• Bulletin of the Korean Chemical Society
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• v.21 no.8
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• pp.813-816
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• 2000

The synthesis of bisphenol A-derived calixarenes has been studied by changing the protecting group of the phe-nol moiety and reaction conditions. Depending on the protecting groups,the corresponding calix[6,7,8]arenes are obtained in different rat ios. For example, whcn mono-p-tert-butyldimethylsilyl-protected bisphenol A is treated with paraformaldehyde and a catalytic amount ofaqueous KOH in refluxing p-xylene with a Dean-Stark water collector for 36 h, the corresponding calix[8]arene, calix[7]arene, and calix[6]arene are producedand separated in the ratio of about 3 : 2 : l and with overall 63% yield. The calixarenes are characterized by NMR spectroscopy and mass analysis. The X-raycrystal structure of the calix[8]arene shows a pleated loop confor-mation, stabilized by intramoIecular hydrogen bonding between the inner phenolic hydroxy groups.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.57-63
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• 2020

To develop simple acrosome staining of horse spermatozoa, this study tested the binding properties of Coomassie brilliant blue G or R on the sperm smears after 3.7% paraformaldehyde (PF) or 35% methanol (MT) fixation. After being fixed with PF and stained with 0.05, 0.1, or 0.2 % of CBB G or R for 2 min, horse spermatozoa were examined for their intact acrosome status. The intact acrosome of fresh horse spermatozoa were 62.6% and 61.5% with 0.05% of the G and R CBB solution, but 80.2 and 79.7% with G type and 78.1 and 76.0% with R type. On the other hand, when MT was used for fixation, the acrosome reacting sperm ratio was 3.5%, but was 9.0% in the case of PF. These results show that the intact acrosome of horse sperm could be judged using a 0.1~0.2% CBB G or R staining technique. PF would be an essential fixative for examining acrosome reacting horse spermatozoa. This method could be used to identify sperm with a damaged acrosome during low-temperature storage or cryopreservation for artificial insemination of horses.

• Applied Microscopy
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• v.24 no.2
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• pp.63-77
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• 1994

This experiment was performed to study the morphological responses of the epidermis of the rat scalp, following X-ray irradiation. Male rats were divided into normal and experimental groups. Rats anesthetized with sodium thiopental, were exposed only on their head areas with a single dose of 3,000rads or 6,000rads, respectively. Radiation was produced by Mitsubishi Linea Accelerator ML-4MV at the speed of 200rads/min. The target distance was 80cm. Animals were sacrificed on six hours, two days and six days following irradiation. By the perfusion fixation through the heart, rats were fixed with 1% glutaraldehyde-1% paraformaldehyde solution. Pieces of the tissue taken from the scalp were refixed in 2.5% glutaraldehyde-1.5% paraformaldehyde solution, followed by post-fixation with 1% osmium tetroxide, and embedded within araldite mixture. The sections were cut on a LKB-V ultratome, stained with uranyl acetate and lead citrate, and were observed with JEM 100CX-II electron microscope. The results were as follow; 1. Six hours after exposure to 3,000rads of X-ray. Disrupted intercellular spaces, within which some amorphous materials were filled, disrupted mitochondria, and vacuoles in the keratinocytes were frequently observed, but six days after exposure to 3,000rads of X-ray, Morphology of the keratinocytes was generally restored. 2. Many of the morphological changes were seen on the six days after exposure to 6,000rads of X-ray. 3. Widened intercellular spaces and thickened dense plaques of the desmosomes were frequently observed after exposure to 6,000rads of X-ray. 4. In the experimental groups, the Langerhans and the Merkel cells were damaged, similarly to the keratinocyte. Above results suggest that head irradiation with the dose of 3,000rads temporarily damaged the epidermis of the scalp, though most of the structures recover within six days, whereas with the dose of 6,000rads it severely damaged the epidermis without showing any recovering tendency.

