Tropical and subtropical Asia's valued tree species under threat.

Tree diversity in Asia's tropical and subtropical forests is central to nature-based solutions. Species vulnerability to multiple threats, which affect provision of ecosystem services, is poorly understood. We conducted a region-wide, spatially explicit assessment of the vulnerability of 63 socioeconomically important tree species to overexploitation, fire, overgrazing, habitat conversion, and climate change. Trees were selected for assessment from national priority lists, and selections were validated by an expert network representing 20 countries. We used Maxent suitability modeling to predict species distribution ranges, freely accessible spatial data sets to map threat exposures, and functional traits to estimate threat sensitivities. Species-specific vulnerability maps were created as the product of exposure maps and sensitivity estimates. Based on vulnerability to current threats and climate change, we identified priority areas for conservation and restoration. Overall, 74% of the most important areas for conservation of these trees fell outside protected areas, and all species were severely threatened across an average of 47% of their native ranges. The most imminent threats were overexploitation and habitat conversion; populations were severely threatened by these factors in an average of 24% and 16% of their ranges, respectively. Our model predicted limited overall climate change impacts, although some study species were likely to lose over 15% of their habitat by 2050 due to climate change. We pinpointed specific natural areas in Borneo rain forests as hotspots for in situ conservation of forest genetic resources, more than 82% of which fell outside designated protected areas. We also identified degraded areas in Western Ghats, Indochina dry forests, and Sumatran rain forests as hotspots for restoration, where planting or assisted natural regeneration will help conserve these species, and croplands in southern India and Thailand as potentially important agroforestry options. Our results highlight the need for regionally coordinated action for effective conservation and restoration.

Especies de Árboles Valoradas y Amenazadas de Asia Tropical y Subtropical Resumen La diversidad de árboles en los bosques tropicales y subtropicales de Asia es un eje central para las soluciones basadas en la naturaleza. La vulnerabilidad de las especies ante las múltiples amenazas, las cuales afectan el suministro de servicios ambientales, es un tema poco comprendido. Realizamos una evaluación regional espacialmente explícita de la vulnerabilidad de 63 especies de árboles de importancia socioeconómica ante la sobreexplotación, incendios, sobrepastoreo, conversión del hábitat y cambio climático. Los árboles se seleccionaron para su evaluación a partir de listas nacionales de prioridades, y las selecciones fueron validadas por una red de expertos de 20 países. Usamos el modelado de idoneidad Maxent para predecir el rango de distribución de las especies, conjuntos de datos espaciales de libre acceso para mapear la exposición a las amenazas y rasgos funcionales para estimar la susceptibilidad a las amenazas. Con base en la vulnerabilidad a las amenazas actuales y al cambio climático, identificamos las áreas prioritarias para su conservación y restauración. En general, el 74% de las áreas más importantes para la conservación de estos árboles quedó fuera de las áreas protegidas y todas las especies estaban seriamente amenazadas en promedio en el 47% de su distribución nativa. Las amenazas más inminentes fueron la sobreexplotación y la conversión del hábitat; las poblaciones estuvieron seriamente amenazadas por estos factores en promedio en el 24% y 16% de su distribución, respectivamente. Nuestro modelo predijo un impacto general limitado del cambio climático, aunque algunas especies estudiadas tuvieron la probabilidad de perder más del 15% de su hábitat para el 2050 debido a este factor. Identificamos áreas naturales específicas en las selvas de Borneo como puntos calientes para la conservación in situ de los recursos genéticos forestales, más del 82% de los cuales estaban fuera de las áreas protegidas designadas. También identificamos áreas degradadas en los Ghats Occidentales, los bosques secos de Indochina y las selvas de Sumatra como puntos calientes para la restauración, en donde la siembra o la regeneración natural asistida ayudarán a conservar estas especies. Además, identificamos campos de cultivo al sur de India y Tailandia como potenciales opciones importantes de agrosilvicultura. Nuestros resultados resaltan la necesidad de acciones regionales coordinadas para la conservación y restauración efectivas.

