Outer Bark Research Articles

Use of Rhizophora sp. leaf extract for healing motile Aeromonas septicemia disease on catfish (Pangasius hypophthalmus)

Catfish (Pangasius hypophthalmus) is a commercially grown aquatic animal, and A. hydrophila has been described to often cause disease to the Motil Aeromonas Septicemia (MAS) specie. In addition, Rhizophora sp. is a plant reported to contain steroidal compounds, saponins, flavonoids, and tannins, and flavonoid content is widely found in mangrove plants, especially in its fruit, roots, leaves, and outer bark. This study, therefore, aims to examine the uses of Rhizopora sp. leaves extract in the treatment of catfish infected by A. hydrophila, conducted using a completely randomized design (RAL) of one factor (dose of treatment with extract), consisting of four levels; T1 (1300 ppm), T2 (1600 ppm), T3 (1900 ppm), and CT (0 ppm) serving as a control. Moreover, the leaves were sliced, air dried in the room for 10 days, milled, and then macerated with 95% ethanol for 24 hours. This dough was filtered and the residue was further macerated 3 more times, and the resulting filtrate was blended and evaporated to the point at which the gel-shaped extract was obtained. Furthermore, the catfish were injected intramuscularly with 0.1 mL / fish suspension of A. hydrophila bacteria, and the treatment was conducted twice (18 and 42 hours post injection) by soaking in a solution of The leaves for 5 minutes. Parameter measurements (total erythrocytes, hemoglobin levels, hematocrit) values, and graduation of fish life were evaluated at day 0, 3 and 14, post administration and the results showed a decreased in the assessed parameters of the infected fish, when compared to normal ones, which was further elevated close to that shown by the normal, on the 14th day. Post-healing treatment survival rate is observed to be influenced by the concentration administered, and the results were as follows; T1 (33.30 %), T2 (84.60 %), T3 (66.60 %) and CT (0 %).

Examination of Extraction Conditions of Chlorogenic Acid and Its Content in Domestic Phellodendron amurense Leaves

Phellodendron amurense is a broad-leaved tree; its outer bark and cork layers are removed and used as a crude medicinal agent known as Phellodendri Cortex. These trees are cultivated for approximately 15 to 20 years, harvested by felling, and processed by separating the outer and inner bark. Conventionally, parts other than the inner bark (i.e., fruit, leaves, and heartwood) remain unused. However, the revenue earned from by-products could contribute to continued cultivation of Phellodendron amurense. Herein, we examined the extraction condition and investigated the content of chlorogenic acid in the leaves of domestic Phellodendron amurense, which possesses antioxidant activity.

The onset of xylogenesis in Smith fir is not related to outer bark thickness.

The resumption of stem growth varies across the ontogenetic development of trees. Compared with younger trees, older ones have thicker outer bark with a temperature-insulating effect that could potentially prevent the stem from warming in the spring. However, the question of whether xylogenesis in old trees is influenced by the thick bark still remains unresolved. We investigated the onset of xylogenesis across the ontogenetic development of Smith fir (Abies georgei var. smithii) trees in the Sygera Mountains, southeastern Tibetan Plateau. The outer bark of older trees was also removed. Xylogenesis was monitored in microcores we collected every 3 days during May and June in 2017. Xylogenesis began in late May in young (<50 yr) and mature (50-100 yr) trees, 1 week earlier than in adult (>100-150 yr) and old (>150-200 yr) trees. Older (>200 yr) trees had the latest onset of xylogenesis, 2 weeks after young trees. The resumption of xylogenesis was similar between the control and bark-removed trees. Growth resumption was delayed in older and bigger trees. Outer bark did not affect the onset of xylogenesis, which indicated that the delayed resumption of growth during the lifespan of trees could be more related to endogenous factors than to an insulating effect of the thick bark of older individuals.

