共查询到20条相似文献,搜索用时 421 毫秒
1.
Li-Hua Zhang Jian Bai Dao-Jiang Yan Ya-Nan Wang Ya-Long Zhang Li Li Bing-Yu Liu You-Cai Hu 《Tetrahedron letters》2019,60(4):375-377
Two unique polyketides, pleosporalesones A–B (1–2), bearing an unusual 6/6/7/6 tetracyclic ring system consisting of a chromone ring and a benzoannulated cycloheptanone ring, were isolated from the solid cultures of Pleosporales sp.. The chemical structures were elucidated by analyses of their extensive spectroscopic data, including 1D/2D NMR, ORD, CD and HR-ESI-MS, and the absolute configurations were established by comparison of their experimental circular dichroism data with those calculated. A plausible biosynthetic pathway for pleosporalesones A–B was proposed. 相似文献
2.
Hua-Yong Lou Lian Jin Tao Huang Dao-Ping Wang Guang-Yi Liang Wei-Dong Pan 《Tetrahedron letters》2017,58(5):401-404
Three new diterpenoids, vulgarisins B–D (1–3), have been isolated from a medicinal plant Prunella vulgaris Linn. These diterpenoids contain a rare 5/6/4/5 fused tetracyclic ring skeleton. Their structures were determined through the analysis of spectroscopic data, and the absolute configuration were further confirmed by single crystal X-ray diffraction as well as CD analysis. All the compounds were evaluated for their cytotoxicity activity, vulgarisins B (1) and C (2) demonstrated modest cytotoxicity activity against human lung carcinoma A549 cell line. 相似文献
3.
Yong-Qian Liang Xiao-Jian Liao Jia-Li Lin Wei Xu Guo-Dong Chen Bing-Xin Zhao Shi-Hai Xu 《Tetrahedron》2019,75(27):3802-3808
Spongiains A-C (1–3), the first examples of spongian diterpenes bearing a pentacyclic skeleton composed of a fused 5/5/6/6/5 ring system through ring A rearrangement, together with four new spongian diterpenes, spongiains D-G (4–7), were isolated from the marine sponge Spongia sp.. The structures with absolute configurations of these compounds were elucidated by the methods of NMR, X-ray diffraction and quantum chemical approaches. The hypothetical biogenetic pathways as well as cytotoxic activities of 1–7 were also discussed. 相似文献
4.
Five new fawcettimine-type alkaloids (1–5) and three new natural products (6–8), along with four known analogues, fawcettimine (9), fewcettidine (10), lycopoclavamine B (11), and lycopladine B (12), were isolated from the whole plant of Lycopodium complanatum var. glaucum Ching. The structures of lycogladines A-H (1–8) were determined based on HRESIMS, 1D and 2D NMR spectroscopic analysis, as well as single-crystal X-ray diffraction. Compound 1 possesses a new ring system that is formed through the linkage of C-13-OC-2, which is rarely present in Lycopodium alkaloids (LAs). Compounds 1–8 were tested for their β-site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1) and acetylcholinesterase (AChE) inhibitory activities. 相似文献
5.
Kai-Liang Ma Wen-Jun Wei Hang-Ying Li Qiu-Yan Song Shi-Hui Dong Kun Gao 《Tetrahedron》2019,75(33):4611-4619
Twenty meroterpenoids with diverse ring systems including five new ones (1, 2, 5, 6, and 15), together with two new (23 and 24) and two known dioxolanone-type secondary metabolites were isolated from Phyllosticta capitalensis, an endophytic fungus from Cephalotaxus fortunei Hook. Compound 1 was the first example with a 9,14-seco ring A and a five-membered ring B in guignardone derivatives. Compound 2 represented a novel guignardone derivative possessing a 5/7/6/5 ring system with CH2-7 attached to C-4 rather than C-6 in ring D. The structures of all new compounds were elucidated using spectroscopic data analyses and electronic circular dichroism comparison. The phytotoxic effects of compounds 1–24 on Lactuca sativa and Lolium perenne were evaluated. Compound 22 showed inhibition activity on the shoots growth of L. sativa and L. perenne, as well as the roots growth of L. perenne. 相似文献
6.
Yunpeng Sun Letian Cui Qiurong Li Pengfei Tang Yongyi Li Wenjun Xu Jun Luo Lingyi Kong 《中国化学快报》2022,33(1):516-518
Mufolinin A(1), a ring A-seco rearranged limonoid with an unprecedented ethyl at C-10 and novel 6/6/6/5 fused-ring skeleton, together with three new potential precursors(ring A-seco limonoids, 2–4) were isolated from Munronia unifoliolata. Their structures and absolute configurations were confirmed by nuclear magnetic resonance(NMR), high resolution electrospray ionization mass spectroscopy(HRESIMS), X-ray crystallography, electronic circular dichroism(ECD) calculations and NMR calculations with... 相似文献
7.
