Antimycobacterial Butanolides from the Root of Lindera akoensis

Three racemic butanolides, majorenolide ( 1 ), majorynolide ( 2 ), and majoranolide ( 3 ), with 18 known compounds, including ten butanolides, i.e., litsenolide A₂ ( 4 ), litsenolide B₂ ( 5 ), litsenolide C₁ ( 6 ), litsenolide C₂ ( 7 ), hamabiwalactone A ( 8 ), hamabiwalactone B ( 9 ), litseakolide A ( 10 ), litseakolide B ( 11 ), isoobtusilactone ( 12 ), and obtusilactone ( 13 ); one lignan, i.e., (±)‐syringaresinol ( 14 ), two flavans, i.e., (+)‐catechin ( 15 ), and (?)‐epicatechin ( 16 ), one coumarin, i.e., scopoletin ( 17 ), and four steroids, i.e., a mixture of β‐sitosterol ( 18 ) and stigmasterol ( 19 ), and a mixture of β‐sitosteryl‐3‐O‐β‐D ‐glucoside ( 20 ) and stigmasteryl‐3‐O‐β‐D ‐glucoside ( 21 ) were isolated from the root of Lindera akoensis. The structures of the isolates were elucidated by in‐depth spectroscopic analysis. Compounds 1 – 3 were previously assigned a δ‐lactone structure, which was then revised to a γ‐lactone structure, based on 1D‐NMR data. The cigar‐HMBC technique was used to confirm the accuracy of the γ‐lactone structure, and the zero [α] value of compounds 1 – 3 suggested that they were considerably racemized. Nine butanolides 1 – 3, 4 – 8 , and 10 showed antimycobacterial activities against M. tuberculosis H₃₇Rv, with MIC values of 15–50 μg/ml.     

Quantitative shotgun proteomics of enriched heterocysts from Nostoc sp. PCC 7120 using 8-plex isobaric peptide tags

The filamentous cyanobacterium Nostoc sp. strain PCC 7120 is capable of fixing atmospheric nitrogen. The labile nature of the core process requires the terminal differentiation of vegetative cells to form heterocysts, specialized cells with altered cellular and metabolic infrastructure to mediate the N2-fixing process. We present an investigation targeting the cellular proteomic expression of the heterocysts compared to vegetative cells of a population cultured under N2-fixing conditions. New 8-plex iTRAQ reagents were used on enriched replicate heterocyst and vegetative cells, and replicate N2-fixing and non-N2-fixing filaments to achieve accurate measurements. With this approach, we successfully identified 506 proteins, where 402 had confident quantifications. Observations provided by purified heterocyst analysis enabled the elucidation of the dominant metabolic processes between the respective cell types, while emphasis on the filaments enabled an overall comparison. The level of analysis provided by this investigation presents various tools and knowledge that are important for future development of cyanobacterial biohydrogen production.     

Evolution of the <Emphasis Type="Italic">DAZ</Emphasis> gene and the <Emphasis Type="Italic">AZFc</Emphasis> region on primate Y chromosomes

Background  

The Azoospermia Factor c (AZFc) region of the human Y chromosome is a unique product of segmental duplication. It consists almost entirely of very long amplicons, represented by different colors, and is frequently deleted in subfertile men. Most of the AZFc amplicons have high sequence similarity with autosomal segments, indicating recent duplication and transposition to the Y chromosome. The Deleted in Azoospermia (DAZ) gene within the red-amplicon arose from an ancestral autosomal DAZ-like (DAZL) gene. It varies significantly between different men regarding to its copy number and the numbers of RNA recognition motif and DAZ repeat it encodes. We used Southern analyses to study the evolution of DAZ and AZFc amplicons on the Y chromosomes of primates.     

Comparison of the developmental potential of 2-week-old preantral follicles derived from vitrified ovarian tissue slices, vitrified whole ovaries and vitrified/transplanted newborn mouse ovaries using the metal surface method

Background

Cryopreservation of preantral follicles or ovarian tissues would enable the storage of large numbers of primordial follicles or preantral follicles and preserves the structural integrity of somatic and reproductive cells. In the present study, we compared the developmental potential of cryopreserved two-week-old mouse preantral follicles, ovarian tissue slices, two-week-old mouse ovaries and newborn mouse ovaries using a metal plate with a high cooling rate for cooling the droplet of vitrification solution.

