Chukrasia Research Articles

Four new limonoids from the seeds of Chukrasia tabularis A. Juss.

Two new C-15 enolic acyl phragmalin-type limonoid orthoesters (1-2) which possessed a C-15-propionyl phragmalin skeleton and two new mexicanolide-type limonoids (3-4) were isolated from the ethanol extract of seeds of Chukrasia tabularis A. Juss. Their structures were established on the basis of spectroscopic analyses and electronic circular dichroism (ECD) exciton chirality method. Additionally, all of the compounds were screened against three human tumor cell lines MCF-7, SMMC-7721, and U2OS.

Antimalarial and cytotoxic properties of Chukrasia tabularis A. Juss and Turraea vogelii Hook F. Ex. Benth

Malaria, caused by plasmodium parasite, is at the moment the highest cause of morbidity and mortality in the tropics. Recently, there is increasing efforts to develop more potent antimalarials from plant sources that will have little or no adverse effects. This study is aimed at investigating the in vivo mice antimalarial and in vitro antiplasmodial effects of two Meliaceae plants commonly used in Nigerian ethnomedicine as part of recipe for treating malaria infection: Chukrasia tabularis and Turraea vogelii. Hot water decoction and methanol extract of both plants were evaluated for their antimalarial activity in vivo using the mice model assay and in vitro using the parasite lactate dehydrogenase (pLDH) assay. The extracts were also assessed for toxicity with brine shrimp lethality assay and in mammalian cell lines using the neural red assay. The in vivo mice model antimalarial study showed that the methanol extract of the stem bark of C. tabularis exhibited the highest % chemosuppression (83.65 ± 0.66) at the highest dosage administered (800 mg/kg) when compared with chloroquine diphosphate, the standard reference drug which had a % suppression of 90.36 ± 0.04 (p < 0.05). The in vitro antiplasmodial study indicated that the aqueous extract of the stem bark of C. tabularis displayed good activity against Plasmodium falciparum chloroquine-sensitive (D6) strain (IC50 of 10.739 μg/mL) and chloroquine-resistant (W2) strain. Chloroquine and artemisinin had <0.163 and <0.0264, respectively.

Two new phragmalin-type limonoids from stems of Chukrasia tabularis

Phytochemical investigation on the stems of Chukrasia tabularis A. Juss led to the isolation of two new phragmalin-type limonoids and three known ones. The structures of the new compounds were elucidated as Chuklarisin A (1) and Chuklarisin B (2) by spectroscopic techniques (IR, HRESIMS, 1D and 2D NMR) and comparing with published data. All the compounds were evaluated for α-glucosidase inhibitory activity in vitro. Compounds 2, 3, and 4 exhibited inhibitory activity against α-glucosidase with IC50 values of 0.96, 0.03, and 0.53mM, respectively (acarbose as positive control, IC50 0.95mM).

Two new phragmalin-type limonoids from Chukrasia tabularis and their α-glucosidase inhibitory activity

Phytochemical investigation on the stems of C. tabularis (Meliaceae) led to the isolation of two new phragmalin-type limonoids, named tabularisins S and T (1–2), along with five known ones (3–7). The structures of the new limonoids were established by spectroscopic methods including UV, IR, HRESIMS, and 1D and 2D NMR. All the compounds were evaluated for α-glucosidase inhibitory activity in vitro. Compounds 2 and 3 exhibited significant inhibitory activity against α-glucosidase with IC50 values of 0.15 and 0.03 mM, respectively (acarbose as positive control, IC50 0.95 mM).

New Phragmalin‐Type Limonoid Orthoesters from the Bark of Chukrasia tabularis var. velutina

AbstractThree new phragmalin‐type limonoid orthoesters, velutabularins K–M (1–3) and seven structurally related known compounds were isolated from the bark of Chukrasia tabularis var. velutina. The structures of these compounds were elucidated by spectroscopic analysis. The structure of 1 was confirmed by single crystal X‐ray diffraction. In addition, the brine shrimp lethality of compounds 1, 3, and the known compounds was evaluated.

Bioactivities of Chukrasia tabularis (A. Juss.)

