Alstonia Macrophylla Research Articles

Alstomaphylines A–K, monoterpenoid bisindole alkaloids from Alstonia macrophylla with AChE inhibitory activity and cytotoxicity

Eleven undescribed monoterpenoid bisindole alkaloids, alstomaphyines A−K (1−11), along with three known analogues were isolated from the leaves and stem bark of the Alstonia macrophylla. Compounds 1−3 were unprecedented dimerization alkaloids incorporating a macroline-type motif with an ajmaline-type motif via a C−C linkage. Their structures and absolute configurations were elucidated by extensive spectroscopic analysis, electronic circular dichroism (ECD) calculation, and CD exciton chirality method. Compounds 1−3 displayed potential inhibitory bioactivity against AChE with IC50 values of 4.44 ± 0.35, 3.59 ± 0.18, and 3.71 ± 0.23 μM, respectively. Enzyme kinetic study revealed compounds 1−3 as mixed competitive AChE inhibitors. Besides, compounds 8 and 12−14 exhibited better cytotoxicity against human cancer cell line HT-29 than cisplatin. Flow cytometry data revealed that compounds 8, 13, and 14 significantly induced the HT-29 cells arrest in G0/G1 phase in a concentration-dependent manner.

Native Metallophytes on Ultramafic Wooded Grassland in Sta Cruz, Mindoro Occidental, Philippines: Insights Into Phytostabilization and Forest Restoration

<p>The native metallophytes species are the optimum choice to restore degraded areas on ultramafic soil. However, a limited restorative floristic survey on the wooded grassland of Mindoro Occidental had been reported. Four 20 m x 20 m plots were established to rapidly assess the plant diversity of a wooded grassland on ultramafic soil in Sta. Cruz, Mindoro Occidental, Philippines. Diversity index (H`), relative density, relative dominance, and importance value (IV) were computed. Physicochemical characteristics and heavy metal contents of the soil in the site were analytically determined. We identified 43 morpho-species of plants belonging to 25 families. Thirty-six of the morpho-species identified are Philippine natives and typically grow on ultramafic forests. Nine species out of the top 10 trees with the highest IV are native ones, with <em>Buchanania arborescens</em> Blume as the most dominant. The estimate of Relative Cover (%) also showed native species. Poles and sapling dominated the area, suggesting that active regeneration is taking place. Further, 72.94% of the ground cover were represented by tree flora recruits (e.g., <em>B. arborescens</em>, <em>Alstonia macrophylla</em>). The sites have overall moderate diversity (H` index of 2.7). The soil contains a high amount of Nickel, Chromium, Iron, and Manganese. There were no Nickel hyperaccumulators but 22 native species showed Aluminum and Silicon hyperaccumulation. Therefore, the study revealed that the surveyed area is home to important metallophytes that have the potential for phytostabilization and reforestation.</p>

Floral composition and diversity of ultramafic forests in Homonhon Island, Eastern Samar, Philippines

The Philippines has suffered tremendous deforestation due to rampant anthropogenic impacts such as mining. In particular, the forests of Homonhon Island are threatened by mining activities. In this study, we assessed its ultramafic vegetation's floristic composition and diversity to initiate its conservation efforts on Homonhon Island. In five sampling areas on the island, we have documented 181 species in 148 genera and 83 families, with 176 native species. Twenty-two species are classified as threatened based on the International Union for Conservation of Nature. On the other hand, in DENR-DAO 2017-11, 38 species are classified as threatened. Homonhon Island exhibits a very high species diversity overall, and the forests in Barangay Bitaugan revealed the highest species diversity among the sampled areas. Alstonia macrophylla and Terminalia surigaensis chiefly dominates the island's forests. Despite being threatened by mining, Homonhon Island's ultramafic forests exhibit a diverse floristic composition worthy of protection. It serves as a sanctuary for many of the Philippines' highly threatened species. Its local government agencies should implement strict protection and management policies to prevent further disturbance to its flora. We can anticipate this study to be used in the restoration, rehabilitation, and conservation of the remaining forests on the island.

