Antitrypanosomal and cytotoxic activities of botanical extracts from Murraya koenigii (L.) and Alpinia mutica Roxb

Four carbazoles (girinimbine, mahanimbine, murrayafoline and murrayanine), isolated from Murraya koenigii, and one kavalactone (5,6-dehydrokawain) and one flavonoid (pinostrobin) isolated, from Alpinia mutica, were tested for their antitrypanosomal activity using in vitro cultured Trypanosoma evansi cell lines. The cytotoxic activities of these compounds were also investigated against mammalian Vero cells using the MTT (3-(4,5- Dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide)-cell proliferation assay. Three carbazole compounds, namely mahanimbine, murrayafoline, and girinimbine, showed a potent antitrypanosomal activity, scoring a median inhibitory concentration (IC₅₀) of 3.13, 6.35 and 10.16 µg/ml, respectively. Girinimbine was the least toxic to Vero cells, and the mean cytotoxic concentration (CC₅₀) and the selectivity index (SI) of this compound were 745.58 ± 42.38 µg/ ml and 73.38, respectively. Girinimbine and the other carbazole compounds possess potential antitrypanosomal activity with comparably low toxicity against mammalian cells. Girinimbine, in particular, is a good candidate to be further investigated as a potential antitrypanosomal agent using in vivo models.

Anti-ulcerogenic activity of dentatin from clausena excavata Burm.f. against ethanol-induced gastric ulcer in rats: Possible role of mucus and anti-oxidant effect

BACKGROUND

Clausena excavata Burm.f. (Rutaceae) has been used for the treatment of stomach disorders including peptic ulcer.

PURPOSE

In this study, we aimed to investigate dentatin isolated from C. excavata Burm.f., for anti-ulcer activity against ethanol ulcer model in rats.

METHODS

Gastric acid output, ulcer index, serum profile, histological evaluation using Hematoxylin and eosin (HE), periodic acid Schiff base stainings and immunohistochemical localization for heat shock proteins 70 (HSP70) were all investigated. Possible involvement of reduced glutathione (GSH), lipid peroxidation, prostaglandin E₂ (PGE₂), superoxide dismutase (SOD) enzymes, radical scavenging, and anti-Helicobacter pylori activity were investigated.

RESULTS

Dentatin showed anti-secretory activity against the pylorus ligature model and protected the gastric mucosa from ethanol ulceration, as revealed by the improved macroscopic and histological appearance. Dentatin significantly increased the gastric homogenate content of PGE₂ GSH and SOD. Dentatin inhibited the lipid peroxidation as revealed by the reduced gastric content of malondialdehyde (MDA). Moreover, dentatin up-regulated HSP70 expression. However, dentatin showed insignificant anti-H. pylori activity.

CONCLUSION

Dentatin possesses gastro-protective activity, which could be attributed to the anti-secretory, mucus production, anti-oxidant, and HSP70 activities.

A New Bioactive Secondary Metabolite from Artocarpus elasticus

Detailed phytochemical investigation has been carried out on the bark of Artocarpus elasticus Reinw. ex Blume, which led to the isolation of artonin E (1), a new dihydrobenzoxanthone derivative named elastixanthone (2), cycloartobiloxanthone (3) and artobiloxanthone (4). Structures of these compounds were elucidated on the basis of various spectroscopic (UV, IR, 1D-NMR and 2D-NMR) and MS data. Compounds 1-3 displayed outstanding scavenging activity for 1,1-diphenylpicrylhydrazyl (DPPH) with IC50 values of 11.5, 21.6 and 40.0 μg/mL, respectively. In addition, compounds 1-3 displayed broad spectrum antimicrobial activities against thirteen different bacterial strains when tested using the disc diffusion assay. Cytotoxic screening revealed that artonin E (1) constantly exhibited strong cytotoxic activity against human estrogen receptor (ER+) positive breast cancer (MCF-7) and human estrogen receptor (ER-) negative (MDA-MB 231) cells in comparison with the other two, with IC50 values of 2.6 and 13.5 μg/mL, respectively, without being toxic towards the WRL68 (human normal liver) cell line (IC50 value more than 30 μg/mL). However, the compound was inactive against HepG2 (human liver carcinoma) cancer cells.

