Yellow-brown Pigment Research Articles

An optimised protocol for the detection of lipofuscin, a versatile and quantifiable marker of cellular senescence.

Lipofuscin is a yellow-brown pigment typically found in the lysosomes that contains a mixture of molecules including lipids, metals and misfolded proteins. The use of Sudan black B to detect lipofuscin accumulation, a well described marker of cellular senescence and ageing, was first described in 2013 by Georgakopoulou, et al. Here, we provide an optimisation of the original protocol. Firstly, we adjusted the staining methodology for increased ease of use on cultured cells. Secondly, we show that Sudan black B-stained lipofuscin emits strong fluorescence in the far-red channel making it suitable for fluorescence microscopy detection and quantification. Moreover, we also demonstrate that this optimised protocol can be utilised in conjunction with standard immunofluorescence staining techniques, making possible the simultaneous detection of lipofuscin and other cellular proteins of interest, like additional markers of senescence. This is a significant advantage over the most commonly used method for senescence detection, based on beta galactosidase enzymatic activity. We therefore believe that these findings and the provided optimised protocol will represent a useful tool for the scientific community in the field of cellular senescence.

Morphological and phylogenetic analyses reveal five new species of Porotheleaceae (Agaricales, Basidiomycota) from China.

The first occurrence of Marasmiellomycena and Pulverulina in the Chinese mycobiota are reported, M.tomentosa and P.flavoalba, two new species and M.albodescendens, a new combination, revealed by phylogenetic analyses and morphological study. These newly-recorded genera, Marasmiellomycena, which can be distinguished by their agaricoid basidiomata, dark-coloured stipe, sarcodimitic tramal structure, stipitipellis with yellow to yellowish-brown pigments and yellow-pigmented thick-walled caulocystidia and Pulverulina, which differs from other genera of Porotheleaceae by its pruinose stipe, decurrent lamellae, inamyloid basidiospores and absence of hymenial cystidia. We also formally describe three other new species of Porotheleaceae collected from Chinese temperate to subtropical zones of Fujian and Zhejiang Provinces: Clitocybulafuscostriata, Gerronemabrunneosquamulosum and Leucoinocybesubglobispora. Furthermore, we include the results of a phylogenetic analysis of Porotheleaceae, based on a multi-locus (ITS, nrLSU and rpb2) dataset. According to this analysis, Chrysomycena, Clitocybula, Delicatula, Hydropodia, Hydropus, Leucoinocybe, Marasmiellomycena, Megacollybia, Pulverulina, Trogia and Vizzinia are monophyletic. However, Gerronema is identified as polyphyletic and, additionally, Porotheleum does not form a monophyletic group either because Porotheleumparvulum and Porotheleumalbidum are "unassigned" in phylogenetic analysis. The results of our phylogenetic analyses, coupled with morphological observations, confirm recognition of these new taxa. Morphological descriptions, photographs, line drawings and comparisons with closely-related taxa are presented for the new species. A key to the 22 species belonging to nine genera of Porotheleaceae in China is also provided.

First Report of Fusarium Wilt on lily (Lilium 'Tresor') Caused by Fusarium armeniacum in Jiangsu Province, China.