Approaches for the amelioration of adverse effects of drought stress on crop plants.

Climate change, water scarcity, population growth, and food shortage are some of the threatening challenges being faced in today's world. Among different types of stresses, drought stress presents a persistent challenge for global food production, however, its harshness and intensity are supposed to expand in the imminent future. The most striking effects of drought stress on plants are stunted growth, severe damage to photosynthetic apparatus, reduction in photosynthesis, reduction in seed germination, and nutrient uptake. To deal with the destructive effect of drought stress on plants, it is necessary to consider its effects, mechanisms of action, the agronomic and genetic basis for sustainable management. Therefore, there is an urgent need for sustainable solutions to cope up with the negative impact of drought stress. This review focuses on the detrimental effects of drought stress on plants' morphological, physiological, and biochemical characteristics and recommends suitable drought management techniques to reduce the severity of drought stress. We summarize the effect of drought stress on physiological and biochemical parameters (such as germination, photosynthesis, biomass, water status, and nutrient uptake) and yield. Overall, in this article, we have reviewed the role of different phytohormones, osmolytes, exogenous compounds, proteins, plant growth-promoting microbes (PGPM), omics approaches, and genome editing technologies like clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (CRISPR-Cas9) in alleviating drought effects in plants. We also proposed that developing drought-tolerant plant varieties requires the combined use of biotechnological and agronomic approaches and cutting-edge genome editing (GE) tools.

Large-scale whole-genome resequencing unravels the domestication history of Cannabis sativa.

Cannabis sativa has long been an important source of fiber extracted from hemp and both medicinal and recreational drugs based on cannabinoid compounds. Here, we investigated its poorly known domestication history using whole-genome resequencing of 110 accessions from worldwide origins. We show that C. sativa was first domesticated in early Neolithic times in East Asia and that all current hemp and drug cultivars diverged from an ancestral gene pool currently represented by feral plants and landraces in China. We identified candidate genes associated with traits differentiating hemp and drug cultivars, including branching pattern and cellulose/lignin biosynthesis. We also found evidence for loss of function of genes involved in the synthesis of the two major biochemically competing cannabinoids during selection for increased fiber production or psychoactive properties. Our results provide a unique global view of the domestication of C. sativa and offer valuable genomic resources for ongoing functional and molecular breeding research.

Exploring DNA quantity and quality from raw materials to botanical extracts.

OBJECTIVES: The aim of this study was to explore the variability in DNA quality and quantity along a gradient of industrial processing of botanical ingredients from raw materials to extracts. METHODS: A data matrix was assembled for 1242 botanical ingredient samples along a gradient of industrial processing commonly used in the Natural Health Product (NHP) industry. Multivariate statistics was used to explore dependant variables for quality and quantity. The success of attaining a positive DNA test result along a gradient of industrial processing was compared among four biotechnologies: DNA barcoding, NGS, Sanger sequencing and qPCR. RESULTS: There was considerable variance in DNA quality and quantity among the samples, which could be interpreted along a gradient from raw materials with greater quantities (50-120 ng/µL) of DNA and longer DNA (400-500bp) sequences to extracts, which were characterized by lower quantities (0.1-10.0 ng/µL) and short fragments (50-150bp). CONCLUSIONS: Targeted molecular diagnostic tests for species identity can be used in the NHP industry for raw and processed samples. Non-targeted tests or the use of NGS for any identity test needs considerable research and development and must be validated before it can be used in commercial operations as these methods are subject to considerable risk of false negative and positive results. Proper use of these tools can be used to ensure ingredient authenticity, and to avert adulteration, and contamination with plants that are a health concern. Lastly these tools can be used to prevent the exploitation of rare herbal species and the harvesting of native biodiversity for commercial purposes.

Origin and evolution of the genus Piper in Peninsular India.