A New Bioactive Secondary Metabolite from Artocarpus elasticus

Detailed phytochemical investigation has been carried out on the bark of Artocarpus elasticus Reinw. ex Blume, which led to the isolation of artonin E (1), a new dihydrobenzoxanthone derivative named elastixanthone (2), cycloartobiloxanthone (3) and artobiloxanthone (4). Structures of these compounds were elucidated on the basis of various spectroscopic (UV, IR, ID-NMR and 2D-NMR) and MS data. Compounds 1-3 displayed outstanding scavenging activity for 1,1-diphenylpicrylhydrazyl (DPPH) with IC5o values of 11.5, 21.6 and 40.0 μg/mL, respectively. In addition, compounds 1-3 displayed broad spectrum antimicrobial activities against thirteen different bacterial strains when tested using the disc diffusion assay. Cytotoxic screening revealed that artonin E (1). constantly exhibited strong cytotoxic activity against human estrogen receptor (ER+) positive breast cancer (MCF-7) and human estrogen receptor (ER-) negative (MDA-MB 231) cells in comparison with the other two, with IC50 values of 2.6 and 13.5 μg/mL, respectively, without being toxic towards the WRL68 (human normal liver) cell line (IC50 value more than 30 [μg/mL). However, the compound was inactive against HepG2 (human liver carcinoma) cancer cells.

Phytochemicals from Mangifera pajang Kosterm and their biological activities

BACKGROUND

Mangifera pajang Kosterm is a plant species from the mango family (Anacardiaceae). The fruits are edible and have been reported to have high antioxidant content. However, the detailed phytochemical studies of the plant have not been reported previously. This study investigates the phytochemicals and biological activities of different parts of Mangifera pajang.

METHODS

The plant samples were extracted with solvents of different polarity to obtain the crude extracts. The isolated compounds were characterized using spectroscopic methods. The extracts and isolated compounds were subjected to cytotoxicity tests using human breast cancer (MCF-7), human cervical cancer (HeLa) and human colon cancer (HT-29) cells. The free radical scavenging activity test was conducted using the DPPH assay. Antimicrobial activity tests were carried out by using the disc diffusion method.

RESULTS

Phytochemical investigation on the kernel, stem bark and leaves of Mangifera pajang led to the isolation of methyl gallate (1), mixture of benzaldehyde (2) and benzyl alcohol (3), mangiferonic acid (4), 3β-hydroxy-cycloart-24-ene-26-oic acid (5), 3β,23-dihydroxy-cycloart-24-ene-26-oic acid (6), lupeol(7) lupenone(8), β-sitosterol(9), stigmasterol(10), trans-sobrerol(11) and quercitrin (12). Crude ethyl acetate and methanol extracts from the kernel indicated strong cytotoxic activity towards MCF-7 and HeLa cells with IC50 values of less than 10 μg/mL, while petroleum ether, chloroform and ethyl acetate extracts of the stem bark showed strong to moderate activity against MCF-7, HeLa and HT-29 cancer cell lines with IC50 values ranging from 5 to 30 μg/mL. As for the antimicrobial assays, only the ethyl acetate and methanol extracts from the kernel displayed some inhibition against the microbes in the antibacterial assays. The kernel extracts showed highest free radical scavenging activity with IC50 values of less than 10 μg/mL, while the ethyl acetate and methanol extracts of leaves displayed only weak activity in the DPPH assays.

CONCLUSIONS

Phytochemical investigations on various parts of Mangifera pajang have identified terpenoids and a flavonol derivative as major constituents. Bioassay studies have indicated that the crude extracts and isolated compounds have potential as naturally-derived anticancer and antimicrobial agents, besides possess high free radical scavenging activity.

