In vitro antiaging activity of polyphenol rich Polyalthia longifolia (Annonaceae) leaf extract in Saccharomyces cerevisiae BY611 yeast cells

ETHNOPHARMACOLOGICAL RELEVANCE

Polyalthia longifolia var. angustifolia Thw. (Annonaceae) is commonly used in traditional medicine as a tonic for rejuvenation and exhibiting good antioxidant activities.

AIM OF THE STUDY

To evaluate P. longifolia methanolic leaf extract (PLME) antiaging activity at 1 mg/mL in Saccharomyces cerevisiae BY611 yeast.

MATERIALS AND METHODS

The antiaging effect of PLME was studied via replicative lifespan assay, antioxidative stress assays, reactive oxygen species (ROS) determination, reduced glutathione (GSH) determination, superoxide dismutase (SOD) and Sirtuin 1 (SIRT1) genes regulation studies and SOD and SIRT1 proteins activities.

RESULTS

The PLME treatment increased the growth and prolonged the lifespan of the yeast significantly (p < 0.05) compared to the untreated yeast group. Besides, the PLME also protected the yeast from oxidative stress induced by 4-mM-H₂O₂ via decreasing (p < 0.05) the ROS from 143.207 to 127.223. The antioxidative action of PLME was proved by spot assay. Phloxine B staining was further confirmed the PLME antioxidative action of PLME, where more whitish-pink live yeast cells were observed. In addition, the PLME also enhanced GSH content significantly (p < 0.05) in yeast treated with PLME from 16.81 to 25.31 μmol. Furthermore, PLME increased the SOD and SIRT1 genes expression significantly (p < 0.05) with ΔCt values of 1.11 and 1.15, respectively. The significantly (p < 0.05) elevated SOD and SIRT1 protein activities were recorded as 51.54 U/mg Prot and 1716 ng/mL, respectively.

CONCLUSIONS

PLME exhibited good antiaging activities in S. cerevisiae, by modulating oxidative stress, enhancing GSH content, and increasing SOD and SIRT1 genes expression.

Phytochemicals from Polyalthia Species: Potential and Implication on Anti-Oxidant, Anti-Inflammatory, Anti-Cancer, and Chemoprevention Activities

Polyalthia belong to the Annonaceae family and are a type of evergreen tree distributed across many tropical and subtropical regions. Polyalthia species have been used long term as indigenous medicine to treat certain diseases, including fever, diabetes, infection, digestive disease, etc. Recent studies have demonstrated that not only crude extracts but also the isolated pure compounds exhibit various pharmacological activities, such as anti-oxidant, anti-microbial, anti-tumor, anti-cancer, etc. It is known that the initiation of cancer usually takes several years and is related to unhealthy lifestyle, as well as dietary and environmental factors, such as stress, toxins and smoking. In fact, natural or synthetic substances have been used as cancer chemoprevention to delay, impede, or even stop cancer growing. This review is an attempt to collect current available phytochemicals from Polyalthia species, which exhibit anti-cancer potentials for chemoprevention purposes, providing directions for further research on the interesting agents and possible clinical applications.

Cleroda-4(18),13-dien-15,16-olide as novel xanthine oxidase inhibitors: An integrated in silico and in vitro study

In the present study, in silico predictions and molecular docking were performed on five clerodane diterpenes (1-5) from Polyalthia longifolia seeds to evaluate their potential as xanthine oxidase (XO) inhibitors. The initial screening was conducted by target prediction using TargetNet web server application and only compounds 3 and 4 showed a potential interaction with XO. Compounds 3 and 4 were subsequently subjected to in silico analyses on XO protein structure (PDB: 1N5X) using Schrödinger Release 2020-3 followed by structural modeling & molecular simulation studies to confirm the initial prediction result and identify the binding mode of these compounds to the XO. Molecular docking results revealed that compounds 3 (-37.3 kcal/mol) and 4 (-32.0 kcal/mol) binds more stably to XO than the reference drug allopurinol (-27.0 kcal/mol). Interestingly, two residues Glu 802 and Thr 1010 were observed as the two main H-bond binding sites for both tested compounds and the allopurinol. The center scaffold of allopurinol was positioned by some π-π stacking with Phe 914 and Phe 1009, while that of compounds 3 and 4 were supported by many hydrophobic interactions mainly with Leu 648, Phe 649, Phe 1013, and Leu 1014. Additionally, the docking simulation predicted that the inhibitory effect of compounds 3 and 4 was mediated by creating H-bond with particularly Glu 802, which is a key amino acid for XO enzyme inhibition. Altogether, in vitro studies showed that compounds 3 and 4 had better inhibitory capacity against XO enzyme with IC50 values significantly (p < 0.001) lower than that of allopurinol. In short, the present study identified cleroda-4(18),13-dien-15,16-olide as novel potential XO inhibitors, which can be potentially used for the treatment of gout.

Chemical composition of the essential oils of four Polyalthia species from Malaysia

Polyalthia is one of the largest genera in the Annonaceae family, and has been widely used in folk medicine for the treatment of rheumatic fever, gastrointestinal ulcer, and generalized body pain. The present investigation reports on the extraction by hydrodistillation and the composition of the essential oils of four Polyalthia species (P. sumatrana, P. stenopetalla, P. cauliflora, and P. rumphii) growing in Malaysia. The chemical composition of these essential oils was determined by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The multivariate analysis was determined using principal component analysis (PCA) and hierarchical clustering analysis (HCA) methods. The results revealed that the studied essential oils are made up principally of bicyclogermacrene (18.8%), cis-calamenene (14.6%) and β-elemene (11.9%) for P. sumatrana; α-cadinol (13.0%) and δ-cadinene (10.2%) for P. stenopetalla; δ-elemene (38.1%) and β-cubebene (33.1%) for P. cauliflora; and finally germacrene D (33.3%) and bicyclogermacrene for P. rumphii. PCA score and HCA plots revealed that the essential oils were classified into three separated clusters of P. cauliflora (Cluster I), P. sumatrana (Cluster II), and P. stenopetalla, and P. rumphii (Cluster III) based on their characteristic chemical compositions. Our findings demonstrate that the essential oil could be useful for the characterization, pharmaceutical, and therapeutic applications of Polyalthia essential oil.