Effect of Alkali Treatment of Alstonia macrophylla (AS) fiber on Dynamic Mechanical and Machinability Properties of Polypropylene (PP) Composites reinforced with Unidirectional AS fiber

Effect of Alkali Treatment of Alstonia macrophylla (AS) fiber on Dynamic Mechanical and Machinability Properties of Polypropylene (PP) Composites reinforced with Unidirectional AS fiber

Nitrogen Rather Than Phosphorus Limits the Productivity of the Dominant Tree Species at Mine-Disturbed Ultramafic Areas in the Southern Philippines

Understanding the stoichiometry of nitrogen (N) and phosphorus (P) plays a pivotal role in the ecological restoration of degraded landscapes. Here, the N and P limitation and stoichiometry of dominant tree species in mine-disturbed ultramafic areas in the Southern Philippines are reported. Field surveys revealed that out of a total of 1491 trees/shrubs recorded from all quadrats, comprising 22 native and 9 non-native species, there were six tree species (native: Alstonia macrophylla Wallich., Buchanania arborescens Blume., Syzygium sp., and non-native: Casuarina equisetifolia L., Terminalia catappa L. and Acacia mangium Wild.) that were found dominant, having >10% relative abundance. Significant differences (p < 0.01) in the leaf N and leaf P content among these species were observed, where C.equisetifolia (due to N fixation ability) and T. catappa had the highest values, respectively. These did not, however, translate to statistical differences in the leaf N:P ratios either in individual species or when grouped by origin (native or non-native). Interestingly, all dominant tree species revealed very low leaf N:P ratios (<4), suggesting that N rather than P limits the productivity in mine-disturbed ultramafic areas, which is also confirmed by low levels of leaf N (<2.0%). Results further revealed a poor correlation between leaf N and leaf N:P ratios (r = 0.13; p = 0.60), while leaf P (r = 0.49; p < 0.05) revealed otherwise, reinforcing that P is not a limiting factor as also shown in high levels of leaf P (>0.20%). Despite the N-limitation, B. arborescens, C. equisetifolia, and T. catappa had the highest leaf N and P content, suggesting their higher suitability for revegetation of the sites. These findings warrant further verification taking into account the plant physiology, phenology, and soil nutrient availability in natural, degraded, and rehabilitated ultramafic environments.

Diversity and carbon sequestration capacity of naturally growth vegetation in ex-nickel mining area in Kolaka, Southeast Sulawesi, Indonesia

Abstract. Purnomo DW, Prasetyo LB, Widyatmoko D, Rushayati SB, Supriyatna I, Yani A. 2022. Diversity and carbon sequestration capacity of naturally growth vegetation in ex-nickel mining area in Kolaka, Southeast Sulawesi, Indonesia. Biodiversitas 23: 1433-1442. Efforts to restore forest integrity on ex-mining lands are essential to improve environmental quality and sequester carbon. One such effort is through revegetation of post-mined land including in ex-nickel mining in Southeast Sulawesi. This research analyzes the diversity of naturally regenerating plant species in the ex-nickel mining area in Kolaka, Southeast Sulawesi and determines several local tree species with the potential for carbon sequestration. Vegetation survey was conducted using a systematic nested sampling method at the post-mined site with three vegetation types: secondary forest, shrubs and bushes, and a reference/control site (i.e., natural forest in the nearby Lamedai Nature Reserve). Different types of vegetation were analyzed based on factors using Discriminant Analysis. Vegetation composition was analyzed using the Importance Value Index. Furthermore, biodiversity indicators were analyzed using Shannon-Wiener Diversity Index, Species Evenness Index, and Sorensen Similarity Index. Carbon absorption was measured using the leaf sample method and carbohydrate test. The results showed that the condition of the research site had been disturbed, and the succession process was still ongoing. The species diversity at all plant levels was classified as moderate category and the distribution of the community was unstable. At the tree level, the undisturbed areas had higher diversity. Eradication of Chromolaena odorata was needed to preserve the native vegetation and accelerate forest succession. Tree species recommended for restoring the ex-nickel mining area and carbon sequestration as core plants include Vitex glabrata R.Br., Alstonia macrophylla Wall. ex G.Don, Lithocarpus celebicus (Miq.) Rehder, Callicarpa pentandra Roxb., Dacryodes rugosa (Blume) H.J.Lam, Cananga odorata (Lam.) Hook.f. & Thomson, Glochidion rubrum Blume, Terminalia bellirica (Gaertn.) Roxb., and Psychotria calocarpa Ruiz & Pav., and other pioneer plants of Mallotus paniculatus (Lam.) Müll.Arg., Macaranga peltata (Roxb.) Müll.Arg., and Macaranga hispida (Blume) Müll.Arg.

