Antimicrobial and cytotoxic constituents of Loranthus globosus

A new labdane diterpenoid, in vitro and in silico cytotoxicity, and protease inhibitory effects of phytochemicals from Juniperus polycarposK. Koch leaves

Cytotoxicity-guided purification of Juniperus polycarpos K. Koch leaves (Cupressaceae) led to the isolation of a new labdane diterpenoid, 3-(acetyloxy)-acetylisocupressic acid (1), together with isocupressic acid (2), 3,4-dimethoxycinnamoyl alcohol (3) and deoxypodophyllotoxin (4). The chemical structures of 1-4 were established by detailed 1D and 2D NMR, HRFAB-MS and LRESI-MS, as well as by comparing the spectral data with those reported in the literature. Compound 1 was ineffective against HepG2 cells and protease enzyme, while 2 showed potent cytotoxicity against HepG2 cells (IC50 of 3.73 μg/mL) compared to cisplatin (IC50 of 12.65 μg/mL). Computational analyses with CDK1 protein (a prominent protein in the cell cycle of HepG2 cells) revealed the binding affinity of 2 (-31.86 kcal/mol) was better than 1 (-19.70 kcal/mol) because the acetoxy groups did not allow binding deeply to the ATP binding site. Compounds 2 and 4 moderately inhibited the protease activity (IC50 = 52.7 and 63.0 μg/mL, respectively). Further in vitro and in vivo studies on the plant are strongly recommended.

Compounds from the Petroleum Ether Extract of Wedelia chinensis with Cytotoxic, Anticholinesterase, Antioxidant, and Antimicrobial Activities

Wedelia chinensis is a folk medicine used in many Asian countries to treat various ailments. Earlier investigations reported that the petroleum ether extract of the plant has potential biological activity, but the compounds responsible for activity are not yet completely known. Therefore, the current work was designed to isolate and characterize the compounds from the petroleum ether extract and to study their bioactivities. Four compounds including two diterepenes (-) kaur-16α-hydroxy-19-oic acid (1) and (-) kaur-16-en-19-oic acid (2), and two steroids β-sitosterol (3), and cholesta-5,23-dien-3-ol (4) were isolated and characterized. Among the compounds, the diterpenes were found to have more biological activities than the steroidal compounds. Compound 1 showed the highest cytotoxicity with LC₅₀ of 12.42 ± 0.87 μg/mL. Likewise, it possesses good antioxidant activity in terms of reducing power. On the contrary, compound 2 exerted the highest antiacetylcholinesterase and antibutyrylcholinesterase activity. Both the diterpenes showed almost similar antibacterial and antifungal activity. The identification of diterpenoid and steroid compounds with multifunctional activities suggests that W. chinensis may serve as an important source of bioactive compounds which should be further investigated in animal model for therapeutic potential in the treatment of different chronic diseases.

Potential, risks, and benefits of the extract recycled from Pteris vittata arsenic-rich biomass as a broiler growth promoter

The arsenic-rich biomass of Pteris vittata is a heavy burden to phytoremediation, but the compositions of extracts recycled from arsenic-rich biomass, such as rutin, may promote broiler growth. As such, this extract can be used to reduce the usage of antibiotics in the broiler industry and the cost of phytoremediation at the same time. Therefore, the critical issues for using extract from arsenic-rich biomass as a growth promoter have been studied, including its effective composition, health and environmental risks, and potential benefits and feasibility. Forty-five compounds were identified in the extract, and they were mainly flavonoids, chlorogenic acids, and proanthocyanidins, which can directly or indirectly influence the growth of broiler. The lifetime carcinogenic risks of broiler edible parts may be maximally increased by 4.75 × 10^-9 due to feeding the extract. The arsenic concentration of the farmland fertilized with the excrement from the broiler fed with the extract may increase by 0.00003-0.01857 mg/kg per year. Results revealed a feasible scenario that the sustainability of phytoremediation and broiler industry could be benefited through wastes from each other.

