共查询到20条相似文献,搜索用时 12 毫秒
1.
2.
Antonio Fiorentino Marina DellaGreca Annunziata Golino Angelina Izzo 《Tetrahedron》2006,62(38):8952-8958
Implementing the phytochemical study of the weed Amaranthus retroflexus, four new sesquiterpene glucosides were isolated from the methanolic extract of the plant. The structures of these metabolites are determined on the basis of the mass spectrometry, and 1D and 2D NMR spectroscopies (DQ-COSY, TOCSY, HSQC, HSQC-TOCSY, HMBC, and NOESY). Two compounds are characterized by a new aglycone and differed from the site of glucosylation. The other two compounds are dimeric diastereoisomers.All the glucoside sesquiterpenes were tested on the wild species Taraxacum officinale to evaluate the role of this weed in the habitat and on the seed of A. retroflexus to verify the potential autotoxic effect of the plant. 相似文献
3.
Ya Jiuan Xu ;Tun Hai Xu ;Ling Zhu Hao ;Hong Feng Zhao ;Sheng Xu Xie ;Yun Shan Si ;Dong Han ;Dong Ming Xu 《中国化学快报》2008,19(7):825-828
Two new steroidal glucosides, 26-O-β-D-glucopyranosyl (25S)-furost-5-ene-1β,3β,22α,26-tetraol l-O-β-D-xylopyranosyl- (1 → 3)-[α-h-rhamnopyranosyl-(1 → 2)]-[β-D-fueopyranoside and (25R) spirost-5-ene-3β,14α-diol-3-β-O-β-L-rhanmopyranosyl- (1 → 2)-[β-D-xylopyranosyl(1 → 4)]-[-β-D-glucopyranoside, were isolated from the Ophiopogon japonicus (L.f.) Ker-Gaw. Their structures were elucidated by spectroscopic methods. 相似文献
4.
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
5.
Kiyota N Shingu K Yamaguchi K Yoshitake Y Harano K Yoshimitsu H Miyashita H Ikeda T Tagawa C Nohara T 《Chemical & pharmaceutical bulletin》2008,56(7):1038-1040
Two new C(28) steroidal glycosides, tuboanosides A (1) and B (2), were isolated from the fruit of Tubocapsicum anomalum MAKINO. Their chemical structures were elucidated on the basis of spectroscopic and X-ray diffraction analysis of the p-bromobenzoyl derivative (4) of tuboanosigenin (3), the sapogenol derivative of these two glycosides. Tuboanosides have the structural peculiarity of an unusual side chain carrying an unusual linkage with a C-21 bound to C-25 on the lactone ring. 相似文献
6.
Kiyota N Shingu K Yamaguchi K Yoshitake Y Harano K Yoshimitsu H Ikeda T Nohara T 《Chemical & pharmaceutical bulletin》2007,55(1):34-36
Three new C(28) steroidal glycosides, isotubocaposides A (1), B (2), and C (3), were isolated from the fruits of Tubocapsicum anomalum MAKINO. Their chemical structures were elucidated on the basis of spectroscopic and X-ray diffraction analysis of p-bromobenzoyl derivative (5) of isotubocaposigenin (4), the sapogenol derivative of these three glycosides. Isotubocaposides have the structural peculiarity of an unusual side chain carrying a C-21 bound to C-24 on the lactone ring. 相似文献
7.
Xin Liu 《Tetrahedron》2004,60(50):11647-11654
In search for bioactive compounds from the roots of Sanguisorba officinalis L. (Rosaceae), four new dimeric triterpene glucosides, namely sanguidioside A, B, C, and D (1-4) were isolated. Alkaline hydrolysis of 1-2 afforded the corresponding dimeric aglycones (1a and 2a). Meanwhile, a ready intra-molecular transesterification was observed, providing dimeric triterpenes 1b and 2b. Alkaline hydrolysis of the crude dimmeric saponin also provided a new dimeric triterpene, sanguidiogenin (9). The structures of all these compounds are elucidated via spectroscopic and chemical methods, and are further confirmed by the X-ray diffraction analysis of the dimeric aglycone 2a. Compound 3 represents the first dimeric saponin of an oleanolic acid and an ursonic acid derivative, while compound 4 is the first dimeric saponin of oleanolic acid derivatives. 相似文献
8.