Physical and Mechanical Properties of Selected Fruit-bearing and Underutilized Tree Species in the Philippines

To help augment the raw material supply of the wood-based industries, the study evaluated the physical and mechanical properties (PMP) of six selected timber species in the Philippines – four fruit-bearing and two underutilized tree species. The fruit-bearing species were “nangka” (Artocarpus heterophyllus Lamk.), “santol” [Sandoricum koetjape (Burm. F.)], “durian” (Durio zibethinus Murray), and “marang” [Litsea perrottetti (Blume) F. Vill.] collected from Bislig, Surigao del Sur (Caraga Region, Mindanao), while the underutilized tree species were “antipolo” [Artocarpus blancoi (Elmer) Merr] and “batino” (Alstonia macrophylla G. Donn) collected from Batangas City and Quezon Province (Region IV, Luzon), respectively. Physical properties included relative density (RD), moisture content (MC), and shrinkage. Mechanical properties covered modulus of rupture, stress at proportional limit, and modulus of elasticity in static bending; compression parallel-and perpendicular-to-grain; shear; hardness; and toughness. Standard testing procedures (ASTM-D143) were followed. Variations on the six species’ PMP were statistically analyzed, including the effect of individual trees and height levels. Among the six species, batino exhibited the highest RD (0.60), followed by nangka (0.49), antipolo (0.47), santol (0.46), marang (0.36), and durian (0.34). The MCs of nangka, santol, durian, antipolo, batino, and marang were 111.07, 121.21, 183.7, 152.68, 85.77, and 189.97% while the volumetric shrinkages (VSs) were 6.67, 6.86, 6.96, 9.07, 12.23, and 9.39%, respectively. The RD of batino was classified moderately high; those of nangka, santol, and antipolo were moderately low; and those of marang and durian were low. There was an inverse relationship between RD and MC in the six species. The VS values of nangka, durian, and santol were classified low; those of batino were medium; and those of antipolo and marang were moderately low. Overall, the mechanical properties of batino were moderately high; those of nangka, santol, and antipolo were moderately low; and those of durian and marang were low. The mechanical properties of the six species were compared with those of the “Philippine mahogany” species traditionally used for construction.

ALSTONIA MACROPHYLLA (APOCYNACEAE): A NEW RECORD OF NATURALIZED SPECIES IN JAVA, INDONESIA

Surianto Effendi & Wendy A. Mustaqim. 2021. Alstonia macrophylla (Apocynaceae): A New Record of Naturalized Species in Java, Indonesia. Floribunda 6(6): 207–212. — Alstonia macrophylla (Apocynaceae), a Malesian widespread species tree, here for the first time is formally reported to be naturally found in Java. The report is based on plants growing in the Ciampea limestone hills, Ciampea sub-district, west of Bogor, West Java. Description, ecology, illustration and a brief discussion regarding the occurrence state of this species as naturalized species in Java are presented. A key to Alstonia species in Java is also given.

Phytochemical study on the flower of Alstonia macrophylla Wall. ex G.Don (Apocynaceae) from Sumbawa Island, Indonesia

Alstonia macrophylla Wall. ex G.Don is a native plant to South East Asia, belonging to Alstonia genus. This species has been reported to have numerous natural chemical compound which perfom multiple pharmacological and biological activities. The aim of this study was to investigated the phytochemical properties of the acetone extract of the flower of lstonia macrophylla Wall. ex G.Don. This is very interesting because phytochemical properties of its flower had been never reported yet. Alstonia macrophylla was harvested from the Natural Forest of Punik, Batu Dulang Village, Batulanteh Subdistrict, Sumbawa Regency, West Nusa Tenggara, Indonesia on Mei 2015. Acetone flower extract of A. macrophylla was analyzed with a GC-MS method to determine the chemical components. Result of GC–MS chromatogram revealed that there were 30 identified components in this extract. The major compounds were Cycloartenol acetate (17.11 %); 5H-1-Pyrindine (12.44 %); Lupeyl acetate (10.12%); Oleic acid (6.08 %); Benzenesulfonic acid, 4-hydroxy- (4.25 %); p-n-Amylphenol (4.23 %); and 4-Methylindole (4.22 %). Here, We reported the first study of phytochemical properties of A. macrophylla. This study help to understand further detail the potential of bioactive compound of A. macrophylla.