In June 2021, a disease of stem and leaf rot was observed on lily cultivar 'Tresor' with approximately 20% disease incidence in fields at Huaiyin District (119°04'N, 33°63'E) of Huaian County, Jiangsu Province. The roots and bulbs of symptomatic plants were brown and rotten, with sunken lesions. Symptomatic plants showed short, discolored leaves, and eventually lead to stem wilt and death of the whole plants (Fig. 1A and Fig. 3C). To isolate the pathogen, necrotized plant tissues were surface sterilized with 2% sodium hypochlorite for 2 min followed by 70% ethanol for 30 s and rinsed with sterile water. About 4 mm × 4 mm of diseased tissues were placed on potato dextrose agar (PDA) followed by incubation at 25°C in the dark for 5 days. The pure cultures were obtained by the hyphal-tip method. A total of four fungal isolates with similar colony characteristics were recovered. To determine the identity of the four isolated fungal isolates, genomic DNA was extracted using the method previously described (Khan et al. 2021), the sequences of the internal transcribed spacer (ITS), the translation elongation factor 1α (TEF1) and the RNA polymerase II beta subunit (RPB2) genes were analyzed with primers ITS1/ITS4 (White et al. 1990), EF1/ EF2 (O'Donnell et al. 1998), and 5F2/7cR (Reeb et al. 2004), respectively. The three gene sequences of four isolates showed 99.9 %-100% identities. The531 bp (ITS), 699 bp (TEF1), and 900 bp (RPB2) sequences of a representative isolate (JH-37) were deposited in GenBank with acce. nos. OR195729, OR195041 and OR195040, respectively. A phylogenetic tree was constructed using the concatenated three gene sequences of JH-37 and that of the related Fusarium species based on Maximum Likelihood (Fig.2). JH-37 was grouped together with the F. armeniacum strain CBS 485.94 (AB587001, GQ915501, GQ915485), and shared 99.9 % concatenated sequence identity. The three gene sequences of the strain JH-37 shared 100%, 99.85%, 99.89% identity to F. armeniacum strain CBS 485.94 using MEGA 7 software (Kuma et al. 2016) analysis, and with 94%, 95% and 100% coverage by BLAST analysis. The colony of JH-37 on PDA at 25°C for 5 days was white with yellow-brown pigmentation in the center (Fig. 1B-C). From 10-day-old cultures grown on Spezieller Nahrstoffarmer agar (SNA), macroconidia (n = 50) were falcate, slender, curved dorsiventrally, tapering towards both ends, 3 to 4 septate, and measured 24.2 to 50.0 × 2.6 to 4.2 μm. The microconidia (n = 50) were straight or slightly curved, septate 0 to 2, and measured 6.8 to 20.0× 2.1 to 3.7 μm (Fig.1D-F). These morphological characteristics were consistent with Fusarium spp. (Leslie and Summerell 2006). A pathogenicity test of JH-37 was performed on potted lily ('Tresor') under greenhouse conditions. Healthy lily bulbs were selected and one bulb was sown in soil of each pot. Inoculation was performed 60 days after sowing. Bulbs of the lily plants were wounded with needles and inoculated with 5 mL of conidia suspension (1×107 conidia/mL) in the soil around bulb or an equal amount of sterilized water as a control. This experiment had three replicates. After 15 days of inoculation, typical symptoms of bulb rotten, and leaf wilt, similar to the original field symptoms, appeared on the inoculated plants but not on the controls (Fig.3). The same fungus was reisolated from the diseased plants, as identified based on morphology and molecular evidence, which confirmed the Koch's postulate. To our knowledge, this is the first report that F. armeniacum caused Fusarium wilt on Lilium spp. in China. Further, our result could help to develop effective disease management strategies against lily wilt disease.

Effect of Cartap hydrochloride (50% SP) insecticide on Liver and Kidney histology of the fish, Cirrhinus mrigala (Hamilton)

Effect of Cartap hydrochloride on the liver and kidney of the Indian major carp, Cirrhinus mrigala was studied. Fingerlings were exposed to sub-lethal (0.0376 mg-1) and lethal (0.376 mg-1 ) concentrations of Cartap hydrochloride for 24 and 96 hours. The histological changes in the liver of fish Cirrhinus mrigala exposed to sublethal and lethal concentrations of cartap hydrochloride were characterized by the formation of the prominent yellowish-brown pigment cytoplasmic vacuoles, pycnotic nuclei, degeneration of hepatopancreatic tissue, eosinophilic granules, Melano macrophages aggregate, appearance of blood streaks, degeneration of hepatopancreatic tissue, hypertrophic nuclei, cytoplasmic degeneration change in the shape of the hepatocytes, disappearance of hepatic cells, hyperplasia of cells, hypertrophic nuclei and degeneration of cell membrane. The kidney of the treated fish showed the appearance of prominent tubular yellowish brown pigment, formation of vacuoles, swelling of glomerulus, separation of the tubular epithelium, tubular architectural loss, damage of bowmans capsule, tubular cytoplasmic degeneration, cloudy swelling degeneration, damage to renal tubules, damaged haemopoitic tissue, necrosis of cell and renal tubules, disorganization of connective tissue, degeneration of cytoplasm, pyknotic nuclei, hypertrophy of nuclei, disintegration of cell membrane were also seen. The results obtained were discussed at length with the available literature. By studying these histological deformities, it was concluded that the pesticide caused enough damage to the liver and kidney of the fish and can influence on the survival of the fish.

Fusarium pernambucanum Causing Leaf Yellow Spot on Melon (Cucumis melo L.), a New Disease in China.