• Korean Journal of Veterinary Research
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• v.36 no.1
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• pp.39-49
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• 1996

The present study was performed to investigate the distribution of neuropeptide Y immunoreactivities in the corpus striatum of the Korean squirrels. The animals were perfused with 4%-paraformaldehyde and the brain was cut serially into $40{\mu}m$ thick coronal sections. Sections either were stained with cresyl violet or were stained immunohistochemically. The corpus striatum was divided into the caudate nucleus, putamen and globus pallidus. Anterior part. however, of the striatum was observed as the combined caudate-putamen. NPY immunoreactive (NPY-IR) neurons were medium-sized. The corpus striatum contained a low level of NPY-IR fibers, whose distribution appeared to be related to the immunoreactive perikarya. Large numbers of NPY-IR neurons in the caudate-putamen and caudate nucleus were expressed in medial and ventral parts. In the anterior part of the putamen NPY-IR neurons were scattered throughout the nucleus; in posterior part were found generally in the lateral and ventral parts. The density of NPY-IR fibers of the putamen were low, whose distribution appeared to be related to the perikarya. The globus pallidus contained NPY-IR fibers only in the lowest density. In brief, NPY-immunoreactivities in the corpus striatum are heterogenous in distribution. These findings may reflect innate characteristics of the specific neural circuit in the corpus striatum itself.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.910-914
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• 2007

In order to synthesize new bioactive compounds and contrasting agents, reactions of glycine and glutamic acid as an animo acid with paraformaldehyde and hypophosphorous acid were executed. Products are 3,7-dihydroxy-3,7-dioxoperhydro-1,5,3,7-diazadiphosphocine-1,5-diacetic acid 1 and 3,7-dihydroxy-3,7- dioxoperhydre-1,5,3,7-diazadiphosphocine-1,5-di-(2-glu taric acid) 3. 2-[5-(1,2-Dicarboxyethyl)-3,7-dihydroxy-3,7-dioxo-315.715-[1,5,3,7] diazadiphosphocan-1-yl]-succinic acid 2 by using aspartic acid was not obtained. Esterification of 3,7- dihydroxy-3,7-dioxoperkydro-1,5,3,7-diaza-diphosphocine-1,5-diacetic acid 1 by treatment of methanol, ethanol, and propanol were executed. 3,7-Dihydroxy-3,7-dioxoperhydro-1,5,3,7-diazadiphosphocine-1,5-diacetic acid methyl ester 4, 3.7-dihydroxy-3,7-dioxoperhydro-1,5,3,f-diazadiphosphocine-1.5-diacetic acid ethyl ester 5, and 3,7-dihydroxy-3,7-dioxoperhydro-1,5,3,7-diazadiphosphocine-1,5-diacetic acid propyl ester 6 were respectively synthesized in good yields. Continuously, we will try synthesis of novel compounds and evaluation of biological activity.

• Applied Microscopy
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• v.23 no.2
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• pp.11-26
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• 1993

This experiment was performed to study the morphological responses of the pigment epithelial cell and the Bruch's membrane of the retina of rat following X-ray irradiation. Male rats were divided into normal and experimental groups. The heads of the rats, under sodium thiopental anesthesia, were exposed to 3,000 rads or 6,000 rads of radiation in a single dose, respectively. The source was a Mitsubishi Linear Accelerator ML-4MV. The target to skin distance was 80cm, and the. dose rate was 200 rads/min. The experimental groups were sacrificed on the 6th hour, 2nd and 6th day after X-ray irradiation. Under anesthesia, 1% glutaraldehyde-1% paraformaldehyde solution(0.1M Millonig's phosphate buffer, pH 7.3) was perfused through the left ventricle and ascending aorta. Pieces of the tissue taken from the posterior region of the retina were fixed in 2.5% glutaraldehyde-1.5% paraformaldehyde(0.1M Millonig's phosphate buffer, pH 7.3) and 1% osmium tetroxide(0.1M Millonig's phosphate buffer, pH7.3), and embedded in araldite mixture. The ultrathin sections contrasted with uranyl acetate and lead citrate were observed with JEM 100 CX-II electron microscope. The results were as follow; 1. The morphological changes of the pigment epithelial cells were not pronounced after exposure to 3,000 rads of X-ray. But on the 6th hour after exposure to 6,000 rads of X-ray, bulging nuclear membrane protruding into the cytoplasm and nuclear chromatin clumped into numerous masses along the nuclear membrane were observed. At the 2nd and 6th day post-irradiation, partial cytolysis or necrosis were seen. 2. The thickness of the Bruch's membrane of the experimental groups were increased in the time and dose range covered by this study, and splitting or diffusing basal laminae of the choriocapillary layer were observed frequently in the experimental group. Above results suggest that large amount(6,000 rads) of head irradiation induce direct hazardous effects on the pigment epitherial cells and Bruch's membrane of the retina of the rat, but pigment epithelial cells are more radioresistant than Bruch's membrane.

