Apoptotic and Cell Cycle Effects of Triterpenes Isolated from Phoradendron wattii on Leukemia Cell Lines

Current antineoplastic agents present multiple disadvantages, driving an ongoing search for new and better compounds. Four lupane-type triterpenes, 3α,24-dihydroxylup-20(29)-en-28-oic acid (1), 3α,23-dihydroxy-30-oxo-lup-20(29)-en-28-oic acid (2), 3α,23-O-isopropylidenyl-3α,23-dihydroxylup-20(29)-en-28-oic acid (3), and 3α,23-dihydroxylup-20(29)-en-28-oic acid (4), previously isolated from Phoradendron wattii, were evaluated on two cell lines of chronic (K562) and acute (HL60) myeloid leukemia. Compounds 1, 2, and 4 decreased cell viability and inhibit proliferation, mainly in K562, and exhibited an apoptotic effect from 24 h of treatment. Of particular interest is compound 2, which caused arrest in active phases (G2/M) of the cell cycle, as shown by in silico study of the CDK1/Cyclin B/Csk2 complex by molecular docking. This compound [3α,23-dihydroxy-30-oxo-lup-20(29)-en-28-oic acid] s a promising candidate for incorporation into cancer treatments and deserves further study.     

A new triterpene from the plant of uncaria macrophylla

Our ongoing investigations on the stem bark of Uncaria macrophylla afforded a new ursolic triterpene, 3β,6β,19α-trihydroxy-urs-12-en-28-oic acid-24-carboxylic acid methyl ester (1), named uncariursanic acid, and three known ursolic triterpenes including 3β,6β,19α-trihydroxy-23-oxo-urs-12-en-28-oic acid (2), 3β,6β,19α-trihydroxy-urs-12-en-28-oic acid (3) and ursolic acid (4). Their structures were elucidated by extensive spectral methods, including 1D and 2D NMR and HR-ESI-MS. The cytotoxicities of the four compounds were evaluated against two cancer cell lines (MCF-7 and HepG2) by the MTT method, and only compound 4 exhibited potent activity.     

Triterpenes from the spores of Ganoderma lucidum and their cytotoxicity against meth-A and LLC tumor cells

Six new highly oxygenated lanostane-type triterpenes, called ganoderic acid gamma (1), ganoderic acid delta (2), ganoderic acid epsilon (3), ganoderic acid zeta (4), ganoderic acid eta (5) and ganoderic acid theta (6), were isolated from the spores of Ganoderma lucidum, together with known ganolucidic acid D (7) and ganoderic acid C2 (8). Their structures of the new triterpenes were determined as (23S)-7beta,15alpha,23-trihydroxy-3,11-dioxolanosta-8, 24(E)-diene-26-oic acid (1), (23S)-7alpha,15alpha23-trihydroxy-3,11-dioxolanosta-8, 24(E)-diene-26-oic acid (2), (23S)-3beta3,7beta, 23-trihydroxy-11,15-dioxolanosta-8,24(E)-diene-26-oic acid (3), (23S)-3beta,23-dihydroxy-7,11,15-trioxolanosta-8, 24(E)-diene-26-oic acid (4), (23S)-3beta,7beta,12beta,23-tetrahydroxy-11,15-dioxolanos ta-8,24(E)-diene-26-oic acid (5) and (23S)-3beta,12beta23-trihydroxy-7,11,15-trioxolanosta-8,24(E )-diene-26-oic acid (6), respectively, by chemical and spectroscopic means, which included the determination of a chiral center in the side chain by a modification of Mosher's method. The cytotoxicity of the compounds isolated from the Ganoderma spores was carried out in vitro against Meth-A and LLC tumor cell lines.     

Two new triterpenes from Duchesnea indica

Two new triterpenes,2α,3β-dihydroxyurs-12-en-18,19-epoxy-28-oic acid(1)and 18,19-seco,2α,3α-dihydroxyl-19-oxo-urs-11, 13(18)-dien-28-oic acid(2)were isolated from the herbaceous part of Duchesnea indica.Their structures were elucidated by spectroscopic analysis,including 2D NMR technique.The isolated compounds exhibited moderate cytotoxic activities against HeLa and L929 cell lines.     

