Antiplasmodial and other constituents from four Indonesian Garcinia spp

Phytochemical profile and diverse pharmacology of Garcinia celebica L

Garcinia celebica L. syn. Garcinia hombroniana Pierre belongs to the family Clusiaceae, is indigenous to Southeast Asian countries. This review aims to provide updated, comprehensive and categorized information on the phytoconstituents and pharmacological effects of this species. The data collection mainly involved searches through databases named Scopus, Google Scholar, Pubmed and Springer Link. Approximately 100 phytochemicals were recorded in this review, with various classes of compounds such as triterpenoids, flavonoids, benzophenones, xanthones, depsidones and sterols identified. The most abundant compounds isolated belong to two chemical classes: triterpenoids and xanthones. Their extracts and pure compounds have been reported for their antibacterial, antiparasitic, hepatoprotective, antioxidant, antidiabetic, antituberculosis, antiplatelet aggregation, anti-neuraminidase and cholinesterase inhibitory activities. This review will provide a comprehensive understanding between the phytochemical components and its medicinal uses that may serve as a valuable resource for future drug development.

Structurally Diverse Cytotoxic Polyphenols from Garcinia gracilis

Thirty-five diverse polyphenols, belonging to seven structure classes, were isolated from Garcinia gracilis, a medicinal and edible plant sampled from Laos. The structures of nine new compounds, gargarcilones A-I (1-3, 5-7, 10, 12, and 17), were established using spectroscopic, X-ray diffraction, and experimental and calculated ECD methods. Additionally, we revised the stereochemical assignment of cochinchinoxanthone and cochinchinoxanthone C. The compounds were evaluated for antiproliferative activity against five human tumor cell lines (HL-60, A549, SMMC-7721, MDA-MB-231, and SW480). Compounds 1-4, 7, and 8 exhibited cytotoxic activity with IC50 values of 0.5-8.9 μM. Compound 3 significantly induced apoptosis in SMMC-7721 cells.

Biphenyls in Clusiaceae: Isolation, structure diversity, synthesis and bioactivity

Clusiaceae plants contain a wide range of biologically active metabolites that have gotten a lot of interest in recent decades. The chemical compositions of these plants have been demonstrated to have positive effects on a variety of ailments. The species has been studied for over 70 years, and many bioactive compounds with antioxidant, anti-proliferative, and anti-inflammatory properties have been identified, including xanthones, polycyclic polyprenylated acylphloroglucinols (PPAPs), benzophenones, and biphenyls. Prenylated side chains have been discovered in many of these bioactive substances. To date, there have been numerous studies on PPAPs and xanthones, while no comprehensive review article on biphenyls from Clusiaceae has been published. The unique chemical architectures and growing biological importance of biphenyl compounds have triggered a flurry of research and interest in their isolation, biological evaluation, and mechanistic studies. In particular, the FDA-approved drugs such as sonidegib, tazemetostat, daclatasvir, sacubitril and trifarotene are closely related to their biphenyl-containing moiety. In this review, we summarize the progress and development in the chemistry and biological activity of biphenyls in Clusiaceae, providing an in-depth discussion of their structural diversity and medicinal potential. We also present a preliminary discussion of the biological effects with or without prenyl groups on the biphenyls.

Morelloflavone as Potential Anticancer Agent Against MCF-7 Breast Cancer Cell Lines: In vitro and In silico Studies

Background:

Breast cancer is most commonly reported to contribute to people's death. Nowadays, cancer treatment is focused on investigating anticancer drugs from natural compounds. Various methods, including in vitro, in vivo, and in silico methods, are used to assess the potential of anticancer compounds. The efficacy of bioactive compounds from medicinal plant origin lies in their affordability and minimized side effects. The Garcinia genus contains bioactive compounds, such as xanthones, benzophenones, triterpenes, biflavonoids, and benzoquinones.

Purpose:

The study aimed at investigating an active compound that can inhibit cancer cell growth and proteins that contribute to cancer cell growth, such as Caspase-9, TNF-α, ER-α, and HER-2.