Methods

Groups of 2 to 4 samples (including of 14-day old preantral follicles, ovarian tissue slices, whole ovaries, and whole newborn ovaries) were exposed to 4% ethylene glycol (EG) in DPBS + 10% FBS for 15 min and then rinsed in a vitrification solution composed of 6 M ethylene glycol and 0.4 M trehalose in DPBS + 10% FBS. Equilibration in room temperature was performed for 20–30 seconds for preantral follicle and 5 min equilibration was performed in an ice bath for ovaries. The samples were dropped onto the surface of metal plate around -180°C in the volume of 2 μl and 6 μl. After thawing, the ovarian tissue was mechanically isolated for collecting the preantral follicles. The thawed newborn ovaries were transplanted under the renal capsule of recipient male mice for 14 days. Preantral follicles collected from each groups were cultured individually in 20-μl droplets of α-MEM culture medium in culture dish for 12 days. On the day 12 of culture, the cumulus-oocyte complexes (COCs) were collected for IVM and IVF. Fertilization and embryo cleavage were scored.

Results

After the vitrification of 14-day-old preantral follicles using 2 μl or 6 μl droplet onto surface of metal plate, the results indicated that no significant difference in survival rate, antral-like cavity formation, COCs collected, 2 cell embryo cleavage and blastocyst development was found in vitrification of the 2 μl and 6 μl droplet groups. As comparing 14-day old ovarian tissue (ovarian tissue slices and whole ovaries) and whole newborn ovaries vitrified in 6 μl droplet, lower success rates of antral-like cavity formation and COCs collection were found in the whole ovaries group.

Conclusion

Our results suggest that the metal plate surface vitrification method is an appropriate and convenient method for cryopreservation of mouse ovaries and preantral follicles. The droplet volume of vitrification solution in 2 μl and 6 μl can be an option.     

Synthesis of biodegradable and electroactive multiblock polylactide and aniline pentamer copolymer for tissue engineering applications

To obtain one biodegradable and electroactive polymer as the scaffold for tissue engineering, the multiblock copolymer PLAAP was designed and synthesized with the condensation polymerization of hydroxyl-capped poly( l-lactide) (PLA) and carboxyl-capped aniline pentamer (AP). The PLAAP copolymer exhibited excellent electroactivity, solubility, and biodegradability. At the same time, as one scaffold material, PLAAP copolymer possesses certain mechanical properties with the tensile strength of 3 MPa, tensile Young 's modulus of 32 MPa, and breaking elongation rate of 95%. We systematically studied the compatibility of PLAAP copolymer in vitro and proved that the electroactive PLAAP copolymer was innocuous, biocompatible, and helpful for the adhesion and proliferation of rat C6 cells. Moreover, the PLAAP copolymer stimulated by electrical signals was demonstrated as accelerating the differentiation of rat neuronal pheochromocytoma PC-12 cells. This biodegradable and electroactive PLAAP copolymer thus possessed the properties in favor of the long-time application in vivo as nerve repair scaffold materials in tissue engineering.     

Synthesis of cellulose-graft-poly(N,N-dimethylamino-2-ethyl methacrylate) copolymers via homogeneous ATRP and their aggregates in aqueous media

Cellulose-graft-poly(N,N-dimethylamino-2-ethyl methacrylate) (cellulose-g-PDMAEMA) copolymers were prepared by homogeneous atom transfer radical polymerization (ATRP) under mild conditions. Cellulose macroinitiator was successfully synthesized by direct acylation of cellulose with 2-bromopropionyl bromide in a room temperature ionic liquid (RTIL), 1-allyl-3-methylimidazolium chloride. Copolymers were obtained via ATRP of N,N-dimethylamino-2-ethyl methacrylate (DMAEMA) with CuBr/pentamethyldiethylenetriamine (PMDETA) as catalyst and N,N-dimethylformamide (DMF) as solvent without homopolymer byproduct. The grafting copolymers were characterized by (1)H NMR, FT-IR, and TGA measurements. The results confirmed that PDMAEMA had been covalently bonded to cellulose backbone. Furthermore, the assemblies or aggregates formed by cellulose-g-PDMAEMA copolymers in water were studied at various concentrations, temperatures, and pH values by means of UV, DLS, TEM, and AFM. The results indicate that the copolymers had the pH- and temperature-responsive properties similar to the expected stimuli-responses by PDMAEMA. The synthetic strategy presented here could be employed in the preparation of other novel biomaterials from a variety of polysaccharides.     

