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1.
Aibrohim Dramae Sutichai Nithithanasilp Wilunda Choowong Pranee Rachtawee Samran Prabpai Palangpon Kongsaeree Pattama Pittayakhajonwut 《Tetrahedron》2013
Two new natural products, samroiyotmycins A (1) and B (2), along with two naturally new novclobiocin 101 (3) and 4-hydroxy-3-(3-methylbut-2-enyl)benzamide (5), and five known substances including neoantimycin, clorobiocin (4), 29-O-methylabierixin, daidzein, and 1-(3-indolyl)-2,3-dihydroxypropan-1-one have been isolated from Streptomyces sp. BCC33756. Their chemical structures were determined based on NMR spectral information and the relative stereochemistry of compound 1 was determined by X-ray crystallographic data. Both samroiyotmycins A and B exhibited antimalarial activity against Plasmodium falciparum K1—multi-drug resistant strain, with IC50 values of 3.65 and 3.16 μg/mL, respectively. Compound 1 was inactive against both cancerous (MCF-7, KB) and non-cancerous (Vero) cells, while compound 2 displayed cytotoxicity against Vero cell with IC50 value of 29.57 μg/mL. 相似文献
2.
Itharat A Plubrukarn A Kongsaeree P Bui T Keawpradub N Houghton PJ 《Organic letters》2003,5(16):2879-2882
[structure: see text] Commonly used among ingredients in Thai traditional anticancer preparations, the rhizome of Dioscorea membranacea Pierre was found potently cytotoxic and possibly contributed to such a therapeutic effect. Bioassay-guided isolation resulted in two novel cytotoxic naphthofuranoxepins, dioscorealides A (1) and B (2), and a new 1,4-phenanthraquinone, dioscoreanone (3). The structure determination, achieved mainly by means of NMR and CD spectral and X-ray crystallographic analyses, and cytotoxicity are discussed here. 相似文献
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4.
Chomchai Suksai Pannee Leeladee Colin Jennings Thawatchai Tuntulani Palangpon Kongsaeree 《Journal of chemical crystallography》2008,38(5):363-368
Abstract The reaction of 1,1′-bis(chlorocarbonyl)ferrocene with bis-aminobenzylcalix[4]arene gave amidoferrocene calix[4]arene monomer
1. Compound 1 crystallized in the monoclinic system P21/c with a = 11.196(6) ?, b = 14.971(11) ?, c = 32.007(2) ?, β = 96.413(4)° and V = 5330.9(6) ?3. X-ray diffraction analyses of 1 showed that the calix[4]arene scaffold was in cone conformation in which the intramolecular hydrogen bonding were formed
through OH groups at the lower rim to stabilize the structure. Moreover, the intramolecular hydrogen bond between the amide
groups of the amidoferrocene unit also presented in the crystal structure. On the other hand, the condensation of 1,1′-bis(chlorocarbonyl)ferrocene
with p-tert-bis-aminobenzylcalix[4]arene resulted in the monomeric 2 and [2 + 2] dimeric compounds 3. 1H-NMR studies signified that the calix[4]arene building block in compounds 2 and 3 adopted the cone conformation.
Index Abstract Synthesis and Characterization of Monomeric and Dimeric Structures of Calix[4]arenes Containing Amidoferrocene
Chomchai Suksai*, Pannee Leeladee, Colin Jennings, Thawatchai Tuntulani*, Palangpon Kongsaeree
The condensation of 1,1′-bis(chlorocarbonyl)ferrocene with p-tert-bis-aminobenzylcalix[4]arene resulted in the monomeric and [2 + 2] dimeric compounds.
相似文献
5.
Siriphan Arthornthurasuk Wantha Jenkhetkan Eukote Suwan Daranee Chokchaichamnankit Chantragan Srisomsap Pakorn Wattana-Amorn Jisnuson Svasti Prachumporn T. Kongsaeree 《Applied biochemistry and biotechnology》2018,186(4):877-894
A novel β-glucosidase from higher termite Microcerotermes annandalei (MaBG) was obtained via a screening method targeting β-glucosidases with increased activities in the presence of glucose. The purified natural MaBG showed a subunit molecular weight of 55 kDa and existed in a native form as a dimer without any glycosylation. Gene-specific primers designed from its partial amino acid sequences were used to amplify the corresponding 1,419-bp coding sequence of MaBG which encodes a 472-amino acid glycoside hydrolase family 1 (GH1) β-glucosidase. When expressed in Komagataella pastoris, the recombinant MaBG appeared as a ~?55-kDa protein without glycosylation modifications. Kinetic parameters as well as the lack of secretion signal suggested that MaBG is an intracellular enzyme and not involved in cellulolysis. The hydrolytic activities of MaBG were enhanced in the presence of up to 3.5-4.5 M glucose, partly due to its strong transglucosylation activity, which suggests its applicability in biosynthetic processes. The potential synthetic activities of the recombinant MaBG were demonstrated in the synthesis of para-nitrophenyl-β-D-gentiobioside via transglucosylation and octyl glucoside via reverse hydrolysis. The information obtained from this study has broadened our insight into the functional characteristics of this variant of termite GH1 β-glucosidase and its applications in bioconversion and biotechnology. 相似文献
6.