Antioxidant, Cytotoxicity, and Antiophidian Potential of Alstonia macrophylla Bark.

The objective of this research was to find the possible pharmacognosy of the bark of the Philippine Alstonia macrophylla Wall. ex G.Don (AM). Gas chromatographic–mass spectral (GC–EI-MS) characterization and energy dispersive X-ray spectroscopy (EDX) were performed to detect the bioactive constituents. EDX analysis of AM bark displayed a high content of potassium (3.26%) and calcium (2.96%). Eight constituents were detected in AM crude dichloromethane (DCM) extracts, which consisted of a long-chain unsaturated fatty acid (17:0) and fatty acid esters such as ethyl hexadecanoate and methyl hexadecanoate. Extraction of AM bark using methanol and dimethyl sulfoxide (MeOH/DMSO) solvents resulted in the identification of 17 constituents, principally alkaloids (alstonerine, 34.38%; strictamin, 5.23%; rauvomitin, 4.29%; and brucine, 3.66%) and triterpenoids (γ-sitosterol, 3.85%; lupeol, 3.00%; 24-methylenecycloartanol, 2.81%; campesterol, 2.71%; β-amyrin, 2.30%; and stigmasterol, 2.13%). MeOH/DMSO samples of AM were used in the selected bioassays. The samples exhibited efficient free radical scavenging activity (IC50 = 0.71 mg/mL) and were noncytotoxic to normal HDFn (IC50 > 100 μg/mL) and neoplastic THP-1 cell lines (IC50 = 67.22 μg/mL) while highly degenerative to MCF-7 (IC50 = 6.34 μg/mL), H69PR (IC50 = 7.05 μg/mL), and HT-29 (IC50 = 9.10 μg/mL). Most interestingly, the AM samples inhibited the northern Philippine Cobra’s (Naja philippinensis Taylor) venom (IC50 = 297.27 ± 9.33 μg/mL) through a secretory phospholipase A2 assay.

Monitoring Growth Performance of Naturally Regenerated Woody Species in an Enriched Pine Stand, Sri Lanka

Monitoring growth performance of newly recruited plant species after applying several silvicultural treatments in monoculture plantations is important to evaluate the success of forest restoration. This study was conducted in 2015 to determine the growth performance of the naturally regenerated woody plant species in an unrestored (UP) and a restored (RP) Pinus caribaea Morelet plantation, in lower Hantana, Sri Lanka. In RP, partial thinning of pines followed by enrichment planting of four broad-leaved tree species in 2003 and total thinning of pines was initiated in 2009. In both sites fifteen plots (5x5m) and within each of them three subplots (1x1m) were demarcated randomly. The height of seedlings (SE, 300 cm in height) and dbh of SA2 and TR in all the plots were recorded. Collectively, 417 individuals (RP=298, UP=119) representing 28 species (RP=24, UP=12) and 22 plant families (RP=18, UP=13) survived by the end of the six months. The mean monthly increment of height (MMIH)of survived species in RP was higher for all the life forms except for SE (SE=1.35, SA1=1.61, SA2= 1.38, TR= 4.45 cmmo-1) than in UP (SE=2.06, SA1= 0.17, SA2= 0.00, TR= 1.65 cmmo-1). The MMIH of trees was significantly higher in RP than UP. The mean monthly increment of dbh (MMID) of survived individuals in RP was higher for both SA2 (0.017 cm per mo-1) and TR (0.027 cm per mo-1) than in UP (SA2= 0.0007, TR= 0.024 cmmo-1). The MMID of SA2 was significantly higher in RP than UP Of the 24 species tested in all four life form categories in RP, 19 (SE=39%, SA1=56%, SA2=69%, TR=85% of the species)had MMIH exceeding 1 cm mo-1while eight (SA2=5%, TR=26%) had dbh increment exceeding 0.05 cm mo-1. In UP, only five species (SE=60%, SA1=100%, SA2=25%, TR=77%of the species) had MMIH exceeding 1cm while one species (Alstonia macrophylla)(SA2=25%, TR=22%) had MMID exceeding0.05 cm mo-1. As the growth performance of the naturally regenerated woody species in RP was higher than UP, we conclude that restoration of pine plantation in mountainous regions of Sri Lanka, using silvicultural techniques is successful in achieving restoration goals. Keywords: Growth performance, Natural regeneration, Pinus plantation, Restoration