The methanol extracts of bark and leaves of Chukrasia tabularis and their organic and aqueous soluble materials were subjected to screenings for antioxidant, cytotoxic, thrombolytic, membrane stabilizing, antimicrobial, analgesic and antidiarrhoel activities. In the DPPH free radical scavenging assay, the methanolic extract of bark of C. tabularis and the aqueous soluble fraction of methanol extract of leaves of C. tabularis revealed the highest free radical scavenging activity with IC50 values of 2.95 ?g/ml and 5.31 ?g/ml, respectively. The pet ether soluble fraction of methanolic extract of leaves and bark of C. tabularis displayed the highest cytotoxic potential having LC50 values 0.0167 ?g/ml and 3.89 ?g/ml, as compared to standard vincristine sulphate (LC50 value of 0.45 ?g/ml). During thrombolytic assay, the aqueous soluble fraction of leaves and carbon tetrachloride soluble fraction of bark of C. tabularis showed 34.04% and 56.37% clot lysis, respectively. In the membrane stabilizing assay, the carbontetrachloride and aqueous soluble materials of methanol extract of leaf inhibited 21.03% and 49.68% hypotonic solution- and heat-induced haemolysis of RBC, respectively. The crude extract of leaves of C. tabularis exhibited mild antibacterial activity, while that of leaves and bark revealed significant central analgesic activity at 400 mg/kg body weight. The crude extracts demonstrated significant peripheral analgesic activity at 200- and 400- mg/kg body weight. On the other hand, the crude extract of leaves of C. tabularis revealed significant antidiarrhoel activity.Bangladesh Pharmaceutical Journal 18(2): 126-131, 2015

Further C-15-acyl phragmalin derivatives from Chukrasia tabularis A. Juss.

Relying on characteristic double UV absorptions (210 and 270nm), sixteen phragmalins with three types of enolic acyl substituents at C-15 were isolated directly from EtOH extracts of the seeds of Chukrasia tabularis A. Juss. Eight of these compounds possessed a C-15-acetyl phragmalin skeleton, and the basic carbon skeleton and absolute configuration of one of these was determined by NMR and X-ray diffraction analysis, while the structures of the other phragmalins were determined via NMR, HR-MS, and CD spectra. Additionally, all of the isolates were tested for inhibition against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 macrophages and cytotoxicity in SMMC-7721, MCF-7 and U2OS tumor cells.

High-resolution densitometry and elemental analysis of tropical wood.

Key message Understanding the mobility and distribution of chemical elements in wood is necessary to apply dendrochemistry. Crystals are likely stable and could be used to analyze changes in nutrient supply. Dendrochemistry uses the variation in wood chemical composition to infer about past environmental conditions and possible effects on tree growth. Elemental or isotopic variation might also help to identify annual growth where tree rings are anatomically not distinct. However, most elements are—to a certain degree—mobile within wood and may be related to anatomical structures. Therefore, understanding what affects elemental distribution is important to make use of and critically assess the potential of dendrochemistry. We studied the variation of wood density and elements at high spatial resolution in wood of six species with anatomically distinct to rather indistinct tree rings from a Thai monsoon forest. Many elements had a higher concentration in parenchyma than in fiber cells, and the co-variation of elements differed strongly between elements and also between species. Strong wood density changes along the ring boundary were found only in Melia azedarach. In all species, the X-ray images showed crystals. EDX spectra showed that these consist of calcium or silicon (in Chukrasia tabularis) as major elemental components. A high concentration of heavy metals (Fe, Cu and Zn) was found in Vitex peduncularis. We conclude that at least for the species studied the radial variation of elemental concentration is unlikely to reveal annual rings that anatomy could not. However, if elements in crystals are more stable than in cell walls or living protoplasts, analyzing the distribution of elements present in crystals may show environmental conditions that, in turn, influence crystal formation and are little known.

Velutinalide C, a New Polycyclic Phragmalin Limonoid from the Leaves of Chukrasia tabularis var. velutina

AbstractVelutinalide C (4), a new polycyclic phragmalin limonoid featuring a C(15)–C(21) linkage and a C4 unit at C(15), together with two known related compounds, chukfuransins C and D (2 and 3, resp.), was isolated from the leaves of Chukrasia tabularis var. velutina. The structure of the new compound 4 was elucidated on the basis of extensive spectroscopic analyses and comparison with literature data.

Phragmalin limonoids from the stem barks of Chukrasia tabularis var. velutina.

