Two new venalstonine derivatives, viz., venacarpines A and B, and one new dioxokopsan derivative, kopsorinine, in addition to the kopsifolines A-F, and 11 other known alkaloids, were isolated from a Malayan Kopsia species. The structures of the new alkaloids were determined using NMR and MS analysis.
Caustic pulping of oil-palm frond-fiber strands was conducted following a central composite design using a two-level factorial plan involving three pulping variables (temperature: 160-180 degrees C, time: 1-2 h, alkali charge: 20-30% NaOH). Responses of pulp properties to the process variables were analyzed using a statistical software (DESIGN-EXPERT). The results indicated that frond-fiber strands could be pulped with ease to about 35-45% yield. Statistically, the reaction time was not a significant factor while the influences of the treatment temperature and caustic charge were in general significantly relative to the properties of the resultant pulps.
The effects of medium strategies [maintenance (M), intermediary (G), and production (P) medium] on cell growth, anthraquinone (AQ) production, hydrogen peroxide (H2O2) level, lipid peroxidation, and antioxidant vitamins in Morinda elliptica cell suspension cultures were investigated. These were compared with third-stage leaf and 1-month-old callus culture. With P medium strategy, cell growth at 49 g l(-1), intracellular AQ content at 42 mg g(-1) DW, and H2O2 level at 9 micromol g(-1) FW medium were the highest as compared to the others. However, the extent of lipid peroxidation at 40.4 nmol g(-1) FW and total carotenoids at 13.3 mg g(-1) FW for cultures in P medium were comparable to that in the leaf, which had registered sevenfold lower AQ and 2.2-fold lower H2O2 levels. Vitamin C content at 30-120 microg g(-1) FW in all culture systems was almost half the leaf content. On the other hand, vitamin E content was around 400-500 microg g(-1) FW in 7-day-old cultures from all medium strategies and reduced to 50-150 microg g(-1) FW on day 14 and 21; as compared to 60 microg g(-1) FW in callus and 200 microg g(-1) FW in the leaf. This study suggests that medium strategies and cell growth phase in cell culture could influence the competition between primary and secondary metabolism, oxidative stresses and antioxidative measures. When compared with the leaf metabolism, these activities are dynamic depending on the types and availability of antioxidants.
Leaf extracts of Melicope lunu-ankenda were chemically studied and found to contain mixtures of hydrocarbons and squalene, fatty acids and esters. A geranylated coumaric acid was isolated as the major compound. The crude dichloromethane and methanol extracts of the leaves were found to be strongly larvicidal with LC50 values below 20 microg mL(-1). This is a first isolation of p-O-geranylcoumaric acid from this plant.
Photosynthetic rate, nitrogen concentration and morphological properties of canopy leaves were studied in 18 trees, comprising five dipterocarp species, in a tropical rain forest in Sarawak, Malaysia. Photosynthetic rate at light saturation (Pmax) differed significantly across species, varying from 7 to 18 micro mol m(-2) s(-1). Leaf nitrogen concentration and morphological properties, such as leaf blade and palisade layer thickness, leaf mass per area (LMA) and surface area of mesophyll cells per unit leaf area (Ames/A), also varied significantly across species. Among the relationships with leaf characteristics, Pmax had the strongest correlation with leaf mesophyll parameters, such as palisade cell layer thickness (r2 = 0.76, P < 0.001) and Ames/A (r2 = 0.73, P < 0.001). Leaf nitrogen concentration and Pmax per unit area also had a significant but weaker correlation (r2 = 0.46, P < 0.01), whereas Pmax had no correlation, or only weakly significant correlations, with leaf blade thickness and LMA. Shorea beccariana Burck, which had the highest P(max) of the species studied, also had the thickest palisade layer, with up to five or more layers. We conclude that interspecific variation in photosynthetic capacity in tropical rain forest canopies is influenced more by leaf mesophyll structure than by leaf thickness, LMA or leaf nitrogen concentration.
Due to the 1997/98 haze problem in South-East Asia and the increasing need for sustainable food production and development, the usual management of crop residues (including pineapple wastes) through burning is prohibited. As a result, the need for alternative uses of pineapple wastes in pineapple production has been emphasized. This study investigated an environmentally friendly means of recycling pineapple leaves for agricultural use. Pineapple leaves were shredded and composted in a composting drum for 30 days. Part of the shredded leaves was ashed in a muffle furnace for 4 h. Humic acid (HA), K-fulvate, and K in HA and compost were analyzed using standard procedures. An ash to water ratio of 1:7 was used to extract 0.1 molar (M) KOH from the shredded leaves. The 0.1 M KOH contained 50% K and was able to extract 20% HA from the composted pineapple leaves. Percent K in the fulvate using 0.1 M KOH was 43. Besides serving as a foliar spray (supplement soil application K fertilizers), source of K for freshwater fish (e.g., tilapia), the HA produced can be used as a soil conditioner. Studies show that between 0.05-0.01 g of HA per kg soil retards runoff by 36% in sandy and sandy loam soils. The K-fulvate can be used as a fluid fertilizer. In addition, the pH of 2 of the K-fulvate suggests it could be used to dissolve phosphate rocks, particularly those in the arid regions where high soil pH does not facilitate the dissolution of these important rocks that serve as one of the sources of phosphorus fertilizer in agriculture.