Polyphenolics with Strong Antioxidant Activity from Acacia nilotica Ameliorate Some Biochemical Signs of Arsenic-Induced Neurotoxicity and Oxidative Stress in Mice

Neurotoxicity is a serious health problem of patients chronically exposed to arsenic. There is no specific treatment of this problem. Oxidative stress has been implicated in the pathological process of neurotoxicity. Polyphenolics have proven antioxidant activity, thereby offering protection against oxidative stress. In this study, we have isolated the polyphenolics from Acacia nilotica and investigated its effect against arsenic-induced neurotoxicity and oxidative stress in mice. Acacia nilotica polyphenolics prepared from column chromatography of the crude methanol extract using diaion resin contained a phenolic content of 452.185 ± 7.879 mg gallic acid equivalent/gm of sample and flavonoid content of 200.075 ± 0.755 mg catechin equivalent/gm of sample. The polyphenolics exhibited potent antioxidant activity with respect to free radical scavenging ability, total antioxidant activity and inhibition of lipid peroxidation. Administration of arsenic in mice showed a reduction of acetylcholinesterase activity in the brain which was counteracted by Acacia nilotica polyphenolics. Similarly, elevation of lipid peroxidation and depletion of glutathione in the brain of mice was effectively restored to normal level by Acacia nilotica polyphenolics. Gallic acid methyl ester, catechin and catechin-7-gallate were identified in the polyphenolics as the major active compounds. These results suggest that Acacia nilotica polyphenolics due to its strong antioxidant potential might be effective in the management of arsenic induced neurotoxicity.

Identification of Polyphenolics from Loranthus globosus as Potential Inhibitors of Cholinesterase and Oxidative Stress for Alzheimer's Disease Treatment

Mistletoes are considered to be the potential medicinal herbs due to their rich traditional uses. Loranthus globosus is a Bangladeshi mango mistletoe that has been reported as folk medicine for various ailments and diseases. In an attempt to explore its effectiveness in Alzheimer's disease (AD), we investigated the antioxidant and acetylcholinesterase inhibitory activity of L. globosus. We report that the crude methanol extract (CME) of the plant contains a good amount of polyphenolics and possesses antioxidant and cholinesterase inhibitory activity. Fractionation of CME with solvents of varying polarity revealed the highest activity and polyphenolic content in the ethylacetate fraction (EAF). Correlation analysis revealed a significant (P < 0.05) association of polyphenolics with the antioxidant and cholinesterase inhibitory properties. Using column chromatography with diaion resin, the polyphenolics (EAF-PP) were isolated from the EAF that displayed the potent antioxidant and cholinesterase inhibitory activities. Kinetic analysis showed that EAF-PP exhibited a competitive type of inhibition. A total of thirty-six compounds including catechin and its different derivatives were identified in the EAF-PP by LC/MS analysis. Bioactivity-guided separation approach afforded the isolation of the two major active compounds catechin and catechin dimer from the EAF-PP. Hence, EAF-PP represents a potential source of antioxidants and cholinesterase inhibitors, which can be used in the management of AD.

Loranthus acaciae: Alternative medicine for β-lactamase producer and methicillin-resistant Staphylococcus aureus