Melon (Cucumis melo L.) is a member of the Cucurbitaceae family, and is an important economic and horticultural crop. In March 2022, melon plants in greenhouses exhibited severe leaf yellow spot symptoms in Changjiang County (109°13'N, 19°28'E), Hainan Province. The incidence of the disease was about 30-50%. Lesions initially appeared as yellow dots on leaves and expanded irregularly. Gradually, brown spots appeared, and finally the whole leaves turned yellow and resulted in blighting and death of foliage (Figure 1.). A total of four symptomatic plants were sampled from about 0.2 ha of an area. Symptomatic leaves were excised, surface disinfected with 2% (w/v) NaOCl, rinsed three times with sterile distilled water, and placed on potato dextrose agar (PDA) followed by incubation at 25°C in the dark for 5 days. The pure cultures were obtained by the hyphal-tip method. A total of eight fungal isolates with similar colony characteristics were recovered from the four symptomatic plants. Three DNA fragments (ITS, TEF1, and RPB2) of the eight isolates showed 100% sequence identity based on the molecular identification methods described below. Therefore, one of the isolates, M2JP-3, was chosen for identification and test of the pathogenicity. The colony of M2JP-3 on PDA at 25°C for 5 days was white with yellow-brown pigmentation in the center (Figure 2A-B). From 10-day-old cultures grown on CLA (Fisher et al. 1982), macroconidia (n = 50) were falcate, slender, curved dorsiventrally, tapering towards both ends, 3 to 7 septate, and measured 24.5 to 52.1 x 3.7 to 4.7 μm. The microconidia (n = 50) were straight or slightly curved, septate 0 to 2, and measured 9.9 to 16.3 x 2.5 to 3.7 μm (Figure 2C-E). For molecular identification, genomic DNA was extracted using the method previously described (Khan et al. 2021),the internal transcribed spacer (ITS), translation elongation factor 1α (TEF1) and DNA-dependent RNA polymerase subunit II (RPB2) were amplified, respectively, using primers ITS1/ITS4 (White et al. 1990), EF1/ EF2 (O'Donnell et al. 1998), and 5F2/7cR (Reeb et al. 2004). The 529 bp (ITS), 723 bp (TEF1), and 965bp (RPB2) sequences were deposited in GenBank with acce. nos. OP303211, OP312675 and OP312674, respectively. A phylogenetic tree was constructed using the concatenated three gene sequences of M2JP-3 and that of the Fusarium incarnatum-equiseti species complex (FIESC) (Xia et al. 2019) based on Maximum Likelihood (Figure 3). M2JP-3 was grouped together with the F. pernambucanum strain NRRL 32864 (accession no. GQ505702 for ITS, GQ505613 for TEF1and GQ505791 for RPB2), and shared 100% concatenated sequence identity. For pathogenicity tests of M2JP-3, seeds of melon cultivar Jinmeiren were surface disinfected and sowed in soil in three replicated pots in a greenhouse at 26 °C under natural light. Healthy leaves of the melon plants were wounded with needles and inoculated with mycelial plugs of M2JP-3 or PDA plugs as control. . Symptoms similar to the original greenhouse symptoms were observed at 7 days after inoculation (Figure 4). The control leaves were asymptomatic. The same fungus was reisolated from the inoculated leaves, as identified based on morphology and molecular evidence, which confirmed the Kochs' postulates. To our knowledge, this is the first time Fusarium pernambucanum has been recorded causing leaf yellow spot disease on melon. Further, findings of the present study will help to develop effective disease management strategies against Fusarium pernambucanum Leaf Yellow Spot on melon in China.

First report of Calonectria pseudopteridis causing brown spot on Eriocaulon buergerianum in Zhejiang province, China.