Potential of Nickel (Ni) Phytoremediation of Adaptive Species on Revegetation Land, PT. Vale Indonesia (Tbk). Pomalaa Site Kolaka Regency

This research aimed to determinate the type of adaptive plant and its potential of phytoremediations on nickel revegetation land, PT. Vale Indonesia Tbk. Pomalaa site Kolaka Regency. The research was carried out in March - October 2016, with stages of explation and identification of adaptive plant species as well as analysis of nicel leaves and soil content using HNO3 or HClO4 method and (AAS) Atomic Absorbtion Spectrophotometry test. 12 types of adaptive plants from 12 genera and 10 family. That grow naturally on nickel revegetation land PT. Vale Indonesia Tbk. site Pomalaa. Species from tree habitus thet freguently found, namely Gymnostoma sumatrana , Sarcotheca celebica , Parinaria corymbosa , Timonius celebicus , Weinnmania fraxinea , Alstonia macrophylla . Based on analysis result, there four species that was categorized as low acummulator Nepenthes maxima , Cheilanthes tenuifolia , Timonius celebicus , Sarcotheca celebica . The highest absorber is S. celebica with nickel content 595 mg/kg dry weight leaves. S. celebica potential to be developed as nickel phytoremedian. Keywords: phytoremediation, nickel, Sarcotheca celebica , Ultramafic

Cultivation of Schizophyllum commune mushroom on different wood substrates

Schizophyllum commune is an edible mushroom grown on wood under natural conditions. Present study focused on cultivation of S.commune on different wood substrates since it is not commercially cultivated. A pure culture of S. commune was obtained by growing a tissue of the mushroom on Potato Dextrose Agar (PDA) medium. Spawns were produced by growing the mycelium on paddy grains. Mushroom was cultivated on sawdust of seven different wood substrates. The maximum yield was observed in sawdust of jackfruit ( Artocarpus heterophyllus ) followed by sawdust of rambutan ( Nephelium lappaceum ) and country almond ( Terminalia catappa ). A significant difference was not observed when mango ( Mangifera indica ) elephant apple ( Dillenia indica ), tulip wood tree ( Harpullia arborea ) and thungfaa ( Alstonia macrophylla ) sawdust used as substrate. The lowest yield was observed in thungfaa ( Alstonia macrophylla ) sawdust. Effect of some additives on the yield was studied and significant difference in yield was observed when rice bran and used-tea leaves used as additives. Effect of rice bran on yield was studied using different ratios of sawdust to rice bran and the highest was observed in 2:1 ratio of sawdust to rice bran. The best incubating temperature for mycelial growth on the substrate was 350C. The composition of the mushroom on a dry weight basis was; 71.4% moisture, 23.35% crude protein and 6% ash. Tested wood species are promising substrates for cultivation of S.communeas cottage industry.

Kirigala forest fragments and the identity as a dipterocarp plantation or Hora Kele of Ingiriya

Fragmentation has exposed the Kirigala forest to the influence of various neighbourhood land-use practices. The present study investigated the floristic, soil and micro-climatic conditions of the forest and demonstrated its degradation due to influences by human induced disturbances. Ten 50 m × 5 m gradsects each accommodating 3 pairs of 10 m × 5 m plots, a total of 60 soil samples and 20 seed traps provided floristic details, seedling emergence from seed bank and annual seed rain of the forest, respectively. Diversity of the edge and the forest interior were compared for the different neighbourhood land use types using the Shannon and Weiner (H) and Simpsons reciprocal (D) indices. Change in the forest structure was illustrated using profile diagrams. Differences in soil pH, soil moisture, nitrogen, available phosphorous and potassium, organic matter content, air temperature, humidity and light intensity between the forest edge and the interior were determined. Soil, microclimate and species richness were combined for clustering of similar areas. The site reported the presence of 55 tree, 12 shrub, 15 herb, 07 climber and 02 vine species including a total of 23 endemic species and 06 invasive species. A higher diversity was observed at the edge, and the highest was observed beside roads as indicated by both diversity indices H and D. Soil and microclimate of the forest varied significantly between the edge and the interior and reflected anthropogenic influences and neighbourhood land use practices. Dominance hierarchy of the trees was Dipterocarpus zeylanicus > Gaertnera vaginans > Aporusa lanceolata , while that for undergrowth/shrubs herbaceous species was Ochlandra stridula > Dracaena thwaitesii > Piper sylvestre . Annual seed rain contained propagules of 23 plant species, while invasive Alstonia macrophylla provided the highest density of seeds. Establishment of foot paths, selective removal of juveniles by root-balling technique and encroachment for crop cultivation have also facilitated the degradation process. It is vital to pay attention on maintaining the ecological stability of this forest before it loses its identity as the Hora Kele of Ingiriya.