Methods:

This study is divided into three steps. The first step is the isolation of the active compound from G. cymosa. The second step is an assessment of cytotoxic activity against MCF-7 cell by using MTT assay, and the last one is an investigation of the molecular mechanism of an active compound against Caspase-9, TNF-α, ER-α, and HER-2 by using in silico studies utilizing various programs, such as PyRx 0.8, PYMOL, and Discovery Studio.

Results:

Morelloflavone from G. cymosa stem barks has exhibited anticancer activity (55.84 μg/mL) eight times lower than doxorubicin (6.99 μg/mL), but it can block the activity of Caspase-9, TNF-α, ER- α, and HER-2. The binding affinity of morelloflavone is the strongest of all ligands.

Conclusion:

The natural flavonoid, morelloflavone, may be a new lead candidate for anticancer agent inhibiting action mechanism of Caspase-9, TNF-α, ER-α, and HER-2, respectively.

Biological Activity Evaluation and In Silico Studies of Polyprenylated Benzophenones from Garcinia celebica

This study aimed to isolate polyprenylated benzophenones from the rootbark of Garcinia celebica and assess their activities in vitro and in silico. The antioxidant activity was evaluated by the DPPH, ABTS, and FRAP methods. The cytotoxicity was evaluated against HeLa, MCF-7, A549, and B16 cancer cell lines. The antiplasmodial activity was performed against the chloroquine-sensitive Plasmodium falciparum strain 3D7. Molecular docking was analyzed on alpha-estrogen receptor (3ERT) and P. falciparum lactate dehydrogenase enzyme (1CET). The prediction of ADMET for the compounds was also studied. For the first time, (-)-cycloxanthochymol, isoxanthochymol, and xanthochymol were isolated from the root bark of Garcinia celebica. The antioxidant and cytotoxicity evaluation showed that all benzophenones exhibited antioxidant activity compared to gallic acid and quercetin as positive controls and also exhibited strong activity against HeLa, MCF-7, A549, and B16 cell lines compared to cisplatin as the positive control. The antiplasmodial evaluation showed that isoxanthochymol exhibited activity against the chloroquine-sensitive P. falciparum strain 3D7. In addition, the in silico molecular docking study supported in vitro activities. The ADMET analysis also indicated the isolated benzophenones are potential oral drug candidates.

Anti-Neuraminidase Bioactives from Manggis Hutan (Garcinia celebica L.) Leaves: Partial Purification and Molecular Characterization

The neuraminidase enzyme (NA) from the influenza virus is responsible for the proliferation and infections of the virus progeny, prompting several efforts to discover and optimize effective neuraminidase inhibitors. The main aim of this study is to discover a new potential neuraminidase inhibitor that comes from Garcinia celebica leaves (GCL). The bioassay-guided isolation method was performed to obtain lead compounds. The binding interaction of the isolated compounds was predicted by using molecular docking studies. Friedeline (GC1, logP > 5.0), two lanastone derivatives (methyl-3α,23-dihydroxy-17,14-friedolanstan-8,14,24-trien-26-oat (GC2) and 24E-3a,9,23-trihydroxy-17,14-friedolanostan-14,24-dien-26-oate (GC3) with LogP > 5.0) and catechin (GC4, LogP = 1.4) were identified. The inhibitory potency of these four compounds on NA from C. perfringens and H₁N₁ was found to be as follows: GC4 > GC2 > GC3 > GC1. All compounds exhibited higher inhibitory activity towards C. perfringens NA compared to H₁N₁ NA. From the molecular docking results, GC4 favorably docked and interacted with Arg118, Arg371, Arg292, Glu276 and Trp178 residues, whilst GC2 interacted with Arg118, Arg371, Arg292, Ile222, Arg224 and Ser246. GC3 interacted with Tyr406 only. GC4 had potent NA inhibition with free energy of binding of −12 kcal/mol. In the enzyme inhibition study, GC4 showed the highest activity with an IC₅₀ of 60.3 µM and 91.0 µM for C. perfringens NA and H₁N₁ NA—respectively.