Relationship between the composition and distribution of nutritional substances, secondary metabolites, and internal secretory structures in the bark tissues of Larix gmelinii var. japonica, L. kaempferi, and their F1 hybrid and susceptibility to vole herbivory

ABSTRACTWe investigated the quantitative composition and distribution of nutritional substances (soluble sugars, starch, and protein), secondary metabolites (terpenoids and phenolic compounds), and the length, area, and density of internal secretory structures (resin ducts and cavities) in the rhytidome (outer bark) and secondary phloem (inner bark) of Kuril larch (Larix gmelinii var. japonica), Japanese larch (L. kaempferi), and their F1 hybrid (L. gmelinii var. japonica × L. kaempferi) in order to clarify the relationship of these parameters to susceptibility to red-backed voles’ herbivory in Hokkaido, Japan. The amounts of most nutritional substances in each of both bark tissues were not significantly different among the three larch taxa. The amounts of carane-type monoterpenoid and labdane-type diterpenoid in both bark tissues of L. gmelinii var. japonica and the F1 hybrid were significantly higher than those of L. kaempferi. The amounts of phenolic compounds in both bark tissues of L. gmelinii var. japonica were significantly lower than those of L. kaempferi. The quantitative composition of most secondary metabolites in both bark tissues of the the F1 hybrid were between L. gmelinii var. japonica and L. kaempferi. The area and density of the resin ducts and cavities, which were containing terpenoids, in both bark tissues of L. gmelinii var. japonica and the F1 hybrid were significantly larger and higher than those of L. kaempferi. These results suggest that L. gmelinii var. japonica and the F1 hybrid utilize some predominant constitutive mono- and diterpenoids as chemical defensive substances in the bark tissues against the voles.

Intake of Radionuclides in the Trees of Fukushima Forests 1. Field Study

The earthquake and tsunami on 11 March 2011 led to a meltdown followed by a hydrogen explosion at the Fukushima–Daiichi nuclear power plant in Japan, causing the dispersal of abundant radionuclides into the atmosphere and ocean. The radionuclides were deposited onto trees and local residences in aerosol or gaseous forms that were partly absorbed by rain or melting snow. Here, we show that the radionuclides attached to the surfaces of trees, in which some radiocesium was incorporated into the xylem through ray cells and through symplastic pathways. The level of incorporated radiocesium varied based on tree species and age because of the ability of radiocesium to attach to the surface of the outer bark. After four years, the radiocesium level in the forest has been decreasing as it is washed out with rainwater into the sea and as it decays over time due to its half-life, but it can also be continuously recycled through leaf tissue, litter, mulch, and soil. As a result, the level of radiocesium was relatively increased in the heartwood and roots of trees at four years after the event. In private forest fields, most trees were left as afforested trees without being used for timber, although some trees were cut down. We discuss an interdisciplinary field study on the immediate effects of high radiation levels upon afforested trees in private forest fields.

Comparative study on radical scavenging activity and phenolic compounds content in water bark extracts of alder (Alnus glutinosa (L.) Gaertn.), oak (Quercus robur L.) and pine (Pinus sylvestris L.)

The radical scavenging activity and the content of proanthocyanidins, tannins, flavonoids, and total phenolic compounds in water extracts from whole bark and outer bark of alder (Alnus glutinosa (L.) Gaertn.), oak (Quercus robur L.) and pine (Pinus sylvestris L.) trees growing in the coastal and continental zones in Kaliningrad region (Russia) were evaluated. The content of proanthocyanidins was highest in extracts from whole alder bark collected in continental zone (3.8 ± 1.2 mg g−1), which was 34–38 times more than in outer part. No significant difference in tannin content in alder and oak bark extracts was revealed. Pine bark samples had less tannins. The whole alder bark showed higher content of flavonoids (9.7–21.5 mg g−1), compared to oak bark (7.2–8.4 mg g−1) and, in particular, pine bark (2.1–5.2 mg g−1). The maximal total phenolic content was found in whole alder bark from continental zone (29.0 ± 5.3 mg g−1). High content of phenolic compounds was determined in whole oak bark (about 18.1 ± 3.5 mg g−1). All investigated species showed approximately 1.3–2.5 times lower total phenolic content in outer bark in comparison to whole bark. Maximal radical scavenging activity of alder extracts (up to 276 ± 29 mg g−1) and minimal of pine extracts (up to 23.8 ± 4.0 mg g−1) was established. A higher level of radical scavenging activity for all samples from continental zone in comparison to samples from coastal zone was revealed. Based on the results of a cluster analysis, it was first demonstrated that the phenolic compounds content and radical scavenging of bark extracts are influenced by a complex of factors, such as tree species, part of the bark and the place of growth. The results of this study proved that whole bark of alder may be considered as a valuable source of phenolic compounds with radical scavenging properties.