The evolution of Peninsular Indian biodiversity has been a fascinating topic of research due to historical connections of this region to the ancient Gondwanaland. We investigated the phylogeny and historical biogeography of nearly all extant species of the genus Piper reported from the region to assess the biogeographical origins and test mechanisms of lineage diversification (dispersal, vicariance and in situ radiation) of this highly diverse genus of angiosperms commonly found in the understory of evergreen forests. The phylogeny of 21 species of Piper reported from Peninsular India was reconstructed for the first time, which included three new putative species from the Western Ghats. We used BEAST for the divergence time estimations (using three constraints), and ancestral range estimations were performed with the dated phylogenetic tree using BIOGEOBEARS. Divergence dating analysis revealed that the genus Piper originated during lower Cretaceous around 110 Ma [95% highest posterior density (HPD): 116-105 Ma] and colonized Peninsular India five times independently, from Southeast Asia starting from the Oligocene. The two major dispersals into India occurred during the periods of 27.3 Ma (95% HPD: 35.8-19.9.) and 15.5 Ma (95% HPD: 24.9-7.11). This was followed by rapid radiations in some lineages with subsequent back dispersals to Southeast Asia. Our study indicates that dispersals from Southeast Asia led to the arrival of Piper to Indian subcontinent following the Indo-Eurasian collision. Members of Piper have colonized and diversified within the climatically stable habitats of Peninsular India. Furthermore, the present study provides evidence for the Miocene overland dispersal of Piper species to Africa from South Asia.

Authentication of Garcinia fruits and food supplements using DNA barcoding and NMR spectroscopy.

Garcinia L. (Clusiaceae) fruits are a rich source of (-)-hydroxycitric acid, and this has gained considerable attention as an anti-obesity agent and a popular weight loss food supplement. In this study, we assessed adulteration of morphologically similar samples of Garcinia using DNA barcoding, and used NMR to quantify the content of (-)-hydroxycitric acid and (-)-hydroxycitric acid lactone in raw herbal drugs and Garcinia food supplements. DNA barcoding revealed that mostly G. gummi-gutta (previously known as G. cambogia) and G. indica were traded in Indian herbal markets, and there was no adulteration. The content of (-)-hydroxycitric acid and (-)-hydroxycitric acid lactone in the two species varied from 1.7% to 16.3%, and 3.5% to 20.7% respectively. Analysis of ten Garcinia food supplements revealed a large variation in the content of (-)-hydroxycitric acid, from 29 mg (4.6%) to 289 mg (50.6%) content per capsule or tablet. Only one product contained quantifiable amounts of (-)-hydroxycitric acid lactone. Furthermore the study demonstrates that DNA barcoding and NMR could be effectively used as a regulatory tool to authenticate Garcinia fruit rinds and food supplements.

Species Adulteration in the Herbal Trade: Causes, Consequences and Mitigation.

The global economy of the international trade of herbal products has been increasing by 15% annually, with the raw material for most herbal products being sourced from South and Southeast Asian countries. In India, of the 8000 species of medicinal plants harvested from the wild, approximately 960 are in the active trade. With increasing international trade in herbal medicinal products, there is also increasing concern about the widespread adulteration and species admixtures in the raw herbal trade. The adverse consequences of such species adulteration on the health and safety of consumers have only recently begun to be recognised and documented. We provide a comprehensive review of the nature and magnitude of species adulteration in the raw herbal trade, and identify the underlying drivers that might lead to such adulteration. We also discuss the possible biological and chemical equivalence of species that are used as adulterants and substitutes, and the consequences thereof to consumer health and safety, and propose a framework for the development of a herbal trade authentication service that can help regulate the herbal trade market.

An endophytic fungus, Gibberella moniliformis from Lawsonia inermis L. produces lawsone, an orange-red pigment.