Seven new phragmalin limonoids, chukvelutilides I-O (1-7), were isolated from the stem barks of Chukrasia tabularis var. velutina. Their structures were elucidated by extensive spectroscopic analysis. Among them, compound 1 showed moderate lethal activity against brine shrimp larvae, with an LC50 value of 84.1 µM.

Phragmalin-type limonoids with NF-κB inhibition from Chukrasia tabularis var. velutina

Chemical investigation on Chukrasia tabularis var. velutina led to the identification of eight new phragmalin-type limonoids (1–8), as well as 20 known analogues. Compounds 1–4 are a rare class of C-15-acyl phragmalin-type limonoids, and particularly compounds 2–4 also possess a δ-lactone ring formed between C-16 and C-30. All the isolates were evaluated for inhibitory effects on NF-κB production, and four of which showed significant inhibitions.

The Fate of Five Rare Tree Species after Logging in a Tropical Limestone Forest (Xuan Son National Park, northern Vietnam)

Rare tropical tree species are endangered due to the disappearance of old-growth forests. Although some undisturbed old-growth and formerly logged forests are protected today, the extent to which rare tree species persist and regenerate in such logged forests is often unclear. In a forested area over limestone in northern Vietnam, we studied the fate of five rare tree species after decades of logging and subsequent nine years of full protection, in comparison with an un-logged forest. Three of the studied species are largely restricted to limestone hills (Excentrodendron tonkinense, Chukrasia tabularis and Garcinia fagraeoides), while two of the species have a wider distribution (Parashorea chinensis and Melientha suavis). The bigger trees of the study species had lower densities and/or differences in the diameter distributions between the two forest types, indicating that these species had formerly been cut. The regeneration stem density of the study species was much lower (46% in M. suavis to 80% in P. chinensis) in the logged than un-logged forest. In the un-logged forest, we found clear relationships between ecological factors and regeneration density in four of the five study species; e.g., the regeneration of E. tonkinense increased with increasing rock-outcrop cover (r = 0.6, p &lt; 0.01). Such relationships were almost absent in the logged forest. The widely distributed generalist species Cleidion javanicum dominated in the tree regeneration of the logged forest. Our results suggest that the studied rare tree species still existed as adults after logging and there was regeneration but at low densities. We assume that the potential for recovery remains, which further justifies the full protection of this and other restoration areas.

Semisynthesis of Libiguin A and Its Analogues by Trans-Lactonization of Phragmalin

Libiguins are limonoids with highly potent sexual activity enhancing effects, originally isolated from the Madagascarian Meliaceae species Neobeguea mahafalensis, where they exist in only minute quantities. Their low natural abundance has hampered mapping of their biological effects. Here we describe an approach to the semisynthesis of libiguin A and its close analogues 1-3 starting from phragmalin, which is a limonoid present in high amounts in a commercially cultivated Meliaceae species, Chukrasia tabularis, allowing the preparation of libiguins in appreciable quantities.

ChemInform Abstract: Chukfuransins A—D, Four New Phragmalin Limonoids with β‐Furan Ring Involved in Skeleton Reconstruction from Chukrasia tabularis.

ChemInformVolume 44, Issue 51 Natural Products ChemInform Abstract: Chukfuransins A—D, Four New Phragmalin Limonoids with β-Furan Ring Involved in Skeleton Reconstruction from Chukrasia tabularis. Ming-Hua Qiu, Ming-Hua Qiu Kunming Inst. Bot., Chin. Acad. Sci., Kunming 650204, Yunnan, Peop. Rep. ChinaSearch for more papers by this authoret al. et al., et al. et al. Kunming Inst. Bot., Chin. Acad. Sci., Kunming 650204, Yunnan, Peop. Rep. ChinaSearch for more papers by this author Ming-Hua Qiu, Ming-Hua Qiu Kunming Inst. Bot., Chin. Acad. Sci., Kunming 650204, Yunnan, Peop. Rep. ChinaSearch for more papers by this authoret al. et al., et al. et al. Kunming Inst. Bot., Chin. Acad. Sci., Kunming 650204, Yunnan, Peop. Rep. ChinaSearch for more papers by this author First published: 02 December 2013 https://doi.org/10.1002/chin.201351226Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume44, Issue51December 17, 2013 RelatedInformation

Chukfuransins A–D, Four New Phragmalin Limonoids with β-Furan Ring Involved in Skeleton Reconstruction from Chukrasia tabularis

Four new phragmalin limonoids (chukfuransins A-D) were isolated from the twigs and leaves of Chukrasia tabularis. Chukfuransins A (1) and B (2) feature a unique C-15/C-20 linkage proposed to be built by a biogenetic pathway involving Michael addition. Chukfuransins C (3) and D (4) feature the C-15/C-21 linkage. Their structures and absolute configurations were established by NMR techniques and X-ray crystallographic analysis.