A major symbiont shift supports a major niche shift in a clade of tree‐killing bark beetles

1. One small clade of bark beetles, out of thousands of species worldwide, has shifted from using phloem to using a combination of phloem and outer bark, or to completely using outer bark.2. The shift to outer bark has been accompanied by a shift to non‐typical bark beetle mutualist fungi in Entomocorticium (Basidiomycota) and Ceratocystiopsis (Ascomycota).3. This study compared the growth and metabolic capabilities of fungi associated with a nearly phloem‐independent species, Dendroctonus brevicomis, with those of mutualist fungi of Dendroctonus ponderosae, a completely phloem‐colonising beetle in a sister clade associated with more typical Ascomycota in Grosmannia and Ophiostoma.4. Only the basidiomycete associated with D. brevicomis could degrade cellulose and lignin, whereas both the ascomycete and basidiomycete could grow in outer bark. Ascomycetes associated with D. ponderosae could not degrade cellulose or lignin or grow in outer bark.5. Beetles and fungi in these mutualisms may best be considered as co‐niche constructors. For niche construction, one organism must modify a resource in a way that enhances its fitness while also influencing fitness of other organisms using the resource. Here, the beetles kill the tree, transport the fungi into the tree, and modify the woody substrate for use by the fungi. They have also evolved mycangia to ensure vertical dissemination of the fungi. In turn, the fungi modify tree tissues and provision nutrients to the host and have evolved traits that support their acquisition and transport by the beetle host in mycangia.

Continuous Synthesis and Application of Novel, Archaeoinspired Tackifiers from Birch Bark Waste

A new family of sustainable tackifying agents with adjustable glass transition temperatures was prepared via torrefaction of outer birch bark waste. The application of the obtained betulin esters a...

Bark in Woody Plants: Understanding the Diversity of a Multifunctional Structure

Most biological structures carry out multiple functions. Focusing on only one function to make adaptive inferences overlooks that manifold selection pressures and tradeoffs shape the characteristics of a multifunctional structure. Focusing on single functions can only lead to a partial picture of the causes underlying diversity and the evolutionary origin of the structure in question. I illustrate this discussion using bark as a study case. Bark comprises all the tissues surrounding the xylem in woody plants. Broadly, bark includes an inner and mostly living region and an outer, dead one. Of all plant structures, bark has the most complex anatomical structure and ontogenetic origin involving two (and often three) different meristems. Traditionally, the wide diversity in bark traits, mainly bark thickness, has been interpreted as the result of the selective pressures imposed by fire regime. However, recent research has shown that explanations based on fire regime cannot account for salient patterns of bark variation globally including the very strong inner bark thickness-stem diameter scaling, which is likely due to metabolic needs, and the very high intracommunity variation in total, inner, and outer bark thickness, and in inner:outer proportions. Moreover, explanations based on fire disregard that in addition to fire protection, bark carries out several other crucial functions for plants including translocation of photosynthates; storage of starch, soluble sugars, water, and other compounds; protection from herbivores, pathogens, and high temperatures; wound closure, as well as mechanical support, photosynthesis, and likely being involved in xylem embolism repair. All these functions are crucial for plant performance and are involved in synergistic (e.g., storage of water and insulation) and trade-off relationships (e.g., protection from fire vs photosynthetic activity). Focusing on only one of these functions, protection from fire has provided an incomplete picture of the selective forces shaping bark diversity and has severely hindered our incipient understanding of the functional ecology of this crucial region of woody stems. Applying a multifunctional perspective to the study of bark will allow us to address why we observe such high intracommunity variation in bark traits, why some bark trait combinations are ontogenetically impossible or penalized by selection, how bark is coordinated functionally with other plant parts, and as a result, to understand how bark contributes to the vast diversity of plant ecological strategies across the globe.