Evaluation of mechanical, thermal and water absorption behaviors of Polyalthia longifolia seed reinforced vinyl ester composites

This study presented a novel utilization of biomass solid waste, named Polyalthia longifolia (Mast tree) seed as a reinforcement in a composite, using a compression molding technique. An attempt was made to reinforce vinyl ester matrix (VE) with Polyalthia longifolia seed filler (PLSF), ranging from 5 to 50 wt% loadings. Mechanical properties of the fabricated Polyalthia longifolia seed filler/vinyl ester (PLSF-VE) composite samples were tested and analyzed. The results showed that the PLSF-VE composite exhibited optimum mechanical properties at 25 % wt of filler loading; ultimate tensile strength and modulus were approximately 32.50 MPa and 1.23 GPa, respectively. The ultimate flexural, impact strengths and hardness were observed around 125 MPa, 31.09 kJ/m² and 36.50, respectively. The heat deflection test and thermo-gravimetric analysis depicted that the PLSF-VE composites withstood up to 66 °C and 430 °C, respectively. Furthermore, the PLSF and its various composite samples were studied, using energy-dispersive X-ray (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM).

Discovery of a Natural Product That Binds to the Mycobacterium tuberculosis Protein Rv1466 Using Native Mass Spectrometry

Elucidation of the mechanism of action of compounds with cellular bioactivity is important for progressing compounds into future drug development. In recent years, phenotype-based drug discovery has become the dominant approach to drug discovery over target-based drug discovery, which relies on the knowledge of a specific drug target of a disease. Still, when targeting an infectious disease via a high throughput phenotypic assay it is highly advantageous to identifying the compound’s cellular activity. A fraction derived from the plant Polyalthia sp. showed activity against Mycobacterium tuberculosis at 62.5 μge/μL. A known compound, altholactone, was identified from this fraction that showed activity towards M. tuberculosis at an minimum inhibitory concentration (MIC) of 64 μM. Retrospective analysis of a target-based screen against a TB proteome panel using native mass spectrometry established that the active fraction was bound to the mycobacterial protein Rv1466 with an estimated pseudo-K_d of 42.0 ± 6.1 µM. Our findings established Rv1466 as the potential molecular target of altholactone, which is responsible for the observed in vivo toxicity towards M. tuberculosis.

Functional Validation of DownRegulated MicroRNAs in HeLa Cells Treated with Polyalthia longifolia Leaf Extract Using Different Microscopic Approaches: A Morphological Alteration-Based Validation

Several microscopy methods have been developed to assess the morphological changes in cells in the investigations of the mode of cell death in response to a stimulus. Our recent finding on the treatment of the IC50 concentration (26.67 μg/mL) of Polyalthia longifolia leaf extract indicated the induction of apoptotic cell death via the regulation of miRNA in HeLa cells. Hence, the current study was conducted to validate the function of these downregulated microRNAs in P. longifolia-treated HeLa cells using microscopic approaches. These include scanning electron microscope (SEM), transmission electron microscope (TEM), and acridine orange/propidium iodide (AO/PI)-based fluorescent microscopy techniques by observing the morphological alterations to cells after transfection with mimic miRNA. Interestingly, the morphological changes observed in this study demonstrated the apoptotic hallmarks, for instance, cell blebbing, cell shrinkage, cytoplasmic and nuclear condensation, vacuolization, cytoplasmic extrusion, and the formation of apoptotic bodies, which proved the role of dysregulated miRNAs in apoptotic HeLa cell death after treatment with the P. longifolia leaf extract. Conclusively, the current study proved the crucial role of downregulated miR-484 and miR-221-5p in the induction of apoptotic cell death in P. longifolia-treated HeLa cells using three approaches-SEM, TEM, and AO/PI-based fluorescent microscope.

Polyalthia Clerodane Diterpene Potentiates Hypoglycemia via Inhibition of Dipeptidyl Peptidase 4

Serine protease dipeptidyl peptidase 4 (DPP-4) is involved in self/non-self-recognition and insulin sensitivity. DPP-4 inhibitors are conventional choices for diabetic treatment; however, side effects such as headache, bronchus infection, and nasopharyngitis might affect the daily lives of diabetic patients. Notably, natural compounds are believed to have a similar efficacy with lower adverse effects. This study aimed to validate the DPP-4 inhibitory activity of clerodane diterpene 16-hydroxycleroda-3,13-dien-15,16-olide (HCD) from Polyalthia longifolia, rutin, quercetin, and berberine, previously selected through molecular docking. The inhibitory potency of natural DPP-4 candidates was further determined by enzymatic, in vitro Caco-2, and ERK/PKA activation in myocyte and pancreatic cells. The hypoglycemic efficacy of the natural compounds was consecutively analyzed by single-dose and multiple-dose administration in diet-induced obese diabetic mice. All the natural-compounds could directly inhibit DPP-4 activity in enzymatic assay and Caco-2 inhibition assay, and HCD showed the highest inhibition of the compounds. HCD down-regulated LPS-induced ERK phosphorylation in myocyte but blocked GLP-1 induced PKA expression. For in vivo tests, HCD showed hypoglycemic efficacy only in single-dose administration. After 28-days administration, HCD exhibited hypolipidemic and hepatoprotective efficacy. These results revealed that HCD performed potential antidiabetic activity via inhibition of single-dose and long-term administrations, and could be a new prospective anti-diabetic drug candidate.

3,4- seco-Norclerodane Diterpenoids from the Roots of Polyalthia laui

Ten new clerodane diterpenoids, polylauioids A-J (1-10), and five known analogues (11-15) were isolated from the roots of Polyalthia laui. Among the new compounds, 3 and 8 are artifacts. The structures were elucidated using spectroscopic methods and by comparison with published NMR spectroscopic data. The absolute configurations of 4, 5, and 7 were defined based on single-crystal X-ray diffraction and electronic circular dichroism data. Compounds 1 and 2 represent the first examples of rearranged 3,4- seco-norclerodane diterpenoids, and a putative biosynthesis pathway for these compounds is proposed. Compounds 1, 4, 6, 7, 9, and 10 showed anti-HIV activities with EC₅₀ values ranging from 12.2 to 35.2 μM.

In vitro antiprotozoal activity and cytotoxicity of extracts and isolated constituents from Greenwayodendron suaveolens

ETHNOPHARMACOLOGICAL RELEVANCE

The Nkundo people (Nkundo area of Bolongo, Mai-Ndombe district, Bandundu Province, DR Congo) use various plant parts of the tree Greenwayodendron suaveolens (Engl. & Diels) Verdc. (syn. Polyalthia suaveolens Engl. & Diels) (Annonaceae) against malaria, but its antiprotozoal constituents are not known.