Wood density variation in four plantation species growing in Bangladesh

Wood density is a unique integrator of strength properties and life-history traits of trees, and has importance in carbon estimation. It varies vertically and radially within individual tree in tropical species. The aim of this study was to determine whether wood density variations were dependent on tree diameter or age by comparing trees of same age but with different diameters for four important plantation species, such as Chukrasia tabularis A. Juss., Dipterocarpus turbinatus Gaertn., Michelia champaca L. and Syzygium grande (Wright) Walp. in Bangladesh. Twenty trees were selected for coring in each species and wood density was measured at 1 cm interval from pith to bark. Steeper regression slopes in small diameter trees and absence of significant relationship between outer wood density and tree diameter imply age-dependent wood density variation in C. tabularis and M. champaca. Conversely, the diameter-dependent wood density was found in S. grande. Steeper regression slopes in small diameter trees and slightly higher outer wood density in large diameter trees suggesting mixed response of both age and diameter in D. turbinatus. Therefore, wood density variation in plantations species is influenced not only by tree age but also diameter, or both which has implications in plantation management and biomass estimation in the tropics.

广州市常见行道树种叶片表面形态与滞尘能力

以广州市常见的18种行道树为对象,通过扫描电镜观察比较了行道树的叶表面形态结构、应用接触角测定仪测定了绿化树种叶片的接触角对滞尘能力的影响。结果表明:不同树种的滞尘量差异显著,18种植物叶片雨后第26天的最大滞尘量在0.066-1.831g/m²,物种间相差达27倍以上。叶表面具有网状结构,气孔密度较大(20<气孔密度<60个)且气孔开口较大(如芒果)容易滞留粉尘;叶表面平滑具有蜡质层,气孔排列整齐,无明显起伏(如红花羊蹄甲、桃花心木、大叶紫薇、鹅掌藤),滞尘能力较弱。植物叶片接触角与滞尘量呈负相关(<em>r</em>=-0.614),接触角<90°的表现为亲水性。易润湿的植物叶片雨后第26天最大滞尘量在1.0-1.831g/m²,叶片表面的形态结构凹凸不平,具有钩状或脊状褶皱、突起等且20<气孔密度<60范围内,测得的接触角较小(芒果、重阳木、高山榕),使得粉尘与植物叶片接触面积较大,粉尘不易从叶面脱落,滞尘能力较强。而接触角较大的盆架树、麻楝、大叶紫薇、鹅掌藤和红花羊蹄甲的滞尘量均<1.0g/m²,其特殊的表面结构和疏水的蜡质使颗粒物不易吸附在植物叶片上,因此滞尘能力较弱。由此可见,植物叶表面蜡质含量和气孔密度及其叶片接触角的大小是影响植物叶片滞尘能力的主要因素,在进行城市绿化时,适当考虑选择叶表面形态有利于滞尘的绿化树种,将可提高城市植被的环境效应。;In this study, we selected eighteen species of common street trees along main roads in Guangzhou Municipality to observe and compare their leaf surface morphology using Scanning Electron Microscopy (SEM), and to evaluate how the contact angle of water droplet on leaf surfaces measured by goniometer influence the dust-retaining capability. It was found that the maximum leaf dust-retaining capabilities per unit area of the eighteen species of trees 26 days after rainfall were 0.066-1.831g/m², indicating significant differences (up to 27 times) among different trees. The plants with network structure on leaf surface, having high stomatal density and large opening of stomata, such as <em>Mangifera Indica</em>, have strong dust-retaining capability; while those whose leaf surfaces are smooth and covered by epicuticular wax with stomata arranged regularly without obvious undulation, such as <em>Bauhinia blakeana</em>,<em> Swietenia mahogani</em>,<em> Lagerstroemia indica Linn</em>. and<em> Scheffera arboricola</em>, have poor dust-retaining capability. There was a significant negative relationship between leaf contact angle and dust-retaining capability (<em>r</em>=-0.614). Leaves with contact angle smaller than 90° demonstrate hydrophilicity. Their maximum dust-retaining capabilities 26 days after rainfall ranged from 1.0 to 1.831 g/m². For leaves with rugged morphological structure, hook or ridge-shaped rumple, prominence and stomata density ranging from 20 to 60, the measured contact angles are smaller, making the contact area between leaf and dust larger. Therefore, it is not easy for dust on such trees as <em>Mangifera Indica</em>, <em>Bischofia Polycarpa</em> and <em>Ficus altissima Bl.</em>, to detach from leaf surface and these species have a strong dust-retaining capability. On the contrary, the special surface structure and hydrophobic wax of tree leaves with larger contact angle, such as <em>Alstonia scholaris</em>,<em> Chukrasia tabularis</em>,<em> Lagerstroemia indica Linn.</em>,<em> Scheffera arboricola </em>and <em>Bauhinia blakeana</em>, make it difficult for dust particles to attach to leaves, resulting in small dust-retaining capabilities of less than 1.0g/m². This study has shown that the wax content of surface foliage, stomata density and contact angle of leaves are the three main factors controlling the dust-retaining capability. It is therefore advisable to consider choosing tree species whose leaf surface morphology enhances dust-retaining capability for urban greening and thus to improve the environmental effectiveness of urban vegetation.