Eriocaulon buergerianum is a traditional Chinese herb, used to treat eye diseases. In July 2020, a severe brown spot disease occurred on E. buergerianuim in Yongjia county (120°19'E, 27°58'N), Zhejiang province, China. Seventy-three plants from a survey of about 150 plants showed brown leaf spots. The spots were yellowish-brown to brown, and primarily affected leaves. As the disease progressed, the spots expanded, and fused. Sixty of the 150 plants wilted (Fig. 1 A-D). Diseased tissues were surface-sterilized in 75% ethanol (30 s), rinsed three times with sterile distilled water, air-dried (5 min), placed on potato dextrose agar (PDA) at 26°C (12-h light/dark cycle), and cultured for 4 days. Hyphal tip technique was used to obtain five isolates, which were transferred to malt extract agar (MEA), oatmeal agar (OA), and PDA. After seven days of growth at 26°C, the colonies had light, yellowish-brown centers with gray-white edges; the reverse sides had reddish- to yellowish-brown centers. Seven-day-old colonies grown on oatmeal agar (OA) produced a sparse aerial mycelium with yellowish-brown centers, and light yellowish-brown centers on the reverse side. Seven-day-old colonies grown on PDA exhibited yellowish-brown, floccose, aerial mycelia with reddish-brown to yellowish-brown pigment on the back (Fig. 1 E-G). The colonies also produced microsclerotia on OA and PDA media. On carnation leaf agar (CLA) and water agar (WA), only macroconidia were produced. Macroconidiophores comprised a stipe bearing penicillate, fertile branches, and a clavate vesicle. Macroconidia were cylindrical, rounded at both ends, colorless, hyaline, 1- to 2-septate, but mainly one, and 71.86 to 96.11 µm (mean = 82.27 µm, n = 50) × 4.13 to 5.21 µm (mean = 4.63 µm, n = 50) (Fig. 1 H-K). Morphological characteristics of the isolate on CLA or WA medium were similar to the Calonectria petridis species complex (Alfenas et al. 2015; Liu et al. 2020). The actin (Act), calmodulin (Cal), internal transcribed spacer (ITS), Histone3 (His3), a fragment of the large subunit nuclear ribosomal DNA (LSU), RNA polymerase II subunit 2 (Rpb2), translation elongation factor 1α (Tef1), and β-tubulin 2 (Tub2) genes were sequenced. The sequences were deposited in GenBank as: His3: Not detected; Act, OM933603, MZ770831, OM933604-OM933606; Cal, OM933607, MZ770832, OM933608-OM933610; ITS, OM955624, MZ720794, OM955625-OM955627; LSU, OM955640, MZ720792, OM955641-OM955643; Rpb2, OM933615, MZ770834, OM933616-OM933618; Tef1, OM933611, MZ770833, OM933612-OM933614; and Tub2, OM933619, MZ770835, OM933620-OM933622. Sequences of the Act, Cal, ITS, LSU, Rpb2, and Tef1 genes of these strains show a 99% match to the ex-type strain Ca. pteridis CBS111793 and Ca. pseudopteridis CBS163.28 (Act, GQ280494, MT335112; Cal, GQ267413, MT335347; ITS, GQ280616, MT359808; LSU, GQ280738, MT359568; Rpb2, KY653438, MT412640; Tef1, FJ918563, MT412878). The Tub2 sequences showed 99% identity with sequences of the ex-holotype Ca. pteridis CBS111793 (Tub2, DQ190578) (Alfenas et al. 2015; Liu et al. 2020; Lombard et al. 2016). Phylogenetic analysis showed that these strains and Ca. pseudopteridis CBS163.28 were clustered in a high-support bootstrap value clade (bootstrap = 85) (Fig. 2). In August 2020, healthy E. buergerianum plants in the blooming-fruiting stage were used to test the pathogenicity of the isolates. The mycelium of isolate GJC3 was cultured on CLA medium at 26°C (12-h light/dark cycle) for ten days. Eight healthy plants were inoculated by spraying with a conidial suspension (10 mL of 1 × 105 conidia/mL). Another eight plants were sprayed with sterilized water 10 mL of sterilized water as controls. The experiment was repeated three times. Pathogenicity tests were performed in the greenhouse (60% relative humidity, 28 to 20°C day/night, temperature range, and natural sunlight). After 15 days, inoculated plants showed yellowish-brown to brown spots and withering of the leaves, whereas the control plants remained healthy (Fig. 1 L-N). Ca. pseudopteridis was reisolated from the inoculated plants, and its morphology and gene sequences were similar to the original isolate GJC3. Ca. pseudopteridis was not isolated from the control plants. Morphological characteristics, molecular data and pathogenicity test identified these organisms as Ca. pseudopteridis. This report provides a basis for further research on biology and management of this disease.

Comparative Toxicant Efficacy of Some Novel Insecticides against Metamorphosis of Papilio demoleus (L.) Larvae

The Papilio demoleus is a key pest of citrus orchards found throughout the year. Their infestation causes defoliation, retards growth, and yields reduction. The five insecticides namely; Emamectin Benzoate 1.9 EC, Belt 480g/L SC (Flubendiamide), Helmet 40 EC (Chlorpyrifos), Coragen (Chlorantraniliprole 18.5% SC), and Regent 5% SC (Fipronil) were tested on C. limon orchard leaves against the larvae population of the lemon butterfly under laboratory conditions during, 2020. The maximum cumulative effect of all treatments was observed in three replications. The mortality of larvae and efficacy of insecticides were recorded after 24, 48, 72, 120, and 168 hours of post-sprays. The result revealed that Belt pesticide proved with maximum larval mortality (66.64±8.16%) followed by Regent (60.26±0.76), Coragen (59.66±7.72), Helmet (57.14±7.65), Emamectin and (56.18±7.50), respectively. It is concluded that the Belt insecticide provided better mortality % against the larval population. The one-way ANOVA showed significant difference among all tested insecticides at p<0.05 level. After insecticide application larvae reduced movement, skin became wrinkled, thin, and yellow-brown pigmentation visibly appeared with loose muscle concentration by releasing hyper-salivation and semi-liquid frass. Thus; it is recommended to be applied at time interval basis to suppress the population of lemon butterflies