Two new triterpenoids from Gypsophila oldhamiana

Two new triterpenoids (1–2) were isolated and elucidated from the roots of Gypsophila oldhamiana, together with four known triterpenoids (3–6). Their structures were identified to be 3β-hydroxyolean-13(18)-ene-23, 28-dioic acid (1), 3β, 12α-dihydroxy-23-carboxyolean-28, 13β-olide (2), 3β, 16α-dihydroxy-23-oxoolean-13(18)-en-28-oic acid (3), gypsogenin (4), quillaic acid (5) and gypsogenic acid (6) by spectral methods. All compounds were tested for their cytotoxicities against human tumour cell lines (lung cancer H460 and gastric cancer SGC-7901) and for their antiangiogenic effects using a zebra fish model. All compounds showed interesting antiangiogenic activities and the significant cytotoxicities against H460.     

New triterpenoids from Gentiana lutea

Three new triterpenoids, 2,3-seco-3-oxours-12-en-2-oic acid, 2,3-seco-3-oxoolean-12-en-2-oic acid, and betulin 3-O-palmitate, have been isolated from the rhizomes and roots of Gentiana lutea, together with five known ones. The structures of the new compounds were determined by spectral and chemical methods.     

New Triterpenes from the Heartwood of Melaleuca leucadendron L.

Fourteen chemical constituents were isolated from the CHCl₃ soluble portion of the heartwood of Melaleuca leucadendron L. These compounds include β-sitosterol (1) , β-sitostenone (2) , 6-hydroxy-4,6-dimethyl-3-hepten-2-one (3) , naphthalene (4) , squalene (5) , 2α3β-dihydroxyurs-12-en-28-oic acid (6) , 3β-hydroxylup-20(29)-en-27,28-dioic acid (7) , 2α,3β-dihydroxyolean-12-en-28-oic acid (8) , 3β,23-dihydroxyolean-12-en-28-oic acid (9) , 2α,3β,23-trihydroxyolean-12-en-28-oic acid (10) , 3β-trans-p-coumaroyloxy-2α,23-dihydroxyolean-12-en-28-oic acid (11) , and three novel oleanane derivatives 23-trans-p-coumaroyloxy-2α,3β-dihydroxyotean-12-en-28-oic acid (12), 3β-trans-caffeoyloxy-2α,23-dihydroxyolean-12-en-28-oic acid (13) , and its isomer 3β-cis-caffeoyloxy-2α,23-dihydroxyolean-12-en-28-oic acid (14) , The three novel compounds were characterized as the two and three O-methylated derivatives, respectively.     

Methyl quadrangularates A-D and related triterpenes from Combretum quadrangulare

From the MeOH extract of leaves of Combretum quadrangulare, fifteen new cycloartane-type triterpenes, methyl quadrangularates A-D (1-4) and N-P (8, 6, 12), methyl 24-epiquadrangularate C (5), quadrangularic acid E (9), 23-deoxojessic acid (10), 1-O-acetyl-23-deoxojessic acid (11), quadragularols A (7) and B (13) and norquadrangularic acids B (14) and C (15) were isolated together with two known cycloartane-type triterpenes, methyl 23-deoxojessate (16) and 4beta,14alpha-dimethyl-5alpha-ergosta-9beta++ +,19-cyclo-24(31)-en-3beta-hydroxy-4alpha-carboxylic acid (17). Betulinic acid (18), beta-sitosterol (19), kamatakenin (20), isokaempferide (21), 5,7,4'-trihydroxy-3,3'-dimethoxyflavone (22) and 5,4'-dihydroxy-3,7,3'-trimethoxyflavone (23) were also obtained from the same extract. The structures of the new compounds were elucidated on the basis of spectral analysis and chemical conversions. All the isolated compounds were tested for their cytotoxicity towards highly liver metastatic murine colon 26-L5 carcinoma cells, and the cycloartane-type triterpenes showed various degrees of cytotoxicity, whereas all the flavonoids possessed strong cytotoxicity with ED50 values equal to or less than 6 microM.     