New triterpenoids and PTP1B inhibitory constituents of Pseudolarix amabilis

Six new triterpenoids, pseudolarins A-F (1-6), were isolated from the twigs of Pseudolarix amabilis, together with four known triterpenoids (7-10) and five known diterpenoids (11-15). Their structures were determined by extensive spectroscopic analysis, and the absolute configuration of 1 was assigned by single-crystal X-ray diffraction. Compound 1 is a 3,4:9,10-diseco-cycloartane triterpenoid possessing an unprecedented 5/5/7/6/5/6/5 ring system. Compounds 1, 5, 7, 9-11, and 13 showed inhibition against protein tyrosine phosphatase 1B (PTP1B) in vitro.

Ganoderma terpenoid extract exhibited anti-plasmodial activity by a mechanism involving reduction in erythrocyte and hepatic lipids in Plasmodium berghei infected mice

Bioactive components of Ganoderma lucidum has recently gained intense research attention due to their acclaimed nutritional and medicinal properties. Thus, the terpenoid extract from the fruit bodies of G. lucidum (GT) was evaluated for activity against Plasmodium berghei in mice in two separate experiments. In addition, the effects of the extract on erythrocyte and hepatic lipids as well as liver HMG-CoA reductase activity before and after the treatments were also assessed. Mice with established infection were administered 100 and 250 mg/kg/day GT alone and in combination with chloroquine (CQ), in either case two separate controls designated: CQ (30 mg/kg chloroquine) and INF-CTR (1 mL DMSO) were also included. Treatment was administered orally for 12 days and parasitemia determined every three days. Percentage survival was significantly increased to 87% from 66% due to combination of GT100 with CQ compared to GT100 alone and to 75% from 62% when GT250 was administered with CQ compared to GT250 alone. Erythrocyte triglycerides, total cholesterol (TC), LDL and phospholipids contents were significantly lower in GT + CQ-treated mice compared to CQ alone and INF-CTR. Similarly, hepatic TC and phospholipid levels were significantly lower in the GT + CQ-treated mice compared to CQ alone and INF-CTR and HMG-CoA reductase activity in the liver was significantly inhibited due to administration of GT + CQ. Data from this study suggest that the anti-plasmodial action of GT could involve mechanisms associated with its hypolipidemic activity. It was also demonstrated that chloroquine, when administered in combination with GT, potentiates its curative effect in P. berghei-infected mice.

Cytotoxic Effects of Pinnatane A Extracted from Walsura pinnata (Meliaceae) on Human Liver Cancer Cells

BACKGROUND

Pinnatane A from the bark of Walsura pinnata was investigated for its anti-cancer properties by analyzing the cytotoxic activities and cell cycle arrest mechanism induced in two different liver cancer cell lines.

METHODS

A 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used to analyze the pinnatane A selectivity in inducing cell death in cancer and normal cells. Various biological assays were carried out to analyze the anti-cancer properties of pinnatane A, such as a live/dead assay for cell death microscopic visualization, cell cycle analysis using propidium iodide (PI) to identify the cell cycle arrest phase, annexin V-fluorescein isothiocyanate (annexin V-FITC)/PI flow cytometry assay to measure percentage of cell populations at different stages of apoptosis and necrosis, and DNA fragmentation assay to verify the late stage of apoptosis.

RESULTS

The MTT assay identified pinnatane A prominent dose- and time-dependent cytotoxicity effects in Hep3B and HepG2 cells, with minimal effect on normal cells. The live/dead assay showed significant cell death, while cell cycle analysis showed arrest at the G₀/G₁ phase in both cell lines. Annexin V-FITC/PI flow cytometry and DNA fragmentation assays identified apoptotic cell death in Hep3B and necrotic cell death in HepG2 cell lines.

CONCLUSIONS

Pinnatane A has the potential for further development as a chemotherapeutic agent prominently against human liver cells.