Lawsone (2-hydroxy-1, 4-napthoquinone), also known as hennotannic acid, is an orange red dye used as a popular skin and hair colorant. The dye is produced in the leaves of Lawsonia inermis L, often referred to as the "henna" tree. In this study, we report the production of lawsone by an endophytic fungus, Gibberella moniliformis isolated from the leaf tissues of Lawsonia inermis. The fungus produced the orange-red dye in potato dextrose agar and broth, independent of the host tissue. Presence of lawsone was confirmed spectrometrically using HPLC and ESI-MS/MS analysis. The fragmentation pattern of lawsone was identical to both standard lawsone and that extracted from plant tissue. This is a first report of lawsone being produced by an endophytic fungus, independent of the host tissue. The study opens up interesting questions on the possible biosynthetic pathway through which lawsone is produced by the fungus.

Evaluating realized seed dispersal across fragmented tropical landscapes: a two-fold approach using parentage analysis and the neighbourhood model.

Despite the importance of seed dispersal for survival of plant species in fragmented landscapes, data on seed dispersal at landscape scales remain sparse. Effective seed dispersal among fragments determines recolonization and plant species persistence in such landscapes. We present the first large-scale (216-km2 ) direct estimates of realized seed dispersal of a high-value timber tree (Dysoxylum malabaricum) across an agro-forest landscape in the Western Ghats, India. Based upon an exhaustive inventory of adult trees and a sample of 488 seedlings all genotyped at 10 microsatellite loci, we estimated realized seed dispersal using parentage analysis and the neighbourhood model. Our estimates found that most realized seed dispersal was within 200 m, which is insufficient to effectively bridge the distances between forest patches. We conclude that using mobility of putative animal dispersers can be misleading when estimating tropical tree species vulnerability to habitat fragmentation. This raises serious concerns about the potential of many tropical trees to recolonize isolated forest patches where high-value tree species have already been removed.

Ecological niche modeling for conservation planning of an endemic snail in the verge of becoming a pest in cardamom plantations in the Western Ghats biodiversity hotspot.

Conservation managers and policy makers are often confronted with a challenging dilemma of devising suitable strategies to maintain agricultural productivity while conserving endemic species that at the early stages of becoming pests of agricultural crops. Identification of environmental factors conducive to species range expansion for forecasting species distribution patterns will play a central role in devising management strategies to minimize the conflict between the agricultural productivity and biodiversity conservation. Here, we present results of a study that predicts the distribution of Indrella ampulla, a snail endemic to the Western Ghats biodiversity hotspot, which is becoming a pest in cardamom (Ellettaria cardamomum) plantations. We determined the distribution patterns and niche overlap between I. ampulla and Ellettaria cardamomum using maximum entropy (MaxEnt) niche modeling techniques under current and future (2020-2080) climatic scenarios. The results showed that climatic (precipitation of coldest quarter and isothermality) and soil (cation exchange capacity of soil [CEC]) parameters are major factors that determine the distribution of I. ampulla in Western Ghats. The model predicted cardamom cultivation areas in southern Western Ghats are highly sensitive to invasion of I. ampulla under both present and future climatic conditions. While the land area in the central Western Ghats is predicted to become unsuitable for I. ampulla and Ellettaria cardamomum in future, we found 71% of the Western Ghats land area is suitable for Ellettaria cardamomum cultivation and 45% suitable for I. ampulla, with an overlap of 35% between two species. The resulting distribution maps are invaluable for policy makers and conservation managers to design and implement management strategies minimizing the conflicts to sustain agricultural productivity while maintaining biodiversity in the region.

Desorption Electrospray Ionization (DESI) Mass Spectrometric Imaging of the Distribution of Rohitukine in the Seedling of Dysoxylum binectariferum Hook. F.

Ambient ionization mass spectrometric imaging of all parts of the seedling of Dysoxylum binectariferum Hook. f (Meliaceae) was performed to reconstruct the molecular distribution of rohitukine (Rh) and related compounds. The species accumulates Rh, a prominent chromone alkaloid, in its seeds, fruits, and stem bark. Rh possesses anti-inflammatory, anti-cancer, and immuno-modulatory properties. Desorption electrospray ionization mass spectrometry imaging (DESI MSI) and electrospray ionization (ESI) tandem mass spectrometry (MS/MS) analysis detected Rh as well as its glycosylated, acetylated, oxidized, and methoxylated analogues. Rh was predominantly distributed in the main roots, collar region of the stem, and young leaves. In the stem and roots, Rh was primarily restricted to the cortex region. The identities of the metabolites were assigned based on both the fragmentation patterns and exact mass analyses. We discuss these results, with specific reference to the possible pathways of Rh biosynthesis and translocation during seedling development in D. binectariferum.

