排序方式: 共有85条查询结果,搜索用时 250 毫秒
51.
Sakornrat Thorroad Prateep Worawittayanont Nisachon Khunnawutmanotham Nitirat Chimnoi Apiwan Jumruksa Somsak Ruchirawat Nopporn Thasana 《Tetrahedron》2014
Eleven Lycopodium alkaloids with lycodine-type, lycopodine-type, and fawcettimine-related skeletons were isolated from the whole plants of Huperzia carinata (Desv. Ex. Poir.) Trevis and Huperzia squarrosa (G. Forst) Trevis (Huperziaceae). Among them, 8,15-dihydrohuperzine A (2), lycocarinatine A (3), and lycoposerramine U N-oxide (11) are new compounds. The structures of these new alkaloids were elucidated on the basis of 2D NMR correlations. Some of these isolated alkaloids were assayed for acetylcholinesterase (AChE) inhibitory activity. 相似文献
52.
Sukontason KL Sukontason K Piangjai S Vogtsberger RC 《Micron (Oxford, England : 1993)》2006,37(1):87-90
The varied ultrastructure of the eggshell of Paracapillaria (Crossicapillaria) philippinensis, collected from a human sample, is reported from a scanning electron microscopy study. Two distinct egg shapes were identified: typical peanut-shaped and swollen peanut-shaped. Both thick and thin eggshells were detected. Thick eggshells are either fairly smooth or bear a beam-like network in relation to the pillars in their surface ultrastructure. Thin eggshells are transparent allowing visibility of the coiled larva within. Presence of the thin shell provides supportive evidence of autoinfection involved in the life cycle of this medically important parasite. 相似文献
53.
Rattana Worayuthakarn Prattya Nealmongkol Somsak Ruchirawat Nopporn Thasana 《Tetrahedron》2012,68(13):2864-2875
An effective synthesis of the multi ring-fused benzoindoloquinolizines has been accomplished by Cu(I)-mediated and MW-assisted C–Namide bond formation of benzo[a]quinolizin-4-ones. The deamination of tetrahydro-2H-pyrido[2,1-a]isoquinolines was also studied and was found to give benzoquinolizines. The benzo[a]quinolizin-4-ones were prepared based on the annulations of C-1 substituted 3,4-dihydroisoquinolines and azlactones. 相似文献
54.
Hunsa Prawat Chulabhorn MahidolSawangjitt Wittayalai Pakamas IntachoteTripetch Kanchanapoom Somsak Ruchirawat 《Tetrahedron》2011,67(31):5651-5655
Five nitrogenous sesquiterpenes having an isonitrile [(−)-axisonitrile-3], a formamide [(+)-axamide-3, axamide-2 and (3S*,5R*,6R*,9R*)-3-formamido-1(10)-cadinene], and an amine [(−)-halichamine] functionality were isolated from the Thai marine sponge Halichondria sp., together with two steroids, ergosterol and ergosterol peroxide. (−)-Axisonitrile-3 was isolated from the natural source for the first time, while (+)-axamide-3 and (−)-halichamine were new metabolites. The structures of these compounds were elucidated on the basis of their spectroscopic data and by chemical transformations. All sesquiterpenes were tested for their cytotoxic activity against six cancer cell lines (HeLa, HuCCA-1, A549, MOLT-3, HepG2, MDA-MB231). Only (−)-axisonitrile-3 showed strong activity to the HepG2 cell line with an IC50 value of 1.3 μM. 相似文献
55.
Sahakitpichan P Disadee W Ruchirawat S Kanchanapoom T 《Chemical & pharmaceutical bulletin》2011,59(9):1160-1162
A new 3-hydroxydihydrobenzofuran glucoside, gnaphaliol 9-O-β-D-glucopyranoside (2), was isolated from the aerial parts of Gnaphalium polycaulon together with 1-{(2R*,3S*-3-(β-D-glucopyranosyloxy)-2,3-dihydro-2-[1-(hydroxyl methyl)vinyl]-1-benzofuran-5-yl}-ethanone or gnaphaliol 3-O-β-D-glucopyranoside (1), (Z)-3-hexenyl O-β-D-glucopyranoside (3) and adenosine (4). The absolute configurations at C-2 and C-3 positions of compound 1 were determined to be 2R and 3R. The structures of these compounds were elucidated on the basis of their physical and spectroscopic data. 相似文献
56.