MATERIALS AND METHODS

The crude 80% ethanol extract from the fruits, leaves, root bark and stem bark and 16 fractions were assessed in vitro for their antiprotozoal activity against Trypanosoma brucei brucei, T. cruzi, Leishmania infantum and the chloroquine and pyrimethamine-resistant K1 strain of Plasmodium falciparum (Pf-K1). Their cytotoxic effects were evaluated against MRC-5 cells. Active constituents were isolated by chromatographic means, identified using spectroscopic methods, and evaluated in the same assays.

RESULTS

The root bark extract showed the highest activity against P. falciparum K1 (IC₅₀ 0.26µg/mL) along with the stem bark alkaloid fraction (IC₅₀ 0.27µg/mL). The root bark alkaloid fraction had a pronounced activity against all selected protozoa with IC₅₀ values <1µg/mL. The 90% methanol fractions of the different plant parts showed a pronounced activity against P. falciparum K1, with IC₅₀ values ranging between 0.36µg/mL and 0.69µg/mL. Four constituents were isolated: the triterpenes polycarpol, and dihydropolycarpol, the latter one being reported for the first time from nature, and the alkaloids polyalthenol and N-acetyl-polyveoline. They were active to a various degree against one or more protozoa, mostly accompanied by cytotoxicity. The highest selectivity was observed for N-acetyl-polyveoline against P. falciparum K1 (IC50 2.8µM, selectivity index 10.9).

CONCLUSIONS

These results may explain at least in part the traditional use of this plant species against parasitic diseases such as malaria in DR Congo.

Cerasoidine, a Bis-aporphine Alkaloid Isolated from Polyalthia cerasoides during Screening for Wnt Signal Inhibitors

A new bis-aporphine alkaloid, cerasoidine (1), was isolated from the root extract of Polyalthia cerasoides together with the known bis-aporphine bidebiline E (2) during screening for compounds with Wnt signal inhibitory activities. The structure of cerasoidine (1) was established by X-ray analysis and shown by chiral HPLC analyses and electronic circular dichroism to be a 57:43 mixture of R(-)- and S(+)-atropisomers. Bidebiline E (2) exhibited inhibition of transcriptional activity of TCF/β-catenin with an IC50 value of 20.2 μM and was also found to inhibit Wnt signaling by decreasing nuclear β-catenin.

16-hydroxy-cleroda-3,13-dien-16,15-olide induced glioma cell autophagy via ROS generation and activation of p38 MAPK and ERK-1/2

16-hydroxy-cleroda-3,13-dien-16,15-olide (HCD), a natural product isolated from medicinal plant Polyalthia longifolia exhibits anticancer activity through caspase-independent apoptosis in brain tumors, as previously reported. This study further attempted to investigate the involvement of HCD-induced autophagy in brain tumor cell lines neuroblastoma N18 and glioma C6 through the induction of reactive oxygen species (ROS) and the activation of p38 and ERK-1/2 pathway. The results demonstrated that HCD increased the hyper-generation of ROS and decreased cellular antioxidant enzymes, such as superoxide dismutase (SOD), glutathione (GSH), glutathione peroxidase (GPx), and glutathione s transferase (GST). Furthermore, HCD increased the expressions of autophagic marker proteins LC3-II and Beclin-1 in a time- and dose-dependent manner. Additionally, HCD was found to significantly induce p-p38 MAPK and p-ERK-1/2 proteins by Western blot, which implies that HCD is a potential therapeutic anticancer agent that exerts its activity through inducing ROS-mediation for the autophagy of brain tumor cells.

A clerodane diterpene from Polyalthia longifolia as a modifying agent of the resistance of methicillin resistant Staphylococcus aureus

BACKGROUND

Staphylococcus aureus infections are raising serious concern across the world. The effectiveness of conventional drugs is continuously decreasing due to global emergence of multidrug resistance (MDR) and therefore, new resistance-modifying agents (RMAs) are highly needed.

HYPOTHESIS

Clerodane diterpene 16α-hydroxycleroda-3,13(14)-Z-dien-15,16-olide (CD) from leaves of Polyalthia longifolia (Sonn.) Thwaites (Annonaceae) as RAM will be useful in improving the current treatment strategies for staphylococcal infections.

STUDY DESIGN

In the present study, we determine the resistance-modifying activity of CD using clinical isolates of MRSA. Further, the influence of CD on innate immune response was also evaluated in vitro and in vivo. The nature of potential interactions was determined by fractional inhibitory concentration indices (FICIs) calculated from microdilution assays and time-kill curves.

RESULTS

The result of in vitro combination study showed that CD significantly reduced MIC of fluoroquinolones up to 16-folds (FICI 0.315-0.500), while in S. aureus infected Swiss albino mice model, combination of CD with norfloxacin, significantly (p<0.01, p<0.001) lowered the systemic microbial burden in blood, liver, kidney, lung and spleen tissues in comparison to CD, norfloxacin alone as well as untreated control. Flow cytometry analysis clearly showed that CD significantly inhibited EtBr efflux and extended post-antibiotic effect. In qRT-PCR analysis, CD alone as well as in combination, significantly modulated the expression of various efflux pump genes including norA up to 2-fold in clinical isolate MRSA-ST2071. Further, the in vitro combination study of the CD (10, 5, 2.5µg/ml) along with the norfloxacin (10µg/ml) depicted a significant decline in the pro-inflammatory cytokines, IL6 and TNF-α. In septic shock mice model, CD did not exhibit any significant changes in the level of pro-inflammatory cytokines.

CONCLUSION

This is the first report on drug resistance-modifying potential of CD through inhibition of MDR efflux pump.

Phytochemical screening and in vivo antimalarial activity of extracts from three medicinal plants used in malaria treatment in Nigeria

The use of plant to meet health-care needs has greatly increased worldwide in the recent times. The search for new plant-derived bioactive agents that can be explored for the treatment of drug-resistant malaria infection is urgently needed. Thus, we evaluated the antimalarial activity of three medicinal plants used in Nigerian folklore for the treatment of malaria infection. A modified Peter's 4-day suppressive test was used to evaluate the antimalarial activity of the plant extracts in a mouse model of chloroquine-resistant Plasmodium berghei ANKA strain. Animals were treated with 250, 500, or 800 mg/kg of aqueous extract. It was observed that of all the three plants studied, Markhamia tomentosa showed the highest chemosuppression of parasites of 73 % followed by Polyalthia longifolia (53 %) at day 4. All the doses tested were well tolerated. Percentage suppression of parasite growth on day 4 post-infection ranged from 1 to 73 % in mice infected with P. berghei and treated with extracts when compared with chloroquine diphosphate, the standard reference drug which had a chemosuppression of 90 %. The percentage survival of mice that received extract ranged from 0 to 60 % (increased as the dose increases to 800 mg/kg). Phytochemical analysis revealed the presence of tannins, saponins, and phenolic compounds in all the three plants tested.