A new megastigmane diglycoside was isolated from the leaves of Carallia brachiata. The structure was determined by spectroscopic methods as 3-hydroxy-5,6-epoxy-beta-ionol -3-O-beta-apiofuranosyl-(1-->6)-beta-glucopyranoside (1). Additionally, 29 known compounds consisting of two megastigmanes, one 1,2-dithiolane derivative, seven aromatic compounds, five condensed tannins, 12 flavonoids, and two glyceroglycolipids were isolated and identified.
The antinociceptive effect of the ethanolic extract of Melastoma malabathricum (MME) was investigated using acetic acid-induced abdominal writhing test and hot-plate test in mice. It was demonstrated that the extract (30-300 mg/kg, i.p.) strongly and dose-dependently inhibited the acetic acid-induced writhing with an ED(50) of 100 (78-160) mg/kg i.p. It also significantly increased the response latency period to thermal stimuli. Furthermore, the nonselective opioid receptor antagonist, naloxone blocked the antinociceptive effect of the extract in both tests, suggesting that M. malabathricum may act both at peripheral and central levels.
The crude methanol extracts of Gelsemium elegans leaves were assessed for their cytotoxic activity using the microculture 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay for cellular viability. This study utilized two different types of human cancer cell lines, CaOV-3 (human ovarian cancer cells) and MDA-MB-231 (human estrogen receptor negative breast cancer cells), allowing for comparison of toxicity of G. elegans against these two cancer cells lines. Our results showed that the methanol extract of G. elegans exhibited high cytotoxicity against the human ovarian cancer cell line CaOV-3 with an IC50 value of 5microg/ml after 96 h incubation. However, G. elegans displayed discernibly less toxicity against the MDA-MB-231 cells with an IC50 value 40microg/ml after 96 h incubation and this effect was dose- and time-dependent, up to 72h and 20-30 microg/ml. In conclusion, our results demonstrated that G. elegans is potently cytotoxic against the human ovarian cancer cell line CaOV-3 and to a lesser extend towards the human breast carcinoma cancer MDA-MB-231 cells, suggesting that the extract is selective towards CaOV-3 cells and may have a chemotherapeutic role for ovarian cancer treatment in the future.
The objective of this study was to determine the anti cancer effects of red spinach (Amaranthus gangeticus Linn) in vitro and in vivo. For in vitro study, microtitration cytotoxic assay was done using 3-(4,5-dimethylthiazol-2-il)-2,5-diphenil tetrazolium bromide (MTT) kit assay. Results showed that aqueous extract of A gangeticus inhibited the proliferation of liver cancer cell line (HepG2) and breast cancer cell line (MCF-7). The IC(50) values were 93.8 mu g/ml and 98.8 mu g/ml for HepG2 and MCF-7, respectively. The inhibitory effect was also observed in colon cancer cell line (Caco-2), but a lower percentage compared to HepG2 and MCF-7. For normal cell line (Chang Liver), there was no inhibitory effect. In the in vivo study, hepatocarcinogenesis was monitored in rats according to Solt and Farber (1976) without partial hepatectomy. Assay of tumour marker enzymes such as glutathione S-transferase (GST), gamma-glutamyl transpeptidase (GGT), uridyl diphosphoglucuronyl transferase (UDPGT) and alkaline phosphatase (ALP) were carried out to determine the severity of hepatocarcinogenesis. The result found that supplementation of 5%, 7.5% and 10% of A. gangeticus aqueous extract to normal rats did not show any significant difference towards normal control (P <0.05). The exposure of the rats to chemical carcinogens diethylnitrosamine (DEN) and 2-acetylaminofluorene (AAF) showed a significant increase in specific enzyme activity of GGT, GST, UDPGT and ALP compared to normal control (P <0.05). However, it was found that the supplementation of A. gangeticus aqueous extract in 5%, 7.5% and 10% to cancer-induced rats could inhibit the activity of all tumour marker enzymes especially at 10% (P <0.05). Supplementation of anti cancer drug glycyrrhizin at suggested dose (0.005%) did not show any suppressive effect towards cancer control (P <0.05). In conclusion, A. gangeticus showed anticancer potential in in vitro and in vivo studies.