• Applied Microscopy
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• v.29 no.1
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• pp.11-23
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• 1999

Ultrastructure of the ependymal cells of X-irradiated rats on their head were studied. Rats weighing $200\sim250gm$ were X-irradiated on their head and neck areas. Total exposures were 3,000 rads or 6,000 rads depending on experimental groups. And irradiated rats were sacrificed on 6 hours, 2 days and 6 days following the radiation exposures. Animals were perfused through the heart with 1% glutaraldehyde-1% paraformaldehyde solution, under ether-anesthesia. The tissues from the wall of lateral ventricles were fixed in the 2% osmium tetroxide solution. The results observed with electron microscope were as follow: 1. In 6 hours group, many ependymal cells were swelled, luminal portions of cytoplasms of some cells protruded into the ventricular lumen, and many cilia were lost or irregularly altered. 2. In 2 days group, ependymal cells were swelled more severely and subependymal edema were pronounced. 3. Protruded cytoplasm contained usually basal bodies of cilia, groups of mitochondria, endoplasmic reticula , etc. 4. Following X-irradiations, some protruded masses contained neural elements including the axon terminals with dense core vesicles. Axons and axon terminals were also found in the enlarged intercellular spaces among ependymal cells. From the above results, the heavy irradiation on the head area of the rat induced alteration of the ependymal cells lining the lateral ventricle. Hence the ependymal functions of selective barrier, protective barrier, and metabolic barrier could be altered following X-irradiation on the head.

• The Korean Journal of Zoology
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• v.22 no.3
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• pp.103-114
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• 1979

The authors observed the ultrastructure of the granular glands in the amphibian skin with an electron microscope. The specimens from the experimental animals (Bombina orientalis, Bufo bufo gargarizans, Rana nigromaculata and Rana rugosa) were fixed in 2.5% glutaraldehyde-paraformaldehyde fixative in phosphate buffer at pH 7.2 prior to fixation in 1% osmium tetroxide, dehydrated in graded ethanol and acetone, embedded in Epon 812 mixture, and sectioned with a LKB-ultramicrotome. the ultrathin sections were contrasted with uranyl acetate and lead citrate and observed with a JEOL-100B electron microscope. The results were as follws: 1. The granular gland in the amphibian skin consisted of the glandular epithelial and the myoepithelial cells. 2. The epithelial cells of the granular gland in the amphibian skin consisted of the dark cells but the light cells were also observed in that of Bombina orientalis. 3. The granular glands of the amphibian skin were in holocrine fashion. 4. The nuclei of the epithelial cells of the amphibian cutaneous granular glands were round or oval and showed small and large inforldings of nuclear envelope. Heterochromatins were mainly distributed near the nuclear envelope. Mitochondria were mainly distributed in the perinuclear portion and rough-surfaced endoplasmic reticulums were developed in the cytoplasm but smooth-surfaced endoplasmic reticulums were not well developed. 5. Secretory granules were round or oval and electron-dense and less electron-dense granules were observed. 6. The authors infer that the differences in electron density of the secretory granules in the granular glands of the amphibian skin are due to difference in the concentrations of secretory substances as related to the processes of its formation, and that those chemical components are identical.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1586-1592
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• 2012

A series of Novel Mannich bases has been synthesized and evaluated $in$ $vitro$ cytotoxic activity against the human hepatocellular carcinoma (HepG2), human lung carcinoma (SK-LU-1), and human breast cancer (MCF-7). Compound $\mathbf{9f}$ was found to be most potent against three cell lines with $IC_{50}$ values of 1.57, 1.16 and 1.21 ${\mu}g$/mL, respectively. In addition, compounds $\mathbf{9g}$, $\mathbf{10f}$ exhibited very significant activity against MCF-7 cell line with $IC_{50}$ values of 2.0 ${\mu}g$/mL.

• Journal of the Korean Chemical Society
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• v.45 no.1
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• pp.51-60
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• 2001

One-pot Mannich reaction of substituted hydroxy aromatic compounds with secondary amines in an aprotic solvent has been studied. The results demonstrate that the relative reactivity and regioselectivity of the Mannich reaction depend on the steric hindrance of amines as well as the nucleophilicity of hydroxy aromatic rings.