Documents

Industrial Crops and Products Volume 22 Issue 3 2005 [Doi 10.1016%2Fj.indcrop.2004.10.001] L. Oliveira; C.S.R. Freire; A.J.D. Silvestre; N. Cordeiro; I.C. -- Steryl Glucosides From Banana Plant Musa Acum (1)

Categories
Published
of 6
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Share
Description
industrial crops
Transcript
  Industrial Crops and Products 22 (2005) 187–192 Steryl glucosides from banana plant  Musa acuminata Colla var  cavendish L. Oliveira a , b , C.S.R. Freire c , A.J.D. Silvestre c , ∗ , N. Cordeiro a , b ,I.C. Torres a , b , D. Evtuguin c a  Departamento de Qu´ımica, Universidade da Madeira, 9000-390 Funchal, Portugal b Centro de Estudos da Macaron´ esia, Universidade da Madeira, 9000-390 Funchal, Portugal c  Departamento de Qu´ımica, Universidade de Aveiro, 3810-193 Aveiro, Portugal Received 6 June 2004; accepted 6 October 2004 Abstract Thechemicalcompositionofthedichloromethaneextractsofseveralvegetalfractionsofbananaplant,  Musaacuminata Collavar  cavendish  have been studied by GC–MS. Several bioactive steryl glucosides, namely campesteryl 3-  - d -glucopyranoside,stigmasteryl 3-  - d -glucopyranoside and sitosteryl 3-  - d -glucopyranoside were identified as the major components of the ex-tracts, accounting for 838.4–1824.3mg/kg of the plant fractions dry weight. The high abundance of these compounds might bean important contribution to the valorization of banana plant agricultural residues.© 2004 Elsevier B.V. All rights reserved. Keywords: Musa acuminata  Colla; Agricultural residues; Extractives; Steryl glucosides; GC–MS 1. Introduction The banana plant is a very important crop in theMadeira Island economy. The sub-tropical climaticconditions of Madeira Island allowed the successfulintroduction of this crop in the middle of the sixteenthcentury. The banana plant is spread all over the island,but it is more abundant on the south coast, on areas upto 300m above the sea level (Nogueira et al., 2003). ∗ Corresponding author. Tel.: +351 234 370 711;fax: +351 34 37 00 84.  E-mail address:  armsil@dq.ua.pt (A.J.D. Silvestre). According to official statistics, the banana plantationsproduce annually  ca . 30.000tons of fruit, which rep-resent a substantial economic profit to this region. Af-ter the harvesting of the single bunch of bananas, greatamountsofagriculturalresiduesareproduced.Pseudo-stems and foliage, are usually left in the soil plantationto be used as organic material. However, those frac-tions,togetherwithrachis,aby-productofbananapro-cessing,couldrepresentanimportantrenewablesourceof fine chemicals and fibres.Among the cultivated species, “Dwarf Cavendish”(  Musa acuminata  Colla var  cavendish ) is nowadays 0926-6690/$ – see front matter © 2004 Elsevier B.V. All rights reserved.doi:10.1016/j.indcrop.2004.10.001  188  L. Oliveira et al. / Industrial Crops and Products 22 (2005) 187–192 the economically most important cultivar in terms of cultivatedareaaswellasproductionvolumeinMadeiraIsland( ca .50–60%ofthetotalbananaproduction).Theagricultural residues produced on the plantations reacharound 15.000ton/year.Thedevelopmentofnewapplicationsforthebananaplant residues would represent an important contribu-tion to increase the economical importance of bananaplantations.Thedetailedstudyonthechemicalcompo-sitionofthedifferentmorphologicalregionsof“Dwarf Cavendish” is an important step to achieve such objec-tive.Inthiscontext,somestudiesconcerningthechem-ical composition of “Dwarf Cavendish” (Cordeiro etal., 2004; Faria et al., 2002; Oliveira et al., 2002) havebeen published. The high content of total extractives( ca . 