The mengkudu (Morinda citrifolia Linn.) plant is a well known medicinal plant. The fruits, leaves and roots of this plant have been widely used in traditional medicine. The purpose of this study was to evaluate the effects of an aqueous extract of the M. citrifolia fruits (25 mg/kg, 50 mg/kg and 100 mg/kg body weight given for a period of 30 days) on sperm quality and histology of testis in mice. Data from this study show that the epididymal sperm count, mortality, motility and sperm morphology in mice given the M. citrifolia fruit extract did not differ from that of the control group. Spermatogenesis was not affected by the treatment. The results obtained here suggest that the aqueous extract of the M. citrifolia fruit (up to 100 mg/kg) did not affect sperm quality and spermatogenesis in mice.
Mengkudu (Morinda citrifolia Linn.) adalah tumbuhan ubatan yang terkenal. Bahagian buah, daun dan akarnya digunakan secara meluas dalam perubatan tradisional. Kajian ini dijalankan untuk menentukan kesan pemberian ekstrak berakua buah M. citrifolia (dos 25mg/kg, 50 mg/kg dan 100 mg/kg berat tubuh mencit selama 30 hari) ke atas kuantiti sperma dan histologi testis mencit. Data daripada kajian ini menunjukkan bilangan sperma epididimis, mortaliti, motiliti dan morfologi sperma mencit kajian tidak berbeza berbanding kumpulan kawalan. Proses spermatogenesis juga tidak terjejas dengan pemberian M. citrifolia. Keputusan kajian ini mencadangkan ekstrak berakua M .citrifolia (sehingga 100 mg/kg) tidak mendatangkan kesan terhadap kualiti sperma dan spermatogenesis mencit.
Forty-nine methanol extracts of 37 species of Malaysian medicinal plants were investigated for their inhibitory effects on platelet-activating factor (PAF) binding to rabbit platelets, using 3H-PAF as a ligand. Among them, the extracts of six Zingiberaceae species (Alpinia galanga Swartz., Boesenbergia pandurata Roxb., Curcuma ochorrhiza Val., C. aeruginosa Roxb., Zingiber officinale Rosc. and Z. zerumbet Koenig.), two Cinnamomum species (C. altissimum Kosterm. and C. pubescens Kochummen.), Goniothalamus malayanus Hook. f. Momordica charantia Linn. and Piper aduncum L. are potential sources of new PAF antagonists, as they showed significant inhibitory effects with IC50 values ranging from 1.2 to 18.4 microg ml(-1).
3,4',5-Trihydroxy-3',7-dimethoxyflavanone was isolated from the ligroin extract of the leaves of Blumea balsamifera, while the acetone extract yielded 3',4',5-trihydroxy-7-methoxyflavanone and a new biflavonoid identifed as 3-O-7''-biluteolin (1). The isolation of 1 is significant since a biflavonoid with a C-O-C linkage of the type [I-3-O-II-7] has not been previously reported from a plant.
Epipremnum pinnatum (L.) Engl. hexane extract produced a significant growth inhibition against T-47D breast carcinoma cells and analysis of cell death mechanisms indicated that the extract elicited a non-apoptotic programmed cell death. T-47D cells exposed to the extract at EC(50) concentration (72 h) for 24 h failed to demonstrate typical DNA fragmentation associated with apoptosis, as carried out using a modified TUNEL assay. In addition, acute exposure to the extract produced an insignificant regulation of caspase-3 and p53 mRNA expression but increased in the c-myc mRNA expression. Ultrastructural analysis using transmission electron microscope demonstrated distinct vacuolated cells, which strongly indicated a Type II non-apoptotic cell death although the changes in chromatin were also detected. The presence of non-apoptotic programmed cell death was then reconfirmed with annexin-V and propidium iodide staining. These findings suggested that up-regulation of c-myc mRNA expression may have contributed to the growth arrest and Type II non-apoptotic programmed cell death in the Epipremnum pinnatum (L.) Engl. hexane extract-treated T-47D cells.
Three new fully dehydrogenated naphthylisoquinoline alkaloids, the 7,1'-coupled ent-dioncophylleine A (3a), the likewise 7,1'-coupled 5'-O-demethyl-ent-dioncophylleine A (4), and the 7,8'-linked dioncophylleine D (5), have been isolated from the leaves of the recently described Malaysian highland liana Ancistrocladusbenomensis. All of them lack an oxygen function at C-6; this so-called Dioncophyllaceae-type structural subclass had previously been found only in naphthylisoquinoline alkaloids from West and Central African plants. Moreover, compounds 3a and 4 are the first fully dehydrogenated, i.e., only axially chiral, naphthylisoquinoline alkaloids of this type that are optically active; compound 5, by contrast, is fully racemic, due to its configurationally unstable biaryl axis. The structural elucidation was achieved by spectroscopic and chiroptical methods. Biological activities of these alkaloids against different protozoan parasites are described.