Recently, we reported high antibacterial efficiency of Loranthus acaciae (LA) against different standard strains of bacteria including Methicillin-Resistant Staphylococcus aureus (MRSA). Therefore, this study aimed to confirm the effectiveness of LA against clinically isolated Staphylococcus aureus (SA) including β-lactamase producer (Blac) and MRSA. Forty-eight SA isolates collected from various clinical samples were used in this study. Antibiotics susceptibility profile was determined for twenty different antibiotics using automated Microscan Walkaway 96 Plus system as recommended by Clinical and Laboratory Standards Institute (CLSI) guidelines. This system also identified β-lactamase producers and MRSA. In the meantime, LA ethanolic extract was fractionated using liquid-liquid fraction method to hexane, dichloromethane DCM and methanol 80% fractions. Antimicrobial activities of LA extract and fraction were performed with agar well diffusion method for all SA isolates, MIC and MBC were also recorded. Phytochemical screening for various phyto-constituent classes of LA ethanolic extract was determined. Out of 48 SA isolates, Cefoxitin-positive MRSA represent 31 (64.6%), Blac 17 (35.4%), and 41 (85.4%) were multidrug-resistant SA, which was resistant at least to one antibiotic from three different categories. All isolates were resistant to ampicillin and penicillin. Antimicrobial activities of LA extract and fractions revealed that ethanol extract was active against all isolated SA with inhibition zone ranged from 33 ± 2.00 to 25 ± 3.05 mm. While DCM exhibited the largest inhibition zone range from 37 ± 3.00 to 33 ± 2.00 mm. This study is first of its kind conforming the high antibacterial activity of LA against SA isolated from a different source of infection. The study concluded that LA extract and fractions are active and give positive result for all isolated SA. Therefore, suitable pharmacological formulation of LA extract as a promising antibacterial agent for the treatment of SA infection should be given extreme priority.

Isolation, Characterization, and HPTLC-Quantification of Compounds with Anticancer Potential from Loranthus Acaciae Zucc

The cytotoxic effects of the crude extract of Loranthus acaciae Zucc. and its n-hexane, chloroform, and n-butanol fractions were assessed against three cancer cell lines using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay. Cell apoptosis was determined using an annexin V-phycoerythrin/7-aminoactinomycin kit. We observed that the L. acaciae n-hexane extract (LAHE) could inhibit cancer cell growth, particularly of MCF7 and A549 cells. Chromatographic purification of LAHE and nuclear magnetic resonance analysis led to the identification of two compounds from this plant species, namely, betulinic acid and β-sitosterol, for the first time. Flow cytometry study suggested that betulinic acid induced cell death via apoptosis, as a distinguished marked enhancement in the early and late apoptosis of human lung (A549) and breast (MCF-7) cancer cell lines. The isolated compounds were further estimated concurrently in LAHE using a validated high-performance thin-layer chromatographic (HPTLC) method on a 10 × 10 cm2 HPTLC plate with chloroform, methanol, and glacial acetic acid (97:2:1, v/v/v) as the mobile phase and a λmax of 540 nm. The amounts of betulinic acid and β-sitosterol in LAHE were 69.46 and 135.53 µg/mg of dried weight of extract, respectively. The excellent cytotoxic effect of LAHE could be attributed to the presence of ample amounts of betulinic acid.

Vascular Epiphytic Medicinal Plants as Sources of Therapeutic Agents: Their Ethnopharmacological Uses, Chemical Composition, and Biological Activities

This is an extensive review on epiphytic plants that have been used traditionally as medicines. It provides information on 185 epiphytes and their traditional medicinal uses, regions where Indigenous people use the plants, parts of the plants used as medicines and their preparation, and their reported phytochemical properties and pharmacological properties aligned with their traditional uses. These epiphytic medicinal plants are able to produce a range of secondary metabolites, including alkaloids, and a total of 842 phytochemicals have been identified to date. As many as 71 epiphytic medicinal plants were studied for their biological activities, showing promising pharmacological activities, including as anti-inflammatory, antimicrobial, and anticancer agents. There are several species that were not investigated for their activities and are worthy of exploration. These epipythes have the potential to furnish drug lead compounds, especially for treating cancers, and thus warrant indepth investigations.

Anti-HIV-1 activities of constituents from the rhizomes of Boesenbergia thorelii

A new lignan, thoreliin A (1), and a new bisnorlignan, thoreliin B (2), were isolated from a MeOH extract of the rhizomes of Boesenbergia thorelii. In addition, the known bisnorlignans 3 and 4, neolignan 5, phenylpropanoids 6-15, as well as benzenoids 18-21 were also obtained from the same source. The structures were elucidated based on their spectroscopic data. By single crystal X-ray analysis, the relative stereochemistry of 1 was confirmed. All isolated compounds were evaluated for anti-HIV-1 activities. Among them, thoreliin A (1) exhibited anti-HIV-1 activities on both HIV-1 reverse transcriptase (41.43% inhibition at 200 μg/mL) and syncytium reduction assays (EC₅₀ 20.6 μM, SI 3.7), while compounds 3-6, 9 and 11-21 showed anti-HIV-1 activity only in the anti-syncytium assay (EC₅₀ 6.6-454.1 μM, SI >1.32-7.75).