Complete assignments of 1H and 13C NMR spectral data for three polyhydroxylated 12-ursen-type triterpenoids from Dischidia esquirolii

The complete assignments of all the (1)H and (13)C NMR signals of three polyhydroxylated 12-ursen-type triterpenes, 6beta,19alpha,22alpha-trihydroxyurs-12-en-3-oxo-28-oic acid (1), 3beta,6alpha,19alpha,23-tetrahydroxyurs-12-en-28- oic acid (2) and 3beta,6beta,19alpha,23-tetrahydroxyurs-12-en-28-oic acid (3), were carried out by means of homo- and hetero-nuclear two-dimensional NMR experiments. Compounds 1-3 were isolated from the aerial parts of Dischidia esquirolii. Of them, 1 and 2 were identified as new polyhydroxylated ursolic acid derivatives. Compound 2 is the C-6 hydroxyl epimer of 3, which was isolated first from Adina rubella, and its structure is revised in this paper.     

Cytotoxic and anti-HIV principles from the rhizomes of Begonia nantoensis

Three new compounds: begonanline (1). nantoamide (2). and methyl (S)-glycerate (3). as well as forty-four known compounds have been isolated and characterized from the rhizomes of Begonia nantoensis. The structures of these compounds were determined by spectral analyses and/or X-ray crystallography. Among them, cucurbitacin B (4). dihydrocucurbitacin B (5). cucurbitacin E (6). dihydrocucurbitacin E (7). cucurbitacin I (8). and (-)-auranamide (9). showed cytotoxicity against four human cancer cell lines. 3beta,22alpha-Dihydroxyolean-12-en-29-oic acid (10), indole-3-carboxylic acid (11), 5,7-dihydroxychromone (12), and (-)-catechin (13) demonstrated significant activity against HIV replication in H9 lymphocyte cells.     

Lupane Triterpene Derivatives Improve Antiproliferative Effect on Leukemia Cells through Apoptosis Induction

Leukemia is one of the most frequent types of cancer. No effective treatment currently exists, driving a search for new compounds. Simple structural modifications were made to novel triterpenes isolated from Phoradendron wattii. Of the three resulting derivatives, 3α-methoxy-24-hydroxylup-20(29)-en-28-oic acid (T1m) caused a decrease in the median inhibitory concentration (IC₅₀) on the K562 cell line. Its mode of action was apparently apoptosis, ROS generation, and loss of mitochondrial membrane potential (MMP). Molecular docking analysis showed T1m to produce lower binding energies than its precursor for the Bcl-2 and EGFR proteins. Small, simple, and viable modifications to triterpenes can improve their activity against leukemia cell lines. T1m is a potentially promising element for future research. Clarifying the targets in its mode of action will improve its applicability.     

New triterpene glucosides from the roots of Rosa laevigata Michx

Two new ursane-type triterpene glucosides, 2alpha,3alpha,24-trihydroxyurs-12,18-dien-28-oic acid beta-D-glucopyranosyl ester (1) and 2alpha,3alpha,23-trihydroxyurs-12,19(29)-dien-28-oic acid beta-D-glucopyranosyl ester (2), were isolated from the roots of Rosa laevigata, together with three known compounds: 2alpha,3beta,19alpha-trihydroxyurs-12-en-28-oic acid beta-Dglucopyranosyl ester (3), 2alpha,3alpha,19alpha-trihydroxyurs-12-en-28-oic acid beta-D-glucopyranosyl ester (4) and 2alpha,3beta,19alpha,23-tetrahydroxyurs-12-en-28-oic acid beta-D-glucopyranosyl ester (5). The structures of new compounds were established on the basis of detailed 1D and 2D NMR spectroscopic analyses. Compounds 2 and 5 exhibited modest in vitro antifungal activities against Candida albicans and C. krusei.     

