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Full-Text Articles in Other Pharmacy and Pharmaceutical Sciences
Antiplasmodial And Antioxidant Isoquinoline Alkaloids From Dehaasia Longipedicellata, Kok Hoong Leong
Antiplasmodial And Antioxidant Isoquinoline Alkaloids From Dehaasia Longipedicellata, Kok Hoong Leong
Kok Hoong Leong
The crude extract of the bark of Dehaasia longipedicellata exhibited antiplasmodial activity against the growth of Plasmodium falciparum K1 isolate (resistant strain). Phytochemical studies of the extract led to the isolation of six alkaloids: two morphinandienones, (+)-sebiferine (1) and (−)-milonine (2); two aporphines, (−)-boldine (3) and (−)-norboldine (4); one benzlyisoquinoline, (−)-reticuline (5); and one bisbenzylisoquinoline, (−)-O-O-dimethylgrisabine (6). Their structures were determined on the basis of 1D and 2D NMR, IR, UV, and LCMS spectroscopic techniques and upon comparison with literature values. Antiplasmodial activity was determined for all of the isolated compounds. They showed potent to moderate activity with IC50 values …
Subditine, A New Monoterpenoid Indole Alkaloid From Bark Of Nauclea Subdita (Korth.) Steud. Induces Apoptosis In Human Prostate Cancer Cells, Kok Hoong Leong
Subditine, A New Monoterpenoid Indole Alkaloid From Bark Of Nauclea Subdita (Korth.) Steud. Induces Apoptosis In Human Prostate Cancer Cells, Kok Hoong Leong
Kok Hoong Leong
In this study, a new apoptotic monoterpenoid indole alkaloid, subditine (1), and four known compounds were isolated from the bark of Nauclea subdita. Complete 1H- and 13C- NMR data of the new compound were reported. The structures of isolated compounds were elucidated with various spectroscopic methods such as 1D- and 2D- NMR, IR, UV and LCMS. All five compounds were screened for cytotoxic activities on LNCaP and PC-3 human prostate cancer cell-lines. Among the five compounds, the new alkaloid, subditine (1), demonstrated the most potent cell growth inhibition activity and selective against LNCaP with an IC50 of 12.2460.19 mM and …
Kingianic Acids A–G, Endiandric Acid Analogues From Endiandra Kingiana, Kok Hoong Leong
Kingianic Acids A–G, Endiandric Acid Analogues From Endiandra Kingiana, Kok Hoong Leong
Kok Hoong Leong
A phytochemical investigation of the methanolic extract of the bark of Endiandra kingiana led to the isolation of seven new tetracyclic endiandric acid analogues, kingianic acids A–G (1–7), together with endiandric acid M (8), tsangibeilin B (9) and endiandric acid (10). Their structures were determined by 1D- and 2D-NMR analysis in combination with HRMS experiments. The structure of compounds 9 and 10 were confirmed by single-crystal X-ray diffraction analysis. These compounds were screened for Bcl-xL and Mcl-1 binding affinities and cytotoxic activity on various cancer cell lines. Compound 5 showed moderate cytotoxic activity against human colorectal adeno-carcinoma (HT-29) and lung …
Design, Synthesis And Cytotoxic Evaluation Of O-Carboxamido Stilbene Analogues, Kok Hoong Leong
Design, Synthesis And Cytotoxic Evaluation Of O-Carboxamido Stilbene Analogues, Kok Hoong Leong
Kok Hoong Leong
Resveratrol, a natural stilbene found in grapes and wines exhibits a wide range of pharmacological properties. Resveratrol is also known as a good chemopreventive agent for inhibiting carcinogenesis processes that target kinases, cyclooxygenases, ribonucleotide reductase and DNA polymerases. A total of 19 analogues with an amide moiety were synthesized and the cytotoxic effects of the analogues on a series of human cancer cell lines are reported. Three compounds 6d, 6i and 6n showed potent cytotoxicity against prostate cancer DU-145 (IC50 = 16.68 μM), colon cancer HT-29 (IC50 = 7.51 μM) and breast cancer MCF-7 (IC50 = 21.24 μM), respectively, which …
Induction Of Apoptosis In Melanoma A375 Cells By A Chloroform Fraction Of Centratherum Anthelminticum (L.) Seeds Involves Nf-Kappab, P53 And Bcl-2-Controlled Mitochondrial Signaling Pathways, Kok Hoong Leong
Kok Hoong Leong
Centratherum anthelminticum (L.) Kuntze (scientific synonyms: Vernonia anthelmintica; black cumin) is one of the ingredients of an Ayurvedic preparation, called “Kayakalp”, commonly applied to treat skin disorders in India and Southeast Asia. Despite its well known anti-inflammatory property on skin diseases, the anti-cancer effect of C. anthelminticum seeds on skin cancer is less documented. The present study aims to investigate the anti-cancer effect of Centratherum anthelminticum (L.) seeds chloroform fraction (CACF) on human melanoma cells and to elucidate the molecular mechanism involved.