Styrenes from the Seeds of Atalantia monophylla

Four new dimeric styrenes, 1-4, were isolated from an EtOAc crude extract of the seeds of Atalantia monophylla. The biosynthetic pathway of 1 is proposed to involve a [2 + 2] cycloaddition, while 2-4 may be generated via a polar mechanism with a carbocation as the key intermediate. The structures of 1-4 were defined from spectroscopic analysis; experimental and calculated ECD spectra were used to characterize their absolute configurations. When tested against two different cancer cell lines, 1-4 were not determined to be cytotoxic (IC₅₀ > 10 μM).

Phytochemical analysis and anti-diabetic, anti-inflammatory and antioxidant activities of Loranthus acaciae Zucc. Grown in Saudi Arabia

The Loranthus genus has been demonstrated to be used in the treatment of wide range of diseases e.g. diabetes, inflammations and cancers. Many species of Loranthus represent a major source of biologically active constituents. Therefore, our study was carried out to investigate the anti-diabetic, anti-inflammatory and antioxidant effects of Loranthus acaciae Zucc. (Loranthaceae) grown in Saudi Arabia. Moreover, our research concerned the guided-fractionation and isolation of possible active compounds from this species. The crude ethanolic extract and its n-hexane, chloroform and n-butanol fractions were investigated for antidiabetic activity utilizing two methods namely, in alloxan-induced diabetic rats and glucose tolerance test in normal rats. Additionally, the anti-inflammatory activity was studied by the carrageenan-induced rat paw oedema method while DPPH free radical scavenging and β-carotene bleaching assays were utilized to determine the antioxidant activity. Various chromatographic and spectroscopic techniques were utilized for the isolation and characterization of the active compounds. Our results exhibited that the crude extract and chloroform fraction has the greatest hypoglycemic and antidiabetic effects. The chloroform fraction and crude extract produced at a dose of 500 mg/kg a significant hypoglycemic effect in diabetic rats with 47.0 and 33.6% reduction in blood sugar levels and in normoglycemic rats 35.6 and 35.4% respectively. A potent anti-inflammatory effect (67.2% at 500 mg/kg) was detected for the chloroform fraction. In addition, the chloroform fraction exhibited a high antioxidative and DPPH-radical inhibitory activity (85.4 and 88.3% respectively). The phytochemical analysis of L. acaciae led to the isolation and characterization of four compounds namely, quercetin 3-O-β-D-glucopyranoside (compound 1), quercetin 3-O-β-(6-O-galloyl)-glucopyranoside (compound 2), (-) catechin (compound 3), and catechin 7-O-gallate (compound 4). Among these compounds quercetin 3-O-β-D- glucopyranoside, quercetin 3-O-β-(6-O-galloyl)-glucopyranoside and catechin 7-O-gallate, are isolated for the first time from this plant.

Anti-inflammatory constituents from Perilla frutescens on lipopolysaccharide-stimulated RAW264.7 cells

Perilla frutescens (L.) Britt. (Lamiaceae) is a traditionally medicinal herb in East Asian countries to treat various diseases. In present study, the low-polarity constituents of the aerial parts of P. frutescens were investigated and their anti-inflammatory effect on lipopolysaccharide (LPS)-stimulated RAW264.7 cells were assayed. Three new furanoid monoterpenoids, named as frutescenones A - C (1-3), together with thirteen known compounds (4-16) were isolated and identified on the basis of extensive spectroscopic analysis and a single-crystal X-ray diffraction study. Among these components, 1 is an unusual monoterpenoid with 2,3'-bifuran skeleton, and 3 is a rare perillaketone-adenine hybrid heterodimer, while the revised NMR arrangements of 4 were reported at the first time. Furthermore, monoterpenoid 4 and alkaloid 15 showed remarkably inhibitory effect on the production of inflammatory mediator (NO) and pro-inflammatory cytokines (TNF-α and/or IL-6) in LPS-stimulated RAW264.7 cells.