Ping-Jyun Sung Mei-Ru Lin Yin-Di Su Michael Y. Chiang Jui-Hsin Su Mo-Chih Cheng Tsong-Long Hwang 《Tetrahedron》2008,64(11):2596-2604
Six 12-hydroxybriaranes, including four new diterpenoids, briaexcavatins I-L (1-4), and two known metabolites, excavatolides C (5) and E (6), have been isolated from the cultured scleraxonia Briareum excavatum. In addition, the gorgonian coral Junceella fragilis yielded a new chlorinated briarane, fragilide C (10). The structures of above compounds were determined by spectroscopic methods and the structures of 5 and 6 were further confirmed by X-ray data analysis for the first time. The absolute configuration of 6 was elucidated by chemical conversion. Some of these briaranes have displayed inhibitory effects on superoxide anion generation by human neutrophils. 相似文献
9.
Kazuhiro Koike Geoffrey A. Cordell Norman R. Farnsworth Andrew A. Freer Christopher J. Gilmore George A. Sim 《Tetrahedron》1980,36(9):1167-1172
From the wood stem and stem bark of the Panamanian plant Rondeletia panamensis (Rubiaceae), three novel diterpenes have been isolated. The structure of oxidopanamensin (2) was determined by single crystal X-ray crystallography of the diacetate derivative. Panamensin (4) was correlated with oxidopanamensin (2) by epoxidation under alkali conditions and with rondeletin (6) by hydrogenation to 14,15-dihydrorondeletin (8). Of the three isolates, panamensin (4) and oxidopanamensin (2) were cytotoxic in the KB test system but rondeletin was inactive. 相似文献
10.
11.
Bioassay-guided fractionation of the methanol extract of Erylus lendenfeldi using engineered strains of budding yeast (Saccharomyces cerevisiae) has resulted in the isolation of the known compound eryloside A (1) and two new compounds, erylosides K (2) and L (3). The structures were established based mainly on 1D and 2D NMR data. The absolute stereochemistry of eryloside A, which had never been fully characterized, was determined using the modified Mosher's method. The absolute stereochemistry of eryloside K was determined by comparison with tetrahydroeryloside A. Compounds 1-3 exhibited selective cytotoxicity against a yeast strain (Δrad50) deficient in double strand break (DSB) repair. 相似文献
12.
Y. Kuwahara H. Fukami R. Howard S. Ishii F. Matsumura W.E. Burkholder 《Tetrahedron》1978,34(12):1769-1774
Chemical an spectroscopic evidence is presented to show that 2,3-dihydro-2,3,5-trimethyl-6-(1-methyl-2-oxobutyl)-4H-pyran-4-one (10) is the sex pheromone produced by the female drugstore beetle, Stegobium paniceum L. 相似文献
13.
Yuka Inatomi Hiroko Murata Jin Murata Munekazu Iinuma Tsutomu Nakanishi 《Tetrahedron letters》2005,46(38):6533-6535
A pair of new atropisomers, (M)- and (P)-cupressuflavone 4′-O-β-d-glucoside, were isolated from Juniperus communis var. depressa, and their absolute structures and axial configurations were determined using 2D NMR and circular dichroism. These are the first reported stable (M)- and (P)-isomers of cupressuflavone glucosides isolated from natural sources. 相似文献
14.
Furukawa M Oikawa N Imohata T Makino M Ogawa S Iida T Fujimoto Y Kitanaka S 《Chemical & pharmaceutical bulletin》2012,60(3):397-401
Three new monoterpene glucosides, ziziphoroside A (1), B (2), and C (3), together with fifteen known compounds were isolated from the whole herb of Z. clinopodioides. The structures of new compounds were determined primarily from 1D-, 2D-NMR and circular dichroism (CD) spectroscopic analyses. The isolated compounds were evaluated for their inhibitory activity against nitric oxide (NO) production by lipopolysaccharide (LPS) and interferon (IFN)-γ activated macrophages, RAW 264.7. Shizonepetoside A (8) and flavones (11, 12, 13) showed potent inhibitory activity against NO production. 相似文献
15.