Cycloartane Triterpenoids with Anti-melanin Deposition Activity

Bioactivity guided separation of the extract of Malaysian Garcinia sp. resulted in the isolation of 23-acetoxy-mangiferonic acid (1) and the absolute configuration of C-23 was elucidated to be R by the advanced Mosher's method. The anti-melanin deposition activity of 1 was caused by the down regulation of tyrosinase gene expression.

Chemical Constituents from Walsura pinnata (Meliaceae)

A phytochemical study on the bark of Walsura pinnata has led to the isolation of a new oleanane triterpene acid, 3-oxo-olean-9(11),12-dien-28-oic acid (1), together with nine known compounds (2–10). Their structures were established on the basis of the detailed spectroscopic analysis, including one- and two-dimensional NMR, ESI-MS and HR-ESI-MS techniques. Compounds 2, 3, 5, 6 and 8 were isolated from W. pinnata for the first time. Compounds 3 and 4 showed in vitro growth inhibitory activity against two human cancer cell lines MCF-7 and SK-OV-3 with IC50 values within the range of 8.85 - 18.28 μg/mL. To the best of our knowledge, this is the first report on the cytotoxic activity of compound 3 towards both cancer cell lines.

Chemical Constituents of Propolis from Vietnamese Trigona minor and Their Antiausterity Activity against the PANC-1 Human Pancreatic Cancer Cell Line

The ethanol extract of propolis from the Vietnamese stingless bee Trigona minor possessed potent preferential cytotoxicity against PANC-1 human pancreatic cancer cells in nutrient-deprived medium, with a PC₅₀ value of 14.0 μg/mL. Chemical investigation of this extract led to the isolation of 15 cycloartane-type triterpenoids, including five new compounds (1-5), and a lanostane-type triterpenoid. The structures of the new compounds were elucidated on the basis of NMR spectroscopic analysis. Among the isolated compounds, 23-hydroxyisomangiferolic acid B (5) and 27-hydroxyisomangiferolic acid (13) exhibited the most potent preferential cytotoxicity against PANC-1 human pancreatic cancer cells under nutrition-deprived conditions, with PC₅₀ values of 4.3 and 3.7 μM, respectively.

Scalemic Caged Xanthones Isolated from the Stem Bark Extract of Garcinia propinqua

Seven new caged xanthones, doitunggarcinones E-K (1-7), all as scalemic mixtures and 10 known compounds (8-17), were isolated from the stem bark extract of Garcinia propinqua. The structures were elucidated on the basis of spectroscopic methods. The separation of the enantiomers of 1-6 was achieved by semipreparative chiral HPLC. The absolute configuration of compound (+)-1 was determined by single-crystal X-ray crystallographic analysis using Cu Kα radiation. The absolute configurations of the other related compounds were determined from comparisons of their ECD spectra with that of compound (+)-1. Compounds (-)-6 and 7 showed cytotoxicity against a colon cancer cell line with IC₅₀ values of 14.23 and 23.95 μM, respectively.

IN VIVO CARBON TETRACHLORIDE-INDUCED HEPATOPROTECTIVE AND IN VITRO CYTOTOXIC ACTIVITIES OF GARCINIA HOMBRONIANA (SEASHORE MANGOSTEEN)

BACKGROUND

Garcinia hombroniana, known as "manggis hutan" (jungle mangosteen) in Malaysia, is distributed in tropical Asia, Borneo, Thailand, Andaman, Nicobar Islands, Vietnam and India. In Malaysia, its ripened crimson sour fruit rind is used as a seasoning agent in curries and culinary dishes. Its roots and leaves decoction is used against skin infections and after child birth. This study aimed to evaluate in vivo hepatoprotective and in vitro cytotoxic activities of 20% methanolic ethyl acetate (MEA) G. hombroniana bark extract.

MATERIALS AND METHODS

In hepatoprotective activity, liver damage was induced by treating rats with 1.0 mL carbon tetrachloride (CCl4)/kg and MEA extract was administered at a dose of 50, 250 and 500 mg/kg 24 h before intoxication with CCl4. Cytotoxicity study was performed on MCF-7 (human breast cancer), DBTRG (human glioblastoma), PC-3 (human prostate cancer) and U2OS (human osteosarcoma) cell lines. 1H, 13C-NMR (nuclear magnetic resonance), and IR (infrared) spectral analyses were also conducted for MEA extract.

