| 1. |
- Abdissa, Negera, et al.
(författare)
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Cytotoxic Quinones from the roots of Aloe dawei
- 2014
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Ingår i: Molecules. - : MDPI AG. - 1420-3049 .- 1431-5157. ; 19:3, s. 3264-3273
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Tidskriftsartikel (refereegranskat)abstract
- Seven naphthoquinones and nine anthraquinones were isolated from the roots of Aloe dawei by chromatographic separation. The purified metabolites were identified by NMR and MS analyses. Out of the sixteen quinones, 6-hydroxy-3,5-dimethoxy-2-methyl-1,4-naphthoquinone is a new compound. Two of the isolates, 5,8-dihydroxy-3-methoxy-2-methylnaphthalene-1,4-dione and 1-hydroxy-8-methoxy-3-methylanthraquinone showed high cytotoxic activity (IC50 1.15 and 4.85 µM) on MCF-7 breast cancer cells, whereas the others showed moderate to low cytotoxic activity against MDA-MB-231 (ER Negative) and MCF-7 (ER Positive) cancer cells.
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| 2. |
- Chepkirui, Carolyne, et al.
(författare)
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A new β-hydroxydihydrochalcone from Tephrosia uniflora, and the revision of three β-hydroxydihydrochalcones to flavanones.
- 2022
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Ingår i: Fitoterapia. - : Elsevier BV. - 1873-6971 .- 0367-326X. ; 158
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Tidskriftsartikel (refereegranskat)abstract
- The CH2Cl2/MeOH (1:1) extract of the stems of Tephrosia uniflora yielded the new β-hydroxydihydrochalcone (S)-elatadihydrochalcone-2'-methyl ether (1) along with the three known compounds elongatin (2), (S)-elatadihydrochalcone (3), and tephrosin (4). The structures were elucidated by NMR spectroscopic and mass spectrometric data analyses. Elongatin (2) showed moderate antibacterial activity (EC50 of 25.3μM and EC90 of 32.8μM) against the Gram-positive bacterium Bacilus subtilis, and comparable toxicity against the MCF-7 human breast cancer cell line (EC50 of 41.3μM). Based on the comparison of literature and predicted data with that obtained experimentally, we propose the revision of the structure of three β-hydroxydihydrochalcones to flavanones.
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| 3. |
- Chepkirui, Carolyne, et al.
(författare)
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Antiplasmodial and antileishmanial flavonoids from Mundulea sericea
- 2021
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Ingår i: Fitoterapia (Milano). - : Elsevier BV. - 0367-326X .- 1873-6971. ; 149
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Tidskriftsartikel (refereegranskat)abstract
- Five known compounds (1–5) were isolated from the extract of Mundulea sericea leaves. Similar investigation of the roots of this plant afforded an additional three known compounds (6–8). The structures were elucidated using NMR spectroscopic and mass spectrometric analyses. The absolute configuration of 1 was established using ECD spectroscopy. In an antiplasmodial activity assay, compound 1 showed good activity with an IC50 of 2.0 μM against chloroquine-resistant W2, and 6.6 μM against the chloroquine-sensitive 3D7 strains of Plasmodium falciparum. Some of the compounds were also tested for antileishmanial activity. Dehydrolupinifolinol (2) and sericetin (5) were active against drug-sensitive Leishmania donovani (MHOM/IN/83/AG83) with IC50 values of 9.0 and 5.0 μM, respectively. In a cytotoxicity assay, lupinifolin (3) showed significant activity on BEAS-2B (IC50 4.9 μM) and HePG2 (IC50 10.8 μM) human cell lines. All the other compounds showed low cytotoxicity (IC50 > 30 μM) against human lung adenocarcinoma cells (A549), human liver cancer cells (HepG2), lung/bronchus cells (epithelial virus transformed) (BEAS-2B) and immortal human hepatocytes (LO2)
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| 4. |
- Chepkirui, Carolyne, et al.