Six new macrocyclic sesterterpenoids 1–6 were isolated from the secretion of a scale insect, Ceroplastes ceriferus Anderson, and their structures determined. Chemical correlation has also been accomplished. Stereochemistry was elucidated by comparison of the CD spectra of the ozonolysis product of 1-acetate and a corresponding synthetic substance of known absolute configuration. 相似文献
16.
Subodh Bhatnagar Judith Polonsky Thierry Prangé Claudine Pascard 《Tetrahedron letters》1984,25(3):299-302
Two new toxic quassinoid glucosides, 15--β-D-glucopyranosyl glaucarubolone 3 and 15--β-D-glucopyranosyl glaucarubol 4, have been isolated from seeds. Their structures were deduced from spectral data and that of 3 established by single-crystal X-ray analysis. 相似文献
17.
Ping-Jyun Sung Chen-Hao Pai Yin-Di Su Tsong-Long Hwang Tung-Yung Fan Jan-Jung Li 《Tetrahedron》2008,64(19):4224-4232
Four new 8-hydroxybriarane diterpenoids, including junceols A-C (1-3) and fragilide D (4), have been isolated from the gorgonian corals Junceella juncea and Junceella fragilis, respectively. The structures of briaranes 1-4 were elucidated by the interpretations of spectral data analysis. Briaranes 1-3 have displayed inhibitory effects on superoxide anion generation by human neutrophils. 相似文献
18.
New diterpenoid glucosides from Siegesbeckia pubescens 总被引:5,自引:0,他引:5
Jiang XIONG Qi Duan JIN Yun Long XU* Kunming Institute of Botany The Chinese Academy of Sciences Kunming 《中国化学快报》2001,(1)
Plants of the genus Siegesbeckia are annual herbs widely distributed in tropical and temperate zones and they are used as a traditional medicine to treat rheumatic arthritis, hypertension, malaria, neurasthenia and snake-bite in China. In previous papers, we reported on five new ent-kaurane and ent-pimarane diterpenoids, siegesbeckioside, siegesbeckiol and siegesbeckic acid1, orientalin A and B, and eight know compounds2,3. The present paper describes the isolation and structural elucidation … 相似文献
19.
Erik L. RegaladoGregory Genta-Jouve Deniz TasdemirPhilippe Amade Clara NogueirasOlivier P. Thomas 《Tetrahedron》2011,67(5):1011-1018
Seven novel steroid glycosides, acanthifoliosides A-F (1-6), and the methyl ester of 6 (7), were isolated from the marine sponge Pandaros acanthifolium as minor components. Acanthifoliosides are characterized by a rare C-15 and C-16 oxidized D ring, which was previously found in saponins produced by starfishes. Very uncommon is the presence of additional sugar residues at C-15 or C-16. Their structures were determined on the basis of extensive spectroscopic analyses, including two-dimensional NMR and HRESIMS data. The absolute configurations of the aglycones were assigned by comparison between experimental and TDDFT calculated CD spectra of 1, whereas the absolute configurations of the monosaccharide units were determined by chiral GC analyses of the acid methanolysates. Some of the acanthifoliosides exhibit moderate antiprotozoal activity but to a lesser extent than the most potent pandarosides. 相似文献
20.
Atta-ur-Rahman Feroz F Zaheer-ul-Haq Nawaz SA Khan MR Choudhary MI 《Natural product research》2003,17(4):235-241
Two new steroidal alkaloids, salonine-A [(20S)-20-(N,N-dimethylamino)-3beta-(tigloylamino)-5alpha-pregn-14-en-2beta,4beta-diol] (1), and salonine-B [(20S)-20-(N,N-dimethylamino)-3beta-methoxy-pregn-5,16-diene] (2), were isolated from the MeOH extract of Sarcococca saligna, along with a known base, alkaloid-C (3). Their structures were elucidated on the basis of spectroscopic methods. All three compounds were found to be cholinesterase inhibitors. 相似文献