D:C-friedooleanane-type triterpenoids from Lagenaria siceraria and their cytotoxic activity

Four new D:C-friedooleanane-type triterpenes, 3 beta-O-(E)-feruloyl-D:C-friedooleana-7,9(11)-dien-29-ol (1), 3 beta-O-(E)-coumaroyl-D:C-friedooleana-7,9(11)-dien-29-ol (2), 3 beta-O-(E)-coumaroyl-D:C-friedooleana-7,9(11)-dien-29-oic acid (3), and methyl 2 beta,3 beta-dihydroxy-D:C-friedoolean-8-en-29-oate (6), together with five known triterpenes with the same skeleton, 3-epikarounidiol (4), 3-oxo-D:C-friedoolena-7,9(11)-dien-29-oic acid (5), bryonolol (7), bryononic acid (8), and 20-epibryonolic acid (9), were isolated from the methanol extract of the stems of Lagenaria siceraria. The structures of those compounds were elucidated using spectroscopic methods. Compounds 3 and 9 showed significant cytotoxic activity against the SK-Hep 1 cell line with IC50 values of 4.8 and 2.1 microg/ml, respectively. Based on these initially promising results, the two D:C-friedooleanane triterpenes merit further study as potential anticancer agents.     

Cytotoxic and apoptotic activities of novel Pd(II) complexes against human leukemia cell lines in vitro

In the investigation for alternative chemotherapeutic strategies against leukemia, Pd(II) complexes were synthesized and investigated for cytotoxic and apoptotic properties on two human leukemia cell lines (HL-60 and K562). Pd(II) complexes (Pd-5a and Pd-6a) with 5a and 6a as ligands were synthesized and characterized by ¹H-NMR and F-TIR. The cytotoxicity of the compounds was quantified using MTT method. Bax, Bcl-2, and caspase 3 gene expression levels were estimated using RT-qPCR. Here we show that Pd(II) complexes have important cytotoxic activity on human leukemia cell lines. RT-qPCR indicated that Bax and caspase 3 gene expression levels were increased after 24 h treatment with Pd-5a and Pd-6a complexes in both HL-60 and K562 cells at some selected dose. Furthermore, Bcl-2 gene expression level decreased after 24 h treatment with Pd-5a and Pd-6a complexes in K562 cells at all selected dose. In HL-60 cells, only one selected Pd-5a dose (25 µM) decreased the gene expression level of Bcl-2. The results obtained in the present investigation indicate that these two newly synthesized Pd(II) complexes have apoptotic effects at appropriate doses through caspase 3 and Bax genes and might represent a novel potentially active agents for the management of human leukemia cell lines.     

New lanostane-type triterpenes from Fomes officinalis

Five new lanostane-type triterpenes, named fomefficinic acid A-E (1-5), were isolated from the dried sclerotium of Fomes officinalis, respectively. Their structures were established as 24-methylene-3-oxo-lanost-8-en-21-oic acid (1), 3alpha,15alpha-dihydroxy-24-methylene-lanosta-7,9(11)-dien-21-oic acid (2), 3alpha,15alpha-dihydroxy-24-methylene-lanost-8-en-21-oic acid (3), 15alpha-hydroxy-3-oxo-24-methylenelanost-8-en-21-oic acid (4), 15alpha-acetoxy-3-oxo-24-methylenelanosta-7,9(11)-dien-21-oic acid (5), by spectral analysis and chemical methods as well as comparison with known compounds.     

Cytotoxic germacranolide sesquiterpene from Inula cappa

A new germacranolide, inulacappolide (1), was isolated from the EtOH extract of the whole plant of Inula cappa along with 16 known compounds. The structure of inulacappolide was a rare 1(10)-saturated type of germacran-6,12-olide, identified as 2alpha-acetoxy-3beta-hydroxy-9beta-angeloyloxygermacra-4-en-6alpha,12-olide by spectral analysis (IR, HR-ESI/MS, (1)H-NMR, (13)C-NMR, HMQC, HMBC, NOESY). In vitro, it showed antiproliferative effects against human cervical cancer HeLa, human leukemia K562 and human nasopharyngeal carcinoma KB cell lines with IC(50) values of 1.2 microM, 3.8 microM and 5.3 microM, respectively.     