Study of an Appropriate Suberinic Acids Binder for Manufacturing of Plywood

In the study, birch outer bark`s suberinic acids (SA), appropriate for binding the plywood, obtained in a water medium and precipitated in two acidification stages under various medium pH levels, were characterized, which could become a sustainable, environmentally friendly alternative to toxic, formaldehyde-containing plywood binders. In the process of obtaining SA, it was found that all SA of the first acidification stage filtrated successfully. With increasing the pH level of precipitation from 2 to 6, the yield of SA decreased from 35.6 to 18.8 wt% from oven dry (o.d.) extracted birch outer bark or 69.5-36.6 wt% from total o.d. raw material SA. Meanwhile, only one sample of SA from the second acidification stage with the initial pH level 6 filtrated successfully, reaching the yield of 4.4 wt% from total o.d. raw material SA. The SA obtained in the first acidification stage at the pH level 2 contained a lower amount of epoxy groups – 1.7 wt% from o.d. SA, but at the same time, the highest acid value – 84.4 mg KOH/g. In turn, increasing the pH level to 6, the amount of epoxy groups increased gradually up to 19.9 wt% from o.d. SA, and the acid value of SA decreased to 67.4 mg KOH/g. The acid value of SA from the second acidification stage was 133.0 mg KOH/g, but epoxy groups in the composition were not observed.

Comparative studies on mineral contents in soil and wild trees samples of Boswellia sacra collected from different locations of Dhofar

Frankincense, the indicator of Dhofar region flourishes in all geographical location of Dhofar. The cultivars of frankincense grown in different location are known by different name such as Shaebi, Sahli, Houjri, Najdi etc. Mineral nutrition has direct effect on both primary and secondary metabolism of plants. Mineral element as nitrogen, phosphorus and potassium plays a major role in primary metabolism. Elements as Na, K, Fe, Mn, Ca, Mg, Zn and Cu were analyzed in soil and samples of various parts (leaves, bark, outer bark, flower, seed, root stem and resin) of Boswellia sacra collected from three different locations of Dhofar. The significant results was found to be that sample ST-1 contain high amount of iron, potassium, zinc, magnesium whereas sample ST-2 contain more amount of iron, magnesium, sodium, and calcium. Sample ST-3 found to be contain significant amount of calcium whereas ST-4 high amount of manganese, iron, sodium, and calcium. Soil samples obtained from Mughsail hill recorded more amounts of manganese, potassium, copper, and magnesium whereas, soil samples from Saddah hills found to contain high amount of magnesium and sodium. Further soil samples collected from valleys contains rich amount of calcium and noticeably the highest value gave by the soil sample obtained by plains followed by soil sample of valleys. On the basis of comparative study of data (Table 1-8) obtained for elements, it can be concluded that plants grown in different location showed difference in accumulation of mineral elements.