A series of preliminary studies was carried out to evaluate the antinociceptive (pain relief) activity of the aqueous extract of Corchorus olitorius L. leaves (COAE) and to determine the influence of temperature and opioid receptors on COAE activity using the abdominal constriction and hot plate tests in mice. COAE, at concentrations of 10, 25, 50, 75, and 100%, showed both peripheral and central antinociception that are non-concentration- and concentration-dependent respectively. The peripheral activity was clearly observed at a concentration of 25% and diminished at a concentration of 100%, while the central activity was observed at all the concentrations of COAE used. Furthermore, the insignificant results obtained indicated that this peripheral activity (at concentrations of 25 and 50%) was comparable to that of morphine (0.8 mg/kg). Pre-heating COAE at a temperature of 80 degrees C and 100 degrees C, or 60 degrees C and 80 degrees C was found to enhance its peripheral and central antinociception respectively. Pre-treatment with naloxone (10 mg/kg), a general opioid receptor antagonist, for 5 min, followed by COAE, was found to completely block its peripheral, but not central, antinociceptive activity. Based on this observation, we conclude that the antinociceptive activity exhibited by C. olitorius is enhanced by the increase in temperature and may be mediated peripherally, but not centrally, at least in part, via an opioid receptor.
A selective and sensitive reversed-phase (RP) high-performance liquid chromatographic method is developed for the quantitative analysis of five naturally occurring flavonoids of Blumea balsamifera DC, namely dihydroquercetin-7,4'-dimethyl ether (DQDE), blumeatin (BL), quercetin (QN), 5,7,3',5'-tetrahydroxyflavanone (THFE), and dihydroquercetin-4'-methyl ether (DQME). These compounds have been isolated using various chromatographic methods. The five compounds are completely separated within 35 min using an RP C18, Nucleosil column and with an isocratic methanol-0.5% phosphoric acid (50:50, v/v) mobile phase at the flow rate of 0.9 mL/min. The separation of the compounds is monitored at 285 nm using UV detection. Identifications of specific flavonoids are made by comparing their retention times with those of the standards. Reproducibility of the method is good, with coefficients of variation of 1.48% for DQME, 2.25% for THFE, 2.31% for QN, 2.23% for DQDE, and 1.51% for BL. The average recoveries of pure flavonoids upon addition to lyophilized powder and subsequent extraction are 99.8% for DQME, 99.9% for THFE, 100.0% for BL, 100.6% for DQDE, and 97.4% for QN.
Citridiol is an extract of the leaves of Corymbia citriodora (Myrtaceae), the lemon eucalyptus, and mostly consists of p-menthane-3,8-diol isomers. The effectiveness of this extract as a repellent against land leeches of the genus Haemadipsa (Haemadipsidae), primarily H. sylvestris, was tested in the laboratory and field, in Peninsular Malaysia. The formulation tested, Mosi-guard Natural spray, contained 40% (w/w) Citridiol in a base of ethanol, water and isopropanol. In the laboratory test, specimens of H. sylvestris that were placed within moist, untreated arenas enclosed by treated paper rings made numerous attempts to cross the rings but were prevented or delayed from crossing over, in a dose-dependent manner. Mortality was high among the leeches that attempted to cross over the paper rings that had been sprayed to saturation point but low among the leeches that attempted to cross over paper rings that had only been partially treated, with a droplet-spray. The field study was carried out using indices that were formulated to reflect the severity of leech attack and the degree of repellency. Heavy or moderate spraying of footwear and trouser legs (tucked into socks) not only gave complete protection against bites by H. sylvestris and H. picta but also provided high enough repellency to keep the treated footwear virtually free of leeches. Even a light spray greatly reduced the numbers of leeches on footwear and delayed their progression toward biting the test subjects, although it failed to prevent bites completely. There was no decline in the repellency of the Citridiol when hourly assessments were made over a 6-h test period in the field. The results of the study show that Citridiol is highly repellent as well as toxic to leeches, and can be effectively used to prevent leech bites in the field.
Andrographolide, neoandrographolide and 14-deoxy-11,12-didehydroandrographolide, ent-labdene diterpenes isolated from Andrographis paniculata showed viricidal activity against herpes simplex virus 1 (HSV-1). None of these compounds exhibited significant cytotoxicity at viricidal concentrations.