Thermochromic properties of pure NiTiO3 and its Cu- or Co-doped derivatives

Nickel titanate is a yellow-brown pigment which adopts the ilmenite crystal structure as corundum and hematite. Since Cr doped Al2O3 and Fe2O3 present a thermochromic behavior, NiTiO3 was also studied for its potential ability to change colour with temperature. Powders were synthesized via a modified Pechini method followed by a calcination step at 700 °C. The thermochromic properties in the 20 °C–400 °C temperature range were collected via the determination of the colorimetric L*a*b* parameters. Namely, the hue continuously shifts from yellow-brown to red-brown, with L*a*b* parameters moving from 60.4/19.2/58.5 to 42.9/30.5/43.1. This colour change is fully reversible even after several cycling. Temperature dependent UV–vis spectroscopy showed that the transparency window at 550–650 nm at room temperature shifts to 575–650 nm at 400 °C. This fully explains the observed colour change. Finally, the effects of Cu or Co doping on NiTiO3 optical and thermochromic properties were also investigated.

Leucoencephalopathy with Pigmented Glia in a Horse with Recurrent Convulsive Seizures

A 7-year-old male Thoroughbred horse exhibited recurrent falls followed by convulsive seizures. The horse was clinically diagnosed with epilepsy and phenobarbital treatment was initiated. However, as seizure control was unsuccessful, the animal was euthanized. At necropsy, yellow-brown linear lesions were found extensively at the U-fibres and cingulate gyrus within the cerebral white matter. Histopathologically, linear demyelination and occasional cavitation were observed. Glial cells with yellow-brown pigment granules, which were autofluorescent, positive to the periodic acid-Schiff reaction and stained with Masson-Fontana and Schmorl's stains, were frequently found within these demyelinating lesions. The pigment granules did not stain with Berlin blue, Luxol fast blue or Sudan III stains. Haematoxylin and eosin staining and immunohistochemistry of serial brain sections revealed that the pigmented glia were derived from glial fibrillary acidic protein-positive astrocytes. Based on these findings, the case was diagnosed as leucoencephalopathy with pigmented glia. This is the first report of the disease in any animal species.

'Colouring' wipes phenomenon: a peculiar skin pigmentation induced by ascorbic acid observed during lockdown.

SummaryDuring the SARS‐CoV‐2 (COVID‐19) pandemic, an unusual outbreak of yellow–brown pigmentation on the skin of children was reported. Because of the restrictions on movement promulgated during the lockdown, most consultancies were performed using teledermatology. Data concerning personal care products and application of topical substances were collected, which revealed use of the same brand of wipes for all patients. A liquid chromatography–mass spectrometry analysis was performed to compare the components of the wipes before and after the observation of the pigmentation, in order to detect the responsible substance. This analysis revealed a level about 10‐fold higher than normal of ascorbic acid and its oxidation products (dehydroascorbic acid and L‐threonic acid) in the wipes associated with the pigmentation. These ‘colouring wipes’ represent a peculiar but harmless phenomenon that highlights the importance of careful questioning about personal care products used by patients.

Gallbladder cholesterolosis in patients with metabolic syndrome and chronic pancreatitis

Cholesterolosis, as a pathological condition caused by metabolic disorders, is potentially associated with metabolic syndrome and chronic pancreatitis. The aim of the study was to assess the prevalence and morphological features of gallbladder cholesterolosis in the contingent of patients with metabolic syndrome and chronic pancreatitis. 82 patients who underwent cholecystectomy for chronic calculous cholecystitis were included in our study. The experimental group consisted of 37 patients with metabolic syndrome and chronic pancreatitis. The comparison group included 45 patients without clinically confirmed metabolic syndrome and chronic pancreatitis. In accordance with the purpose and objectives, morphological examination of the gallbladder wall was performed. Data to be analyzed were processed using the statistical software package SPSS 20.0 for Windows. The gender and age structure of the studied contingent did not differ from that described in the scientific literature. The morphological picture of cholesterolosis did not differ in the study groups. In a mucous membrane considerable polymorphism of folds (villi) was noted. There were signs of desquamation and regeneration in the epithelium. There was a violation of the structure Rokitansky-Aschoff sinuses. In some crypts microconcretions were defined. Atrophy and sclerosis of the stroma of the villi were detected in the mucous membrane. Significant expansion of the lumen of the veins in the own plate of the mucous membrane and the perimuscular layer of the gallbladder wall was noteworthy. Signs of stasis were found in the lumen of blood vessels. The lumen of the arteries was narrowed in places due to swelling and accumulation of yellow-brown pigment. Signs of spasm and significant sclerosis of the wall were identified. Dystrophic changes in the endothelium contribute not only to the development of uneven plethora of stagnant nature with significant edema, but also hemorrhage. Significant swelling of all layers was characteristic, causing their disintegration. Significant dilation of lymphatic vessels causes a significant thickening of the gallbladder wall. In some places, there is uneven hypertrophy of the muscle layer. There was an excessive increase in the tortuosity ducts of Luschka. According to the study, patients with metabolic syndrome and chronic pancreatitis, operated on for chronic calculous cholecystitis, along with maintaining the gender and age structure of the contingent, there is a significantly higher incidence of gallbladder cholesterolosis.