SYNTHESIS OF BETULIN DIFORMATE AND ALLOBETULIN FORMATE DIRECTLY FROM OUTER BIRCH BARK

One of the promising directions of birch bark utilization is its extractive treatment with obtaining a number of valuable chemical components among which the most relevant is betulin. As a rule, the methods of betulin esters are multistage and based on classical reactions of betulin acylation; betulin should be preliminarily extracted from birch bark.&#x0D; The purpose of the present research was synthesis of the betulin diformate and allobetulin formate directly from the birch bark without a separate stage of the betulin preparation. The external layer of the bark of birch, Betula pendula Roth was ground to particle size of 10–20 mm and used as the raw material. The method is based on combined extraction of betulin from outer birch bark and its formylation with formic acid at reflux for 16 hours. During the treatment of birch bark with formic acid, along with betulin extraction into solution, its formylation into betulin diformate and allobetulin formate occurs. The yield of the formation of betulin diformate and allobetulin formate of the mass of acylated upper bark (a.u.b.) was 40 and 10%, respectively. The first fraction of betulin diformate was obtained from the resulted solution by evaporating 3/4 of the solution and poured it in water to form beige precipitate, whereas the second fraction was extracted by treating the resulted birch bark by acetone followed by evaporation. However, the allobetulin formate was formed from the second treatment of resulted birch bark by chloroforrm followed by evaporation. Betulin diformate was found to be the main component of this extraction, and it was recrystallized from ethyl alcohol to afford beige powder, and its melting point is 165 °C. The structures of betulin diformate and allobetulin formate are confirmed by 1H NMR, 13C NMR, and FTIR spectroscopy.

Origin and development of reproductive buds in jabuticaba cv. Sabará (Plinia jaboticaba Vell)

The fruits of jabuticaba trees are highly valued in Brazil and eaten fresh and processed. An alternative method to improve jabuticaba cultivation is to offer the fruit throughout the year. However, this requires more information about the buds, which are located close to the bark surface. In this way, the objective of this work was to characterize the origin and development of reproductive buds of jabuticaba cv. Sabará. We collected jabuticaba branches, peeled them, and investigated the origin of the flower sprouts. In addition, buds were collected at different stages of development in the main stem (trunk), fixed, and analyzed. Based on our results, vegetative buds are axillary and shown a primary origin. In contrast, reproductive buds grow in the bark of the branches and the trunk; they are a result of the cellular activity of vascular cambium and only occur after de development of the periderm and the formation of the rhytidome. The reproductive buds were divided in four different stages of development. Stage 0 was characterized by the absence of meristematic activity and stage 1 by the presence of a previous meristem oriented towards the outer bark, that marks the beginning of reproductive bud formation. In stages 2 we observed an increase in meristem dimensions, and at stage 3, the buds were completely developed. In March reproductive budburst led to a low intensity flowering and in August led to a high intensity flowering, due to climatic conditions that the buds were exposed.

Isolation, structure determination and structure\u2013activity relationship of anti-toxoplasma triterpenoids from Quercus crispula Blume outer bark

Toxoplasma gondii is an intracellular protozoan parasite of which infection can result in serious symptoms for fetuses or people who have weakened immune system. In our effort to discover novel anti-toxoplasma substances from tree barks, only outer bark extract from Quercus crispula Blume (mizunara) was revealed to show potent anti-toxoplasma activity. Isolation of the active principles was performed to identify three pentacyclic triterpenoids, namely 29-norlupane-3,20-dione, oleanolic acid acetate and ursolic acid acetate. These structures were determined by combining a series of spectral data, computational simulation and synthetic approach. All isolated compounds exhibited notable activities at IC50 of 6.8–24.4 μM and high selectivities against the parasite. The structure–activity relationship study conducted to probe key structure(s) indicated that the lack of free hydroxyl group at 3-position highly contributes to both the titer of activity and the selectivity. Moreover, skeleton and functionalities of E-rings were also suggested to affect to the activity. The present study demonstrated not only that the extract from Q. crispula Blume could be a promising source of toxoplasmacidal agent, but also that related extractive triterpenoids can be modified to furnish anti-toxoplasma activity.

