbohydrate-based ligands for any receptor; however, because the derivatized beads mimic the polyvalent presentation of cell surface carbohydrates, the screen may prove especially valuable for discovering new compounds that bind to proteins participating in cell adhesion.

Evaluation of antimuscarinic activity in human volunteers: a teaching aid in clinical pharmacology

The antimuscarinic activity of oxyphenonium bromide, diphenhydramine hydrochloride and astemizole were evaluated in six volunteers. The parameters used were salivary secretion, heart rate and pupillary size. The results indicated that the changes in heart rate and pupillary size and measurements were not convenient parameters for class room demonstration. However, salivary secretion and dryness of mouth were found to be reliable parameters for measurement. It was concluded that simple procedures like evaluation of antimuscarinic activity could be introduced as teaching aids in clinical pharmacology for undergraduate students.

Incidence of helminthic infections and comparative study of pyrantel pamoate with levamisole and mebendazole in hospital patients at Barisal, Bangladesh

A study was carried out to find out the incidence of helminthic infections in hospitalized patients at Sher-e-Bangla Medical College, Barisal and to determine the comparative efficacy of pyrantel pamoate, levamisole, and mebendazole. It was observed that 76.2 per cent of total hospitalized patients were infected with intestinal helminths. Polyparasitism (52.6 per cent) was more frequent than single infection (21.8 per cent). Amongst these, 47.5 per cent was suffering from Asearis lumbricoides (AL), 42.5 per cent from Hookworm (H.W) and 65.8 per cent from trichuris trichura (TT). Out of 255 cases examined separately, 40 per cent was suffering from Enterobious vermicularis (EV) infection. The comparative study showed that mebendazole produced egg negative stool in 90.9 per cent of AL, 95.6 per cent of HW and 86.8 per cent of TT after eight days of treatment. On the other hand, pyrantel pamoate cured AL in 93.3 per cent, HW in 78.5 per cent and TT in 34.2 per cent eases. Levamisole cured 75 per cent AL, 4.1 per cent H.W. and 22.2 per cent TT within the same period.

New 6-Aryl-2-pyrones from Gentiana pedicellata*

Three new 6-aryl-2-pyrones, viz. pedicellin ( 1), pedicellanin ( 2), and pedicellatin ( 3), have been isolated from the whole plant of GENTIANA PEDICELLATA W ALL., collected when in flower. The compounds have been characterized on the basis of chemical transformation and comprehensive spectral evidence. This is the first report of occurrence of 6-aryl-2-pyrones in a member of the family Gentianaceae. The other secondary metabolites, e.g. triterpene, secoiridoid, and degraded carotenoid, present in this species are typical of the GENTIANA. 1 and 2 produced significant adaptogenic and anti-stress effects in animal models thereby justifying the use of the title species in popular medicine.

Toxic substances produced by Fusarium V: occurrence of zearalenone, diacetoxyscirpenol, and T-2 toxin in moldy corn infected with Fusarium moniliforme Sheld

Sweet corn infected with Fusarium moniliforme Sheld. (CMI-IMI 204057) while growing in the fields was shown to contain zearalenone, diacetoxyscirpenol, and T-2 toxin. Assays by spectral, chemical, and biological methods established the presence of these substances, with zearalenone being the most abundant. In vitro cultures of the fungus also produced the three toxins.

Chemical constituents of Gentianaceae XXIV: Anti-Mycobacterium tuberculosis activity of naturally occurring xanthones and synthetic analogs

Anti-Mycobacterium tuberculosis H37 RV data are presented for the individual xanthones of Canscora decussata Schult and Swertia purpurascens Wall (Gentianaceae); a few, from the former species, showed significant activity. Additionally, sturcture--activity relationships of these compounds are evaluated on the basis of the minimum inhibitory concentration data of 18 naturally occurring xanthones bearing 1,3,5- 1,3,5,6-, 1,3,6,7-, 1,3,5,8-, 1,3,5,6,7-, and 1,3.6,7,8-oxygenated patterns and six synthetic analogs.