Oxygenated Theonellastrols: Interpretation of Unusual Chemical Behaviors Using Quantum Mechanical Calculations and Stereochemical Reassignment of 7α-Hydroxytheonellasterol     

A-Young Shin  Hyi-Seung Lee  Yeon-Ju Lee  Jong Seok Lee  Arang Son  Changhoon Choi  Jihoon Lee 《Marine drugs》2020,18(12)

A total of eight new oxygenated 4-exo-methylene sterols, 1–8, together with one artifact 9 and six known sterols 11–16, were isolated from the marine sponge Theonella swinhoei collected from the Bohol province in Philippines. Structures of sterols 1–8 were determined from 1D and 2D NMR data. Among the sterols, 8α-hydroxytheonellasterol (4) spontaneously underwent an allylic 1,3-hydroxyl shift to produce 15α-hydroxytheonellasterol (9) as an artifact; this was rationalized by quantum mechanical calculations of the transition state. In addition, the 1,2-epoxy alcohol subunit of 8α-hydroxy-14,15-β-epoxytheonellasterol (5) was assigned using the Gauge-Independent Atomic Orbital (GIAO) NMR chemical shift calculations and subsequent DP4+ analysis. Finally, comparison of the ¹³C chemical shifts of isolated 7α-hydroxytheonellasterol (6) with the reported values revealed significant discrepancies at C-6, C-7, C-8, and C-14, leading to reassignment of the C-7 stereochemistry in the known structure.  相似文献   

Physical Stress Induced Reduction of Proliferating Cells and Differentiated Neuroblasts Is Ameliorated by Fermented Laminaria japonica Extract Treatment     

Hyo Young Jung  Woosuk Kim  Hyun Jung Kwon  Dae Young Yoo  Sung Min Nam  Kyu Ri Hahn  Sun Shin Yi  Jung Hoon Choi  Dae Won Kim  Yeo Sung Yoon  In Koo Hwang 《Marine drugs》2020,18(12)

Laminaria japonica is widely cultivated in East Asia, including South Korea. Fucoidan, a main component of L. japonica, protects neurons from neurological disorders such as ischemia and traumatic brain injury. In the present study, we examined the effects of extract from fermented L. japonica on the reduction of proliferating cells and neuroblasts in mice that were physically (with electric food shock) or psychologically (with visual, auditory and olfactory sensation) stressed with the help of a communication box. Vehicle (distilled water) or fermented L. japonica extract (50 mg/kg) were orally administered to the mice once a day for 21 days. On the 19th day of the treatment, physical and psychological stress was induced by foot shock using a communication box and thereafter for three days. Plasma corticosterone levels were significantly increased after exposure to physical stress and decreased Ki67 positive proliferating cells and doublecortin immunoreactive neuroblasts. In addition, western blot analysis demonstrated that physical stress as well as psychological stress decreased the expression levels of brain-derived neurotrophic factor (BDNF) and the number of phosphorylated cAMP response element binding protein (pCREB) positive nuclei in the dentate gyrus. Fermentation of L. japonica extract significantly increased the contents of reduced sugar and phenolic compounds. Supplementation with fermented L. japonica extract significantly ameliorated the increases of plasma corticosterone revels and decline in the proliferating cells, neuroblasts, and expression of BDNF and pCREB in the physically stressed mice. These results indicate that fermented L. japonica extract has positive effects in ameliorating the physical stress induced reduction in neurogenesis by modulating BDNF and pCREB expression in the dentate gyrus.  相似文献   

Control of root‐knot nematodes using Waltheria indica producing 4‐quinolone alkaloids     

Ja Yeong Jang  Quang Le Dang  Gyung Ja Choi  Hae Woong Park  Jin‐Cheol Kim 《Pest management science》2019,75(8):2264-2270

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Preparation of plastic and biopolymer multilayer films by plasma source ion implantation     

Shin GH  Lee YH  Lee JS  Kim YS  Choi WS  Park HJ 《Journal of agricultural and food chemistry》2002,50(16):4608-4614