Assessing product adulteration in natural health products for laxative yielding plants, Cassia, Senna, and Chamaecrista, in Southern India using DNA barcoding.

Medicinal plants such as Cassia, Senna, and Chamaecrista (belonging to the family Fabaceae) are well known for their laxative properties. They are extensively used within indigenous health care systems in India and several other countries. India exports over 5000 metric tonnes per year of these specific herbal products, and the demand for natural health product market is growing at approximately 10-15% annually. The raw plant material used as active ingredients is almost exclusively sourced from wild populations. Consequently, it is widely suspected that the commercial herbal products claiming to contain these species may be adulterated or contaminated. In this study, we have attempted to assess product authentication and the extent of adulteration in the herbal trade of these species using DNA barcoding. Our method includes four common DNA barcode regions: ITS, matK, rbcL, and psbA-trnH. Analysis of market samples revealed considerable adulteration of herbal products: 50% in the case of Senna auriculata, 37% in Senna tora, and 8% in Senna alexandrina. All herbal products containing Cassia fistula were authentic, while the species under the genus Chamaecrista were not in trade. Our results confirm the suspicion that there is rampant herbal product adulteration in Indian markets. DNA barcodes such as that demonstrated in this study could be effectively used as a regulatory tool to control the adulteration of herbal products and contribute to restoring quality assurance and consumer confidence in natural health products.

Genetic Structure, Diversity and Long Term Viability of a Medicinal Plant, Nothapodytes nimmoniana Graham. (Icacinaceae), in Protected and Non-Protected Areas in the Western Ghats Biodiversity Hotspot.

BACKGROUND AND QUESTION: The harvesting of medicinal plants from wild sources is escalating in many parts of the world, compromising the long-term survival of natural populations of medicinally important plants and sustainability of sources of raw material to meet pharmaceutical industry needs. Although protected areas are considered to play a central role in conservation of plant genetic resources, the effectiveness of protected areas for maintaining medicinal plant populations subject to intense harvesting pressure remain largely unknown. We conducted genetic and demographic studies of Nothapodytes nimmoniana Graham, one of the extensively harvested medicinal plant species in the Western Ghats biodiversity hotspot, India to assess the effectiveness of protected areas in long-term maintenance of economically important plant species. METHODOLOGY/PRINCIPAL FINDINGS: The analysis of adults and seedlings of N. nimmoniana in four protected and four non-protected areas using 7 nuclear microsatellite loci revealed that populations that are distributed within protected areas are subject to lower levels of harvesting and maintain higher genetic diversity (He = 0.816, Ho = 0.607, A = 18.857) than populations in adjoining non-protected areas (He = 0.781, Ho = 0.511, A = 15.571). Furthermore, seedlings in protected areas had significantly higher observed heterozygosity (Ho = 0.630) and private alleles as compared to seedlings in adjoining non-protected areas (Ho = 0.426). Most populations revealed signatures of recent genetic bottleneck. The prediction of long-term maintenance of genetic diversity using BOTTLESIM indicated that current population sizes of the species are not sufficient to maintain 90% of present genetic diversity for next 100 years. CONCLUSIONS/SIGNIFICANCE: Overall, these results highlight the need for establishing more protected areas encompassing a large number of adult plants in the Western Ghats to conserve genetic diversity of economically and medicinally important plant species.

Pyrenacantha volubilis Wight, (Icacinaceae) a rich source of camptothecine and its derivatives, from the Coromandel Coast forests of India.