五叶木通中一个新的三萜成分

对五叶木通藤茎进行了较为系统的研究, 从其体积分数为80%的乙醇提取物的正丁醇部分分离得到3个三萜成分, 通过理化性质和波谱分析鉴定为: 3α,24-二羟基-30-去甲齐墩果烷-12,20(29)-双烯-28-酸(Ⅰ); 3α,24,29-三羟基齐墩果烷-12-烯-28-酸(Ⅱ); 2α,3β,23-三羟基齐墩果烷-12-烯-28-酸(Ⅲ). 其中化合物Ⅱ为新化合物, 命名为木通茎酸(Quinatic stem acid).     

19-nor-11-Oxooleanan-12-ene and 18,19-seco-19-oxours-11,13(18)-diene triterpenes from Diospyros decandra bark

Four new triterpenes, 2α,3β-dihydroxy-19-nor-11-oxo-20-dimethylurs-12-en-24,28-dioic acid (equivalent to 2α,3β-dihydroxy-19-nor-11-oxoolean-12-en-24,28-dioic acid), 2α,3β-dihydroxy-18,19-seco-19-oxours-11,13(18)-dien-24,28-dioic acid, 2α,3β,19α-trihydroxy-11-oxours-12-en-24,28-dioic acid and 2α,3β,19α-trihydroxy-28-1′-β-d-[glucopyranosyl-(1″→6′)-glucopyranosyl]-urs-12-en-24,28-dioic acid were isolated from the methanol extract of the bark of Diospyros decandra as their acetate-methyl ester derivatives. The first two compounds represent the biosynthetic transformation products of 2α,3β,19-trihydroxyurs-24,28-dioic acid via oxidative rearrangement of ring E.     

New triterpenoid saponins from Stelmatocrypton khasianum

Four new triterpenoid saponins, designated as stelmatotriterpenosides E-H (1-4), together with three known compounds, asterbatanoside B (5), 2alpha,3beta,19alpha,23-tetrahydroxy-olean-12-en-28-oic acid-3-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl ester (6) and 2alpha,3beta,19alpha,23-tetrahydroxy-urs-12-en-28-oic acid-3-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl ester (7), were isolated from the stems of Stelmatocrypton khasianum. On the basis of chemical and spectral evidence, the structures of 1-4 were established as 2alpha,3beta,23-trihydroxy-olean-12-en-28-oic acid-3-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (1), 2alpha,3beta,23-trihydroxy-urs-12-en-28-oic acid-3-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl ester (2), 2alpha,3beta,19alpha-trihydroxy-urs-12-en-28-oic acid-3-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl-(1-->2)-beta-D-glucopyranosyl ester (3), and 2beta,3beta,19alpha-trihydroxy-urs-12-en-24,28-dioic acid-24-O-beta-D-glucopyranosyl-28-O-beta-D-glucopyranosyl diester (4).     

Design, synthesis, and biological evaluation of novel spin-labeled derivatives of podophyllotoxin as potential antineoplastic agents. Part XII

Five novel nitroxyl spin-labeled ester derivatives of podophyllotoxin (11a-11e) have been prepared and their structural information on these nitroxyl spin-labeled ester derivatives of podophyllotoxin (11a-11e) using (1)HNMR spectroscopy was efficiently obtained by application of the in situ reduction of representative nitroxyl spin-labeled ester derivative of podophyllotoxin 11e with phenylhydrazine for the preparation of N-hydroxylamine 12 in the NMR tube. These novel derivatives were further evaluated for their in vitro cytotoxic activity against five neoplastic cell lines (K562, HL-60, SPCA-1, Lewis, and L-1210) using MTT assay. Most of the target compounds (except for all these compounds against SPCA-1) exhibited more pronounced cytotoxicity against several neoplastic cell lines than that of the prototypical inhibitor etoposide.