Punirun T Peewasan K Kuhakarn C Soorukram D Tuchinda P Reutrakul V Kongsaeree P Prabpai S Pohmakotr M 《Organic letters》2012,14(7):1820-1823
Fluoride-catalyzed stereoselective nucleophilic addition of PhSCF(2)SiMe(3) (1) to α-carboethoxycycloalkanones 2 followed by intramolecular radical cyclization of the resulting cis-3 adduct afforded the corresponding gem-difluoromethylenated bicyclic compounds 4, which underwent ring-expansion followed by the Baeyer-Villiger-type oxidation of the resulting macrocyclic ketone intermediates to give gem-difluoromethylenated macrocyclic lactones 5. 相似文献
7.
[reaction: see text] An unusually bridged epidithiodiketopiperazine, pretrichodermamide A (3), was isolated from the fungus Trichoderma sp. BCC 5926. During the extensive effort to crystallize 3 for X-ray crystallographic analysis, conversion of this compound to trichodermamide A with coproduction of S(8) occurred. 相似文献
8.
Manat Pohmakotr Darunee Soorukram Patoomratana Tuchinda Samran Prabpai Palangpon Kongsaeree Vichai Reutrakul 《Tetrahedron letters》2004,45(22):4315-4318
The vicinal dianions derived from chiral succinic acid derivatives, 1,4-bis[(4R,5S)-3,4-dimethyl-2-oxo-5-phenylimidazolidin-1-yl]butane-1,4-dione and 1,4-bis[(4S,5R)-3,4-dimethyl-2-oxo-5-phenylimidazolidin-1-yl]butane-1,4-dione react with arylmethyl bromides with high diastereo- and regio-selectivity to provide the corresponding chiral α-arylmethylated succinic acid derivatives; the (R)-products are converted into (R)-β-arylmethyl-γ-butyrolactones and (R)-α-arylmethyl-γ-butyrolactones. 相似文献
9.
Jittra Kornsakulkarn Siriporn Saepua Rapheephat Suvannakad Sumalee Supothina Nattawut Boonyuen Masahiko Isaka Samran Prabpai Palangpon Kongsaeree Chawanee Thongpanchang 《Tetrahedron》2017,73(25):3505-3512
Twelve new compounds, including nine tropolones, nemanolones A?I (1–9), three 7-isochromenones, nemanecins A?C (10–12), and a new naturally isolated 4-isochromanone (13), along with two known compounds, 7,8-dihydroxy-3-methyl isochroman-4-one (XJP), and chaetoquadrin F, were isolated from culture broth of the fungus Nemania sp. BCC 30850. Structures of these compounds were elucidated by NMR and MS spectroscopic analyses. Nemanolones exhibited cytotoxic activities and two of them, compounds 1 and 2, also showed antibacterial activity against Bacillus cereus and antifungal activity against Candida albicans. 相似文献
10.
Kwanjai KanokmedhakulSomdej Kanokmedhakul Ruchiruttikorn SuwannatraiKasem Soytong Samran Prabpai Palangpon Kongsaeree 《Tetrahedron》2011,67(30):5461-5468
Five new meroterpenoids, chevalones A-D (1-4), aszonapyrone B (8), and a new sequiterpene alkaloid, eurochevalierine (5), together with four known compounds, sequiterpene (6), terpenoid pyrrolobenzoxazine named CJ-12662 (7), meroterpenoid, aszonapyrone A (9), and ergosterol were isolated from the fungus Eurotium chevalieri. The structures were established on the basis of spectroscopic evidence. The configurations of 1 and 5 were determined by X-ray analysis. The biosynthetic pathway of 1-3, 8, and 9 were proposed. Chemical transformation of aszonapyrone A (9) was also studied. Compounds 4, 5, and 7 exhibited antimalarial activity against Plasmodium falciparum, while 3, 5, and 7 showed antimycobacterial activity against Mycobacterium tuberculosis. In addition, compounds 2-7 showed cytotoxicity against cancer cell lines. 相似文献