Camptothecine, a potent eukaryotic topoisomerase inhibitor, is an important anticancer compound. The global demand for this compound was estimated to be $1 billion in 2003 and is only further expected to increase. Partly to meet the expected increase in demand, in the recent past, several efforts have been made to discover newer and alternative plant and fungal sources of camptothecine. In this study we report a rich source of camptothecine and its natural derivatives, Pyrenacantha volubilis (Icacinaceae) from the eastern coast of peninsular India. Camptothecine and its derivatives were analyzed using high performance liquid chromatography (HPLC) coupled with electrospray mass spectrometry (ESI-MS) in all plant parts such as twigs, leaves, roots, seedling, ripened whole fruit, fruit coat, seed coat and cotyledons. Cotyledons and ripened whole fruits contained the highest amount of camptothecine (1.35% and 0.60% dry weight respectively). LC-MS and ESI-MS/MS analyses revealed besides camptothecine, other derivatives and precursors such as 10-hydroxycamptothecine, 9-methoxycamptothecine, 20-deoxycamptothecine, deoxypumiloside, strictosidine and strictosamide. Pure camptothecine was isolated from fruits and structurally confirmed using NMR. Seed extracts were found to be effective against breast cancer, ovarian, colon and carcinoma cell lines (with IC50 values of 4.0 µg/mL, 6.5 µg/mL, 25.0 µg/mL and 25.0 µg/mL respectively). We discuss the results in the context of exploring alternative sources of camptothecine.

Forest trees in human modified landscapes: ecological and genetic drivers of recruitment failure in Dysoxylum malabaricum (Meliaceae).

Tropical agro-forest landscapes are global priority areas for biodiversity conservation. Little is known about the ability of these landscapes to sustain large late successional forest trees upon which much forest biodiversity depends. These landscapes are subject to fragmentation and additional habitat degradation which may limit tree recruitment and thus compromise numerous ecosystem services including carbon storage and timber production. Dysoxylum malabaricum is a large canopy tree species in the Meliaceae, a family including many important tropical timber trees. This species is found in highly fragmented forest patches within a complex agro-forest landscape of the Western Ghats biodiversity hot spot, South India. In this paper we combined a molecular assessment of inbreeding with ecological and demographic data to explore the multiple threats to recruitment of this tree species. An evaluation of inbreeding, using eleven microsatellite loci in 297 nursery-reared seedlings collected form low and high density forest patches embedded in an agro-forest matrix, shows that mating between related individuals in low density patches leads to reduced seedling performance. By quantifying habitat degradation and tree recruitment within these forest patches we show that increasing canopy openness and the increased abundance of pioneer tree species lead to a general decline in the suitability of forest patches for the recruitment of D. malabaricum. We conclude that elevated inbreeding due to reduced adult tree density coupled with increased degradation of forest patches, limit the recruitment of this rare late successional tree species. Management strategies which maintain canopy cover and enhance local densities of adult trees in agro-forest mosaics will be required to ensure D. malabaricum persists in these landscapes. Our study highlights the need for a holistic understanding of the incipient processes that threaten populations of many important and rare tropical tree species in human dominated agro-forest landscapes.

Genetic structure and demographic history of the endangered tree species Dysoxylum malabaricum (Meliaceae) in Western Ghats, India: implications for conservation in a biodiversity hotspot.

The impact of fragmentation by human activities on genetic diversity of forest trees is an important concern in forest conservation, especially in tropical forests. Dysoxylum malabaricum (white cedar) is an economically important tree species, endemic to the Western Ghats, India, one of the world's eight most important biodiversity hotspots. As D. malabaricum is under pressure of disturbance and fragmentation together with overharvesting, conservation efforts are required in this species. In this study, range-wide genetic structure of twelve D. malabaricum populations was evaluated to assess the impact of human activities on genetic diversity and infer the species' evolutionary history, using both nuclear and chloroplast (cp) DNA simple sequence repeats (SSR). As genetic diversity and population structure did not differ among seedling, juvenile and adult age classes, reproductive success among the old-growth trees and long distance seed dispersal by hornbills were suggested to contribute to maintain genetic diversity. The fixation index (F IS) was significantly correlated with latitude, with a higher level of inbreeding in the northern populations, possibly reflecting a more severe ecosystem disturbance in those populations. Both nuclear and cpSSRs revealed northern and southern genetic groups with some discordance of their distributions; however, they did not correlate with any of the two geographic gaps known as genetic barriers to animals. Approximate Bayesian computation-based inference from nuclear SSRs suggested that population divergence occurred before the last glacial maximum. Finally we discussed the implications of these results, in particular the presence of a clear pattern of historical genetic subdivision, on conservation policies.