Flower color digitizing and pigment distribution in garden pansy

The garden pansy (Viola × wittrockiana) is a large hybrid flower and most popular for its abundant flower colors. The flower colors of 12 pansy accessions were measured by using colorimeter and the pigments distribution within their petal cells were investigated. The result indicated a vast majority of the visual color of flower was consistent with the result surveyed by colorimeter in pansy. The pigments were mainly distributed in the upper and dorsal epidermal cells and most of them show the similar colors to those measured using colorimeter. The red pigment was found to be distributed in the visual blue petals and yellowish brown or khaki pigment in visual white petals. The results suggested the flower color of pansy can be objectively and accurately measured with colorimeter, and investigating pigment color and distribution in petals can help understanding pansy flower color better.

Aqueous Two-Phase System Extraction of Polyketide-Based Fungal Pigments Using Ammonium- or Imidazolium-Based Ionic Liquids for Detection Purpose: A Case Study.

Demand for microbial colorants is now becoming a competitive research topic for food, cosmetics and pharmaceutics industries. In most applications, the pigments of interest such as polyketide-based red pigments from fungal submerged cultures are extracted by conventional liquid–liquid extraction methods requiring large volumes of various organic solvents and time. To address this question from a different angle, we proposed, here, to investigate the use of three different aqueous two-phase extraction systems using either ammonium- or imidazolium-based ionic liquids. We applied these to four fermentation broths of Talaromyces albobiverticillius (deep red pigment producer), Emericella purpurea (red pigment producer), Paecilomyces marquandii (yellow pigment producer) and Trichoderma harzianum (yellow-brown pigment producer) to investigate their selective extraction abilities towards the detection of polyketide-based pigments. Our findings led us to conclude that (i) these alternative extraction systems using ionic liquids as greener extractant means worked well for this extraction of colored molecules from the fermentation broths of the filamentous fungi investigated here; (ii) tetrabutylammonium bromide, [N4444]Br-, showed the best pigment extraction ability, with a higher putative affinity for azaphilone red pigments; (iii) the back extraction and recovery of the fungal pigments from ionic liquid phases remained the limiting point of the method under our selected conditions for potential industrial applications. Nevertheless, these alternative extraction procedures appeared to be promising ways for the detection of polyketide-based colorants in the submerged cultures of filamentous fungi.

Multimodal approach to reveal the effect of light irradiation on chemical composition of lipofuscin granules of human RPE tissues

The accumulation of lipofuscin (LF) in tissues is considered as one a hallmark of the aging process. Usually formed in yellow-brown pigment aggregates or granules primarily composed of lipid residues and proteins, the exact chemical composition of LF varies among tissues. LF of the retinal pigment epithelium (RPE) is known to contain byproducts of the visual cycle, including one of the fluorophores in LF bis-retinoid N-retinyl-N-retinylidene ethanolamine (A2E). The last is characterized by high photoreactivity and implicates in age-related macular degeneration. Photoinduced production of reactive oxygen species (ROS) is shown among the main modes of A2E toxicity although particular photochemistry of A2E have yet to be completely identified. In this work we study changes in chemical composition of LF granules of human RPE under light irradiation using vibrational spectroscopy (femtosecond broadband CARS) and mass-spectrometry (TOF-SIMS) approach accompanied by measurements of fluorescence properties of the LF.

