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ABSTRACT: As part of our continuing efforts in the search for potential biologically active compounds from medicinal plants, we have isolated 18 compounds including two novel nitrogen containing diterpenes from extracts of the fruits of Vitex agnus-castus. These isolates, along with our previously obtained novel compound vitexlactam A (1), were evaluated for potential biological effects, including cancer chemoprevention. Chemically, the nitrogenous isolates were found to be two labdane diterpene alkaloids, each containing an α , β -unsaturated γ -lactam moiety. Structurally, they were elucidated to be 9 α -hydroxy-13(14)-labden-16,15-amide (2) and 6 β -acetoxy-9 α -hydroxy-13(14)-labden-15,16-amide (3), which were named vitexlactams B and C, respectively. The 15 known isolates were identified as vitexilactone (4), rotundifuran (5), 8-epi-manoyl oxide (6), vitetrifolin D (7), spathulenol (8), cis-dihydro-dehydro-diconiferylalcohol-9-O- β -D-glucoside (9), luteolin-7-O-glucoside (10), 5-hydroxy-3,6,7,4'-tetramethoxyflavone (11), casticin (12), artemetin (13), aucubin (14), agnuside (15), β -sitosterol (16), p-hydroxybenzoic acid (17), and p-hydroxybenzoic acid glucose ester (18). All compound structures were determined/identified on the basis of 1D and/or 2D NMR and mass spectrometry techniques. Compounds 6, 8, 9, and 18 were reported from a Vitex spieces for the first time. The cancer chemopreventive potentials of these isolates were evaluated for NADP(H):quinone oxidoreductase type 1 (QR1) induction activity. Compound 7 demonstrated promising QR1 induction effect, while the new compound vitexlactam (3) was only slightly active.
Evidence-based Complementary and Alternative Medicine 01/2013; 2013:432829. · 4.77 Impact Factor
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ABSTRACT: Phytochemical study of the leaves of the medicinal plant Isodon rubescens led to the isolation of three novel abietane diterpenoids, rubesanolides C-E (1-3). These diterpenes contain a unique γ-lactone subgroup formed between C-8 and C-20. Their structures were determined from analysis of spectroscopic data, and were further confirmed by X-ray crystallographic data. The compounds were evaluated for their antibacterial activity, and rubesanolide D (2) demonstrated inhibition activity against biofilm formation of the dental bacterium Streptococcus mutans.
Organic & Biomolecular Chemistry 05/2012; 10(26):5039-44. · 3.70 Impact Factor
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Juan Zou,
Lutai Pan,
Qiji Li,
Junhua Zhao,
Jianxin Pu,
Ping Yao,
Ningbo Gong, Yang Lu,
Tamara P Kondratyuk,
John M Pezzuto,
Harry H S Fong, Hongjie Zhang,
Handong Sun
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ABSTRACT: From the medicinal plant Isodon rubescens, we isolated two novel diterpenes, rubesanolides A (1) and B (2). The compounds contain a unique β-lactone subgroup. This is the first discovery for a natural diterpene having rings A, B, and C in chair, boat, and twist-chair conformations, respectively. The structures were elucidated by analysis of spectroscopic data, and the absolute configuration of 1 was determined by X-ray diffraction.
Organic Letters 02/2011; 13(6):1406-9. · 5.86 Impact Factor
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ABSTRACT: As prophylactic therapies and vaccines against viral infections continue to improve, drug resistant strains are continuing to arise; therefore it is imperative to develop new therapeutics against these diseases. For highly pathogenic viruses, such as Ebola and H5N1 influenza virus, the need for antivirals is even more urgent due to limited therapeutics against these viruses. Furthermore, the high pathogenicity of such viruses often makes it difficult to work with such agents. In this report, we describe a protocol called "One-stone-two-birds" which provides a safe and efficient screening system to identify anti-flu (entry) and anti-HIV (replication) activities. Using plant extracts as an example, we demonstrate the utility of this protocol in antiviral screening.
Journal of Antivirals and Antiretrovirals 01/2011; 3:8-10.
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Hongmei Cao,
Rui Yu,
Yongsoo Choi,
Zhong-Ze Ma, Hongjie Zhang,
Wei Xiang,
David Yue-Wei Lee,
Brian M Berman,
Kamal D Moudgil,
Harry H S Fong,
Richard B van Breemen
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ABSTRACT: Eleven authenticated botanicals used in the traditional Chinese medicine Huo-Luo-Xiao-Ling Dan were screened for ligands to cyclooxygenase (COX) using pulsed ultrafiltration liquid chromatography-mass spectrometry, and a mass spectrometry-based enzyme assay was used to determine the concentration of each of 17 ligands that inhibited COX-1 or COX-2 by 50% (IC(50)). Acetyl-11-keto-beta-boswellic acid, beta-boswellic acid, acetyl-alpha-boswellic acid, acetyl-beta-boswellic acid, and betulinic acid were COX-1 selective inhibitors with IC(50) values of approximately 10 microM. Senkyunolide O and cryptotanshinone were COX-2 selective inhibitors with IC(50) values of 5 microM and 22 microM, respectively. Roburic acid and phenethyl-trans-ferulate inhibited COX-1 and COX-2 equally. COX inhibition and the IC(50) values of most of these natural product ligands have not been reported previously.