The plasma source ion implantation (PSII) technique was used to improve the adhesion between linear low-density polyethylene (LLDPE) and biopolymer. LLDPE was treated with the PSII using O(2) or CF(4) gas to modify its surface. After modification, chitosan or corn zein was used for coating on LLDPE. Wettability of the LLDPE surface was evaluated with a contact angle meter by the sessile drop method. X-ray photoelectron spectroscopy (XPS) was used to analyze the LLDPE surface. Before and after treatment, in the case of LLDPE treated with O(2) PSII, oxygen-containing functional groups were formed on the implanted surface. In the CF(4) PSII treated LLDPE, it was observed that the fluorine concentration on the surface of LLDPE remarkably increased and hydrophobic groups were formed by chemical reaction. Bilayer films coated with chitosan or corn zein showed 10 times lower oxygen permeability. Tensile strength of multilayer films was decreased a little compared with that of LLDPE. The plastic and biopolymer multilayer films have potential for food packaging application because of their O(2) gas barrier property and easy recyclability of the multilayer film.  相似文献   

Lidocaine hydrochloride—sodium bicarbonate as an anesthetic for soft-shelled turtle Pelodiscus sinensis     

In-Seok Park  Sung Hwoan Cho  Jun Wook Hur  Gyeng-Cheol Choi  Sung-Yong Oh  Dong Soo Kim  Jae-Seong Lee 《Fisheries Science》2006,72(1):115-118

ABSTRACT:   Attempts were made to understand how the different sizes (mean body weight of 4.1 ± 0.8 g for small and 182.6 ± 23.7 g for large) of the soft-shelled turtle Pelodiscus sinensis are affected by different temperature (25°C or 30°C), and different concentrations (700, 1000 and 1300 p.p.m.) of anesthetic lidocaine hydrochloride–sodium bicarbonate. The soft-shelled turtles were fed to satiation once daily. Three-way anova design (size × temperature × concentration of lidocaine hydrochloride) with duplicate was used. Twenty each of large and small soft-shelled turtles were distributed into six 30-L tanks. Exposure time of the soft-shelled turtle was affected by all factors (temperature, concentration and size). Exposure time of the soft-shelled turtle for anesthetizing decreased with increase in temperature and in concentration of lidocaine hydrochloride, and decrease in size. Recovery time for the soft-shelled turtle was also affected by all factors. Recovery time of the soft-shelled turtle increased with increase in temperature, concentration of lidocaine hydrochloride, and size. According to these results, lidocaine hydrochloride (1000 p.p.m.)–sodium bicarbonate seemed an effective anesthetic for sedating and handling the soft-shelled turtle. However, when an anesthetic is recommended for wide use, especially on commercially important edible organisms, the time organism takes to metabolize and excrete anesthetic chemicals from its body to a safe level must be given to allow fitness for human consumption.  相似文献   

Cellular apoptosis susceptibility gene messenger ribonucleic acid in the ovary of red seabream: molecular cloning and correlation with acquisition of oocyte maturational competence     

C.Y. Choi  A. Takemura  F. Takashima 《Fish physiology and biochemistry》2000,23(2):119-125

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Gametogenetic cycle and reproductive effort assessed by two methods in 3 age classes of Pacific oysters, Crassostrea gigas, reared in Normandy     

Juliette Royer  Catherine Seguineau  Kyung-Il Park  Stphane Pouvreau  Kwang-Sik Choi  Katherine Costil 《Aquaculture (Amsterdam, Netherlands)》2008,277(3-4):313-320