Investigation of suberinic acids-bonded particleboard

Birch outer bark and residual veneer shorts are one of the main leftovers from plywood production and have a high potential to be converted into value-added products. Birch (Betula pendula) outer bark contains up to 45% (dry basis) of suberin and has been recognized as a promising resource of suberinic acids (SA), where the bonding potential has been proven. Therefore, this study assesses the application of SA as formaldehyde free bio-based adhesive for the production of particleboards (PBs) made of birch wood particles obtained from residual veneer shorts. The solids of ethanol extracted outer bark were hydrolytically depolymerized and SA obtained. A two stage design of experiments, in terms of screening and optimization, was used varying three PB preparation parameters: amount of the binder (c 20–30%), hot-pressing temperature (T 220–230 °C), and duration (t 2–6 min). The binder was evaluated by thermogravimetric, differential scanning calorimetric, Fourier transform infrared spectrometric and scanning electron microscopic analyses. SA-bonded PBs were evaluated in terms of modulus of elasticity and modulus of rupture in the bending test, internal bond strength, and thickness swelling. The properties of the optimized SA-bonded PB (c = 21%, T = 226 °C, t = 5 min) are in the range of PBs standard EN 312 type P3 (requirements of non load-bearing boards for use in humid environment). The achieved superior internal bond strength (2.7 ± 0.5 N mm−2) and instrumental analyses confirmed a high potential of natural SA-based binder to be used in PB production.

Evaluation of the effect of inner and outer bark extracts of sugar maple (Acer saccharum var. saccharum) in combination with citric acid against the growth of three common molds

The bark of trees is an abundant material for chemical by-products. The combination effects of different concentrations of Acer saccharum var. saccharum inner (IB) and outer (OB) bark acetone extracts with citric acid (CA) applied to Leucaena leucocephala wood were evaluated against the growth of three common molds (Trichoderma viride, Fusarium subglutinans, and Aspergillus niger). IB, OB, and CA solutions were prepared at 0.25% and 0.5% and their combinations were formulated in equal amounts. Acetone extracts of IB and OB were analyzed for their chemicals composition and phenolic compounds using GC/MS and PHLC, respectively. The IB acetone extract contained 4-hydroxy-4-methyl-2-pentanone (31.67%), palmitic acid (15.52%), and linoleic acid (11.14%), while the OB acetone extract contained 1,2-benzenedicarboxylic acid, bis(2-ethylhexyl) ester (9.34%), (Z,E)-9,12-tetradecadien-1-ol (8.86%), and cis-tetrahydro-6-methoxy-2H-pyran-3-ol (5.72%). The HPLC analysis indicated the presence of 14 phenolic compounds in IB extract with major constituents caffeine (362.88 µg/g extract), and p-hydroxy benzoic acid (358.06 µg/g extract), while OB contained 12 compounds with major constituents p-hydroxy benzoic acid (8950.5 µg/g extract), gallic acid (5261 µg/g extract) and salicylic acid (572.38 µg/g extract). High total phenolic content in OB (292.67 mg GAE/g) was associated with high antioxidant activity with an IC50 values of 1.77 and 4.14 μg/mL, as measured by DPPH and β-Carotene-linoleic acid, respectively. The combination treatment of IB0.25%+ OB0.25%+CA0.25% produced the highest antifungal effects against growth of T. viride with an inhibition percentage (IP) of 10.37%, IB0.5%+CA0.5% (IP 16.66%) with F. subglutinans, while CA0.5% and OB0.25%, showed IP of 27.77% and 23.70% with A. niger, respectively. The combination effects of IB, OB and CA could be used as biocide agents for preventing mold growth on wood.