Two New Phragmalin-Type Limonoids from Chukrasia tabularis var. velutina

Two new phragmalin-type limonoids with different structural skeletons, chuktabrin K (1) and tabulalin J (2), were isolated from the stem barks of Chukrasia tabularis var. velutina in the course of our ongoing research work in this area. Compound 1 was a 16-norphragmalin with an enolic alkyl appendage at C-15, and the carbonate moiety in 1 was also rare in natural organic molecules. The basic skeleton of compound 2 was a D-ring-opened phragmalin. Their structures were elucidated on HR-ESI-MS, 1H and 13C-NMR, HSQC, HMBC, and ROESY experiments.

Phylogenetic Relationships of &lt;i&gt;Santalum album&lt;/i&gt; and its Adulterants as Inferred from Nuclear DNA Sequences

The East Indian sandalwood, <i>Santalum album,</i> valued for its fragrant oil yielding heartwood is a major ingredient in indigenous medicines and perfumes. Scarcity of sandal has led to illegal felling of sandal trees, and adulteration of sandalwood and oil. This study represents the first molecular phylogeny of <i>S. album</i> and its adulterant species <i>Osyris wightiana</i>, <i>Erythroxylum monogynum, Buxus sempervirens, Ximenia americana, Osyris lanceolata, </i>and <i>Chukrasia tabularis</i> through 18S and 26S rDNA sequencing. In the Maximum Parsimony (MP) tree for 18S and 26S rDNA data sets, moderate to high bootstrap support was obtained for the nodes. For 18S rDNA data sets, the tree had <i>B. sempervirens </i>and<i> X. Americana</i> as the upper branch, with <i>E. monogynum</i> branched separately to the cluster. The lower branch had <i>S. album </i>and<i> O. wightiana</i> with <i>O. lanceolata</i> joining separately to both clades of the tree. In the MP tree for 26S rDNA datasets, <i>S. album </i>and <i>O. wightiana</i> formed the major cluster with <i>X. americana</i> clustering separate and <i>B. sempervirens</i> and <i>O. wightiana </i>as the lower branch with<i> C. tabularis</i> clustering separate to the tree. The molecular data presented here provided useful information for resolving the phylogenetic relationship of these plants. Inferences from this study are in accordance with Cronquist’s system of classification of flowering plants where all the species originate from a single phylogenetic tree of Rosidae.

Chukrasones A and B: Potential Kv1.2 Potassium Channel Blockers with New Skeletons from Chukrasia tabularis

Two new limonoids, chukrasone A (1) incorporating a highly rearranged A/B ring system and chukrasone B (2) possessing the first 16,19-dinor limonoid backbone with an extended C3 unit at C-15, were isolated from Chukrasia tabularis. Their structures were characterized on the basis of detailed spectroscopic analysis. Compounds 1 and 2 exhibited potential inhibition of the delayed rectifier (I(K)) K(+) current.