Evaluation of antinociceptive activity of ethanol extract of bark of Polyalthia longifolia

ETHNOPHARMACOLOGICAL RELEVANCE

Polyalthia longifolia var. pendula is a very popular herb in Bangladesh due to its traditional uses in treatment of rheumatism, bone fracture and gastric ulcer. The present study was conducted to investigate the antinociceptive activity of ethanol extract of P. longifolia (EEPL) bark.

MATERIALS AND METHODS

Hot plate and tail immersion tests, acetic acid-induced writhing test, glutamate and formalin-induced paw licking tests in mice were employed in this study. In all the experiments EEPL was administered orally at the doses of 50, 100 and 200mg/kg body weight. To investigate the possible participation of opioid system in EEPL-mediated effects, naloxone was used to antagonize the action.

RESULTS

EEPL showed a significant antinociceptive activity against both heat and chemical-induced nociception. The effects were dose-dependent and significant at the doses of 100 and 200mg/kg of EEPL. Besides, pretreatment with naloxone caused significant inhibition of the antinociceptive activity induced by EEPL, revealing the possible involvement of the opioid receptors.

CONCLUSION

These results indicate the antinociceptive activity of the bark of P. longifolia and support the ethnomedical use of this plant in treatment of different painful conditions.

Highly selective colorimetric detection and estimation of Hg2+ at nano-molar concentration by silver nanoparticles in the presence of glutathione

The present study investigated the colorimetric detection of mercury (Hg(2+)) ions by using silver nanoparticles (Ag NPs) in the presence of glutathione. The nanoparticles used in the study were synthesized biologically by using Polyalthia longifolia leaf extract. The synthesized nanoparticles were characterized by UV-visible spectrophotometer, transmission electron microscope, X-ray diffraction, particle size analyzer and zeta sizer. The particles were spherical in shape and it possesses the effective diameter of 5 nm. The zeta potential of the particles was determined to be -28.6 mV. Ag NPs-glutathione conjugates were able to detect Hg(2+) in nanomolar level. Ag NPs-glutathione conjugates upon interaction with Hg(2+) changes from yellowish brown to pale yellow and finally colorless. The study may be applied for the qualitative and quantitative estimation of mercury at very low concentration.

Synergistic anticancer effect of the extracts from Polyalthia evecta caused apoptosis in human hepatoma (HepG2) cells

OBJECTIVE

To evaluate the anticancer activity of the extract fraction of Polyalthia evecta (P. evecta) (Pierre) Finet & Gagnep and the synergistic anticancer effect of the extracts from P. evecta by using the ATR/FT-IR spectroscopy.

METHODS

The 50% ethanol-water crude leaf extract of P. evecta (EW-L) was prepared and was further fractionated to isolate various fractions. The anticancer activity was investigated from cytotoxicity against HepG2 using a neutral red assay and apoptosis induction by evaluation of nuclei morphological changes after DAPI staining. Synergistic anticancer effects of the extracts from P. evecta were performed using the ATR/FT-IR spectroscopy.

RESULTS

The result showed that the EW-L showed higher cytotoxicity and apoptosis induction in HepG2 cells than its fractionated extracts. The hexane extract exhibited higher cytotoxicity and apoptosis induction than the water extracts, but less than the EW-L. The combined water and hexane extracts apparently increased cytotoxicity and apoptosis induction. The %apoptotic cells induced by the extract mixture were increased about 2-fold compared to the single hexane extract.

CONCLUSIONS

The polar extract fraction is necessary for the anticancer activity of the non-polar extract fraction. The ATR/FT-IR spectra illustrates the physical interaction among the constituents in the extract mixture and reveals the presence of polyphenolic constituents in the EW-L, which might play a role for the synergistic anticancer effect.

Bioactive 6S-styryllactone constituents of Polyalthia parviflora

Parvistones A-E (1-5), five new styryllactones possessing a rare α,β-lactone moiety and a 6S configuration, were isolated from a methanolic extract of Polyalthia parviflora leaves. The structures and the absolute configuration of the isolates were elucidated using NMR spectroscopy, specific rotation, circular dichroism, and X-ray single-crystal analysis. Compounds 8, 9, 11, and 12 were isolated for the first time. The results were supported by comparing the data measured to those of 6R-styryllactones. Moreover, a plausible biogenetic pathway of the isolated compounds was proposed. The structure-activity relationship of the compounds in an in vitro anti-inflammatory assay revealed the 6S-styryllactones to be more potent than the 6R derivatives. However, the effect was opposite regarding their cytotoxic activity. In addition, 6S-styrylpyrones isolated showed more potent anti-inflammatory and cytotoxic activity when compared to the 1S-phenylpyranopyrones obtained.

Indolosesquiterpene alkaloids from the Cameroonian medicinal plant Polyalthia oliveri (Annonaceae)

The stem bark of Polyalthia oliveri was screened for its chemical constituents using liquid chromatography high resolution mass spectrometry resulting in the isolation of three indolosesquiterpene alkaloids named 8α-polyveolinone (1), N-acetyl-8α-polyveolinone (2) and N-acetyl-polyveoline (3), together with three known compounds, dehydro-O-methylisopiline (4), N-methylurabaine (5) and polycarpol (6). The structures of the compounds were elucidated by means of high resolution mass spectrometry and different NMR techniques and chemical transformations. Their absolute configurations were assigned by ab-initio calculation of CD and ORD data (for 2 and 3) and X-ray diffraction analysis (for 2). Compounds 2 and 3 exhibited moderate antiplasmodial activity against erythrocytic stages of chloroquine-sensitive Plasmodium falciparum NF54 strain and low cytotoxicity on rat skeletal myoblast (L6) cell line.

