A new oligostilbene trimer, malaysianol F (1), together with ten known stilbenes (2–11), were successfully separated and purified from the acetone extract of the lianas of Gnetum microcarpum. Malaysianol D (2) was isolated for the first time in Gnetum plants. The tanninless crude extract (52.5 g) was fractionated using a vacuum liquid chromatography (VLC) technique to give five major fractions. Fraction 2 (4.68 g), 3 (4.79 g) and 4 (9.29 g) were all subjected to further isolation and purification using VLC, column chromatography (CC) and repetitive radial chromatography (RC) techniques with the best solvent system to yield malaysianol F (1) (6.2 mg), malaysianol D (2) (62.5 mg), malaysianol E (3) (2.4 mg), ε-viniferin (4) (10 mg), resveratrol (5) (6.5 mg), gnetol (6) (3.5 mg), gnetucleistol C (7) (12.2 mg), isorhapontigenin (8) (8 mg), cuspidan B (9) (3.2 mg), parvifolol D (10) (4.8 mg) and gnetifolin M (11) (2.5 mg). Their structures were determined on the basis of the analysis of spectral evidence by extensive NMR data analyses and comparison with the related published data. Several compounds were tested for anti-inflammatory activity. Their inhibitory effect on Prostaglandin E₂ (PGE₂) was tested using radioimmunoassay techniques. Compound 6 exhibited significant concentration-dependent inhibitory effects on PGE₂ production with IC₅₀ values of 1.84 µM comparable with the positive control, indomethacin (IC₅₀ 1.29 µM).

Non-steroidal Anti-inflammatory Drugs (NSAIDs) have been shown to be effective in inflammatory and pain management. However, this group of drugs can also cause various undesirable side effects such as dyspepsia, upper gastrointestinal and renal effects. Thus, it is necessary to continue searching for new sources of anti-inflammatory and pain-relieving agents from natural sources, which exert lesser or, possibly, no side effects. Muntingia calabura L. is known locally as Kerukup siam [1]. This plant has been claimed by the Peruvian folklore to possess medicinal values which include soothing gastric ulcers, relieving headache and cold, reducing swelling of the prostate gland and antiseptic [1]. This study focuses on understanding the antinociceptive effects of the extracts using Sprague Dawley (S.D.) rats. In the present study, activity-guided studies of the methanolic extract of Muntingia calabura collected in Shah Alam, Selangor, Malaysia were conducted for their antinociceptive property using formalin test [2]. Seven fractions of petroleum ether extract labelled A-G were separately administered (orally) with distilled water or 10% DMSO as negative controls and morphine and aspirin as a positive control. Fraction D showed the most significant antinociceptive activity when compare to other fractions (Table 1). At the dose of 300mg/kg, fraction D exhibited 66.2% and 81.4% antinociception in first (analgesic) and second phase (inflammation) respectively. Fraction D showed no significant different (p<0.5) when compared to aspirin (100mg/kg) as a positive control. In further experiment, active compounds from fraction D will be identified and their antinociceptive and anti-inflammation properties will be investigated. Acknowledgement: This study was supported by the National Science Fellowship (NSF) scholarship from Ministry of Science Technology and Innovation Malaysia (MOSTI). References: [1]. Morton JF (1987) Jamaica cherry in fruit of warm climates. Miami. pp: 65–69. [2]. Rosland JH, Tjolsen A, Maehle B & Hole K (1990). Pain 42: 235–242.