Prevalence and progression of macroscopic lesions in Orbicella annularis and O. faveolata on shallow fringing reefs of St. Kitts

The endangered corals Orbicella annularis and O. faveolata are crucial to Caribbean reefs because of their large size and contribution to reef framework. The objective of this study was to describe the prevalence and progression of macroscopically evident lesions affecting Orbicella spp. in shallow fringing reefs in St. Kitts. Cross-sectional surveys in the spring of 2017 demonstrated 8 predominant lesion patterns affecting 59% of corals (95% CI: 55.8-62.1%), including annular yellow-brown pigmentation, focal brown pigmentation, focal bleaching, diffuse bleaching, annular black surface deposit, focal tissue loss with skeletal erosion, focal grey pigmentation, and growth anomaly. Longitudinal surveys of 47 tagged corals were performed from August 2016-May 2017 to track lesion progression. The 2 most common lesions, annular yellow-brown pigmentation (n = 30), and focal brown pigmentation (n = 21), showed mean (±SD) partial colony mortality growth of 0.26 ± 0.5 and 0.21 ± 0.45 cm2 d-1, respectively. Annular pigmentation progression severity was associated with a marginating band of bleaching (ordinal odds ratio [OOR] = 11.0), and yellow rather than brown color (OOR = 3.8). Bleaching lesions (n = 13), occurring during a time of elevated sea surface temperature, were most severe during October-December 2016, and persisted through April 2017, months after heat stress had subsided. Annular black surface deposits (n = 3) were associated with rapid progression of acute tissue loss, whereas focal tissue loss with skeletal erosion (n = 2) regressed within months, and focal grey pigmentation (n = 2) was quiescent for the length of the study. This study enforces concern for the extent to which Orbicella spp. are declining due to disease.

Distribution, Virulence and Diversity of Leptosphaeria maculans and Leptoshaeria biglobusa at Major Brassica Growing Areas of Ethiopia

A study was conducted to investigate the virulence and diversity of blackleg in major brassica growing areas of Ethiopia. The highest blackleg severity was recorded at Holeta on station canola type cultivar with severity range of 3.5% to 25.6%. The rest visited fields were free from black leg disease. Most of the fields were found covered with Brassica carinata which is under species has BB genome which confers resistance to blackleg. A total of 48 fungal isolates were recovered from leaves and steam of Brassica species. 52% of the isolate goes to L. biglobusa followed by L. maculans 31.25%. Morphological characteristics of the isolates were studied on a PDA medium at 25 ± 1°C: Colonies were found circular in shape after 5 days, and were observed in isolates: BLHH-1, BLHH-2, BLHH-3, BHLL-4, LM-1, LM-2, LB-1, and LB-2. Mycelia were loose, colored white to white smoke. Some of them form colonies with irregular round shape and lobular edges. The pycnidia of the fungus were black, globose to subglobose in shape, the single-celled conidia, hyaline and fusiform with diameters of 4–5 × 1.5–2 μm. From the result slow growth was observed on L. maculans isolate with high sporulation, whereas faster growth rate was observed on L. biglobosa with low sporulation. For the purpose of isolates separation, based on pigment formation on liquid Czapek agar, it was observed that after 30 days isolates LM-1, LM-2, LB-1 and LB-2 where produce yellow-brown pigment which indicate places isolates in a group of non-aggressive strains in conformity with the L. biglobosa. Isolate BLHH-1, BLHH-2, BLHH-3 and BLHH-4 which did not produce pigment; the situation indicates the aggressiveness of the isolate and which is under group L. maculans. Blackleg were found less distributed in major growing areas of Ethiopia, however L. maculans and L. biglobosa were confirmed their presence based on morphological and cultural characteristics. So in line with resistance variety development other management options need to be address to make rapeseed return to production.

In silico study on interaction between human polo-like kinase 1 and cyanobacterial sheath pigment scytonemin by molecular docking approach

Cancer is one of the major causes of death throughout the globe. It is expected that the number of new reports with cancer cases will reach twenty two million in the coming two decades. Africa, Central and South America and Asia will have more than 60 percent of the world’s new cancer reports and 70 percent of the world’s deaths from cancer will be contributed by these continents. Hence, drug discovery for treatment of cancer is the most worked area of this century. Polo-like kinase 1 (PLK-1) is highly expressed in human tumors and is important target of anti-cancerous drugs owing to its role in cell cycle events. It is crucial in maintenance of stability of genome and during different stages of mitosis. Scytonemin is a lipid-soluble and yellow-brown pigment exclusively synthesized by several cyanobacterial species in response to ultraviolet-A radiation. It functions as a photoprotective compound and can act as non-competitive and competitive inhibitor of PLK-1. Other kinases such as Myt1, cyclin-dependent kinase 1/cyclin B, checkpoint kinase 1 and protein kinase C are also inhibited by scytonemin. In the present study, molecular docking approach has been employed for positioning the inhibitor (dimethoxyscytonemin) into the active site of PLK-1 for determining the most probable binding mode. Based on the docking studies, the models which are developed could be utilized for understanding the structure-activity relationships of the scytonemins and for the prescreening and designing of novel inhibitors of PLK-1.

