" which is the dried stem of genus Dendrobium, has been used to treat fever, inflammation, and similar conditions. 1,2) Within genus Dendrobium, Dendrobium nobile LINDL. and D. officinale K. KIMURA et MIGO were originally used as "Xiao Huang Cao Shi Hu." However, these plants are very rare, and therefore, other plants of genus Dendrobium, including D. loddigesii ROLFE, D. moniliforme (L.) SW., and D. lohohense TANG et WANG, have also been distributed as "Xiao Huang Cao Shi Hu" in medicinal herb markets in China. D. loddigesii parasitic on the trees and the rocks in Laos to South China.During our screening of herbal medicines for active compounds with inhibitory activities against nitric oxide (NO) production, some plants of the genus Dendrobium were found to be as active as the herbal medicines.3) Thus, we investigated 80% MeOH extracts of D. loddigesii in order to isolate inhibitors of NO production. New phenanthrenes, loddigesiinols A (1) and B (7), and stilbenes, loddigesiinols C (8) and D (9), were isolated from the active portions, i.e., the n-hexane and EtOAc extracts, along with known compounds, including five phenanthrenes, three stilbenes, two lignans, and three sterols. Here, we describe the isolation and structure determinations of the new compounds, loddigesiinols A (1) and B (7) and loddigesiinols C (8) and D (9), and evaluate their effects against NO production and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging.The 80% MeOH extract of D. loddigesii was partitioned in succession with n-hexane, EtOAc, and n-BuOH. The EtOAc extract, which showed strong inhibitory activity against NO production (inhibition rate: 43.4% at 30 mg/ml), was chromatographed on a silica gel column, and then purified using normal and reverse phase HPLC to obtain compounds 9-12 and 16-18. Another active fraction, n-hexane extract (inhibition rate: 43.6% at 30 mg/ml), was also separated by normal and reverse phase column chromatography, and then purified by HPLC to obtain compounds 1-8 and 13-15. Compounds 2-6 and 10-18 were found to be identical to moscatin 4) (plicatol B 5) ), 5-hydroxy-2,4-dimethoxyphenanthrene, 6) lusianthridin, 7) rotundatin 8) (plicatol C 5) ), hircinol, 9) moscatilin 10) (aloifol II 11) ), gigantol, 12) batatasin III, 11) stigmasterol, b-sitosterol, sitostenone, dehydrovomifoliol, 13) (Ϫ)-pinoresinol, 14) and (Ϫ)-medioresinol, 15) respectively, by comparisons with spectroscopic data from the existing literature.Loddigesiinol A (1) was obtained as a pale brownish amorphous powder. Its molecular formula was determined to be C 16 H 14 O 3 by high resolution (HR)-electron ionization (EI)-mass spectra (MS). The UV spectrum showed absorption peaks at 211, 259, 282, 315, and 362 nm, indicating the presence of a phenanthrene skeleton. 16) In the IR spectrum, absorption at 3286 cm Ϫ1 indicated hydroxy groups. 1 H-NMR revealed meta-coupled signals at d H 6.81 (d, Jϭ2.4 Hz) and 6.99 (d, Jϭ2.4 Hz), indicating the presence of a tetrasubstituted phenyl group; a spin system at d H 7.13 (dd, Jϭ7.5...
Mallotus philippinensis MUELL. ARG. (Euphorbiaceae) iswidely distributed in the forestes of Kelara. The Granular hairs on the surface of fruits is called Kamala. It has been used as a drug and dye. Earlier investigations on Kamala dye have afforded various flavonoides.2-5) Kamala powder is used as an anthelmintic and cathartic in traditional medicine. 6) Macrophages play an important role in non-specific host defense mechanisms. 7) In macrophages, bacterial LPS alone or in combination with cytokines like interferon-g (IFN-g) is one of the best-characterized stimuli to induce the transcription of genes encoding pro-inflammatory proteins, resulting in cytokine release and synthesis of enzymes such as cyclooxygenase-2 (COX-2) 8) and inducible nitric oxide synthase (iNOS). 9) NO is a short-lived bioactive molecule that participate in the physiology and pathophysiology of many systems.10) NO is synthesized in vivo from L-arginine by NOS with NADPH and oxygen as cosubstrates.11) Large amounts of NO may lead to tissue damage. In inflammatory disease such as rheumatoid arthritis, excessive NO production by activated macrophages has been observed. Therefore, it would be valuable to develop potent and selective inhibitors of NO for potential therapeutic use.Previously, we reported that mallotophilippens A and B, phloroglucinol derivatives from M. philippinensis, suppressed the NO production and iNOS gene expression. 3)In this work, we isolated three novel chalcone derivatives, 1, 2 and 3 ( Fig. 1), from the hexane-soluble fraction and investigated the inhibitory effects of those compounds on NO generation from activated macrophages. Results and DiscussionCompound 1 (Table 1), indicated a 2,2-dimethylpyran system.The arrangement of the substituents and the placement of the pyran at the 4aЈ/8aЈ positions were established from the results of the heteronuclear multiple bond connectivity (HMBC) experiments (Fig. 2). The chelated hydroxyl group in ring B showed the expected Kumage-gun, Kagoshima 891-3604, Japan. Received June 6, 2004; accepted August 27, 2004 Three novel chalcone derivatives, mallotophilippens C (1), D (2) and E (3) were isolated from the fruits of Mallotus philippinensis MUELL. ARG. These compounds were identified, using chemical and spectral data, as 1-[6-(3,7-dimethyl-octa-2,6-dienyl)-5,7-dihydroxy-2,2-dimethyl-2H-chromen-8-yl]-3-(4-hydroxy-phenyl)-propenone, 3- (3,4-dihydroxy-phenyl)-1-[6-(3,7-dimethyl-octa-2,6-dienyl)
Kadsura coccinea (LEM.) A. C. SMITH is widely distributed throughout southwestern of China. Plant extracts have been used in Chinese folk medicine for treatment of cancer and dermatosis and as an anodyne to relieve aches in China. 2)Previous investigations of K. coccinea have yielded some lignans and triterpenoids. [3][4][5][6][7][8][9][10][11][12] However, little work on the isolation and characterization of anti-inflammatory constituents from this plant has been made. As a part of our continuing phytochemical investigation of anti-allergic agents from natural sources, 1) the chemical composition of the rhizoma of K. coccinea has been examined.The roots of K. coccinea were extracted with 80% acetone. The extract was then partitioned with hexane, chloroform, ethyl acetate, n-butanol and water, successively. The chloroform fractions showed strong NO production inhibitory activity. Further bioassay-directed fractionation of this fraction led to the isolation of two new dibenzocyclooctadiene lignans, kadsuralignan A (1), kadsuralignan B (2), and one new arylnaphthalene lignan kadsuralignan C (3), with three known dibenzocyclooctadiene lignans gomisin R (4), schizanrin F (5), and schizanrin H (6).To our knowledge, it's the first report about arylnaphthalene lignan was isolated from K. coccinea.Here, we describe the isolation, structure elucidation and biological evaluation of these compounds.The configuration of biphenyl groups in all isolated dibenzocyclooctadiene lignans was determined basing on their characteristic circular dichroism (CD) spectra. The CD spectra of 1, 2, 4-6 showed a positive Cotton effect around 215-225 nm and a negative Cotton effect around 230-255 nm, suggesting that these dibenzocyclooctadiene lignans possessed an S-biphenyl configuration as gomisin B. 13,14)Kadsuralignan A (1) was obtained as colorless needles and assigned to possess a molecular formula of C 22 H 26 O 7 by high resolution electron impact ionization MS (HR-EI-MS) ([M] ϩ , m/z 402.1679) with ten unsaturation. The UV spectrum of 1 possessed characteristic UV spectrum (l max 220, 255, 289sh nm) of dibenzocyclooctadiene lignans.15) It possessed a biphenyl moiety due to two aromatic protons at d 6.67 and 6.34 (each 1H, s, H-4 and H-11) and twelve carbon atoms at d 150. 6, 138.3, 148.5, 113.5, 133.7 and 121.1 (C-1, 2, 3, 4, 5, 16, respectively); d 138.2, 102.5, 148.7, 135.7, 141.1, 119.2 (C-10, 11, 12, 13, 14, 15, respectively). Moreover, one methylenedioxy moiety at d 5.97 (2H, s, CH 2 -19) and three methoxyl groups at d 3.63, 3.79 and 3.95 (each 3H, s) occurred, and predictably located them at the biphenyl rings. In the cyclooctadiene ring, two secondary methyl groups at d 0.93 (3H, d, Jϭ7.5 Hz) and 1.16 (3H, d, Jϭ6.9 Hz) were assigned to CH 3 -17 and CH 3 -18, respectively. Moreover, the signal of oxygenated methine at d 83.9, 4.61 (1H, d, Jϭ11.7 Hz, C-9 and H-9).The detailed analysis of 1 using 1 H-1 H COSY and HMQC disclosed partial structure unit with correlated protons: CH 2 -CH(CH 3 )-CH(CH 3 )-CH(OH), this unit should...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.