Novel Potent Hypoglycemic Compounds from Euonymus laxiflorus Champ. and Their Effect on Reducing Plasma Glucose in an ICR Mouse Model

α-Glucosidase inhibitors (aGIs) have been used as an effective therapy for type-2 diabetes, which remains a global health issue. The aim of this study was to achieve bioactivity-guided isolation, identification and evaluation of hypoglycemic compounds from Euonymus laxiflorus Champ. trunk bark (ELCTB). Eleven active compounds were isolated and identified as walterolactone A/B β-d-pyranoglucoside (1), 1-β-d-glucopyranosyloxy-3,5-dimethoxy-4-hydroxybenzene (9), (−)-gallocatechin (10), schweinfurthinol 9-O-β-d-pyranoglucoside (11), 1-O-(3-methyl)-butenoyl-myo-inositol (12), leonuriside (14), (+)-catechin (19), methyl galloate (20), (−)-catechin (23), and condensed tannins (5 and 18). Of these 11, novel 4 compounds (1, 11, 12, and 14) were found as new α-glucosidase inhibitors. Notably, in vitro results indicated that compounds 1, 5, 10–12, 18, and 19 showed potent activity (IC₅₀ = 0.076−31 µg/mL), and their activities were at a higher level than that of acarbose, a commercial inhibitor (IC₅₀ = 1345 µg/mL). In animal tests, the major inhibitor, condensed tannin (18), demonstrated significant reduction of plasma glucose in mice with no symptoms of diarrhea at the dose of 100 mg/kg bw. The results suggest that Euonymus laxiflorus Champ. is a rich source of bioactive compounds for development as health food or drugs with potent hypoglycemic effect. The results of this study also enriched the current novel biological activities of constituents from Euonymus laxiflorus species.

In vitro acetylcholinesterase inhibitory activity and the antioxidant properties of Aegle marmelos leaf extract: implications for the treatment of Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is a progressive neurodegenerative disorder clinically characterized by loss of memory and cognition. The effective therapeutic options for AD are limited and thus there is a demand for new drugs. Aegle marmelos (Linn.) (A. marmelos) leaves have been used in traditional medicine to promote intellect and enhance memory. In this study, we evaluated A. marmelos for its acetylcholinesterase (AChE) inhibitory activity and antioxidant property in vitro in the treatment of AD.

METHODS

A crude methanol extract and four fractions (petroleum ether, chloroform, ethyl acetate and aqueous) were prepared from the leaves of A. marmelos. The preparations were assessed for AChE inhibitory activity by the Ellman method, and their antioxidant properties were assessed by several assays: reducing power, scavenging of 1,1-diphenyl-2-picrylhydrazyl free radical and hydroxyl radical, and inhibition of lipid peroxidation. Qualitative and quantitative analyses of endogenous substances in A. marmelos were performed by the standard phytochemical methods.

RESULTS

Among the different extracts tested, the ethyl acetate fraction exhibited the highest inhibition of AChE activity. In the same way, ethyl acetate fraction showed the highest reducing activity and radical scavenging ability towards the 1,1-diphenyl-2-picrylhydrazyl (half maximal inhibitory concentration = 3.84 μg/mL) and hydroxyl free radicals (half maximal inhibitory concentration = 5.68 μg/mL). The antiradical activity of the ethyl acetate fraction appeared to be similar to that of the reference standard butylated hydroxytoluene and catechin used in this study. In addition, the ethyl acetate fraction displayed higher inhibition of brain lipid peroxidation. Phytochemical screening of different extractives of A. marmelos showed the presence of phenols and flavonoids, alkaloid, saponin, glycoside, tannin and steroids. Quantitative analysis revealed higher contents of phenolics (58.79-mg gallic acid equivalent/g dried extract) and flavonoids (375.73-mg gallic acid equivalent/g dried extract) in the ethyl acetate fraction.