M. calabura L. or locally known as „Kerukup Siam“, belongs to the family Elaeocarpacea [1]. This plant is native to American continent and is widely cultivated in warm areas of Asian region, including Malaysia [2]. The leaf is used to provide relief from gastric ulcers and to reduce swelling of the prostate gland as reported in Peru folklore medicinal uses. The aim of the present study is to determine the in vitro cytotoxic activity of Muntingia calabura leaf against cancer (HL60 and MCF-7) and normal (WRL68) cell lines using MTT [3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide] assay as described by Mosmann [3] but with slight modifications. The crude methanolic extract of M. calabura (MCME) was suspended in distilled water to afford an aqueous MeOH solution and then partitioned with petroleum ether and EtOAc to give petroleum ether, EtOAc and aqueous extracts. The EtOAc extract showed significant cytotoxic activity when tested against HL60 (IC₅₀=27.48±3.60µg/ml) and was further fractionated using vacuum liquid chromatography with gradient mixture of hexane-EtOAc (from 9:1 to 1:9) as solvent systems. Seven fractions were obtained (F1-F7), and subjected to cytotoxic activity against HL60, MCF7 and WRL68 cell lines. The IC₅₀ values of the M. calabura extracts and fractions are shown in Table 1. Fraction 5 tested against HL60 showed strong inhibition (IC₅₀=3.98±0.09µg/ml) as compared to the other cell lines as well as other fractions. Fraction 5 will be isolated further and the bioactive compounds responsible for the activity will be determined in the future study. Keywords: Muntingia calabura, Elaeocarpacea, cytotoxic, MTT assay Acknowledgement: The authors wish to thank Faculty of Pharmacy, UiTM Malaysia for financial assistance. References: [1]. Morton, J.F. (1987) Jamaica Cherry. In Fruits of Warm Climates. Miami: J.F. Morton; p.65 [2]. Chin WY (1989) A guide to the wayside trees of Singapore. BP Singapore Science Centre, pp: 145. [3]. Mosmann T (1983) Journal of Immunol Methods 65: 55–63.

Bouea macrophylla Griff., a species belonging to the Anacardiaceae family is a flowering plant native to Southeast Asia and also known as kundang, kundang daun besar, and setar in Malaysia. The fruit can be eaten raw or as a pickle, while the young leaves can be consumed as salads. It has been claimed to be able to accelerate wound healing, prevent cancer, reduce the risk of stroke, and be good for blood circulation. The previous study on the plant from the same genus, known as B. oppositofolia has shown the presence of various. The present study was designed to isolate and elucidate flavonoids from this plant. The twig extract of kundang was purified by using several chromatographic techniques including Vacuum Liquid Chromatography (VLC), Column Chromatography (CC), and preparative-Thin Layer Chromatography (pTLC). The structures of isolated compounds were characterized by using spectroscopic methods including Nuclear Magnetic Resonance (NMR), infrared (IR), and ultraviolet (UV) spectral data, as well as comparison with the data reported in the literature. Five flavonoids were isolated and purified from the twigs of B. macrophylla which includes one flavanonol known as garbanzol; one flavonol which is resokaempferol; one flavandiol characterized as catechin; and two flavandiol known as mollisacacidin and guibourtacacidin. The results of the glucose uptake experiment indicated that the extract and compounds tested affected the glucose uptake rate of the insulin-resistant C₂C₁₂ cell line as compared to the standard. This is the first report describing the elucidation of the stated compounds from B. macrophylla as well as its glucose uptake study.

Background: Dryobalanops rappa is a plant species belonging to the family of Dipterocarpaceae. Nevertheless, the active compounds present in D. rappa have never been investigated. Objective: The aim of this research is to isolate and characterize compounds from Dryobalanops rappa and to study its bioactivity against human MCF-7 breast cancer and A549 lung cancer cell lines and several bacterial strains. Methods: The isolation step was carried out using a combination of chromatographic techniques. The structure of the isolated compounds was elucidated mainly using NMR spectroscopy. The cytotoxic activity of isolated compounds was determined with MTT assay, and the antimicrobial was screened using a modified resazurin microtiter-plate assay. Results: Isolation and purification of methanolic extract of D. rappa stem bark yielded 14 known oligomeric resveratrol types of compounds (1-14). Results showed that isolated ampelopsin E (5) and vaticanol C (14) displayed moderate activity against human MCF-7 breast cancer and A549 lung cancer cell lines with IC₅₀ values 14.3 and 10.7 μg/mL, respectively. Interestingly, acetate derivative of isolated laevifonol (2) and ampelopsin F (3) was found to possess potent activities towards MCF-7 cancer cell line with IC₅₀ values 2.8 and 3.3 μg/mL, respectively, in comparison to the parental compounds that demonstrated weak activities (IC₅₀ > 50 μg/mL). For the antibacterial assay, compounds 10 and 12 showed moderate activities towards Gram-positive bacterial strains (MIC ≤ 50 μM). Conclusion: 14 known oligomeric resveratrol types of compounds have been isolated. The activity of 14 against A549 cell line, 5 against MCF-7 cell line, and 10 and 12 against Gram-positive bacterial strains were the most promising results of this study. While the strong cytotoxicity of acetate derivative (2 and 3) against MCF-7 cell line has revealed the potential of resveratrol oligomers to be used as a template for designing new anticancer drugs.