Two methods were used to estimate the reproductive output of female Pacific oysters reared in Normandy: histology with image analysis and ELISA (Enzyme-Linked ImmunoSorbent Assay) which allowed the quantification of egg protein. Condition indices, gonad area and gametogenetic stages of the oysters were determined in the entire population (males and females) between May and October 2005. All investigations were performed in 3 age classes: oysters in their first, second or third years (corresponding to spat, half-grown and market-sized oysters, respectively). Both quantitative histology and ELISA provided similar results in terms of reproductive effort (illustrated by the gonado-somatic index, GSI) except during the GSI drop, corresponding to spawning, which was less marked with the ELISA method. Growth depended on oyster age, the sex ratio was well balanced and the reproductive cycle was synchronized in all age classes. In the 3 age classes, most of the oysters were ripe and ready to spawn on August 8, and ten days after the post-spawning stage was observed in 40% of spat oysters and 70% of half-grown and market-sized bivalves. The major difference between age classes was observed in the reproductive investment, with spat having a lower reproductive output. For example, in males and females, the gonad area reached 78–79% in the median animal section at full maturity (August 8) in half-grown and marketable oysters while it attained only 59% in spat. At the same time, GSI in females was, respectively in spat and the 2 oldest age classes, 33% (quantitative histology)–36% (ELISA) and 55% (quantitative histology)–60% (ELISA). The mean assessed gonad weight and fecundities increased with the age of the oysters: 1.3 g and 12 million eggs, 7.8 g and 135 million eggs, and 11.5 g and 146 million eggs in spat, half-grown and market-sized oysters, respectively. Marked differences thus appear between 2 and 3-year-old oysters and spat. As early as their first reproductive cycle, the young oysters not only showed the reproductive features of the species in Normandy, but also a pronounced lower reproductive effort. This lower energy demand could explain their higher survival rate.  相似文献   

Involvement of androgens and growth hormone in the synthesis of vitellogenin in Japanese eel (Anguilla japonica)     

H.C. Kwon  S.H. Choi  Y.U. Kim  S.O. Son  J.Y. Kwon 《Fish physiology and biochemistry》2003,28(1-4):351-352

Immature eels positively responded to estradiol-17β (E₂) injection in terms of vitellogenin (Vg) synthesis but not to growth hormone (GH) or 17α-methyltestosterone (MT) injection. However, injection of MT or GH combined with E₂ strongly increased Vg synthesis. In in vitro experiments, eel hepatocytes treated with E₂, GH, or MT alone did not produce detectable amount of Vg, whereas the combination of E₂ with GH or MT, or both greatly increased Vg synthesis in the hepatocytes.  相似文献   

A recombinant Eimeria protein inducing interferon-gamma production: comparison of different gene expression systems and immunization strategies for vaccination against coccidiosis   总被引：17，自引：0，他引：17  

Lillehoj HS  Choi KD  Jenkins MC  Vakharia VN  Song KD  Han JY  Lillehoj EP 《Avian diseases》2000,44(2):379-389

A rabbit antiserum against an 18- to 27-kD native protein fraction (F3) from Eimeria acervulina merozoites identified a cDNA (3-1E) containing a 1086-base pair insertion with an open reading frame of 170 amino acids (predicted molecular weight, 18,523). The recombinant 3-1E cDNA expressed in Escherichia coli produced a 60-kD fusion protein and a 23-kD protein after factor Xa treatment of the fusion protein. Both proteins were reactive with the F3 antiserum by western blot analysis. A rabbit antiserum against a synthetic peptide deduced from the amino acid sequence of the 3-1E cDNA reacted with a 27-kD recombinant 3-1E protein expressed in Sf9 insect cells and a 20-kD native protein expressed by E. acervulina sporozoites and Eimeria tenella sporozoites and merozoites. By immunofluorescence staining, a monoclonal antibody produced against the recombinant 3-1E protein reacted with sporozoites and merozoites of E. acervulina, E. tenella, and Eimeria maxima. Spleen lymphocytes from E. acervulina-immune chickens showed antigen-specific proliferation and interferon (IFN)-gamma production upon stimulation with the recombinant 3-1E protein, indicating that the protein activates cell-mediated immunity during coccidiosis. Immunization of chickens with either the E. coli- or Sf9-expressed recombinant 3-1E protein with adjuvant, or direct injection of the 3-1E cDNA, induced protective immunity against live E. acervulina. Simultaneous injection of the recombinant 3-1E protein, or the 3-1E cDNA, with cDNAs encoding chicken IFN-gamma or interleukin (IL)-2/15 further enhanced protective immunity. These results indicate that the recombinant E. acervulina 3-1E cDNA or its polypeptide product may prove useful as vaccines against avian coccidiosis.  相似文献   

Role of chicken IL-2 on gammadelta T-cells and Eimeria acervulina-induced changes in intestinal IL-2 mRNA expression and gammadelta T-cells   总被引：14，自引：0，他引：14  

Choi KD  Lillehoj HS 《Veterinary immunology and immunopathology》2000,73(3-4):309-321

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