CONCLUSION

The results suggest that the ethyl acetate fraction of A. marmelos is a significant source of polyphenolic compounds with potential AChE inhibitory property and antioxidant activity and, thus, may be useful in the treatment of AD.

Prostratin and 12-O-tetradecanoylphorbol 13-acetate are potent and selective inhibitors of Chikungunya virus replication

A chemical study of the Vietnamese plant species Trigonostemon howii led to the isolation of a new tigliane-type diterpenoid, trigowiin A (1), along with several known coumarins and phenylpropanoids. The planar structure and the relative configuration of compound 1 were elucidated based on spectroscopic analysis, including 1D- and 2D-NMR experiments, mass spectrometry, and comparison with literature data. Trigowiin A (1) exhibited moderate antiviral activity in a virus-cell-based assay for Chikungunya virus (CHIKV). Since the structure of compound 1 is closely related to those of well-known tigliane diterpenoids such as prostratin (2), phorbol (3), 12-O-tetradecanoylphorbol 13-acetate (TPA) (4), and 4α-TPA (5), the antiviral activity of the latter compounds was also evaluated against CHIKV, as well as in virus-cell-based assays of two additional members of the genus Alphavirus (Sindbis virus, SINV, and Semliki forest virus, SFV). Whereas prostratin inhibited CHIKV replication with a moderate EC(50) of 2.6 μM and a selectivity index (SI) approximating 30, compound 4 proved to be an extremely potent inhibitor, with an EC(50) of ∼3 nM and a SI near 2000. Interestingly, no or very little activity was observed on the replication of SINV and SFV.

Bioassay-guided isolation of neuroprotective compounds from Loranthus parasiticus against H₂O₂-induced oxidative damage in NG108-15 cells

ETHNOPHARMACOLOGICAL RELEVANCE

A parasite plant, Loranthus parasiticus (Loranthaceae), which is generally known as benalu teh (in Malay), Sang Ji Sheng (in Chinese), and baso-kisei (in Japan) distributed in south and southwest part of China, has been used as a folk medicine for the treatment of schizophrenia in southwest China. Loranthus parasiticus has various uses in folk and traditional medicines for bone, brain, kidney, liver, expels wind-damp, and prevents miscarriage.

AIM OF THE STUDY

The current study was designed to evaluate the neuroprotective activity of Loranthus parasiticus against hydrogen peroxide (H(2)O(2))-induced oxidative damage in NG108-15 hybridoma cells, so as to present evidence for the traditional use of this parasite plant in the treatment of oxidative stress related neurodegenerative diseases.

MATERIALS AND METHODS

Dried and ground leaves of Loranthus parasiticus were extracted and fractionated into Loranthus parasiticus ethanol extract (LPEE), Loranthus parasiticus ethyl acetate fraction (LPEAF), and Loranthus parasiticus aqueous fraction (LPAF), which were subjected to neuroprotective activity assessment by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability assay. Bioassay-guided fractionation and isolation was performed subsequently to identify the most neuroactive compound. Mechanism studies underlying the present neuroprotection model of the isolated neuroactive compound was evaluated by employing 2,7-dichlorofluorescein diacetate (DCFH-DA) for intracellular reactive oxygen species (ROS) measurement, annexin V/propidium iodide (PI) for translocation of membrane phosphatidyleserine to identify cells undergo apoptosis, 5,5',6,6'-tetrachloro-1,1',3,3' tetraethylbenzimidazolylcarbocyanine iodide (JC-1) for mitochondrial membrane potential (MMP) detection, and PI for cell cycle events analysis.