Anti-proliferative and apoptotic properties of a peptide from the seeds of Polyalthia longifolia against human cancer cell lines

The peptides produced enzymatically from various plants have shown various biological activities including cytotoxicity. Different types of cytotoxic peptides have been reported from the seeds and leaves of Violaceae, Rubiaceae and Annonaceae families. In this study, we report purification and characterization of peptide(s) showing cytotoxic activity against A549 and HeLa cancer cell lines from the seeds of Polyalthia longifolia (Annonaceae). Seed proteins of P. longifolia were extracted and hydrolyzed using trypsin. The enzyme hydrolysate was applied on to a Sephadex G10 column and eluted using Tris-HC1 buffer (pH 7.5). Two fractions F1 and F2 were obtained, of which F2 showed significant cytotoxic activity against lung (A549) cancer cells at 10 microg/mL and cervical (HeLa) cancer cell lines at 30 microg/mL, as revealed by the MTT assay. DNA fragmentation was observed in the tested cancer cell lines treated with F2 peptide at a concentration of 10microg/mL and 30 pg/mL, respectively. Further, increased number of apoptotic cells was observed in sub-G0 phase of cell cycle of A549 and HeLa cell lines, when treated with 10 microg/mL and 30 microg/mL of F2, as revealed by the flow cytometric analyses. FTIR spectrum of F2 peptide detected the presence of stretching vibrations of carboxylic acid OH residue with peak at 3420 cm-and carbonyl (C=O) groups at 1636 cm-1, respectively. RP-HPLC analysis of F2 peptide showed a single peak at a retention time of 12.8 min detected at 280 nm, depicting the purity of F2 to be more than 90%. LC-ESI-MS/MS analysis showed the average theoretical mass of F2 to be 679.8 using m/z ratios. In conclusion, the findings suggest that F2 peptide is an effective inducer of apoptosis of cancer cells, thus offers an important strategy in the development of cancer therapeutics.

(+)-rumphiin and polyalthurea, new compounds from the stems of Polyalthia rumphii

Two new compounds, (+)-rumphiin (3) and polyalthurea (7), together with seven known ones, 3,4,5-trimethoxy benzoic acid (1), (-)-seselinone (2), cannabisin D (4), allantoin (5), oxostephanine (6) and a mixture of beta-sitosterol (8) and stigmasterol (9) were isolated from the stems of Polyalthia rumphii. The chemical structures of 3 and 7 were elucidated by the combination of spectroscopic data, and the absolute configuration of 3 at C-2 was determined by the matrix method to be R. All compounds were evaluated for their cytotoxicity on four human cancer cell lines, which demonstrated that 3 was a moderate bioactive lignan, and 6 showed significant anticancer activity against SPC-A-1 and BEL-7402 cell lines with IC50 values of 1.47 and 1.73 microg/mL, respectively.

Acute oral toxicity of Polyalthia longifolia var. pendula leaf extract in Wistar albino rats

CONTEXT

Polyalthia longifolia (Sonn.) Thw. var. pendula (Annonaceae), a tall evergreen tree, is cultivated all over India. The plant is used in traditional systems of medicine for the treatment of fever, skin diseases, and hypertension.

OBJECTIVE

The present study evaluated the acute oral toxicity of Polyalthia longifolia var. pendula leaf extract in Wistar albino rats.

MATERIAL AND METHODS

The parameters evaluated daily after oral drug administration of the extract (540, 1080, 2160 and 3240 mg/kg body weight) were mortality, signs of toxicity, feed and water consumption and body weight changes up to 14 days. The effect of different doses of the extract on organ weight, biochemical and hematological parameters were evaluated on the 15th day.

RESULTS AND CONCLUSION

Methanol extract of Polyalthia longifolia leaf up to the dose level 3240 mg/kg body weight did not produce any toxic effects or deaths; the extract was well tolerated by the rats. It did not alter body weight, feed and water consumption. The organ weight, biochemical and hematological analysis did not show any dose-dependent changes in any of the parameters examined in animals of both sexes. The acute oral administration of the methanol extract of Polyalthia longifolia leaf was not toxic and safe in a single dose.

Anticancer activities of constituents from the stem of Polyalthia rumphii

Nine known compounds were firstly isolated from the chloroform extract of Polyalthia rumphii stem by anticancer activity guidance, and the chemical structures were identified by using spectroscopic and physico-chemical analysis. Cytotoxic evaluation against four cancer cell lines was performed on all these compounds, which showed that K562 could be significantly inhibited by partial compounds with IC(50) values at the range from 40 to 60 μ/mL.

New gastroprotective labdeneamides from (4S,9R,10R) methyl 18-carboxy-labda-8,13(E)-diene-15-oate

Starting from the diterpene (4S,9R,10R) methyl 18-carboxy-labda-8,13(E)-dien-15-oate (PMD) and its 8(9)-en isomer [PMD 8(9)-en], 11 amides were prepared and assessed for a gastroprotective effect in the ethanol/HCl-induced gastric lesions model in mice. Basal cytotoxicity of the compounds was determined on the following human cell lines: normal lung fibroblasts (MRC-5), gastric epithelial adenocarcinoma (AGS), and hepatocellular carcinoma (Hep G2). All compounds are described for the first time. At the single oral dose of 0.1 mg/kg, compounds 1, 10, and 11 presented a strong gastroprotective effect, at least comparable with that of the reference compound lansoprazole at 1 mg/kg, reducing gastric lesions by 76.7, 67.7, and 77.2 %, respectively. The leucyl amide methyl ester 3, tryptophanyl amide methyl ester 5, and benzyl amide 6 of PMD presented a selective basal cytotoxicity on Hep G2 cells with IC₅₀ values of 136.8, 105.3, and 94.2 µM, respectively, while the IC₅₀ values towards AGS cells were 439.5, 928.0, and 937.3 µM, respectively. The three compounds did not affect fibroblast viability with IC₅₀ values > 1000 µM. Compounds 7, 8, 10, and 11 showed no toxic effect against the three selected cell lines.

[Study on chemical constituents from branches and leaves of Polyalthia nemoralis]

OBJECTIVE

To investigate the chemical constituents of the branches and leaves of Polyalthia nemoralis.

METHOD

The compounds were isolated and purified by silica gel, macroporous adsorption resin and Sephadex LH-20 column chromatographic methods. Their chemical structures were elucidated on the basis of physicochemical properties and spectral data.

RESULT

Fourteen compounds were isolated and identified as syringic acid (1), 3-methoxy-4-hydroxycinnamic acid (2), vanillic acid (3), 4-hydroxybenzoic acid (4), mauritianin (5), (+)-xylopinidine (6), (+)-oblongine(7), (+)-tembetarine (8), eythritol (9), D-mannitol (10), ethyl-beta-D-glucopyranoside (11), (+)-magnoflorine (12), stepharanine (13), (2S, 4R)-4-hydroxy-2-piperidine-carboxylic acid (14), respectively.