Antiproliferative xanthone derivatives from Calophyllum inophyllum and Calophyllum soulattri

Structure-activity relationships of eleven xanthones were comparatively predicted for four cancer cell lines after the compounds were subjected to antiproliferative assay against B-lymphocyte cells (Raji), colon carcinoma cells (LS174T), human neuroblastoma cells (IMR-32) and skin carcinoma cells (SK-MEL-28). The eleven chemical constituents were obtained naturally from the stem bark of Calophyllum inophyllum and Calophyllum soulattri. Inophinnin (1) and inophinone (2) were isolated from Calophyllum inophyllum while soulattrin (3) and phylattrin (4) were found from Calophyllum soulattri. The other xanthones were from both Calophyllum sp. and they are pyranojacareubin (5), rheediaxanthone A (6), macluraxanthone (7), 4-hydroxyxanthone (8), caloxanthone C (9), brasixanthone B (10) and trapezifolixanthone (11). Compound 3 was found to be the most cytotoxic towards all the cancer cell lines with an IC50 value of 1.25μg/mL while the simplest xanthone, compound 8 was inactive.

Evaluation of biological activities of Alpinia mutica Roxb. and its chemical constituents

Phytochemicals investigation on rhizomes of Alpinia mutica has afforded five compounds namely 5,6-dehydrokawain (1), flavokawin B (2), pinostrobin (3) and pinocembrin (4) together with β-sitosterol (5). All crude extracts of the plant demonstrated strong cytotoxicity against CEMss (human T4 lymphoblastoid) cancer cells with IC50 values less than 19 μg/mL, while flavokawin B (2) was the most cytotoxic isolate with IC50 value 1.86±0.37 μg/mL. Most of the crude extracts and isolated compounds showed weak activity in antimicrobial and diphenylpicrylhydrazyl (DPPH) radical scavenging activity tests.

Phenolic contents, antioxidant and cytotoxic activities of Elaeocarpus floribundus Blume

Elaeocarpus floribundus is higher plant that has been used as traditional medicine for treating several diseases. There is no previous report on phytochemicals and bioactivity studies of this species. In this investigation, triterpenoids friedelin, epifriedelanol and β-sitosterol were isolated from its leaves and stem bark. Determination of total phenolic content of methanolic extract of leaves and stem bark was carried out using Folin-Ciocalteu reagent. All extracts and isolated compounds were subjected to screening of antioxidant activity using DPPH free radical scavenging method and cytotoxic activities by MTT assay towards human T4 lymphoblastoid (CEM-SS) and human cervical (HeLa) cancer cells. In the total phenolic content determination, methanolic extract of leaves gave higher value of 503.08±16.71 mg GAE/g DW than stem bark with value of 161.5±24.81 mg GAE/g DW. Polar extracts of leaves and stem bark possessed promising antioxidant activity with methanol extract of stem bark exhibited strongest activity with IC50 value of 7.36±0.01 μg/ml. In the cytotoxic activity assay, only chloroform extract of leaves showed significant activity with IC50 value of 25.6±0.06 μg/ml against CEM-SS cancer cell, while friedelin and epifriedelanol were found to be active against the two cancer cells with IC50 values ranging from 3.54 to 11.45 μg/ml.

A Phenylbutenoid Dimer, cis-3-(3',4'-Dimethoxyphenyl)-4-[(E)-3''',4'''-Dimethoxystyryl] Cyclohex-1-ene, Exhibits Apoptogenic Properties in T-Acute Lymphoblastic Leukemia Cells via Induction of p53-Independent Mitochondrial Signalling Pathway

The current study was designed to evaluate the in vitro cytotoxicity effect of a phenylbutenoid dimer, cis-3-(3',4'-dimethoxyphenyl)-4-[(E)-3 (‴) ,4 (‴) -dimethoxystyryl]cyclohex-1-ene (ZC-B11) isolated from the rhizome of Zingiber cassumunar on various cancer cell line, and normal human blood mononuclear cells, and to further investigate the involvement of apoptosis-related proteins that leads, to the probable pathway in which apoptosis is triggered. Cytotoxicity test using MTT assay showed selective inhibition of ZC-B11 towards T-acute lymphoblastic leukemia cells, CEMss, with an IC50 value of 7.11 ± 0.240  μ g/mL, which did not reveal cytotoxic effects towards normal human blood mononuclear cells (IC50 > 50  μ g/mL). Morphology assessments demonstrated distinctive morphological changes corresponding to a typical apoptosis. ZC-B11 also arrested cell cycle progression at S phase and causes DNA fragmentation in CEMss cells. Decline of mitochondrial membrane potential was also determined qualitatively. In the apoptosis-related protein determination, ZC-B11 was found to significantly upregulate Bax, caspase 3/7, caspase 9, cytochrome c, and SMAC and downregulate Bcl-2, HSP70, and XIAP, but did not affect caspase 8, p53, and BID. These results demonstrated for the first time the apoptogenic property of ZC-B11 on CEMss cell line, leading to the programmed cell death via intrinsic mitochondrial pathway of apoptosis induction.