7–19%), found in the different morphological re-gions has incentivated the study of the composition of this fraction.As part of a research project aiming to find new ap-plications for the banana plants vegetal residues pro-ducedaftertheharvestingoffruits,wehavebeenstudy-ing the chemical composition of the plant tissues fromdifferentmorphologicalregionsof“DwarfCavendish”(  M. acuminata  Colla var  cavendish) , from Madeira Is-land.Inthepresentpaperwereporttheidentificationof threesterylglucosides,isolatedfromthedifferentmor-phological regions of the plant, in considerably highamounts, which might contribute to the valorisation of the residues of “Dwarf Cavendish” plantations. 2. Experimental 2.1. Materials and methods Maturebananaplants“DwarfCavendish”,wereran-domly selected from a banana plantation in Funchal,Madeira Island. The banana plants were harvested andseparated into five fractions corresponding to differentmorphologicalregions.Thepseudo-stemswerehandlyseparated into leaf sheaths and floral stalk. The foliagewas also separated in petioles/midrib and leaf blades.Rachis was collected in a Banana Cooperative. Afterseparation, the samples were air dried during 2 weeks.All morphological parts were milled and sieved. The40–60mesh fraction was used for chemical analysis.The powdered samples (3 × 20g) from differentmorphological regions of “Dwarf Cavendish” wereSoxhlet extracted with dichloromethane for 6h. Thesolventwasevaporatedtodrynessandtheextractswereweighed. The results were expressed in percent of drymaterial.Before GC–MS analysis, nearly 20mg of eachdried extract were dissolved in 250  l of pyridineand compounds containing hydroxyl and carboxylgroups were converted into trimethylsilyl (TMS)ethers and esters, respectively, by adding 250  lof bis(trimethylsilyl)trifluoroacetamide and 50  l of trimethylchlorosilane. After the mixture had stood at70 ◦ C for 30min, the derivatized extracts were anal-ysed by GC–MS (Freire et al., 2002a, 2002b). Eachsample was injected twice. GC–MS analysis were per-formed using a Trace Gas Chromatograph 2000 SeriesequippedwithaFinniganTraceMSmassspectrometer,using helium as carrier gas (35cm/s), equipped withDB-1 J&W capillary column (15m × 0.32mmi.d.,0.25  m film thickness). The chromatographic con-ditions were as follows: initial temperature: 100 ◦ Cfor 3min; temperature rate: 5 ◦ C/min; final tempera-ture: 340 ◦ C for 12min; injector temperature: 320 ◦ C;transfer-line temperature: 290 ◦ C; split ratio: 1/100(Freireetal.,2002a,2002b).Quantificationoftheanal-ysedcompoundswascalculatedasanaverageofthesixGC–MS runs of each fraction. 3. Results and discussion The GC–MS analysis (Fig. 1) of thedichloromethane extracts of the different morphologi-cal regions has shown that they are composed mainlyby long chain fatty acids, (including several   - and  -hydroxyfatty acids), long chain aliphatic alcoholsandsterols(with  -sitosterol,followedbystigmasteroland campesterol as the major components). Minoramounts of aromatic acids, mono-glycerides and fattyacids steryl esters (namely cycloartenyl octadecanoateand 24-methylenecycloartenyl octadecanoate) werealso detected in the extracts of all fractions. All thesecomponents were identified based on their characteris-tic retention times and fragmentation patterns (Freireet al., 2002a, 2002b).However, the most abundant chromatographicpeaks (Fig. 1) are eluted at long retention times (43.0–44.5min). These peaks were identified ascampesteryl 3-  - d -glucopyranoside  1 , stigmasteryl   L. Oliveira et al. / Industrial Crops and Products 22 (2005) 187–192  189Fig. 1. GC–MS chromatogram of the dichloromethane extract of leaf blades from  M. acuminata  Colla var  cavendish . FAc: fatty acids; FAlc:fatty alcohols; St: sterols; Mg: monoglicerides; StGc: steryl glucosides; StEs: steryl esters. 