Siwen Niu Zuowang Fan Xixiang Tang Qingmei Liu Zongze Shao Guangming Liu Xian-Wen Yang 《Tetrahedron letters》2018,59(4):375-378
Three new cyclopiane diterpenes (1–3) and one rare spirocyclolide (5) were isolated from the deep-sea-derived fungus Penicillium commune MCCC 3A00940, along with 11 known compounds. The planar structures of the new compounds were determined by extensive analysis of their NMR and HRESIMS spectra, and the absolute configurations were established on the basis of specific rotation data in association with calculated ECD spectra. Four of the cyclopiane diterpenes (1–4), with a rigid 6/5/5/5 fused tetracyclic ring framework, are rarely found in Nature. Notably, conidiogenone J (1) is the first naturally occurring enantiomer of the cyclopiane diterpenes. Additionally, penijanthine B (6) and 3-hydroxy-5-methoxystilbene (14) exhibited moderate antiallergic effects with IC50 values of 30 and 33?μM, respectively. 相似文献
8.
Jianjun Zhao Shuzong Du Kun Hu Yali Hu Fan Xia Yansong Ye Jian Yang Yin Nian Gang Xu 《中国化学快报》2023,34(4):107737-214
Nineteen diterpenoids, including saldigitin A(1) bearing an unprecedented 10-methylated 6/7/6 carbon ring system, two new icetexanes(2, 3), and two new nor-abietanes(5, 6) were characterized from the roots of Salvia digitaloides. Their structures were elucidated by the analysis of the spectroscopic data,X-ray crystallography, and TDDFT calculations of ECD spectra. The novel architecture of 1 should be biogenetically derived through the cleavage and re-cyclization of the B/C rings from the normal... 相似文献
9.
Wenjun Zhang Guangtao Zhang Liping Zhang Wei Liu Xiaodong Jiang Hongbo Jin Zhiwen Liu Haibo Zhang Aihua Zhou Changsheng Zhang 《Tetrahedron》2018,74(47):6839-6845
Polycyclic tetramate macrolactams (PTMs) are widely distributed in nature and are generated from a compact biosynthetic pathway. Bioinformatics analysis of the draft genome sequence of marine-derived Streptomyces sp. SCSIO 40060 revealed the presence of a putative PTM-encoding biosynthetic gene cluster (BGC). Comparison of this PTM BGC with those from the databank by genome mining suggests that Streptomyces sp. SCSIO 40060 should produce PTMs with a 5/6/5 type of carbocyclic ring. Subsequently, a 40-L scale of cultivation of Streptomyces sp. SCSIO 40060 led to the isolation and characterization of four known PTMS, ikarugamycin (1), epoxyikarugamycin (2), capsimycin (3), capsimycin C (4), and three new PTMs, hydroxyikarugamycins A–C (5–7). The planar structures of 5–7 were assigned by comprehensive spectroscopic analysis and the absolute configurations of 5 and 6 were unequivocally determined by X-ray diffraction analysis. The absolute structure of 7 was deduced by comparing ECD spectra of 5–7. Capsimycin (3) showed antimicrobial activity against methicillin-resistant Staphylococcus aureus with a MIC value of 16?μg/mL and displayed cytotoxicity against several cancer cell lines with IC50 values ranging from 2.62 to 6.87?μM. 相似文献
10.
Min Fan Xue-Jiao Chen Xing-De Wu Li-Dong Shao Xu Ji Qin-Shi Zhao 《Tetrahedron letters》2018,59(32):3065-3068
Salvifarinin A (1), a rearrangement product of Languidulane-type clerodane diterpenoids with a 6/5/7 tricyclic ring skeleton fused with γ-lactone ring and furan ring, and two new biogenetically related diterpernoids, salvifarinins B (2) and C (3), were isolated from the aerial parts of Salvia farinacea. The absolute configuration of 1 was elucidated by extensive spectroscopic methods, and confirmed by single crystal X-ray diffraction and bio-inspired semisynthesis. The plausible biogenetic pathway was also proposed. Compound 2 displayed a potent effect on reducing hepatic steatosis. 相似文献
11.