CONCLUSION

All the compounds were isolated from the genus Polyalthia for the first time; compounds 6 and 13 showed inhibitation activities against multi tumor cell lines.

A new azafluorenone from the roots of Polyalthia cerasoides and its biological activity

Chromatographic separation of the ethyl acetate extract of roots of Polyalthia cerasoides has led to the isolation of the new compound, 6,8-dihydroxy-7-methoxy-1-methyl-azafluorenone. This compound exhibited potent cytotoxic activities with IC50 values in the range of 2.64-3.58 microg x mL(-1) for A549, GLC4 and GLC4/Adr cells, but was not recognized by ABCC1/MRP1 protein. The compound also showed very strong inhibition of M. tuberculosis using a broth microdilution method, with an MIC value of 0.78 microg x mL(-1), which was equal to that of ofloxacin, one of the four antibiotic drugs used as a positive control.

An unusual bisnor-clerodane diterpenoid from Polyalthia simiarum

The stem bark of Polyalthia simiarum has yielded a new bisnor-type clerodane diterpenoid, 2-oxo-14,15-bisnor-3,11E-kolavadien-13-one (1), and three previously known clerodane derivatives, kolavenic acid (2), 16beta-hydroxycleroda-3,13(14)Z-dien-15,16-olide (3), and 16-oxocleroda-3,13(14)E-dien-15-oic acid (4). The structures of these compounds were unambiguously determined by extensive NMR studies as well as by comparison with related compounds. Till now this is the second report of the occurrence of any unusual C-18 clerodane diterpenoid from nature. The crude light petroleum extract and the purified compound 3 demonstrated moderate free radical scavenging activity with IC50 values of 21.5 and 23.5 microg/mL, respectively.

Polyacetylenes from the roots of Polyalthia debilis

Six new linear polyacetylenic C25 and C27 acetogenins (1-6), named debilisones A-F, have been isolated from a methanol extract of roots of Polyalthia debilis. Structures of these compounds were determined by spectroscopic techniques. The absolute configuration at C-17 of 2 was assigned by the modified Mosher's method. Compounds 2, 3, and 5 exhibited moderate antimycobacterial activity against Mycobacterium tuberculosis with MIC values of 25.0, 12.5, and 25.0 microg/mL, respectively.

Antiproliferative, apoptotic and antimutagenic activity of isolated compounds from Polyalthia cerasoides seeds

Phytochemical investigation of the petroleum ether extract fraction of Polyalthia cerasoides seeds led to the isolation of two phytosterols (alpha-spinasterol and spinasterol) and a clerodane di-terpenoid. The structures of these compounds were elucidated using IR, (1)H-NMR, (13)C-NMR and Mass spectral analysis. Further, these compounds were tested for antiproliferative action against CACO-2 cell line and apoptotic action was determined by nuclear staining and DNA fragmentation analysis. The results showed that the compounds exhibited antiproliferative action at various concentrations with an IC(50) value of 28.6+/-4.34nM/ml, 57.7+/-6.81nM/ml and 60.0+/-7.10nM/ml for clerodane diterpenoid, spinasterol and alpha-Spinasterol respectively. Furthermore, the isolated compounds were screened for antimutagenic effect against methylmethane sulfonate (MMS) induced mutation. Phytosterols showed protective effect, whereas clerodane diterpenoid was less effective to MMS induced chromosomal aberrations. Our research contributes to the characterization of phytochemical constituents and to understand the ability of these compounds to antiproliferative and antimutagenic responses from the seed extracts.

Antitumor and antioxidant activity of Polyalthia longifolia stem bark ethanol extract

In the present study, the ethanol extract of stem bark of Polyalthia longifolia Benth. and Hook (Annonaceae) was screened for its in vitro and in vivo antitumor activity. In vitro cytotoxicity of P. longifolia extract was assessed in murine cancer cells and in human cancer cells by Trypan blue exclusion assay and MTT assay, respectively. P. longifolia extract showed concentration-dependent cytotoxicity in Ehrlich's ascites carcinoma (EAC) and Dalton's ascites lymphoma (DLA) cells with IC50 values of 45.77 and 52.52 microg/mL, respectively. In the MTT assay, the IC50 values of P. longifolia extract against HeLa and MCF-7 cells were 25.24 and 50.49 microg/mL, respectively. In vivo antitumor activity against Ehrlich's ascites tumor and Dalton's solid tumor models was assessed by administering 50 and 100 mg/kg of P. longifolia extract, i.p., for 7 consecutive days. P. longifolia extract, at a dose of 100 mg/kg, significantly enhanced mean survival time (MST) and marginally improved hematological parameters when compared to EAC control mice. And the same dose significantly reduced the tumor volume as compared to control DLA inoculated mice. Positive control, cisplatin (3.5 mg/kg, i.p., single dose), significantly enhanced MST and improved hematological parameters when compared to EAC and significantly reduced the tumor volume when compared to DLA control. In vitro antioxidant potential of P. longifolia extract was also determined owing to the role of reactive oxygen species in tumor initiation and progression. P. longifolia extract scavenged DPPH radicals, reduced ferric ions and inhibited lipid peroxidation with IC50 values of 18.14, 155.41 and 73.33 microg/mL, respectively.

Anti-HIV-1 diterpenoids from leaves and twigs of Polyalthia sclerophylla

Bioassay-guided fractionation and purification of the anti-HIV-1-active MeOH extract from the leaves and twigs of Polyalthia sclerophylla led to the isolation of two new compounds, ENT-kaur-sclerodimer ( 1) and cyclotucanol 3-palmitate ( 2), along with the known ENT-kaur-16-en-19-oic acid ( 3), 15 beta-hydroxy- ENT-kaur-16-en-19-oic acid ( 4), 15 beta-acetoxy- ENT-kaur-16-en-19-oic acid ( 5), 15-oxo- ENT-kaur-16-en-19-oic acid ( 6), 16 alpha,17-dihydroxy- ENT-kauran-19-oic acid ( 7), 16 alpha-hydroxy- ENT-kauran-19-oic acid (xylopic acid) ( 8), a pseudodimer (15 alpha-hydroxy- ENT-kaur-16-en-19-oic acid/17-hydroxy- ENT-kaur-15-en-19-oic acid) ( 9), ermanin, nicotiflorin, and allantoin. Among these isolates, compound 3 was the most active in both anti-syncytium (EC (50) 13.7 microg/mL and selectivity index 3.1) and HIV-1 reverse transcriptase (IC (50) 34.1 microg/mL) assays.