(författare)
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Benzo[b]naphtho[2,1-d]furans and 2-Phenylnaphthalenes from Streblus usambarensis
- 2023
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Ingår i: Journal of Natural Products. - : American Chemical Society (ACS). - 0163-3864 .- 1520-6025. ; 86:4, s. 1010-1018
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Tidskriftsartikel (refereegranskat)abstract
- Three new benzo[b]naphtho[2,1-d]furans, usambarins A–C (1–3), five new 2-phenylnaphthalenes, usambarins D–H (4–8), a new flavan (9), and a new phenyl-1-benzoxepin (10) as well as two known compounds (11 and 12) were isolated from the extract of the stem and roots of Streblus usambarensis (Moraceae). The structures were deduced using NMR spectroscopic and mass spectrometric analyses, and those of compounds 1 and 4 were confirmed by X-ray crystallography. Usambarin D (4) demonstrated moderate antibacterial activity (MIC 9.0 μM) against Bacillus subtilis, while none of the tested compounds were effective against Escherichia coli.
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| 5. |
- Endale, Milkyas, 1980, et al.
(författare)
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Anthraquinones of the roots of Pentas micrantha
- 2013
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Ingår i: Molecules. - : MDPI AG. - 1420-3049 .- 1431-5157. ; 18:1, s. 311-321
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Tidskriftsartikel (refereegranskat)abstract
- Pentas micrantha is used in the East African indigenous medicine to treat malaria. In the first investigation of this plant, the crude methanol root extract showed moderate antiplasmodial activity against the W2- (3.37 μg/mL) and D6-strains (4.00 μg/mL) of Plasmodium falciparum and low cytotoxicity (>450 μg/mL, MCF-7 cell line). Chromatographic separation of the extract yielded nine anthraquinones, of which 5,6-dihydroxylucidin-11-O-methyl ether is new. Isolation of a munjistin derivative from the genus Pentas is reported here for the first time. The isolated constituents were identified by NMR and mass spectrometric techniques and showed low antiplasmodial activities.
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| 6. |
- Endale, Milkyas, et al.
(författare)
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Antiplasmodial Quinones from Pentas longiflora and Pentas lanceolata
- 2012
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Ingår i: Planta Medica. - : Georg Thieme Verlag KG. - 0032-0943 .- 1439-0221. ; 78:1, s. 31-35
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Tidskriftsartikel (refereegranskat)abstract
- The dichloromethane/methanol (1 : 1) extracts of the roots of Pentas longiflora and Pentas lanceolata showed low micromolar (IC50 = 0.9-3 µg/mL) in vitro antiplasmodial activity against chloroquine-resistant (W2) and chloroquine-sensitive (D6) strains of Plasmodium falciparum. Chromatographic separation of the extract of Pentas longiflora led to the isolation of the pyranonaphthoquinones pentalongin (1) and psychorubrin (2) with IC50 values below 1 µg/mL and the naphthalene derivative mollugin (3), which showed marginal activity. Similar treatment of Pentas lanceolata led to the isolation of eight anthraquinones (4-11, IC50 = 5-31 µg/mL) of which one is new (5,6-dihydroxydamnacanthol, 11), while three - nordamnacanthal (7), lucidin-ω-methyl ether (9), and damnacanthol (10) - are reported here for the first time from the genus Pentas. The compounds were identified by NMR and mass spectroscopic techniques.
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| 7. |
- Endale, Milkyas, 1980, et al.
(författare)
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Busseihydroquinones A-D from the Roots of Pentas bussei
- 2012
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Ingår i: Journal of Natural Products. - : American Chemical Society (ACS). - 1520-6025 .- 0163-3864. ; 75, s. 1299-1304
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Tidskriftsartikel (refereegranskat)abstract
- Four new naphthohydroquinones, named busseihydroquinones A–D (1–4), along with a known homoprenylated dihydronaphthoquinone (5), were isolated from the CH2Cl2/MeOH (1:1) extract of the roots of Pentas bussei. Although the genus Pentas is frequently used by traditional healers for the treatment of malaria, only marginal activities against the chloroquine-sensitive (D6) and the chloroquine-resistant (W2) strains of Plasmodium falciparum were observed for the crude root extract and the isolated constituents of this plant.