Induction of selective cytotoxicity and apoptosis in human T4-lymphoblastoid cell line (CEMss) by boesenbergin a isolated from boesenbergia rotunda rhizomes involves mitochondrial pathway, activation of caspase 3 and G2/M phase cell cycle arrest

Background

Boesenbergia rotunda (Roxb.) Schlecht (family zingiberaceae) is a rhizomatous herb that is distributed from north-eastern India to south-east Asia, especially in Indonesia, Thailand and Malaysia. Previous research has shown that the crude extract of this plant has cytotoxic properties. The current study examines the cytotoxic properties of boesenbergin A isolated from Boesenbergia rotunda.

Methods

MTT assay was used to check the cytotoxicity of boesenbergin A. The morphological assessment of apoptosis was monitored using normal and fluorescence microscopy. The early and late phase of apoptosis was investigated using annexin V and DNA laddering assays, respectively. The mitochondrial membrane potential (MMP) was assessed by fluorescence microscopy. Human apoptosis proteome profiler assays were performed to investigate the mechanism of cell death. In addition, the protein levels of Bax, Bcl2 and HSP 70 were also analyzed using western blot. Assays of caspase =-3/7, -8 and =-9 were carried out in order to test for induction during treatment. Lastly, cell cycle progression was analyzed using flow cytometry.

Results

Boesenbergin A was found to have the highest toxicity towards CEMss cancer cells (IC₅₀ = 8 μg/ml). The morphology of CEMss cells after treatment showed evidence of apoptosis that included blebbing and chromatin condensation. The annexin V assay revealed that early apoptosis is induced after treatment. The DNA laddering assay confirmed that DNA fragmentation had occurred during late apoptosis. The cell cycle analysis indicated that boesenbergin A was able to induce G2/M phase arrest in CEMss cells. The activity of caspases -3/7, -8 and -9 was increased after treatment which indicates both intrinsic and extrinsic pathways are induced during apoptosis. The involvement of mitochondria was established by increased mitochondrial membrane potential and up and down regulation of Bcl2 and Bax proteins as well as HSP70.

Conclusion

In conclusion, the results demonstrated that boesenbergin A induced apoptosis of CEMss cells through Bcl2/Bax signaling pathways with the involvement of caspases and G2/M phase cell cycle arrest. The current findings warrant further research on boesenbergin A as a novel chemotherapeutic agent for leukemia intervention including studies in animal models.

Antioxidant, antimicrobial and tyrosinase inhibitory activities of xanthones isolated from Artocarpus obtusus F.M. Jarrett

One of the most promising plants in biological screening test results of thirteen Artocarpus species was Artocarpus obtusus FM Jarrett and detailed phytochemical investigation of powdered dried bark of the plant has led to the isolation and identification of three xanthones; pyranocycloartobiloxanthone A (1), dihydroartoindonesianin C (2) and pyranocycloartobiloxanthone B (3). These compounds were screened for antioxidant, antimicrobial and tyrosinase inhibitory activities. Pyranocycloartobiloxanthone A (1) exhibited a strong free radical scavenger towards DPPH free radicals with IC₅₀ value of 2 µg/mL with prominent discoloration observed in comparison with standard ascorbic acid, α-tocopherol and quercetin, The compound also exhibited antibacterial activity against methicillin resistant Staphylococcus aureus (ATCC3359) and Bacillus subtilis (clinically isolated) with inhibition zone of 20 and 12 mm, respectively. However the other two xanthones were found to be inactive. For the tyrosinase inhibitory activity, again compound (1) displayed strong activity comparable with the standard kojic acid.