6-Hydroxycleroda-3,13-dien-15,16-olide protects neuronal cells from lipopolysaccharide-induced neurotoxicity through the inhibition of microglia-mediated inflammation

Polyalthia longifolia var. pendula is used as an antipyretic agent in indigenous systems of medicine. Microglia-mediated inflammation plays an important role in the pathway leading to neuronal cell death in a number of neurodegenerative diseases. The aim of this study was to investigate the effects of 6-hydroxycleroda-3,13-dien-15,16-olide (PL3) extracted from Polyalthia longifolia var. pendula on lipopolysaccharide(LPS)-induced inflammation in microglia-like HAPI cells and primary microglia cultures. In microglia-neuron co-cultures, LPS decreased the cell viability of neuroblastoma SH-SY5Y cells. LPS-induced cell death was attenuated by the NOS inhibitor, L-NAME, the COX-2 inhibitor, NS-398 or the NADPH oxidase inhibitor, DPI, respectively. In LPS-treated microglia cells, PL3 decreased the expression of iNOS, COX-2, gp91 (phox), and NF- kappaBp65, the degradation of I kappaB alpha, and the production of NO, PGE (2), iROS, and TNF- alpha. PL3 also enhanced the expression of HO-1, a cytoprotective and anti-inflammatory enzyme. Moreover, PL3 reduced LPS-activated microglia-induced cell death. The present results suggest that PL3 inhibits microglia-mediated inflammation and inflammation-related neuronal cell death. Therefore, PL3 has potential use for the treatment of inflammation-related neurodegenerative diseases.

[2-Pyridinethiolate derivatives from branches and leaves of Polyalthia nemoralis and their cytotoxic activities]

OBJECTIVE

To investigate the active constituents of the branches and leaves of Polyalthia nemoralis.

METHOD

The compounds were isolated and purified by silica gel, macroporous adsorption resin and Sephadex LH-20 column chromatographic methods. Their chemical structures were elucidated on the basis of physicochemical properties and spectral data.

RESULT

Eight compounds were isolated and identified as: zincpolyanemin (1), nickel bis-(pyridine-N-oxide-2-thiolate) (2), cupric bis (pyridine-N-oxide-2-thiolate (3), 2-methanesulfonyl-pyridine (4), 2-pyridinethiolate N-oxide (5), 2,2'-dithiodipyridine (6), 2-thiohydroxypyridin-N-oxide-2-S-beta-D-gluco pyranoside (7) and pyridine-N-oxide (8), respectively.

CONCLUSION

Compounds 2, 4-6, 8 were new natural products. The bioassays in vitro against five human tumor cell lines with MTT method showed stronger cytotoxic activities (IC50 0.05-0.09 mg x L(-1)) for compounds 1-3 and 6, and weaker cytotoxic activities (IC50 5.49-7.71 mg x L(-1)) for compound 5.

Bioactive azafluorenone alkaloids from Polyalthia debilis (Pierre) Finet & Gagnep

This study investigated bioactive extracts of Polyalthia debilis (Annonaceae) with antimicrobial, antimalarial and cytotoxic activities. Extensive chromatographic isolations provided azafluorenone alkaloids; onychine (1) and 7-methoxyonychine (2) together with a mixture of β–sitosterol and stigmasterol. The two alkaloids were isolated from the P. debilis for the first time. Isolated fractions containing a mixture of triterpenoids (C7, C8 and C9) exhibited the most potent antimicrobial activity against many bacterial strains with minimum inhibitory concentration of 64 μg/mL. Fractions with antimalarial and cytotoxic activities were also observed. The findings suggest the potential use of P. debilis in medicinal applications.

Constituents of Polyalthia longifolia var. pendula

Three new clerodane-type diterpenes, 6alpha,16-dihydroxycleroda-3,13-dien-15-oic acid (1), 6alpha,16-dihydroxycleroda-4(18),13-dien-15-oic acid (2), and 4alpha,18beta-epoxy-16-hydroxyclerod-13-en-15-oic acid (3), and four new protoberberine alkaloids, (-)-8-oxo-10-hydroxy-2,3,9-trimethoxyberberine (4), (-)-8-oxo-2,11-dihydroxy-3,10-dimethoxyberberine (5), (-)-8-oxo-11-hydroxy-2,3,9,10-tetramethoxyberberine (6), and (-)-8-oxo-2,10-dihydroxy-3,9,11-trimethoxyberberine (7), together with 11 known substances, were isolated from a methanol extract of the stems of Polyalthia longifolia var. pendula. The structures of 1-7 were elucidated on the basis of spectroscopic data analysis. Compounds were evaluated for their antiproliferative activities against A549 and MCF-7 cancer cells, and among the substances tested, only 16-oxo-cleroda-3,13-dien-15-oic acid (8) exhibited cytotoxicity.

[Aporphine alkaloids from branches and leaves of Polyalthia nemoralis]

OBJECTIVE

To investigate the aporphine alkaloids in the branches and leaves of Polyalthia nemoralis.

METHOD

The compounds were isolated and purified by silica gel and Sephadex LH-20 column chromatographies. Their chemical structures were elucidated on the basis of physicochemical properties and spectral data.

RESULT

Five aporphine alkaloids were isolated and identified as: bidebiline A (1), annobraine (2), lanuginosine (3), liriodenine (4), oxostephanosine (5), respectively.

CONCLUSION

For the first time, Compounds 2 and 5 were obtained from Polyalthia while 1, 3 and 4 isolated from this plant. The bioassays in vitro against five human tumor cell lines with MTT method showed moderate cytotoxic activities (IC50 1 mg x L(-1)) of compounds 3-5.

Antimicrobial evaluation of clerodane diterpenes from Polyalthia longifolia var. pendula

Phytochemical investigation of the ethanolic extract of leaves of Polyalthia longifolia var. pendula has led to the isolation of seven clerodane diterpenoids and five alkaloids. (-)-14, 15-bisnor-3, 11E-kolavadien-13-one (1), (-)-16-oxocleroda-3,13(14)E-dien-15-oic acid (2), (-)-16alpha-hydroxycleroda-3,13 (14)Z-dien-15,16-olide (3), (+)-(4-->2)-abeo-16(R/S)-2, 13Z-kolavadien-15, 16-olide-3-al (4), (-)-3beta, 16beta-dihydroxycleroda-4(18), 13(14)Z-dien-15,16-olide (5), (-)-3, 12E-kolavadien-15-oic acid-16-al (6), (-)-labd-13E-en-8-ol-15-oic acid (7), liriodenine (8), (-)-anonaine (9), (+)-isoboldine (10), (-)-asimilobine (11) and hordenine (12) have been isolated. This is the first report of 1, 6 and 10 from this plant species while 12 is reported for first time from this genus. Clerodane derivatives 1-7 were evaluated for their antimicrobial activity. Diterpene 3 was found to be most potent agent with MIC value of 6.25 microg/mL against Staphylococcus aureus and Sporothrix schenckii.