Christian Licht Somsak Orankitjaroen Patcharakorn Viriyasrisuwattana Thibaut Weller 《Comptes Rendus Mecanique》2014,342(4):234-239
A rigorous study of the asymptotic behavior of the system constituted by a very thin linearly piezoelectric plate bonded on a linearly elastic body supplies various models for an elastic body monitored by a piezoelectric patch. 相似文献
57.
Sukontason K Sukontason KL Piangjai S Boonchu N Chaiwong T Ngern-Klun R Sripakdee D Vogtsberger RC Olson JK 《Micron (Oxford, England : 1993)》2004,35(8):671-679
Antennal sensilla of some forensically important fly species in the families Calliphoridae (Chrysomya megacephala, Chrysomya rufifacies, Chrysomya nigripes and Lucilia cuprina), Sarcophagidae (Parasarcophaga dux) and Muscidae (Musca domestica) were studied using scanning electron microscopy. Five types of sensilla were observed: trichoid, basiconic, coeloconic, styloconic and sensory pit. Only trichoid sensilla are found on the scape of the antenna, while both trichoid and styloconic sensilla are located on the antennal pedicels of all species studied. Basiconic sensilla are the most numerous of the sensilla found on the antennae of both sexes of all fly species studied and are comprised of two subtypes: large and small basiconic sensilla. Coeloconic sensilla are characterized by short pegs, with either grooved or smooth surfaces, that are sunken into deep depressions. No marked difference was observed in the number, morphological structure or distributional pattern of any of the sensilla among the species studied, with the exception of there being more numerous sensory pits detected in female P. dux compared to the other species. The suggested function of each antennal sensillum was based on comparison with results of other investigations on similar sensilla. 相似文献
58.
Sukontason K Sukontason KL Piangjai S Boonchu N Kurahashi H Hope M Olson JK 《Micron (Oxford, England : 1993)》2004,35(5):391-395
Fly eggs found in corpses can be utilized as entomological evidence in forensic investigations of deaths if the species of fly and the developmental rate at a temperature similar to the death scene are known. The species identification of fly eggs is particularly important, and previously, scanning electron microscope has been used for this purpose. Herein, we report a simple technique, using light microscopy, to identify forensically important eggs of Chrysomya rufifacies (Macquart), Chrysomya megacephala (Fabricius), Chrysomya pacifica Kurahashi, Chrysomya nigripes Aubertin, Aldrichina grahami (Aldrich), Lucilia cuprina (Wiedemann), Musca domestica L. and Megaselia scalaris (Loew). A 1% potassium permanganate solution was used to stain egg surfaces for 1 min, followed by dehydration in 15, 70, and 95%, absolute alcohol (each solution for 1 min) and the eggs were permanently mounted. The characteristics are based on the width of plastron, morphology of plastron area surrounding the micropyle and chorionic sculpturing, with the length of egg being used as supplemental feature. 相似文献
59.
Jutatip Boonsombat Pornsuda Chawengrum Chulabhorn Mahidol Prasat Kittakoop Somsak Ruchirawat 《Natural product research》2020,34(8):1097-1104
AbstractA new 22,26-seco physalin, physalin XI (1) together with 5 known compounds, were isolated from the dichloromethane extract of Physalis angulata L. The structure of isolated compounds was elucidated by spectroscopic analysis. The effects of isolated compounds on in vitro cytotoxicity were investigated. Compound 1 was assessed for its cytotoxicity against cancer cell lines (HepG2, HeLa, HuCCA-1, T47-D and A-549) and a normal cell line (MRC-5), and the result showed that it has no activity. Compounds 2 and 4 are highly toxic to H69AR and MDA-MB-23 cell lines. This property appears to be related to the presence of their conjugated double bond or epoxy groups and is a more reliable indication of toxicity than substitution on C(5)–C(6). 相似文献
60.
The regioselective cyclization/dehydration sequence of ortho diketo phenoxyethers induced by DBU has been explored. The results demonstrated a high degree of selectivity with preference for 6-exo-trig cyclization leading to the formation of γ-benzopyranone derivatives in good yield. 相似文献