Anti-tumour promoting activity and antioxidant properties of girinimbine isolated from the stem bark of Murraya koenigii S

Girinimbine, a carbazole alkaloid isolated from the stem bark of Murraya koenigii was tested for the in vitro anti-tumour promoting and antioxidant activities. Anti-tumour promoting activity was determined by assaying the capability of this compound to inhibit the expression of early antigen of Epstein-Barr virus (EA-EBV) in Raji cells that was induced by the tumour promoter, phorbol 12-myristate 13-acetate. The concentration of this compound that gave an inhibition rate at fifty percent was 6.0 µg/mL and was not cytotoxic to the cells. Immunoblotting analysis of the expression of EA-EBV showed that girinimbine was able to suppress restricted early antigen (EA-R). However, diffused early antigen (EA-D) was partially suppressed when used at 32.0 µg/mL. Girinimbine exhibited a very strong antioxidant activity as compared to a-tocopherol and was able to inhibit superoxide generation in the 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced differentiated premyelocytic HL-60 cells more than 95%, when treated with the compound at 5.3 and 26.3 µg/mL, respectively. However girinimbine failed to scavenge the stable diphenyl picryl hydrazyl (DPPH)-free radical.

In vitro anti-inflammatory, cytotoxic and antioxidant activities of boesenbergin A, a chalcone isolated from Boesenbergia rotunda (L.) (fingerroot)

The current in vitro study was designed to investigate the anti-inflammatory, cytotoxic and antioxidant activities of boesenbergin A (BA), a chalcone derivative of known structure isolated from Boesenbergia rotunda. Human hepatocellular carcinoma (HepG2), colon adenocarcinoma (HT-29), non-small cell lung cancer (A549), prostate adenocarcinoma (PC3), and normal hepatic cells (WRL-68) were used to evaluate the cytotoxicity of BA using the MTT assay. The antioxidant activity of BA was assessed by the ORAC assay and compared to quercetin as a standard reference antioxidant. ORAC results are reported as the equivalent concentration of Trolox that produces the same level of antioxidant activity as the sample tested at 20 µg/mL. The toxic effect of BA on different cell types, reported as IC₅₀, yielded 20.22 ± 3.15, 10.69 ± 2.64, 20.31 ± 1.34, 94.10 ± 1.19, and 9.324 ± 0.24 µg/mL for A549, PC3, HepG2, HT-29, and WRL-68, respectively. BA displayed considerable antioxidant activity, when the results of ORAC assay were reported as Trolox equivalents. BA (20 µg/mL) and quercetin (5 µg/mL) were equivalent to a Trolox concentration of 11.91 ± 0.23 and 160.32 ± 2.75 µM, respectively. Moreover, the anti-inflammatory activity of BA was significant at 12.5 to 50 µg/mL and without any significant cytotoxicity for the murine macrophage cell line RAW 264.7 at 50 µg/mL. The significant biological activities observed in this study indicated that BA may be one of the agents responsible for the reported biological activities of B. rotunda crude extract.

The methanolic extract of Boesenbergia rotunda (L.) Mansf. and its major compound pinostrobin induces anti-ulcerogenic property in vivo: possible involvement of indirect antioxidant action

ETHNOPHARMACOLOGICAL RELEVANCE

Boesenbergia rotunda (L) Mansf. has been used for the treatment of gastrointestinal disorders including peptic ulcer. In the current study we aimed to investiagte the anti-ulcer activities of methanolic extract of B. rotunda (MEBR) and its main active compound, pinostrobin on ethanol-induced ulcer in rats. The possible involevement of lipid peroxidation, nitric oxide, cyclooxygenases and free radical scavenging mechanisms also has been investigated.

MATERIALS AND METHODS

Pinostrobin was isolated form the rhizomes of B. rotunda. Ulcer index, gastric juice acidity, mucus content, gross and histological gastric lesions and thiobarbituric acid reactive substances (TBARS) were evaluated in ethanol-induced ulcer in vivo. The effect of pinostrobin into lipopolysaccharide/interferon-γ stimulated rodent cells, COX-1 and COX-2 activities were done in vitro.