Four new alkaloids from Polyalthia nemoralis (Annonaceae)

Four new alkaloids, polynemoralines A (1), B (2), C (3), and D (4), were isolated from the branches and leaves of Polyalthia nemoralis A DC. The structures of 1-4 were elucidated mainly on the basis of spectroscopic methods. The structure of 4 was confirmed by X-ray diffraction analysis.

Synthesis of kalasinamide, a putative plant defense phototoxin

The first total synthesis of the azaanthracene kalasinamide (1) is described, and the discrepancy in the reported (13)C NMR data and melting points for the natural product from two different sources is resolved. Kalasinamide is prone to autosensitized photooxidation, in solution and in the solid state, to give the corresponding quinone, marcanine A (8). This transformation may be representative of a novel and more general step in the biosynthesis of (aza)anthraquinones. Through its ability to generate toxic singlet oxygen, kalasinamide may serve a protective role, defending the plant against predation and the invasion of microbial pathogens, following mechanical insult.

Bioactive constituents of the roots of Polyalthia cerasoides

A new dimeric aporphine alkaloid, bidebiline E (1), and a new natural product, octadeca-9,11,13-triynoic acid (2), along with three known sesquiterpenes, alpha-humulene (3), caryophyllene oxide (4), and (-)-alpha-cadinol (5), and four known isoquinoline alkaloids, laudanosine (6), codamine (7), laudanidine (8), and reticuline (9), were isolated from the roots of Polyalthia cerasoides. The structures of compounds 1 and 2 were established on the basis of their 1D and 2D NMR spectroscopic data. Among these isolates, 1, 2, 4, 7, and 8 exhibited antimalarial activity against Plasmodium falciparum, while 1- 3 showed antimycobacterial activity against Mycobacterium tuberculosis using in vitro assays.

Cytotoxic styryl-lactones from the leaves and twigs of Polyalthia crassa

Four new styryl-lactones, crassalactones A-D (1-4), were isolated from a cytotoxic ethyl acetate-soluble extract of the leaves and twigs of Polyalthia crassa, together with seven known compounds, (+)-3-acetylaltholactone, (+)-altholactone, aristolactam AII, cinnamic acid, (+)-goniofufurone, (+)-goniopypyrone, and (+)-howiinol A. Their structures were determined on the basis of spectroscopic methods. The absolute configuration of 1-3 was established by chemical conversions. Single-crystal X-ray analysis and the Mosher ester method were used to confirm the absolute stereochemistry of 4. Cytotoxic evaluation against several mammalian cancer cell lines was performed on all new isolates, aristolactam AII, and the modified (+)-tricinnamate derivative 11 obtained from 1.

Antifilarial activity in vitro of polycarpol and 3-O-acetyl aleuritolic acid from cameroonian medicinal plants against Onchocerca gutturosa

Previous results have revealed the antifilarial activities of crude extracts and pure compounds from some Cameroonian medicinal plants against Onchocerca volvulus and Onchocerca gutturosa. In our efforts to find new filaricidal agents against adult male O. gutturosa worms, we have isolated and screened three compounds: polycarpol and polyveoline from Polyalthia suaveolens (Annonaceae) and 3-O-acetyl aleuritolic acid from Discoglypremna caloneura (Euphorbiaceae). Only polycarpol and 3-O-acetyl aleuritolic acid exhibited significant inhibitory activities on the vitality of adult male worms of O. gutturosa using Amocarzine as positive control compound. The motility reduction values were 28.6 and 57.1%, and the inhibition of MTT reduction values 80.0 and 64.8% respectively.

2-substituted furans from the roots of Polyalthia evecta

Four new 2-substituted furans, 19-(2-furyl)nonadeca-5,7-diynoic acid (1), 19-(2-furyl)nonadeca-5-ynoic acid (2), 1-(2-furyl)pentacosa-7,9-diyne (3), and ester 21-(2-furyl)heneicosa-14,16-diyne-19-(2-furyl)nonadeca-5,7-diynoate (4) have been isolated from the roots of Polyalthia evecta. Their structures were established by spectroscopic techniques. Compounds 1 and 1a showed antiplasmodial activity. The acids 1 and 2 exhibited antiviral activity against Herpes simplex type 1. In addition, 5 also showed cytotoxicity against the NCI-H187 cell line.

Screening of Thai medicinal plant extracts and their active constituents forIn Vitro antimalarial activity

To discover antimalarial substances from plants cultivated in Thailand 80%-EtOH extracts from selected plants were screened for in vitro antimalarial activity against the drug resistant K1 strain of Plasmodium falciparum. In total, 86 Thai medicinal plant samples representing 48 species from 35 genera in 16 families were screened and two species (Polyalthia viridis and Goniothalamus marcanii) were found to show notable antimalarial activity (IC50: 10.0 and 6.3 microg/mL). Marcanine A and 16-hydroxycleroda-3,13(14)Z-dien-15,16-olide were identified as the respective major active constituents in P. viridis and G. marcanii, respectively.

Antimicrobial activity of clerodane diterpenoids from Polyalthia longifolia seeds

The diterpenoids 16alpha-hydroxy-cleroda-3,13 (14)-Z-diene-15,16-olide (1) and 16-oxo-cleroda-3, 13(14)-E-diene-15-oic acid (2), isolated from the hexane extract of the seeds of Polyalthia longifolia, demonstrated significant antibacterial and antifungal activities.

New antimalarial bis-dehydroaporphine alkaloids from Polyalthia debilis

Four new dimeric aporphinoids named bidebilines A-D (1-4), bis-7,7'-dehydroanonaine (1), 7-dehydroanonaine-7'-dehydro-8'-methoxyanonaine (2), bis-7,7'-dehydro-8,8'-dimethoxyanonaine (3), and bis-7,7'-dehydro-10,10'-dimethoxyanonaine (4), were isolated from the roots of Polyalthia debilis. Their structures were established on the basis of spectral evidence. Compounds 3 and 4 exhibited moderate antimalarial activity with IC(50) values of 5.4 and 4.1 microg/mL, respectively.