《中国化学快报》2022,33(10):4587-4594
By integrating one strain-many compounds (OSMAC) and LC–MS-based molecular networking strategies, distachydrimanes A–F (1–6), six novel phenylspirodrimane dimers and hybrids representing two types of unprecedented terpenoid-polyketide hybrid skeletons, were isolated from the modified fermented rice substrate of a coral-derived fungus Stachybotrys chartarum. All the structures incorporating their absolute configurations were elucidated based on comprehensive spectroscopic analyses, mainly including HRESIMS and NMR data, single-crystal X-ray diffraction (Cu Kα), and comparison of the experimental electronic circular dichroism (ECD) data. Architecturally, compounds 1–6 represent an unprecedented class of dimeric phenylspirodrimanes with an unexpected C-18–C-23′ linkage, of which compounds 1–3 also feature an unexpected 5-methyl-1,3-benzenediol moiety via a carbon-carbon linkage. The bioactivity assay demonstrated that compounds 1, 5 and 6 induced cell proliferation inhibition, G0/G1 cell cycle arrest, senescence and mitochondrial-mediated apoptosis in L1210 cells, highlighting their potentials as a new category of anticancer agents. 相似文献
12.
《中国化学快报》2023,34(2):107512
Eight polycyclic furanobutenolide-containing norcembrane diterpenoids featuring C19 frameworks (1–8) were rapidly recognized and isolated from the Hainan soft coral Sinularia sp. by the HSQC-based small molecule accurate recognition technology. Yonarolide A (1a), featuring an unprecedented 5/6/4/4/7 pentacyclic ring skeleton, was surprisingly obtained as a transformed product by leaving compound 1 under indoor natural light, and was further proved to be a [2 + 2] cycloaddition product of 1 by photochemical reaction. The absolute stereochemistry of 1a and the three known norcembrane diterpenoids 1, 4, and 7 were determined by using X-ray diffraction (XRD) analyses. Further, with the aid of XRD analysis, the structure of scabrolide B (2), which was previously reported of possessing 5/6/7 tricyclic skeleton, was firmly revised as 2a with the rare inelegane skeleton featured by the highly oxygenated 5/7/6 tricyclic carbocycle. 相似文献
13.
Naonobu Tanaka Yuyu Jia Kanji Niwa Kiyoshi Imabayashi Yutaka Tatano Hideki Yagi Yoshiki Kashiwada 《Tetrahedron》2018,74(1):117-123
Seven new phloroglucinol derivatives, myrtucommunins A–D (1–4), 6-methylisomyrtucommulone B (5), 4-methylmyrtucommulone B (6), and 2-isobutyryl-4-methylphloroglucinol 1-O-β-d-glucopyranoside (7), and one new chromone derivative, undulatoside A 6′-O-gallate (8), were isolated from the leaves of Myrtus communis (Myrtaceae). Myrtucommunins A–D (1–4) were conjugates of polymethylated acylphloroglucinol and flavonol rhamnoside. The absolute configurations of the rhamnosyl moieties for 1–4 were confirmed to be l in each case by HPLC analyses, while those of the aglycones were assigned by comparisons of the experimental and TDDFT calculated ECD spectra. 6-Methylisomyrtucommulone B (5) and 4-methylmyrtucommulone B (6) were assigned as 6/6/6 tricyclic acylphloroglucinol derivatives with a racemic nature. Antimicrobial activities of 1–8 and related known compounds were evaluated. 相似文献
14.
Ken-ichi Nakashima Masayoshi Oyama Tetsuro Ito Yukihiro Akao Joko Ridho Witono Dedy Darnaedi Toshiyuki Tanaka Jin Murata Munekazu Iinuma 《Tetrahedron》2012,68(10):2421-2428
Six novel quinolinone alkaloids bearing a phenylpropanoid or a coumarin moiety, named melicodenines C–H (1–6), two new cinnamyl alcohol derivatives, named melicodins A (7) and B (8), and a new coumarinolignan, named melicodin C (9), were isolated from the leaves of Melicope denhamii (Seem.) T. G. Hartley. Their structures were established by spectroscopic analyses including extensive 2D-NMR experiments. Compounds 1–5 and 9 possess a cyclobutane ring and are hypothetically produced by a [2+2] cycloaddition, whereas compound 6 is presumed to form through a Diels–Alder cycloaddition followed by the elimination of an acetone molecule. Ten quinolinone alkaloids (1–6, 10–13) and a coumarinolignan (9) were tested for anti-proliferative activity against DLD-1 human colon cancer cells. Melicodenine G (5) showed the most potent inhibitory activity, causing the induction of apoptosis with an IC50 value of 9.4±0.3 μM. 相似文献
15.