3-  - d -glucopyranoside  2  and sitosteryl 3-  - d -glucopyranoside  3  (Fig. 2). Their identification as TMS derivatives was based on their characteristicmass spectra and by comparison with literature data(Guti´errez and del R´ıo, 2001). The mass spectra(Fig. 3) of TMS derivatives of steryl glycosides, do not show the corresponding molecular ions, however theirmolecular weight can be determined indirectly basedon the mass of [M-15], [M-15-90] and [M-15-90-90]ions. The loss of the sugar moiety (tetra-TMS) withcharge retention on the sugar portion and cleavage of the glucose C O glycosidic bond, produces an ion at m  /   z  451, which then loses trimethylsilanol producinga more intense peak at  m  /   z  361. Furthermore, the highrelative intensity of the fragment ion at  m  /   z  204 (thebase peak) and the lower abundance of that at  m  /   z  217isanindicationofthehexosepyranosideconfiguration.Finally, the cleavage of the steryl 3-C O bond withcharge retention on the sterol moiety would produceintense ions with  m  /   z  383, 395 and 397 for sterylglucosides  1 – 3 , respectively.  -Sitosteryl glucoside was the most abundant com-ponent, followed by the stigmasteryl and campesterylglucosides (Table 1). Compounds  1 – 3  account for838.4–1824.3mg/kg (reported to the vegetal frac-tion dry weight) of steryl glucosides in the differentparts of banana plant. Though such high amounts of steryl glucosides were found in the vegetal parts of “Dwarf Cavendish” we have also checked their pres-ence in the fruit pulp and peel in different matura-tion stages. The GC–MS analysis of the correspond-ing dichloromethane extracts revealed that steryl glu-cosideswereonlydetectedinminoramountsinthefruitpulp and peel. Although these type of compounds areubiquitousintheplantkingdom(GrunwaldandHuang,1989),inmostspeciestheyarefoundinsmallamounts. Table 1Steryl glucosides identified in  M. acuminata  Colla var  cavendish  (mg/kg of the vegetal fraction dry weight)Peak Compound Petioles/midrib Leaf blades Floral stalk Leaf sheaths Rachis 1  Campesteryl 3-  - d -glucopyranoside 139 . 01 101 . 0 119 . 2 223 . 8 106 . 4 2  Stigmasteryl 3-  - d -glucopyranoside 352 . 1 208 . 9 263 . 3 624 . 1 290 . 8 3  Sitosteryl 3-  - d -glucopyranoside 1050 . 4 1350 . 5 678 . 8 976 . 4 441 . 2Total 1541 . 51 1660 . 4 1061 . 3 1824 . 3 838 . 4  190  L. Oliveira et al. / Industrial Crops and Products 22 (2005) 187–192 Fig. 2. Structures of the steryl glucosides  1 – 3  identified in different morphological fractions of   M. acuminata  Colla var  cavendish . In the case of banana species, they have already beenreportedintraceamountsin  Musaparadisiaca L.fruits(Ghoshal and Saini, 1984).Steryl glucosides belong to the phytosterols fam-ily. These compounds have been intensively investi-gated during the last decades due to the wide varietyof health benefits, (particularly their ability to lowerbloodcholesterol)associatedwiththeirinclusioninhu-man diet (e.g. Moreau et al., 2002; Qu´ılez et al., 2003).Furthermore, in recent years, steryl glucosides, andparticularly the   -sitosteryl derivative, have deservedparticular attention because of their specific proper-ties. A wide number of pharmacological activities,such as: hepatoprotective (Banskota et al., 2000), anti-inflammatory(Bouicetal.,1999;Delporteetal.,1998)among others, have been attributed to  -sitosteryl glu-coside; however, its known anti-mutagenic and anti-cancer activities (Kiriakidis et al., 1997; Park et al.,2003), in general related to the consumption soy de-rived products, are probably the most relevant. Sincethere is an increasing market demand for functionalfoods enriched in phytosterols as complements of nor-mal diets, the identification of new abundant vegetalsourcesofthesecompoundsmightbeanimportantcon-tribution to fill such demand and it will also contributeto the valorisation of such plants.In conclusion, the results presented above demon-strate that  M. acuminata  Colla var  cavendish  vegetalparts can be a good source of steryl glucosides, partic-ularly when they are expected to be used in functionalfoods. Such application can represent an importantcontribution to the valorisation of “Dwarf Cavendish”residues, and to increase the economical importance of banana plantations in Madeira Island.
Search
Similar documents
View more...
Tags
Related Search
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks