共查询到20条相似文献,搜索用时 31 毫秒
1.
Three novel dimeric sesquiterpenoids, named parviflorenes G-I (1-3), have been isolated from Curcuma parviflora (Zingiberaceae), and their structures were elucidated by means of spectroscopic studies. Absolute stereochemistry of parviflorene G (1) as well as previously isolated related compounds, parviflorenes A (4), B (5), D (6), and F (7), was revealed by CD spectral data and chemical means. Parviflorenes G (1) and I (3) were cytotoxic against HeLa cells, while parviflorenes A (4) and F (7) were cytotoxic against all tested tumor cell lines in the human cancer cell line panel assay. 相似文献
2.
A new dimer of C16N2 type alkaloid, complanadine B (1), and two new C16N type alkaloids, obscurumines A (2) and B (3), have been isolated from the club moss Lycopodium complanatum and L. obscurum, respectively. The structures and stereochemistry of 1-3 were elucidated by combination of 2D NMR spectra and chemical transformation. Complanadine A (4) isolated together with 1 induced secretion of neurotrophic factors from human astrocytoma cells. 相似文献
3.
A novel C-27 norwithasteroid, withaphysanolide A (1) containing a pyran ring was isolated from the aerial parts of Physalis divericata. Four known withaphysalins (2-5) and five physalins (6-10) were also isolated. The structural assignment for 1 was done based on spectroscopic and single-crystal X-ray diffraction data. Logical biosynthetic pathways were postulated. Compounds 6, 7, and 10 displayed potent cytotoxic activity against HCT-116 and H460 human cancer cell lines, with IC50 values less than 2.0 μM. 相似文献
4.
Kan’ichiro IshiuchiTakaaki Kubota Haruaki IshiyamaShigeki Hayashi Toshiro ShibataJun’ichi Kobayashi 《Tetrahedron letters》2011,52(2):289-292
New Lycopodium alkaloids, lyconadins C (1) and F (2), were isolated from the club moss Lycopodium complanatum. Lyconadin C (1) is a new C16N2-type Lycopodium alkaloid possessing unique fused-tetracyclic ring system consisting of a cycloheptene ring fused to a decahydroquinoline and pyridone rings. Lyconadin F (2) possesses a primary amide moiety in its molecular, which is the first example of Lycopodium alkaloids. Biogenetically, lyconadins C (1) and F (2) might be related to lyconadins A (4) and B (5). The structures and relative stereochemistry of 1 and 2 were elucidated on the basis of spectroscopic data. The absolute stereochemistry of 2 was elucidated by chemical correlations with lyconadin B (5) through hemiaminal form of lyconadin F (3). 相似文献
5.
Haruhisa Kikuchi Yuko Sahashi Asami Haganuma Yoshiteru Oshima 《Tetrahedron letters》2004,45(33):6225-6228
Paecilomycine A (1), B (2), and C (3) were isolated from cultivated fruiting bodies of Paecilomyces tenuipes (Isaria japonica), which is a popular entomopathogenic fungus used in folk medicine and health foods in China, Korea, and Japan. The structures of 1-3 were deduced from their spectroscopic data and their absolute configurations were elucidated by preparing their MPA esters. Compound 1 showed activity in the neurotrophic factor biosynthesis in glial cells. 相似文献
6.
Michelle Farrugia Nicholas Trotter Soumini Vijayasarathy Angela A. Salim Zeinab G. Khalil Ernest Lacey Robert J. Capon 《Tetrahedron letters》2014
Chemical fractionation of the southern Australian marine sponge Phoriospongia sp. (CMB-03107) yielded phorioadenine A (1) as a nematocidal agent and the first reported example of a 6-N-acyladenine natural product. The structure of 1 was confirmed by spectroscopic analysis and the chemical synthesis of racemic (1a) and enantiomeric (1b) analogues. HPLC–ESIMS analysis of the crude sponge extract with comparisons to the synthetic 6-N-acyladenosine 2a provided evidence that the biosynthetically related adenosine, phorioadenosine A (2), was present as a trace co-metabolite. The rare starfish metabolite asterubine (3) was also isolated as a co-metabolite, and its structure confirmed by spectroscopic analysis and chemical synthesis. Biological investigations confirmed that natural products 1–3 and synthetic analogues 1a–e and 2a were not cytotoxic to multiple mammalian cancer cell lines, or Gram-positive or -negative bacteria. Nematocidal activity (inhibition of larval development of Haemonchus contortus) detected in the Phoriospongia sp. extract was attributed to 1 (LD99 31 μg/mL), with preliminary structure–activity relationship investigations confirming the importance of the N-acyl side chain. 相似文献
7.
Five novel prenylated polyketides, harrisotones A-E (1-5) representing a rare spirocyclic skeleton, along with a new hydroperoxypolyketide harrisonol A (6), were isolated from the stems and leaves of Harrisonia perforata. The structures of harrisotones A-E (1-5) were extensively elucidated on the basis of spectroscopic analysis, especially 2D NMR and CD spectra. A plausible origin of compounds 1-5 was rationalized biogenetically, and traced back to harrisonol A (6). Harrisotones A-C (1-3) and harrisonol A (6) exhibited significant cytotoxicity against P-388 and/or A-549 tumor cell lines. 相似文献
8.
Masahiko Isaka Rachada HaritakunSumalee Supothina Wilunda ChoowongSuchada Mongkolsamrit 《Tetrahedron》2014
Six new compounds, an N-hydroxypyridone glucoside, orbiocrellin A (1), its aglycone orbiocrellin B (2), chromone glucosides 3 and 4, a dihydrochromone 5a/5b, and a chromone 6, were isolated from the scale-insect pathogenic fungus Orbiocrella sp. BCC 33248. Orbiocrellin A (1) exhibited antimalarial activity against Plasmodium falciparum K1 (IC50 3.1 μg/mL) while it was non-cytotoxic. In contrast, orbiocrellin B (2) showed both antimalarial (IC50 2.1 μg/mL) and cytotoxic (NCI-H187 cells, IC50 0.70 μg/mL) activities. 相似文献
9.
Kehokorins A (1)-C (3), three novel dibenzofurans, have been isolated from field-collected fruit bodies of the myxomycete, Trichia favoginea var. persimilis, and their structures were elucidated by spectral data. Kehokorin A (1) was a α-l-rhamnopyranoside of kehokorin B (2), while kehokorin C (3) was a 1-demethoxy analog of 2. Kehokorin A (1) was cytotoxic against HeLa cells with an IC50 value of 1.5 μg/mL. 相似文献
10.
Cheng-Qi Fan 《Tetrahedron》2007,63(1):115-119
Two novel Daphniphyllum alkaloids with unprecedented skeletons, namely paxdaphnines A (1) and B (2), have been isolated from the seeds of Daphniphyllum paxianum. Paxdaphnine A (1) is a 19-nor-Daphniphyllum alkaloid with highly caged skeleton, and paxdaphnine B (2) is the first 1,19-bisnor-Daphniphyllum alkaloid. The relative structures of 1 and 2 were elucidated by spectral methods, and their unique biosynthetic pathway postulated. The absolute structure of 1 was determined by X-ray diffraction of the iodide derivative (1a) of 1, and the absolute stereochemistry of 2 was proposed by correlation with the biosynthetic pathway for 1. 相似文献
11.
A new indole alkaloid, 7β-hydroxy-7H-mitraciliatine (1) and a new oxindole alkaloid, isospeciofoleine (2) together with nine known alkaloids were isolated from Mitragyna speciosa and characterized by NMR, CD, and MS spectroscopic data analyses. The 1H and 13C NMR spectroscopic data of isospeciofoline (3), isorotundifoline (4), paynantheine (5), and 3-isopaynantheine (6) were also reported for the first time. 相似文献
12.
Atallah F Ahmed Ru-Ting ShiueGuey-Horng Wang Chang-Feng DaiYao-Haur Kuo Jyh-Horng Sheu 《Tetrahedron》2003,59(37):7337-7344
Three new norcembrane-based diterpenoids, leptocladolides A (1), B (4) and C (5), along with five known metabolites 6-10, have been isolated from the dichloromethane extract of a Taiwanese soft coral Sinularia leptoclados. Furthermore, a chemical investigation on the dichloromethane extract of S. parva has resulted in the isolation of two new related isomers, 1-epi-leptocladolide A (2) and 7E-leptocladolide A (3), in addition to 1 and 7. The structures of new metabolites 1-5 were elucidated on the basis of extensive spectroscopic analyses and their relative stereochemistries were determined by NOESY experiments. The new metabolites 1 and 3 have been shown to exhibit significant cytotoxic activity against KB and Hepa59T/VGH cancer cell lines. 相似文献
13.
A novel polyprenylated phloroglucinol garcinialone (1) along with a known compound isoxanthochymol (2) have been isolated from the roots of Garcinia multiflora. The structures of 1 and 2 were elucidated spectroscopically, by 1D and 2D NMR and mass spectrometry. 相似文献
14.