Pharmacological Research 02/2010; 61(6):519-24. · 4.44 Impact Factor
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ABSTRACT: Phytochemical study of the aqueous extract of the flowering tops of Lamium album led to identification of the antiviral iridoid isomers lamiridosins A and B (1, 2). These compounds were found to significantly inhibit hepatitis C virus entry (IC(50) 2.31 muM) in vitro. Studies of 14 iridoid analogues showed that, while the parent iridoid glucosides demonstrated no anti-HCV entry activity, the aglycones of shanzhiside methyl ester (4), loganin (5), loganic acid (6), geniposide (10), verbenalin (12), eurostoside (15), and picroside II (17) exhibited significant anti-HCV entry and anti-infectivity activities.
Journal of Natural Products 11/2009; 72(12):2158-62. · 3.13 Impact Factor
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Hongjie Zhang,
Shengxiang Qiu,
Pamela Tamez,
Ghee Teng Tan,
Zeynep Aydogmus,
Nguyen Van Hung,
Nguyen Manh Cuong,
Cindy Angerhofer,
D. Doel Soejarto,
John M. Pezzuto,
Harry H.S. Fong
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ABSTRACT: Antimalarial bioassay-directed fractionation led to the isolation of a new active indole alkaloid, decursivine (1), from the leaves and stems of Rhaphidophora decursiva Schott (Araceae). In addition, a leaf sample yielded the structurally-related compound serotobenine (2), previously reported from a taxonomically unrelated family, which was not active against Plasmodium falciparum. The structure of 1 was elucidated by spectroscopic means, and its antimalarial activity was observed with IC 50 values of 3.93 and 4.41µg/ml against the D6 and W2 clones of Plasmodium falciparum, respectively.
09/2008; 40(3):221-224.
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ABSTRACT: As a part of the UIC-based ICBG project in Laos, plants were collected based on ethnomedical interviews and evaluated for antimalarial activity. A CHCl3 extract from the vine of Gongronema napalense (Wall.) Decne. (Asclepiadaceae) showed promising anti-malarial activity while exhibiting low levels of cytotoxicity and was thus followed up with further fractionation and biological evaluation. Bioassay-guided fractionation led to the isolation of a new steroidal glycoside, gongroneside A, which showed antimalarial activity in vitro with an IC50 value of 1.60 and 1.39 μM against the Plasmodium falciparum D6 and W2 clones, respectively.
Asian journal of traditional medicines. 01/2008; 3(6):203-210.
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ABSTRACT: Two new flavonoid glycosides, 5-hydroxy-7,8-dimethoxy (2R)-flavanone-5-O-beta-D-glucopyranoside (1) and 5-hydroxy-7,8,2',5'-tetramethoxy-flavone-5-O-beta-D-glucopyranoside (2), and a new diterpenoid, andrographic acid (3), along with andrographidine A (4) were isolated from Andrographis paniculata, and their structures were determined on the basis of physicochemical and spectroscopic analysis. Compound 3 was evaluated for cytotoxicity to KB cells along with andrographolide, isoandrographolide, neoandrographolide and 14-deoxy-11,12-didehydroandrographolide obtained from A. paniculata in the present study. Cytotoxicity was observed for andrographolide and isoandrographolide with ED50 values of 6.5 and 5.1 microg/ml, respectively.
CHEMICAL & PHARMACEUTICAL BULLETIN 04/2007; 55(3):455-8. · 1.59 Impact Factor
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ABSTRACT: Bioassay directed-fractionation led to isolation of 12 compounds from the roots of Bursera tonkinensis Guillaum (Burseraceae), including burselignan, bursephenylpropane, and burseneolignan. Of the 12 compounds, only 4'-demethyldesoxypodophyllotoxin exhibited significant cytotoxic activities against KB, Col2 and LNCaP cell lines.
Phytochemistry 01/2006; 66(23):2745-51. · 3.35 Impact Factor
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06/2004;
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ABSTRACT: Bioactivity-directed fractionation of the methanolic extract of the stem and fruits of Senna obliqua led to the isolation of two known antimycobacterial natural products, quinquangulin (1) and rubrofusarin (2). Both compounds had minimum inhibitory concentrations (MICs) of 12.0 microg/mL against Mycobacteriatuberculosis in radiometric culture. This is the first report of antimycobacterial activity associated with naphthopyrone compounds. Their structures were determined by spectroscopic means including 1D and 2D NMR techniques and further confirmed by X-ray crystallographic analysis.
Journal of Natural Products 03/2004; 67(2):225-7. · 3.13 Impact Factor
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ABSTRACT: Four phenylpropanoid esters, cimiracemates A-D (1-4), along with three known compounds, isoferulic acid, ferulic acid and methyl caffeate were isolated from the EtOAc fraction of the rhizome of Cimicifuga racemosa. The structures of the esters were elucidated by means of spectral data, including 2D NMR spectroscopy.
Phytochemistry 11/2002; 61(4):409-13. · 3.35 Impact Factor
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ABSTRACT: A new ent-kaurene diterpene, pseudoirroratin A (1), and a known diterpene, pseurata A, were isolated from Isodon pseudo-irrorata. Compound 1 showed significant cytotoxicity against the Lu1, SW626, LNCaP, KB, and HOS cancer cell lines with IC(50) values of 0.26 (0.75), 0.20 (0.57), 0.90 (2.59), 0.90 (2.59), and 0.50 (1.44) microg/mL (microM), respectively. The structure of 1 was elucidated by spectroscopic means including 1D and 2D NMR techniques.
Journal of Natural Products 03/2002; 65(2):215-7. · 3.13 Impact Factor