Yong-Hui Ge Jian-Xin Zhang Su-Zhen Mu Yan Chen Fu-Mei Yang Yang Lű Xiao-Jiang Hao 《Tetrahedron》2012,68(2):566-572
Ten new limonoids, named munronoids A–J (1–10), were isolated from Munronia unifoliolata Oliv. These limonoids involved in the skeletons of peieurianin, evodulone, euphane, and havanensin-types of limonoids, and their structures were established on the basis of spectroscopic data and X-ray crystallographic method. Compounds 1 and 2 were rollout of the conjugated Δ8,30 and Δ14,15 double bonds in peieurianin-type, 3–6 featuring a γ-lactone ring instead of the β-substituted furan ring were found in the evodulone-type for the first time. The insecticidal and anti-TMV activities of compounds 1–10 were also evaluated. 相似文献
16.
Chiu-Fai Kuok Jian Zhang Chun-Lin Fan Qing-Wen Zhang Run-Zhu Fan Dong-Mei Zhang Xiao-Qi Zhang Wen-Cai Ye 《Tetrahedron letters》2017,58(28):2740-2742
An unprecedented indole alkaloid melosline A (1), with 6/5/6/6 tetracyclic ring skeleton, together with a new alkaloid melosline B (2) and one known compound (3) were isolated from the leaves and twigs of Alstonia scholaris. The new structures were elucidated by comprehensive spectroscopic analysis. The absolute configuration of compound 1 was confirmed by comparison of experimental data with calculated electronic circular dichroism (ECD). Compound 1 exhibited moderate cytotoxicity against MCF-7 cancer cell lines. 相似文献
17.
Xiang-Fang Liu Yang Shen Fan Yang Mark T. Hamann Wei-Hua Jiao Hong-Jun Zhang Wan-Sheng Chen Hou-Wen Lin 《Tetrahedron》2012,68(24):4635-4640
Six new polyketides, simplexolides A–E (1–5) and a furan ester, plakorfuran A (6), together with four known furanylidenic methyl esters (7–10) were isolated from the marine sponge Plakortis simplex. Compounds 1–5 feature a tetrahydrofuran ring opened seco-plakortone skeleton. These new structures, including relative configurations, were determined on the basis of extensive analysis of spectroscopic data. The absolute configurations of 1–6 were established by the modified Mosher’s method, and the CD exciton chirality method. However, configurations of the remote stereocenters at C-8 in compounds 1–5 were not determined. Antifungal, cytotoxicity, antileismanial, and antimalarial activities of these polyketides were evaluated. 相似文献
18.
One new sesquiterpene lactone possessing novel variations in the structure, corialactone E (1), one new neolignan, coriarianeolignan A (2), together with three known apocarotenoids (3-5) and one known neolignan (6), have been isolated from a CHCl3 extract of the roots of Coriaria nepalensis. 相似文献
19.
Li Zhang Jing Shi Cheng Li Liu Lang Xiang Shi Ying Ma Wei Li Rui Hua Jiao Ren Xiang Tan Hui Ming Ge 《Tetrahedron letters》2018,59(51):4517-4520
Three new borrelidin-type macrolactones, designated as borrelidins J?L (4–6), together with borrelidin A (1), borrelidin E (2), and 12-desnitrile-12-carboxyl-borrelidin (3) were isolated from a plant endophytic Streptomyces sp. NA06554. Their structures were determined by extensive spectroscopic analysis including HRESIMS, 1D and 2D NMR data. The antibacterial activities for compounds 1–6 were examined. Borrelidins A (1) and L (6) showed potent and moderate antibacterial activity against Micrococcus luteus, respectively, whereas other derivatives (2–5) are almost inactive, which allows us to propose a plausible structure-activity relationship. 相似文献
20.
Jian Xiao Li-Bin Lin Jia-Yao Hu Dong-Zhu Duan Wei Shi Qiang Zhang Wen-Bo Han Le Wang Xiao-Ling Wang 《Tetrahedron letters》2018,59(18):1772-1775
Pestalustaines A (1) and B (2), one unique sesquiterpene possessing an unusual 5/6/7-fused tricyclic ring system and one unprecedented coumarin derivative bearing 6/6/5/5-fused tetracyclic ring system, were isolated from the plant-derived Pestalotiopsis adusta. Their structures with absolute configurations were established by extensive NMR analysis, X-ray crystallography, and CD spectra associated with TD-DFT calculation. Hypothetical biosynthetic pathways for compounds 1 and 2 are proposed. Compounds 1 and 2 showed weak to moderate cytotoxic activities against three human tumor cell lines HeLa, HCT116, and A549, whose IC50 values were ranged from 21.01 to 55.43?μM. 相似文献