RESULTS

Among those tested extract and fractions (LPEE, LPEAF, and LPAF) in our previous screening, LPAF significantly (P<0.01) yielded the highest neuroprotective activity with 78.00±1.85% cell viability in a dose dependent manner, supporting a neuroprotective role for LPAF in vitro. AC trimer and (+)-catechin have been isolated from LPAF successfully through bioassay-guided fractionation and isolation approach and (+)-catechin exhibited stronger neuroprotective activity as compared with AC trimer. (+)-Catechin increased cell viability and decreased the level of intracellular reactive oxygen species (ROS) in a dose-dependent manner against H(2)O(2)-induced oxidative stress in NG108-15 cells. Moreover, (+)-catechin reduced total annexin V positive cells (early and late apoptotic cells), attenuated the collapsed of MMP, and inhibited cell cycle arrested at sub-G(1) population following H(2)O(2) insult.

CONCLUSION

Collectively, the use of Loranthus parasiticus as folk medicine in the treatment of mental disorder was attributed to the presence of proanthocyanidins in this parasite plant. These findings support the traditional use of Loranthus parasiticus which is capable in managing neurological disorder where oxidative stress is implicated.

Toxicological studies of two compounds isolated from Loranthus globosus Roxb

The sub-acute toxicities of two compounds 3,4-dimethoxycinnamyl alcohol (1) and 3,4,5-trimethoxycinnamyl alcohol (2) isolated from the plant Loranthus globosus Roxb were studied on long Evan's rats. The studies included the gross general observation such as changes in body weight, haematological profiles [total count of Red Blood Cells (RBC) and White Blood Cells (WBC), differential count of WBC, platelet count and Haemoglobin (Hb)%], biochemical parameters of blood [Serum Glutamate Oxaloacetate Transaminase (SGOT), Serum Glutamate Pyruvate Transaminase (SGPT), Serum Alkaline Phosphatase (SALP), urea and creatinine) and histopathology of the liver, kidney, heart and lung of both control and experimental groups of rats. The changes in haematological and biochemical parameters were statistically not significant after the administration of compounds 1 and 2 in a dose of 300 microg/rat/day for consecutive 14 days. No abnormality was found in the histopathology of the liver, kidney, heart and lung in the experimental groups of rats following same dose when compared with control group. This preliminary study suggests that the isolated compounds may be used safely for clinical trial.

Metabolism of (-)-grandisin from Piper solmsianum in Coleoptera and Lepidoptera species

The biotransformation of the major Piper solmsianum leaf phenylpropanoids, such as the tetrahydrofuran lignan grandisin and derivatives was investigated in the beetle Naupactus bipes as well as in the caterpillars Heraclides hectorides and Quadrus u-lucida. Analysis of fecal material indicated that metabolism occurred mainly through mono- and di-O-demethylation at para positions of 3,4,5-trimethoxyphenyl rings of tetrahydrofuran lignans during digestion by these insects. Additionally, 3-hydroxy-4,5-dimethoxycinnamyl and 3,4,5-trimethoxycinnamyl alcohols were identified in fecal extracts of N. bipes.

Isolation of flavonol rhamnosides fromloranthus tanakae and cytotoxic effect of them on human tumor cell lines

Loranthus tanakae Fr. et Sav. (Loranthaceae) is a species of mistletoe, a semiparasitic plant growing on the branches of Quercus and Betula species as host trees. In our ongoing search for bioactive compounds from endemic species in Korea, we have investigated to isolate the chemical constituents responsible for the antitumor effect of the MeOH extract of L. tanakae. The ethylacetate soluble part of the MeOH extract demonstrated a marginal inhibition on the proliferation of the tumor cell lines such as A549 (non small cell lung), SK-OV-3 (ovary), SK-MEL-2 (melanoma), XF498 (central nerve system), and HCT-15 (colon) in vitro. Thus, the activity-guided isolation procedure upon the ethylacetate soluble part of the extract has been carried out and finally four flavonoid rhamnopyranosides (1-4) were isolated as active principle. The structures of 1-4 were elucidated by the physicochemical and spectral data as rhamnetin 3-O-alpha-L-rhamnoside (1), quercetin 3-O-alpha-L-rhamnoside (2), rhamnocitrin 3-O-alpha-L-rhamnoside (3), and kaempferol 3-O-alpha-L-rhamnoside (4).