RESULTS

Pre-treatment with MEBR, pinostrobin or omeprazole protected the gastric mucosa as seen by reduction in ulcer area and mucosal content, reduced or absence of submucosal edema and leucocytes infiltration. Pinostrobin significantly (p<0.05) lowered the elevated TBARS level into gasteric homogenate. Pinostrobin did not produced significant in vitro inhibition of NO from LPS/IFN-γ activated rodent cells without affecting the viability of these cells. Further, the compound did bot revleaed inhibitory effects on both COX- 1& 2 enzymes. The antioxidant assays also exhibited non significance in vitro.

CONCLUSION

Thus it can be concluded that MEBR possesses anti-ulcer activity, which could be attributed to indirect anti-oxidant mechanism of pinostrobin but not to the intervention with nitric oxide and COX inflammation pathways.

Two new acridone alkaloids from Glycosmis macrantha

Extraction and chromatographic separation of the extracts of dried stem barks of Glycosmis macrantha lead to isolation of two new acridone alkaloids, macranthanine (1) and 7-hydroxynoracronycine (2), and a known acridone, atalaphyllidine (3). The structures of these alkaloids were determined by detailed spectral analysis and also by comparison with reported data.

Lignans and other constituents from aerial parts of Haplophyllum villosum

During our phytochemical investigation of Haplophyllum villosum (Rutaceae), a perennial herb from Iran, a new 4,8-diaryl-3,7-dioxobicyclo-(3,3,0)-octane type lignan, eudesmin A (1), together with four known compounds–eudesmin (2), haplamine (3), umbelliferone (4) and scopoletin (5)–were isolated from aerial parts of the plant. The structures of the compounds were elucidated using NMR spectral analysis (¹H-NMR,¹³C-NMR, HSQC, COSY and HMBC) as well as UV, IR and MS spectra and comparison with previously reported data.

Bioactive sesquiterpenes from Curcuma ochrorhiza and Curcuma heyneana

Curcuma ochrorhiza ('temu putih') and C. heyneana ('temu giring') are two Zingiberaceous species which are commonly used in traditional medicine in Malaysia and Indonesia. Phytochemical investigations on these Curcuma species have resulted in the isolation of six sesquiterpenes, namely zerumbone (1), furanodienone (2), zederone (3), oxycurcumenol epoxide (4), curcumenol (5) and isocurcumenol (6), along with phytosterols stigmasterol and alpha-sitosterol. Compounds 1 and 2 were obtained for the first time for C. ochrorhiza while 4 was new to C. heyneana. The hexane extract of C. ochrorhiza and sesquiterpenes 1 and 3 showed very strong cytotoxicity activity against T-acute lymphoblastic leukaemia cells (CEM-SS), with IC(50) values of 6.0, 0.6 and 1.6 microg mL(-1), respectively. Meanwhile, constituents from C. heyneana (4-6) demonstrated moderate inhibition against CEM-SS in cytotoxic assay, with IC(50) values of 11.9, 12.6 and 13.3 microg mL(-1), respectively. The crude extracts and sesquiterpenes isolated were moderately active against certain bacteria tested in antimicrobial screening.

A new anthraquinone from Morinda citrifolia roots

An investigation of Morinda citrifolia roots afforded a new anthraquinone, 2-ethoxy-1-hydroxyanthraquinone (1), along with five other known anthraquinones: 1-hydroxy-2-methylanthraquinone (2), damnacanthal (3), nordamnacanthal (4), 2-formyl-1-hydroxyanthraquinone (5) and morindone-6-methyl-ether (6). This is the first report on the isolation of morindone-6-methyl-ether (6) from this plant. The structures of these compounds were elucidated based on spectroscopic analyses such as NMR, MS and IR. Biological evaluation of five pure compounds and all the extracts against the larvae of Aedes aegypti indicated 1-hydroxy-2-methylanthraquinone (2) and damnacanthal (3) were the extracts to exhibit promising larvicidal activities.

A new cytotoxic carbazole alkaloid from Clausena excavata

A new carbazole alkaloid, 3-carbomethoxy-2-hydroxy-7-methoxycarbazole, Clausine-TY (1), together with two known carbazole alkaloid, Clausine-H (2) and Clausine-B (3), were isolated from the ethyl acetate extract of the stem bark of the Malaysian Clausena excavata. The structures of these compounds were elucidated by spectroscopic analyses. The new carbazole alkaloid shows significant cytotoxicity against CEM-SS cell line.