RESULTS

In hepatoprotective activity evaluation, MEA extract at a higher dose level of 500 mg/kg showed significant (p<0.05) potency. In cytotoxicity study, MEA extract was more toxic towards MCF-7 and DBTRG cell lines causing 78.7% and 64.3% cell death, respectively. MEA extract in 1H, 13C-NMR, and IR spectra exhibited bands, signals and J (coupling constant) values representing aromatic/phenolic constituents.

CONCLUSIONS

From the results, it could be concluded that MEA extract has potency to inhibit hepatotoxicity and MCF-7 and DBTRG cancer cell lines which might be due to the phenolic compounds depicted from NMR and IR spectra.

Allanblackia floribunda Oliv.: An aphrodisiac plant with vasorelaxant properties

ETHNOPHARMACOLOGICAL RELEVANCE

Allanblackia floribunda Oliv. is one of the most commonly used medicinal plant in Cameroon. The stem bark of the plant is traditionally used for its aphrodisiac and antihypertensive properties.

AIM OF THE STUDY

To validate the traditional uses of Allanblackia floribunda stem bark ethanol extract through the evaluation of their aphrodisiac and vasorelaxant properties.

MATERIALS AND METHODS

The extract's ability to increase sexual desire and the frequencies of erection (mount), intromission and prolonged latency of ejaculation were studied on adult male rats. The vasodilator effect was investigated using isolated rat aorta rings. Tests were conducted using fractions obtained by reverse phase column-chromatography (CC), after the acquisition of the HPLC fingerprint of the ethanol extract, resulted the most active in previous studies.

RESULTS

The CC allowed the isolation of five fractions whose aphrodisiac and vasodilator activities were tested and compared with those of the whole extract. Four compounds were identified and characterized, three of them, Fukugiside, Morelloflavone and Volkensiflavone, are secondary metabolites known to be in Allanblackia floribunda; the fourth, Spicataside, is a biflavonoid glycoside known to be present in the genus Garcinia but never found neither in Allanblackia floribunda nor in Allanblackia genus. The crude ethanolic extract (CEE) induced a relaxation on aorta rings with EC₅₀=11±2μg/mL and Morelloflavone displayed a similar activity with EC₅₀=42±6μg/mL; for all the other compounds only the vasodilation % at the maximum concentration assessable (90μg/mL) was determined: 30±8 (Fukugiside), 24±6 (Spicataside), 33±4 (Morelloflavone+Volkensiflavone), 47±1 (Volkensiflavone). Regarding the activity on male sexual behaviour, only CEE and Fukugiside showed activity in the 9 parameters evaluated.

CONCLUSIONS

These results may support the traditional uses of Allanblackia floribunda as aphrodisiac plant with antihypertensive properties suggesting the phytocomplex as responsible for the claimed activity.

Chemical Constituents of Mangifera indica and Their Antiausterity Activity against the PANC-1 Human Pancreatic Cancer Cell Line

Human pancreatic cancer cell lines such as PANC-1 have an altered metabolism, enabiling them to tolerate and survive under extreme conditions of nutrient starvation. The search for candidates that inhibit their viability during nutrition starvation represents a novel antiausterity strategy in anticancer drug discovery. A methanol extract of the bark of Mangifera indica was found to inhibit the survival of PANC-1 human pancreatic cancer cells preferentially under nutrient-deprived conditions with a PC50 value of 15.5 μg/mL, without apparent toxicity, in normal nutrient-rich conditions. Chemical investigation on this bioactive extract led to the isolation of 19 compounds (1-19), including two new cycloartane-type triterpenes, mangiferolate A (1) and mangiferolate B (2). The structures of 1 and 2 were determined by NMR spectroscopic analysis. Among the isolated compounds, mangiferolate B (2) and isoambolic acid (12) exhibited potent preferential cytotoxicity against PANC-1 human pancreatic cancer cells under the nutrition-deprived condition with PC50 values of 11.0 and 4.8 μM, respectively.