Endophytic fungi from Miquelia dentata Bedd., produce the anti-cancer alkaloid, camptothecine.

Camptothecine (Campothecin, CPT), a quinoline alkaloid, is a potent inhibitor of eukaryotic topoisomerase I. Several semi-synthetic derivatives of CPT are in clinical use against ovarian, small lung and refractory ovarian cancers. While CPT is produced by several plant species belonging to the Asterid clade, in recent years, efforts have been made to isolate endophytic fungi from some of these plants as possible alternative sources of CPT. In this study we report the isolation of three endophytic fungi from fruit and seed regions of Miquelia dentata (Icacinaceae), that produce CPT, 9-methoxy CPT (9-MeO-CPT) and 10-hydroxy CPT (10-OH-CPT). All the three fungi identified as, Fomitopsis sp. P. Karst (MTCC 10177), Alternaria alternata (Fr.) Keissl (MTCC 5477) and Phomposis sp. (Sacc.) produced CPT, 9-MeO-CPT and 10-OH-CPT in mycelial mats in shake flasks containing potato dextrose broth. Methanolic and ethyl acetate extracts of these fungal species were cytotoxic to colon and breast cancer cell lines. We discuss these results in the context of the recent interest in endophytic fungi as possible alternative sources of plant secondary metabolites.

Fusarium proliferatum, an endophytic fungus from Dysoxylum binectariferum Hook.f, produces rohitukine, a chromane alkaloid possessing anti-cancer activity.

Rohitukine is a chromane alkaloid possessing anti-inflammatory, anti-cancer and immuno-modulatory properties. The compound was first reported from Amoora rohituka (Meliaceae) and later from Dysoxylum binectariferum (Meliaceae) and Schumanniophyton problematicum (Rubiaceae). Flavopiridol, a semi-synthetic derivative of rohitukine is a potent CDK inhibitor and is currently in Phase III clinical trials. In this study, the isolation of an endophytic fungus, Fusarium proliferatum (MTCC 9690) from the inner bark tissue of Dysoxylum binectariferum Hook.f (Meliaceae) is reported. The endophytic fungus produces rohitukine when cultured in shake flasks containing potato dextrose broth. The yield of rohitukine was 186 µg/100 g dry mycelial weight, substantially lower than that produced by the host tissue. The compound from the fungus was authenticated by comparing the LC-HRMS and LC-HRMS/MS spectra with those of the reference standard and that produced by the host plant. Methanolic extract of the fungus was cytotoxic against HCT-116 and MCF-7 human cancer cell lines (IC(50) = 10 µg/ml for both cancer cell lines).

Dysoxylum binectariferum Hook.f (Meliaceae), a rich source of rohitukine.

Rohitukine, a chromane alkaloid, is a precursor of flavopiridol, a promising anti-cancer compound. Currently in Phase III clinical trials, flavopiridol is a potent inhibitor of several cyclin-dependent kinases (CDKs). Rohitukine was first reported from Amoora rohituka (0.083% dry weight) followed by that in Dysoxylum binectariferum (0.9% dry weight), both belonging to the family Meliaceae. Here, we report incredibly high yields of rohitukine (7% dry weight) in trees of D. binectariferum from the Western Ghats, India. Crude extracts of the tree were found to be highly effective against ovarian and breast cancer lines tested.