Biopolyester prepared using unsaturated betulin (betulinol) extracted from outer birch bark and dicarboxylic acid dichlorides and its thermal-induced crosslinking

Betulin, also called betulinol, with two hydroxyl moieties extracted from white birch bark, and acid dichloride (ClCO(CH2)mCOCl) were successfully polycondensed to give the corresponding aliphatic biopolyester (ABIOS) in the presence of pyridine; in particular, in the case of sebacoyl dichloride (m = 8), derived from sebacic acid contained in castor oil of Ricinus seed, the ABIOS8 was obtained in a fairly high yield of 91%, with Mw = ∼23,800 and Mw/Mn = ∼2.1, even at room temperature. By contrast, the polymerization using other acid dichlorides with short methylene chains, i.e., m = 2, 4, 5, and 7, and long methylene chains, i.e., m = 10, resulted in relatively lower yields with a lower molecular weight, Mw. The ABIOS8 with (CH2)8 showed a high glass transition temperature (Tg ≈ 150 °C) superior to that of polylactic acid (PLA) known as a typical biopolyester. A colorless transparent film of ABIOS8 was easily fabricated by the solvent-casting method using THF or CHCl3 as solvent. Furthermore, the ABIOS8 gradually became insoluble in solvents such as THF when heated to 250 °C even under a nitrogen atmosphere. It was deduced that the CC bond in the isopropenyl moiety (H2CC(CH3)) as the third substituent within the betulin mother molecule in ABIOS8 acted as a thermally induced cross-linker.

Hydrophilic Extracts of the Bark from Six Pinus Species

Pine barks are important biomass resources because they are utilised in the production of pine wood and rosins. However, no chemical study has been conducted on the hydrophilic status of pine barks in Indonesia. This aim of this study is to explore the hydrophilic extracts of the barks from six Pinus species (P. elliotii, P. caribeae, P. oocarpa, P. merkusii P. montezumae, and P. insularis). The hydrophilics of pine barks were analysed using gas chromatography-mass spectrometry. The presence of polyphenol contents in the ethanol extracts obtained from the barks of six Pinus species was determined using the tannin-formaldehyde method, Folin-Cioucalteu assay, and vanillin-HCl assay. The ethanol and hot water soluble extractives derived from inner barks were higher in quantity when compared to those derived from the outer bark samples. The polyphenol measurement showed that the highest value of total phenol content was derived from the outer bark of P. montezumae whereas those of the total phenol and tannin- formaldehyde contents were derived from the inner and outer barks of P. oocarpa. GC-MS analysis revealed that nitrogenous compounds are dominant constituents in the inner and outer barks of the six species, followed by sugars and monophenolics, respectively.

Medicinal Properties of a Naturally Occurring Pentacyclic Triterpenoid Lupeol

Lupeol is a 6-6-6-6-5 fused pentacyclic lupane type triterpenoid present in different plants. Various medicinal properties of lupeol have been reported for the treatment of different types of cancer, tumor, ulcer, diabetis, various infectious diseases, cardiovascular diseases, wounds, arthritis, chronic inflammation etc. In this review, the medicinal properties of lupeol has been discussed. A useful procedure for the isolation of lupeol from the dried outer bark of Bombax ceibacommonly known as "Shimul"(in Bengali) and its detailed characterization has also been reported.

Hydrophobic and antibacterial textile fibres prepared by covalently attaching betulin to cellulose

Betulin, a natural compound extractable from the outer bark of birch, can be used to improve the properties of cellulosic textile fibres. Herein, oxidation was performed to prepare carboxyl-functionalized cellulose, which was subsequently covalently attached by betulin through esterification. The surface-modified cellulosic textile fibres showed a substantially improved hydrophobicity, as indicated by a water contact angle of 136°. Moreover, the material showed excellent antibacterial properties, as indicated by over 99% bacterial removal and growth inhibition, in both Gram-positive and Gram-negative bacterial assays. The method of surface-modification of the cellulosic materials adapted in this study is simple and, to the best of our knowledge, has not been carried out before. The results of this study prove that betulin, a side-stream product produced by forest industry, could be used in value-added applications, such as for preparing functional materials. Additionally, this modification route can be envisaged to be applied to other cellulose sources (e.g., microfibrillated cellulose) to achieve the goal of functionalization.