In vivo antitrypanosomal activity of Garcinia hombroniana aqueous extract

The anti-Trypanosoma evansi activity of Garcinia hombroniana (seashore mangosteen) leaves aqueous extract was tested on experimentally infected Sprague-Dawley rats. Treatment of infected rats with G. hombroniana extract resulted in a significantly extended post-infection longevity (p < 0.05), compared to the untreated control group. The possible mode of antitrypanosomal effect of the plant extract was also investigated on cultured T. evansi in HMI-9 medium with the addition of 25 µg/ml G. hombroniana aqueous extract. It was observed that the addition of G. hombroniana extract resulted in the inhibition of trypanosomal kinetoplast division, with no significant inhibitory effect on nuclear division. It is concluded from the current study that the aqueous extract of G. hombroniana has a potential antitrypanosomal activity through the inhibition of kinetoplast division, as one of the possible mechanisms of its antitrypanosomal effect. This plant could serve as a possible source of new antitrypanosomal compounds.

Complete NMR assignments of bioactive rotameric (3 → 8) biflavonoids from the bark of Garcinia hombroniana

The genus Garcinia is reported to possess antimicrobial, anti-inflammatory, anticancer, hepatoprotective and anti-HIV activities. Garcinia hombroniana in Malaysia is used to treat itching and as a protective medicine after child birth. This study was aimed to isolate the chemical constituents from the bark of G. hombroniana and explore their possible pharmacological potential. Ethyl acetate extract afforded one new (1) and six (2-7) known 3 → 8 rotameric biflavonoids. Their structures were elucidated by UV, IR and NMR (1D and 2D) spectroscopy together with electron ionization/ESI mass spectrometric techniques and were identified as (2R, 3S) volkensiflavone-7-O-rhamnopyranoside (1), volkensiflavone (2), 4″-O-methyl-volkensiflavone (3), volkensiflavone-7-O-glucopyranoside (4), morelloflavone (5), 3″-O-methyl-morelloflavone (6) and morelloflavone-7-O-glucopyranoside (7). The absolute configuration of compound 1 was assigned by circular dichroism spectroscopy as 2R, 3S. The coexistence of conformers of isolated biflavonoids in solution at 25 °C in different solvents was confirmed by variable temperature NMR studies. At room temperature (25 °C), compounds 1-7 exhibited duplicate NMR signals, while at elevated temperature (90 °C), a single set of signals was obtained. Compound 5 showed significant in vitro antioxidant activities against 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis-3-ethyl benzthiazoline-6-sulfonic acid radicals. The antibacterial studies showed that compounds 5 and 6 are the most active against Staphylococcus aureus, Bacillus subtilis and Escherichia coli. Compounds 3 and 6 also showed moderate antituberculosis activity against H38 Rv. Based on the research findings, G. hombroniana could be concluded as a rich source of flavanone-flavone (3 → 8) biflavonoids that exhibit rotameric behaviour at room temperature and display significant antioxidant and antibacterial activities.

Cytotoxic benzophenone and triterpene from Garcinia hombroniana

Garcinia hombroniana (seashore mangosteen) in Malaysia is used to treat itching and as a protective medicine after child birth. This study was aimed to investigate the bioactive chemical constituents of the bark of G. hombroniana. Ethyl acetate and dichloromethane extracts of G. hombroniana yielded two new (1, 9) and thirteen known compounds which were characterized by the spectral techniques of NMR, UV, IR and EI/ESI-MS, and identified as; 2,3',4,5'-tetrahydroxy-6-methoxybenzophenone(1), 2,3',4,4'-tetrahydroxy-6-methoxybenzophenone (2), 2,3',4,6-tetrahydroxybenzophenone (3), 1,3,6,7-tetrahydroxyxanthone (4), 3,3',4',5,7-pentahydroxyflavone (5),3,3',5,5',7-pentahydroxyflavanone (6), 3,3',4',5,5',7-hexahydroxyflavone (7), 4',5,7-trihydroxyflavanone-7-rutinoside (8), 18(13→17)-abeo-3β-acetoxy-9α,13β-lanost-24E-en-26-oic acid (9), garcihombronane B (10), garcihombronane D (11), friedelan-3-one (12), lupeol (13), stigmasterol (14) and stigmasterol glucoside (15). In the in vitro cytotoxicity against MCF-7, DBTRG, U2OS and PC-3 cell lines, compounds 1 and 9 displayed good cytotoxic effects against DBTRG cancer cell lines. Compounds 1-8 were also found to possess significant antioxidant activities. Owing to these properties, this study can be further extended to explore more significant bioactive components of this plant.