Antimicrobial and antimalarial properties of medicinal plants used by the indigenous tribes of Andaman and Nicobar Islands, India

In this study, methanol extracts of six medicinal plants (Alstonia macrophylla, Claoxylon indicum, Dillenia andamanica, Jasminum syringifolium, Miliusia andamanica and Pedilanthus tithymaloides) traditionally used by Nicobarese tribes of Andaman and Nicobar Islands were studied for antimicrobial and antimalarial activities as well as preliminary photochemical analysis. Plants were collected from Car Nicobar of Andaman and Nicobar Islands and the ethnobotanical data were gathered from traditional healers who inhabit the study area. The methanol extracts were obtained by cold percolation method and the antimicrobial activity was found using agar well diffusion method. Among the plants tested, J. syringifolium, D. andamanica, C. indicum were most active. The antimalarial activity was evaluated against Plasmodium falciparum chloroquine-sensitive MRC-2 isolate. The crude extract of M. andamanica showed excellent antimalarial activity followed by extracts of P. tithymaloides, J. syringifolium and D. andamanica. The chemical injury to erythrocytes was also carried out and it showed that, there were no morphological changes in erythrocytes by the methanol crude extracts. The in vitro antimicrobial and antimalarial activity might be due to the presence of alkaloids, flavonoids, triterpenes, sterols, tannins and saponins in the methanol extracts of tested plants.

Isolation and Characterization of Alkaloids Extracted from Medicinal Plant in Malaysia: Alstonia macrophylla

Isolation and Characterization of Alkaloids Extracted from Medicinal Plant in Malaysia: Alstonia macrophylla

Catalytic and synergistic antibacterial potential of green synthesized silver nanoparticles: Their ecotoxicological evaluation on Poecillia reticulata

In the present study, stable silver nanoparticles (AgNPs) were fabricated at a rapid rate from leaf extract of medicinally important plant Alstonia macrophylla. Biosynthesized AgNPs are of spherical shape and narrow size (70nm), exhibiting a surface plasmon resonance peak at 435nm, and a zeta potential of -30.8 mV and have a crystalline nature. A diverse biochemical consortium of protein, terpenoids, phenolics, and flavonoids in leaf extract of A. macrophylla was found to be responsible for AgNP synthesis as evidenced from qualitative-quantitative chemical analysis and Fourier transform infrared spectroscopy studies. Nitroaromatic compounds are anthropogenic pollutants with long-lasting environmental persistence and are needed to transform into less toxic derivatives. 4-Nitrophenol and p-nitroaniline were reduced to less hazardous and commercially useful 4-aminophenol and p-phenylenediamine by phytosynthesized AgNPs. Rate constants of 0.052 and 0.040Min(-1) were calculated for 4-nitrophenol and p-nitroaniline reduction, respectively. Thin-layer chromatography also confirms the reduction of these nitroaromatic compounds. Combinational studies could be one of the strategies to overcome microbial resistance to antibiotics. In synergistic antibacterial assay, the highest increase in a fold area of 3.84 was reported against Staphylococcus aureus using a combination of AgNPs with penicillin. Biosynthesized AgNPs were found to be less toxic (LC50 = 9.13 ppm) than chemically synthesized AgNPs having a LC50 value of 2.86 ppm against nontarget fish Poecillia reticulata. Our green nanosynthesis method offers a faster rate of formation of stable AgNPs having antibacterial and catalytic potential with lower environmental toxicity.

Macroline, akuammiline, sarpagine, and ajmaline alkaloids from Alstonia macrophylla

A total of seventeen alkaloids, comprising six macroline (including alstofolinine A, a macroline indole incorporating a butyrolactone ring-E), two ajmaline, one sarpagine, and eight akuammiline alkaloids, were isolated from the stem-bark and leaf extracts of the Malayan Alstonia macrophylla. The structure and relative configurations of these alkaloids were established using NMR, MS and in several instances, confirmed by X-ray diffraction analysis. Six of these alkaloids were effective in reversing multidrug-resistance (MDR) in vincristine-resistant KB cells.