Palm oil mill effluent (POME) cultured marine microalgae as supplementary diet for rotifer culture

Malaysia is the world’s leading producer of palm oil products that contribute US$ 7.5 billion in export revenues. Like any other agro-based industries, it generates waste that could be utilized as a source of organic nutrients for microalgae culture. Present investigation delves upon Isochrysis sp. culture in POME modified medium and its utilization as a supplement to Nanochloropsis sp. in rotifer cultures. The culture conditions were optimized using a 1 L photobioreactor (Temp: 23°C, illumination: 180 ∼ 200 μmol photons m⁻²s⁻¹, n = 6) and scaled up to 10 L outdoor system (Temp: 26–29°C, illumination: 50 ∼ 180 μmol photons m⁻²s⁻¹, n = 3). Algal growth rate in photobioreactor (μ = 0.0363 h⁻¹) was 55% higher compared to outdoor culture (μ = 0.0163 h⁻¹), but biomass production was 1.3 times higher in outdoor culture (Outdoor = 91.7 mg m⁻²d⁻¹; Photobioreactor = 69 mg m⁻²d⁻¹). Outdoor culture produced 18% higher lipid; while total fatty acids (FA) was not significantly affected by the change in culture systems as both cultures yield almost similar concentrations of fatty acids per gram of sample (photobioreactor = 119.17 mg g⁻¹; outdoor culture = 104.50 mg g⁻¹); however, outdoor cultured Isochrysis sp. had 26% more polyunsaturated fatty acids (PUFAs). Rotifers cultured in Isochrysis sp./ Nanochloropsis sp. (1:1, v/v) mixture gave similar growth rate as 100% Nanochoropsis sp. culture (μ = 0.40 d⁻¹), but had 45% higher counts of rotifers with eggs (t = 7, maximum). The Isochrysis sp. culture successfully lowered the nitrate (46%) and orthophosphate (83%) during outdoor culture.     

Common themes and variations in serine protease autotransporters

The serine protease autotransporters of the Enterobacteriaceae (SPATEs) represent a group of large-sized, multi-domain exoproteins found only in pathogenic enteric bacteria. These proteins contain a highly conserved channel-forming C-terminal domain, which functions together with YaeT/Omp85 to facilitate secretion of the passenger domain to the cell surface. The C-terminal domain also mediates autoproteolytic cleavage, which releases the passenger from the bacterial cell. The passenger folds into a characteristic parallel beta-helical stalk-like structure with an N-terminal globular domain that performs serine proteolytic activity. Here, we review and discuss recent findings that have led to a better understanding of these unique features in this virulence protein family, including their biogenesis, structural architecture, sequence variation, sub-grouping, evolution and biochemical function.     

Synergistic effects of cinnamaldehyde in combination with eugenol against wood decay fungi

The combined effects of using cinnamaldehyde with catechin, quercetin or eugenol against wood decay fungi were examined by comparing their isoeffective concentrations to that of individual compound. Among all combinations, cinnamaldehyde with eugenol revealed the strongest synergy against Laetiporus sulphureus. The synergism was due to the interference of fungal cell wall synthesis and cell wall destruction plus radical scavenging effect. Results also suggested that antioxidant with fungicidal effect might be a better candidate than pure antioxidant for the system of fungicide/antioxidant.     

Optimization of conditions for protease production by Chryseobacterium taeanense TKU001

A protease-producing bacterium was isolated and identified as Chryseobacterium taeanense TKU001. An extracellular metalloprotease with novel properties of solvent- and surfactant-stable was purified from the culture supernatant of C. taeanense TKU001 with shrimp shell wastes as the sole carbon/nitrogen source. The optimized condition for protease production was found when the culture was shaken at 37 degrees C for 3 days in 50 mL of medium containing 0.5% shrimp shell powder (SSP) (w/v), 0.1% K2HPO4, and 0.05% MgSO4.7H2O. Two extracellular proteases (FI and FII) were purified and characterized, and their molecular weights, pH and thermal stabilities were determined. The molecular masses of TKU001 protease FI and FII determined by SDS-PAGE and gel filtration were approximately 41 kDa and 75 kDa, respectively. The optimum pH, optimum temperature, pH stability, and thermal stability of TKU001 protease FI were 8, 60 degrees C, pH 6-9, and 60 degrees C, respectively. The optimum pH, optimum temperature, pH stability, and thermal stability of TKU001 protease FII were 7, 60 degrees C, pH 7-9, and 50 degrees C, respectively. TKU001 protease FI and FII were both inhibited completely by EDTA, indicating that the TKU001 protease FI and FII were metalloproteases. TKU001 protease FI and FII retained more than 75% of its original protease activity after preincubation for 10 days at 4 degrees C in the presence of 25% most tested organic solvents. Additionally, the TKU001 protease FI retained 79%, 80%, and 110% of its original activity in the presence of 2% Tween 20, 2% Tween 40, and 2% Triton X-100, respectively. However, at the same condition, the activity of TKU001 protease FII retained 100%, 100%, and 121% of its original activity, respectively. This is the first report of C. taeanense being able to use shrimp shell wastes as the sole carbon/nitrogen source for proteases production. The novelties of the TKU001 protease include its high stability to the solvents and surfactants. These unique properties make it an ideal choice for application in detergent formulations and enzymatic peptide synthesis.