Ping-Jyun Sung Li-Fan Chuang Jimmy Kuo Tung-Yung Fan Wan-Ping Hu 《Tetrahedron letters》2007,48(23):3987-3989
A novel chloride-containing 14C norsesquiterpenoid, rumphellatin A (1), was isolated from the Formosan gorgonian coral Rumphella antipathies. The structure of metabolite 1 was determined on the basis of spectral data analysis and the configuration of 1 was further supported by molecular mechanics calculations. Rumphellatin A (1) showed activity against Gram-negative bacteria. 相似文献
15.
Takuji MamemuraNaonobu Tanaka Azusa ShibazakiTohru Gonoi Jun’ichi Kobayashi 《Tetrahedron letters》2011,52(28):3575-3578
Two new meroterpenoids, yojironins A (1) and B (2), were isolated from the whole plants of Hypericum yojiroanum, together with two new prenylated acylphloroglucinols, yojironins C (3) and D (4). Their structures were elucidated by spectroscopic data. Yojironins A (1) and B (2) are biogenetically unique meroterpenoids, which seem to be composed of two acetate units with a 2-methylbutanoyl group and three isoprene units. Yojironin A (1) exhibited antimicrobial activity. 相似文献
16.
Preecha Phuwapraisirisan Serm Surapinit Sitthidesch Sombund Santi Tip-pyang 《Tetrahedron letters》2006,47(22):3685-3688
Three new furanocoumarins, named feroniellins A (1), B (2), and C (3), were isolated from the roots of Feroniella lucida. Compounds 1-3 are novel structures having an oxolane, oxane, and oxepane moiety. Their overall structures and configurations were determined by spectral and chemical methods. The cytotoxicities of 1-3 were evaluated against human KB and HeLa carcinoma cells. 相似文献
17.
A new dimeric sesquiterpenoid with two eudesmane skeletons through a urea linkage, halichonadin A (1), as well as three new eudesmane sesquiterpenoids having a carbamate, an isonitrile, or an amino functionality, halichonadins B (2), C (3), and D (4), respectively, have been isolated from a marine sponge Halichondria sp., and the gross structures and relative stereochemistry of 1-4 were elucidated on the basis of spectral data and chemical means. 相似文献
18.
Jae-Hoon ChoiNobuhiko Ozawa Yasuhiro YamakawaKaoru Nagai Hirofumi HiraiHirokazu Kawagishi 《Tetrahedron》2011,67(35):6649-6653
Leccinine A (1) along with a known compound (2), were isolated from the edible mushroom Leccinum extremiorientale. The structure of 1 was determined by the interpretation of spectral data. Leccinine A showed protective activity against endoplasmic reticulum stress-dependent cell death. Seven analogues (3-9) of 1 were synthesized in order to evaluate the structure-activity relationship, and the result indicated that the formamide group of 1 was indispensable for the activity. 相似文献
19.
Ping-Jyun Sung Yin-Di Su Gung-Ying Li Michael Y. Chiang I.-Chu Huang Lee-Shing Fang Wei-Hsien Wang 《Tetrahedron》2009,65(34):6918-1258
Three polyoxygenated briaranes, including two new compounds, excavatoids A (1) and B (2), and a known metabolite, briaexcavatin I (3), were isolated from the cultured octocoral Briareum excavatum. Moreover, the wild type B. excavatum, collected off southern Taiwan coast, yielded two new 5,6-epoxybriaranes, excavatoids C (4) and D (5). The structures of new compounds 1, 2, 4, and 5 were determined by spectroscopic methods and the structure of 1 was further confirmed by X-ray diffraction data analysis. The X-ray structure for briaexcavatin I (3) was also reported for the first time. Excavatoid A (1) is the first briarane which possesses six hydroxy groups and a 17-methoxy group. Excavatoid C (4) is the first 12,13-secobriarane which possesses a novel pentacyclic skeleton with an ?-lactone. Excavatoid D (5) displayed moderate inhibitory effects on superoxide anion generation and elastase release by human neutrophils. 相似文献
20.
A new metabolite, infectopyrone (1), has been isolated from the filamentous fungus Alternaria infectoria. The structure of 1 was elucidated by analysis of 2D NMR spectroscopic data. Compound 1 is an α-pyrone resembling known toxins, and is a useful phenotaxonomic marker for the A. infectoria species-group. Infectopyrone (1) was also produced by species within Stemphyllium and Ulocladium, and found in mouldy food. 相似文献