Cytotoxic And Antioxidant Compounds From The Stem Bark Of Goniothalamus Tapisoides Mat Salleh, Kok Hoong Leong
Cytotoxic And Antioxidant Compounds From The Stem Bark Of Goniothalamus Tapisoides Mat Salleh, Kok Hoong Leong
Kok Hoong Leong
Eleven compounds:goniomicin A (1), goniomicin B (2), goniomicin C (3), goniomicin D (4), tapisoidin (5), goniothalamin (6), 9-deoxygoniopypyrone (7), pterodondiol (8), liriodenine (9), benzamide (10) and cinnamic acid (11), were isolated from the stem bark of Goniothalamus tapisoides. All compounds were identified by spectroscopic analysis and, for known compounds, by comparison with published data. Goniothalamin (6) exhibited mild cytotoxic activity towards a colon cancer cell line (HT-29), with an IC50value of 64.17 ± 5.60 μM. Goniomicin B (2) give the highest antioxidant activity in the DPPH assay among all compounds tested, with an IC50 of 0.207 μM.
Triterpenes And Steroids From The Leaves Of Aglaia Exima (Meliaceae), Kok Hoong Leong
Triterpenes And Steroids From The Leaves Of Aglaia Exima (Meliaceae), Kok Hoong Leong
Kok Hoong Leong
A study on the leaves of Aglaia exima led to the isolation of one new and seven known compounds: six triterpenoids and two steroids. Their structures were elucidated and analyzed mainly by using spectroscopic methods; 1D and 2D NMR, mass spectrometry, UV spectrometry and X-ray. All the triterpenoids and steroids were measured in vitro for their cytotoxic activities against eight cancer cell lines; lung (A549), prostate (DU-145), skin (SK-MEL-5), pancreatic (BxPC-3), liver (Hep G2), colon (HT-29), breast (MCF-7) and (MDA-MB-231). The new cycloartane triterpenoid, 24(E)-cycloart-24-ene-26-ol-3-one 1, showed potent cytotoxic activity against colon (HT-29) cancer cell line (IC50 11.5 μM).
Spectaflavoside A, A New Potent Iron Chelating Dimeric Flavonol Glycoside From The Rhizomes Of Zingiber Spectabile Griff, Kok Hoong Leong
Spectaflavoside A, A New Potent Iron Chelating Dimeric Flavonol Glycoside From The Rhizomes Of Zingiber Spectabile Griff, Kok Hoong Leong
Kok Hoong Leong
The rhizomes of Zingiber spectabile yielded a new dimeric flavonol glycoside for which the name kaempferol-3-O-(4″-O-acetyl)-α-l-rhamnopyranoside-(I-6,II-8)-kaempferol-3-O-(4″-O-acetyl)-α-l-rhamnopyranoside; spectaflavoside A (1) was proposed, along with kaempferol and its four acetylrhamnosides (2–6), demethoxycurcumin (7) and curcumin (8). The structure of spectaflavoside A was elucidated by spectroscopic methods including, 1D and 2D NMR techniques. This is the first report on the occurrence of a dimeric flavonol glycoside in the Zingiberaceae and the second in nature. Spectaflavoside A was found to be a potent iron chelating agent.