DIVERSITY AND DISTRIBUTION OF LICHENS OF AMBULUWAWA MOUNTAIN

Ambuluwawa Mountain in Gampola District reaches to a height of 1065 meters and vegetationis mostly disturbed.To study lichens three sites, each 100m2 in area, at different elevations (high <990m), (mid 950-870m) and (low 700- 650m) were selected. Three trees Alstonia macrophylla, Albizzia lebbek,Macaranga tomentosa were selected to study corticolous lichens. Alstonia macrophylla waspresent in all sites while Albizzia lebbek was present in sites one and three. Macarangatomentosa was present in site two only. Rocks were used for sexicolous species. Totalpercentage lichen cover and the total number of different lichens were recorded by placing250cm2 quadrate randomly on trunks of trees (six trees and four quadrate /tree and three rocksper site). Light intensity, bark pH of trees and relative humidity were measured in all sites.In site one, Parmotrema reticulatum had the highest percentage cover (29.3%) while Buel/ia sp.I had the second highest coverage value (10.6%) onA macrophylla. On rocks, Diploschistes sp.had the highest coverage value while Aspicilia sp. and Toninia sp. was recorded with fairly highcoverage. On the trunks of A. lebbek, several species (If Usnea were recorded in this site.In site two, on A. macrophyl/a, Pertusaria sp. 1 was recorded with highest coverage (14.3%)while Pyrenula sp. and Letrouitia sp. 1 had coverage values of 11.46 and 6.67 respectively. Onrocks a species of Leotogium, Dirinaria aegialita and Pertusaria species were recorded withhigher coverage values. Pertusaria sp. was recorded from all three substrates in this site.In site three, on A. lebbek, Parmotrema reticulatum gave the highest coverage value whileDrynaria aegilita had the second higher value. Heterodermia sp.3 had the highest percentagecover on rocks.Twenty-five different lichens were identified in site one while site two and three had lessernumber of lichens. Total number of lichens on A. lebbek and A. macrophylla differ significantlyat lower elevation but not in other two sites at higher elevation,Statistical analyses of coverage values of lichens on different substrate within a site did not showa significant difference. Coverage values of lichens cn same trees, among sites also did not showa significant difference except on A. macrophylla. Lichen coverage on rocks was notsignificantly different between sites one and three.Light intensity and relative humidity may be having a grater influence on the distribution oflichens. Effect of bark pH on lichen coverage was difficult to interpret.Forty-five lichens species, which belong to nine genera, were identified in this locality. Eightlichen species were found to be new records in Sri Lanka.Presence of indicator species such as Letrouitia, Diploschistes, Leptogium, Heterdermia andPyrenula with good coverage on Ambuluwawa Mountain indicates absence of air pollution inthis area.

Plant Diversity and Aboveground Carbon Stock Along Altitudinal Gradients in Quezon Mountain Range in Southern Mindanao, Philippines

Plant diversity, aboveground biomass, and carbon stock along portions of Quezon Mountain Range were assessed in three elevation gradients, e.g., low (400-799 m a.s.l.), middle (800-1,199 m a.s.l.), and high (1,200-1,600 m a.s.l.) in Southern Mindanao using quadrat sampling technique. A total of 146 plant species were identified including threatened Shorea contorta, Parashorea malaanonan, Dillenia philipinensis, Alstonia macrophylla, Cinammomum mercadoi, Palaqium luzoniense, Neolitsea vidalii, Dacrycarpus elatumi, and Dacrycarpus imbricatus. On the average, low diversity was recorded in all gradients particularly in low and middle elevation ranges where alteration of vegetation cover, and proliferation of bio-invasive Piper aduncum were observed. Biomass and carbon stock were largest in high elevation where the inaccessible old growth forest is located compared to a proposed mine site in low and middle elevation that are predominated by grassland, farmlands, disturbed secondary growth forest, and human settlements. Overall, carbon stocks ranged from 33.8 to 192.0 MgC ha-1 suggesting the good potential of the area to mitigate climate change. Sustainable management of biodiversity and carbon stock is needed by apportioning productive and protective zones in the mountain.