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| 8. |
- Erdelyi, Mate, 1975-
(författare)
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Pterocarpans and isoflavones from the root bark of Millettia micans and of Millettia dura
- 2016
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Ingår i: Phytochemistry Letters. - 1874-3900 .- 1876-7486. ; 21, s. 216-220-
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Tidskriftsartikel (refereegranskat)abstract
- From the CH2Cl2/CH3OH (1:1) extract of the root bark of Millettia micans, a new pterocarpan, (6aR,11aR)-3-hydroxy-7,8,9-trimethoxypterocarpan (1), named micanspterocarpan, was isolated. Similar investigation of the CH2Cl2/CH3OH (1:1) extract of the root bark of Millettia dura gave a further new pterocarpan, (6aR,11aR)-8,9-methylenedioxy-3-prenyloxypterocarpan (2), named 3-O-prenylmaackiain, along with six known isoflavones (3-8) and a chalcone (9). All purified compounds were identified by NMR and MS, whereas the absolute configurations of the new pterocarpans were established by chriptical data analyses including quantum chemical ECD calculation. Among the isolated constituents, calopogonium isoflavone B (3) and isoerythrin A-4′-(3-methylbut-2-enyl) ether (4) showed marginal activities against the 3D7 and the Dd2 strains of Plasmodium falciparum (70–90% inhibition at 40 μM). Maximaisoflavone B (5) and 7,2′-dimethoxy-4′,5′-methylenedioxyisoflavone (7) were weakly cytotoxic (IC50 153.5 and 174.1 μM, respectively) against the MDA-MB-231 human breast cancer cell line. None of the tested compounds showed in-vitro translation inhibitory activity or toxicity against the HEK-293 human embryonic kidney cell line at 40 μM.
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| 9. |
- Gumula, Ivan, et al.
(författare)
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Flemingins G–O, Cytotoxic and Antioxidant Constituents of the Leaves of Flemingia grahamiana
- 2014
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Ingår i: Journal of Natural Products. - : American Chemical Society (ACS). - 0163-3864 .- 1520-6025. ; 77:9, s. 2060-2067
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Tidskriftsartikel (refereegranskat)abstract
- The known flemingins A–C (1–3) and nine new chalcones, named flemingins G–O (4–12), along with deoxyhomoflemingin (13) and emodin (14) were isolated from a leaf extract of Flemingia grahamiana. The isolated chalcones were found to have a geranyl substituent modified into a chromene ring possessing a residual chain, as shown by spectroscopic methods. The leaf extract showed an IC50 value of 5.9 μg/mL in a DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay. The chalcones flemingins A, B, C, G, and H were active in the DPPH radical scavenging assay (ED50 4.4–8.9 μM), while flemingins A and C showed cytotoxicity against MCF-7 human breast cancer cells (IC50 8.9 and 7.6 μM, respectively).
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| 10. |
- Irungu, Beatrice N., et al.
(författare)
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Constituents of the Roots and Leaves of Ekebergia capensis and Their Potential Antiplasmodial and Cytotoxic Activities
- 2014
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Ingår i: Molecules. - : MDPI AG. - 1420-3049 .- 1431-5157. ; 19:9, s. 14235-14246
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Tidskriftsartikel (refereegranskat)abstract
- A new triterpenoid, 3-oxo-12β-hydroxy-oleanan-28,13β-olide (1), and six known triterpenoids 2–7 were isolated from the root bark of Ekebergia capensis, an African medicinal plant. A limonoid 8 and two glycoflavonoids 9–10 were found in its leaves. The metabolites were identified by NMR and MS analyses, and their cytotoxicity was evaluated against the mammalian African monkey kidney (vero), mouse breast cancer (4T1), human larynx carcinoma (HEp2) and human breast cancer (MDA-MB-231) cell lines. Out of the isolates, oleanonic acid (2) showed the highest cytotoxicity, i.e., IC50’s of 1.4 and 13.3 µM against the HEp2 and 4T1 cells, respectively. Motivated by the higher cytotoxicity of the crude bark extract as compared to the isolates, the interactions of oleanonic acid (2) with five triterpenoids 3–7 were evaluated on vero cells. In an antiplasmodial assay, seven of the metabolites were observed to possess moderate activity against the D6 and W2 strains of P. falciparum (IC50 27.1–97.1 µM), however with a low selectivity index (IC50(vero)/IC50(P. falciparum-D6) < 10). The observed moderate antiplasmodial activity may be due to general cytotoxicity of the isolated triterpenoids.
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| 11. |
- Kiganda, Ivan, et al.