Daphnifolin, a new xanthone from Mesua daphnifolia (Guttiferae)

A new tetraoxygenated xanthone, daphnifolin (1,3,5-trihydroxy-4-methoxyxanthone), along with three other xanthones, were isolated from the stem bark extracts of Mesua daphnifolia. Their structures were characterized on the basis of 1D and 2D NMR spectral data.

Furoquinoline alkaloids fromMelicope bonwickii(F.Muell.) T.Hartley

Investigation on the leaves of Melicope bonwickii (F.Muell.) T.Hartley (Rutaceae) afforded a new 7-(2'-hydroxy-3'-chloroprenyloxy)-4-methoxyfuroquinoline (1) together with the known 7-(2',3'-epoxyprenyloxy)-4-methoxyfuroquinoline (2), evellerine (3) kokusaginine (4) and an amide aurantiamide acetate (5). Compounds 1 and 2 showed significant activity against cervical cell lines (Hela).

DPPH free radical scavenger components from the fruits of Alpinia rafflesiana Wall. ex. Bak. (Zingiberaceae)

The methanol extract of the dried ripe fruits of Alpinia rafflesiana was investigated for its DPPH free radical scavenger constituents. 2',3',4',6'-Tetrahydroxychalcone (7), which has never been isolated from natural sources was found to be most active as a DPPH free radical scavenger with the IC50 value of 55 microM. Other known compounds isolated from this species include 5,6-dehydrokawain (1), flavokawin B (2). 1,7-diphenyl-5-hydroxy-6-hepten-3-one (3), (-)-pinocembrin (4), cardamonin (5) and (-)-pinostrobin (6). The DPPH free radical scavenger compounds were detected using TLC autographic analysis. The percentage inhibition of DPPH free radical scavenging activity was measured on isolates (5-7) using colorimetric analysis.

Antitumour-promoting and cytotoxic constituents of etlingera elatior

Phytochemical studies on rhizome of Etlingera elatior have resulted in the isolation of 1,7-bis(4-hydroxyphenyl)-2,4,6-heptatrienone (1), demethoxycurcumin (2), 1,7-bis(4-hydroxyphenyl)-1,4,6-heptatrien-3-one (3), 16-hydroxylabda-8(17),11,13-trien-16,15-olide (4), stigmast-4-en-3-one (5), stigmast-4-ene-3,6-dione (6), stigmast-4-en-6b-ol-3-one (7), 5α,8α-epidioxyergosta-6,22-dien-3β-ol (8). 1 and 4 were new compounds. Compounds 5 and 7 displayed high antitumour-promoting activity. Ethyl acetate extract showed a very significant cytotoxic activity against CEM-SS and MCF-7 cell lines (4 μg/ml and 6.25 μg/ml respectively). The antitumour-promoting activity was determined by EBV-EA assay and cytotoxic activity was determined by MTT assay.

A new flavonoid and Sulphur-containing amides fromGlycosmis Chlorosperma

A new flavonoid, dihydroglychalcone-A, was isolated from the leaves extract of Glycosmis chlorosperma in addition to two known sulphur-containing amides, dambullin and gerambullin. The structure of the new compound was assigned as 2'-hydroxy-4,6'-dimethoxy-3',4'-(2",2"-dimethylpyrano)dihydrochalcone. The extract of the leaves was also found to exhibit antimicrobial and cytotoxic activities.

Coumarins from Malaysian Micromelum minutum

In a continuation of our study of the Rutaceae, detailed chemical investigation on Micromelum minutum (Rutaceae) collected from Sepilok, Sabah, Malaysia gave four new coumarins. The structures of the coumarins have been fully characterised by spectroscopic methods as 3",4"-dihydrocapnolactone 1, 2',3'-epoxyisocapnolactone 2, 8-hydroxyisocapnolactone-2',3'-diol 3 and 8-hydroxy-3",4"-dihydrocapnolactone-2',3'-diol 4.