Rearranged benzophenones and prenylated xanthones from Garcinia propinqua twigs

The first phytochemical investigation of Garcinia propinqua has led to the isolation and identification of three new compounds, including two rearranged benzophenones, doitunggarcinones A (1) and B (2), and a xanthone, doitunggarcinone C (3), together with seven known compounds (4-10). The structures of 1-3 were elucidated on the basis of spectroscopic methods, including UV, IR, NMR, and MS. The antibacterial activity of the 10 isolates was evaluated against Escherichia coli TISTR 780, Salmonella typhimurium TISTR 292, Staphylococcus aureus TISTR 1466, and methicillin-resistant Staphylococcus aureus (MRSA) SK1.

Isolation and structural elucidation of indole alkaloids from Geissospermum vellosii by mass spectrometry

Alkaloids from the stem bark of Geissospermum vellosii possess a variety of therapeutic properties including antimalarial activities, activity as a sexual stimulant and inhibition of the proliferation of HIV and herpes viruses. Methods currently used to isolate the active components from G. vellosii are time-consuming, labor intensive, and result in low recovery. In addition, there is a lack of sensitive and accurate analytical methods for the structural characterization and identification of alkaloid components in minor quantities. A combination of high performance counter-current chromatography and ESI tandem mass spectrometry (MS(n)) was established to isolate alkaloids from the stem bark of G. vellosii, and study their electrospray ionization mass spectrometry fragmentation behavior. Five indole alkaloids were successfully isolated and identified by nuclear magnetic resonance and mass spectrometry. The multi-stage tandem mass spectrometric data were used to study their fragmentation pattern and set a model for detailed structure characterization of related indole alkaloids. The presence of the even mass fragment ion suggestive of an odd number of nitrogen at m/z 144 corresponding to C(10)H(9)N was characteristic to indole alkaloids. The results of the experiments demonstrated that the combination of high performance counter current chromatography and ESI-MS(n) is a sensitive, selective and effective approach for rapid isolation and characterization of alkaloids from G. vellosii.

Triterpenoids

This review covers the isolation and structure determination of triterpenoids, including squalene derivatives, protostanes, lanostanes, holostanes, cycloartanes, dammaranes, euphanes, tirucallanes, tetranortriterpenoids, quassinoids, lupanes, oleananes, friedelanes, ursanes, hopanes, serratanes and saponins; 278 references are cited.

Antiplasmodial Natural Products

Malaria is a human infectious disease that is caused by four species of Plasmodium. It is responsible for more than 1 million deaths per year. Natural products contain a great variety of chemical structures and have been screened for antiplasmodial activity as potential sources of new antimalarial drugs. This review highlights studies on natural products with antimalarial and antiplasmodial activity reported in the literature from January 2009 to November 2010. A total of 360 antiplasmodial natural products comprised of terpenes, including iridoids, sesquiterpenes, diterpenes, terpenoid benzoquinones, steroids, quassinoids, limonoids, curcubitacins, and lanostanes; flavonoids; alkaloids; peptides; phenylalkanoids; xanthones; naphthopyrones; polyketides, including halenaquinones, peroxides, polyacetylenes, and resorcylic acids; depsidones; benzophenones; macrolides; and miscellaneous compounds, including halogenated compounds and chromenes are listed in this review.