(författare)
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Antiviral Rotenoids and Isoflavones Isolated from Millettia oblata ssp. teitensis
- 2023
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Ingår i: Journal of Natural Products. - 0163-3864 .- 1520-6025. ; 87:4, s. 1003-1012
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Tidskriftsartikel (refereegranskat)abstract
- Three new (1-3) and six known rotenoids (5-10), along with three known isoflavones (11-13), were isolated from the leaves of Millettia oblata ssp. teitensis. A new glycosylated isoflavone (4), four known isoflavones (14-18), and one known chalcone (19) were isolated from the root wood extract of the same plant. The structures were elucidated by NMR and mass spectrometric analyses. The absolute configuration of the chiral compounds was established by a comparison of experimental ECD and VCD data with those calculated for the possible stereoisomers. This is the first report on the use of VCD to assign the absolute configuration of rotenoids. The crude leaves and root wood extracts displayed anti-RSV (human respiratory syncytial virus) activity with IC50 values of 0.7 and 3.4 μg/mL, respectively. Compounds 6, 8, 10, 11, and 14 showed anti-RSV activity with IC50 values of 0.4-10 μM, while compound 3 exhibited anti-HRV-2 (human rhinovirus 2) activity with an IC50 of 4.2 μM. Most of the compounds showed low cytotoxicity for laryngeal carcinoma (HEp-2) cells; however compounds 3, 11, and 14 exhibited low cytotoxicity also in primary lung fibroblasts. This is the first report on rotenoids showing antiviral activity against RSV and HRV viruses.
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| 12. |
- Makungu, Marco, et al.
(författare)
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Pterocarpans and isoflavones from the roots of Millettia micans and of Millettia dura
- 2016
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Ingår i: Advances in Drug Discovery and Development. ; 1:1, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- From the CH2Cl2/CH3OH (1:1) extract of the root bark of Millettia micans, a new pterocarpan, (6aR,11aR)-7,8,9-trimethoxy-3-hydroxypterocarpan (1), named micanspterocarpan, was isolated. Similarinvestigation of the CH2Cl2/CH3OH (1:1) extract of the root bark of Millettia dura gave a further new pterocarpan,3-O-prenylmaackiain (2) along with six known isoflavones (3-8) and a chalcone (9). All purifiedcompounds were identified by NMR and MS, and the absolute configuration of 1 was established by quantumchemical CD calculation. The isolated constituents, calopogonium isoflavone B (3) and isoerythrin A-4'-(3-methylbut-2-enyl) ether (4) showed marginal activities against the 3D7 and the Dd2 strains of Plasmodiumfalciparum (70-90% inhibition at 40 M). Maximaisoflavone B (5) and 7,2'-dimethoxy-4',5'-methylenedioxyisoflavone (7) were weakly cytotoxic (IC50 153.5 and 174.1 uM, respectively) against theMDB-MB-231 human breast cancer cell line. None of the tested compounds showed toxicity against theHEK-293 human embryonic kidney cell line at 40 uM.
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| 13. |
- Yaouba, Souaibou, et al.
(författare)
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Crystal structures and cytotoxicity of ent-kaurane-type diterpenoids from two Aspilia species
- 2018
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Ingår i: Molecules. - : MDPI AG. - 1420-3049 .- 1431-5157. ; 23:12
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Tidskriftsartikel (refereegranskat)abstract
- © 2018 by the authors. A phytochemical investigation of the roots of Aspilia pluriseta led to the isolation of ent-kaurane-type diterpenoids and additional phytochemicals (1–23). The structures of the isolated compounds were elucidated based on Nuclear Magnetic Resonance (NMR) spectroscopic and mass spectrometric analyses. The absolute configurations of seven of the ent-kaurane-type diterpenoids (3–6, 6b, 7 and 8) were determined by single crystal X-ray diffraction studies. Eleven of the compounds were also isolated from the roots and the aerial parts of Aspilia mossambicensis. The literature NMR assignments for compounds 1 and 5 were revised. In a cytotoxicity assay, 12α-methoxy-ent-kaur-9(11),16-dien-19-oic acid (1) (IC50 = 27.3 ± 1.9 µM) and 9β-hydroxy-15α-angeloyloxy-ent-kaur-16-en-19-oic acid (3) (IC50 = 24.7 ± 2.8 µM) were the most cytotoxic against the hepatocellular carcinoma (Hep-G2) cell line, while 15α-angeloyloxy-16β,17-epoxy-ent-kauran-19-oic acid (5) (IC50 = 30.7 ± 1.7 µM) was the most cytotoxic against adenocarcinomic human alveolar basal epithelial (A549) cells.
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