The involvement of dityrosine crosslinks in lipofuscin accumulation in Alzheimer’s disease

Lipofuscin is hydrophobic and insoluble yellow-brown pigment that accumulates in the nervous system of individuals and considered to be a biomarker of aging. However, it has been reported that amyloid-containing Alzheimer neurons contain a large amount of lipofuscin and lysosomal protease enzymes suggesting that the accumulation of Aβ may contribute to lipofuscin formation under oxidative stress conditions. Probing the contribution of oxidative stress using dityrosine cross-links as a marker will help to raise our understanding of the mechanism underlying the increased lipofuscin accumulation in Alzheimer (AD). In order to establish whether oxidised Aβ42 is found in lipofuscin pigments in AD brains, immunogold labelling for dityrosine and Aβ42 in lipofuscin of AD and control age matched brains was carried out. Single immunogold labelling of dityrosine was observed in the lipofuscin granules of control age-matched human brain. Interestingly, TEM immunogold labelling of dityrosine in lipofuscin of AD brain reveals two different labelling areas, low-and high-density dityrosine labelling. The quantification of immunogold particles shows significantly more dityrosine labelling in AD brain compared to age-matched controls. TEM immunogold co-labelling of dityrosine and Aβ in AD brain reveals some colocalisation within lipofuscin, although some areas showed low levels of Aβ labelling. These results may indicate that dityrosine cross-links could be generated from oxidation of various proteins that contain tyrosine residues. Our data show that dityrosine cross-links are increased in lipofuscin in AD brain, highlighting the important role played by dityrosine cross-links in the accumulation of lipofuscin in higher levels in AD compared to control brains.

THE INFLUENCE OF TANNIN PREPARATIONS ON THE CONTENT AND FORM OF ANTHOCYANINS OF MODEL WINE SYSTEMS IN THE CONDITIONS OF INDUCED OXIDATION

The article considers how oenological tannins effect on the content of anthocyanins, phenolic substances, and their forms that influence the stability of the colour of rosé and red wines. The research material was wine model systems that underwent induced oxidation for a week at a temperature of 45±5 °C with limited access of air. Tannins of different botanical origin were used in the study: hydrolyzable ones – Oaktan FU (oak wood), Tannal W4 (Tara pods), CW Tannal (chestnut wood), and Tannal W2 (gallnuts); and condensed ones – Tannin WG (grape stones), Taniraisin (grape skin), Tannal QW (quebracho wood). The source of anthocyanins was an alcohol extract from the skins of European red grapes. It was obtained by 24 hours long extraction with ethyl alcohol, and with the addition of hydrochloric acid (0.01%). It has been determined that in the course of induced oxidation, the content of phenolic compounds tends to decrease in a wavelike manner in all samples. The anthocyanin content reduces intensively and becomes practically twice as low on the first day of oxidation. The total amount of phenolic compounds becomes 2 to 6 times lower depending on the variant of the experiment. It has been established that condensed tannins of grape origin contribute to the preservation of the total content of phenolic substances (including anthocyanins) in wine, unlike hydrolyzable tannins obtained from other plants. But their application leads to polymerization of anthocyanins, which will result in the appearance of yellow-brown pigments in the red colour of wine. Hydrolyzable tannins obtained from gallnuts and tara trees preserve the red colour of wine for a long time, unlike condensed tannins, due to their antioxidant capacity. Hydrolyzable tannins obtained from tara and quebracho trees will help obtain wine with rich red shades.

Fabrication and performance of PSf/CA ultrafiltration membranes: Effect of additives for fouling resistance and selective polyphenol removal from apple juice

This work focused on the addition of different pore formation-controlling agent to a polysulfone/cellulose acetate blend membrane via immersion precipitation using phase inversion technique to improve the fouling resistance and selective polyphenol removal of apple juice. The membranes were prepared by blending hydrophilic polyvinylpyrrolidone (PVP) and amphiphilic Pluronic F127 (Plu) with polysulfone/cellulose acetate matrix in N-methyl-2-pyrrolidone. The morphology, mechanical strength, flux permeation, flux recovery ratio, and polyphenol separation of these membranes were characterized. It was found that the fabricated membranes with addition of PVP and Plu were more effective than the membrane without a pore formation-controlling agent. The flux recovery of the membranes with combined pore formers after ultrafiltration of bovine serum albumin increased from 12.4% to 66.9%. The selectivity of polyphenols increased from 6% to 79% with an improved flux recovery of 79%, which shows the reduction of yellowish-brown pigment in apple juice.