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COCONUT OIL AND COCONUT OIL ETHANOL DERIVATIVES AS FUEL FOR
DIESEL ENGINES
By
RICHARD K. SOLLY
SUMMARY
Coconot oil has been shown to successrully ruel a small high speed stationary diesel engine at low to medium loadillg. At higher lo"ding. there was evidence that combustion was not complete. leading to a decrease in the Ihermal dficiency or Ihe engine. ThiS' errecl is most likely due 10 Ihe lower injeclor alomizalion of-Ihe coconul oil compared lo .diesel oil as a ,onsequence or Ihe I.M rold higher viscosity or cOCOnul oil. These results are similar 10 Ihose reported for diesel engines operating ror hundreds or hours on pea nUl oil and sunnower oil. where coking or Ihe injeclor lead 10
contamination or Ihe lubricating oil wilh non-combusle<] ruel and sticking pislon . rings. Other properties or coconul oil 10 which allemion must be paid in ils use as a
diesel ruel, are the high solidiricalion lemperature and Ihe relatively low solubililY in admixture with diesel oil. Due to the low solubility. admixture with diesel oil . did not ~ubstantially decrease Ihe lemperature at which solid particles or coconut oil were rormed .
A new ruel . Cocohol. produced by chemical combination or ethanol and coconut oil was shown to operate high speed d iesel-cng~n~ al a grealer Ihermal efficiency than diesel oil. Cocohol is miscible wilh diesel oil. coconui oi l and elhanol. The high speed diesel engine was operated successrully on a Cocohol j cthanol ruel conlaining up to 40% or elhanol by volume. Our sludies confirm recenl reports on a chemically relaled
·ruelto Cocohol,produced rrom sunnower sel'd oil,lhal "rler 100 hours or operalion . . there was less cyclinder coking. less exhausl smoke and increased engine thcrmal efficiency when compared to normal diesel oil. Chemical evidence indicalcs Iha! Cocohol will be stable indefinitely and ideal ror the occasional operation or dicsel engines in rural areas . Preliminary evidence suggests thai il is a superior ruelto diesel oil. Cocohol could be produced rrom resources currenlly available within the Soulh Pacific.
INTRODUCTION
Automotive engines in current general use are almost exclusively or two basic types . The spark ignition engine has a spark discharge to initiale the combustion' or the ruel. The compression ignit ion engine uses the hea t or compression a lone ror this purpose.
spark ignition engines. High compression is a re4uirement or the ignilion process and Ihis yields higher erriciency. The ruel is injected at high pressure as a liquid. so volalility is not a major ractor. The combustion characleristics require ruels containing molecules ha ving a long chain or atoms .' This is the opposite or spark ignition engines. ror which ruels containing Ihe molecules in a highly branched rorm are prererred . A moderale volatility is required to rorm a co'mbustion mi x lure to start the engine. As with
The ruel requirements or compression ignidon or diesel engines are less stringent than those or
spark ignition, diesel engines hav~ been designed to utilize a readily available petroleum fraction with a boiling point greater than that of the fuel for spark ignition engines and below that of heavy industrial heating oil.
Diesel fuel contains many chemica l compounds with 12 to 18 carbon atoms per rt]olecule and a boiling range of 200-300°C. Cetane (hexadecane) containing 16 carbon atoms and 34 hydrogen atoms, is used as the "standard" diesel fuel for combustion characteristics. Vegetable oils a lso contain a mixture of.chemical compounds in )"hich·three "fatty acid" molecules are chemically combined with one glycerol molecule. The chain length of the "fatty acid" section of the vegetable oil has 12 to 18 carbon atoms. However, as there are 3 of these chains per vegetable oil molecule, it is approximately -) times as large as an average petroleum diesel oil m.olecule. The major effect of this larger size is seen in the physical properties and ·chemical properties as listed in Table I. The viscosity, solidification point, boiling point and flash point are greatly increased for coconut oil compared to diesel oil.
Recent studies on the use of vegetable oils;s a fuel have been by Galloway and Ward (1980), who found that peanut , sunflower, corn and soybean oil could operate a diesel engine satisfactorily. Extensive tests using crude peanut oil and Lister type SR2 twin cyclinder air cooled 10 H.P. diesel engines, however, revealed that the performance of the engine operating on peanut oil deteriorated with time. This was explained as being due to coking of the injector leading to poor combustion
53
with conseq<!ent crank case oil dilution and sticking -piston rings . Bruwer (1980) has also reported similar combustion characteristics with sunflower oil. Cruz (1980) has carried out extensive tests in the Philippines on the use of ~oconut oil as a fuel in three types of diesel engines and found that on an averagr the thermal efficiency of the coconut o il was compatible to that of diesel.
The objectives of this study were as follows:
(a) to further investigate the use of local coconut oil as fuel in diesel engines,
(b) to produce Cocohol by reacting coconut oil with ethanol and to study it s combustion characteristics.
MATERIAL AND METHOD
ENGINE
A Yanmar Model TS60C 6 H.P . single cycli nder water cooled diesel engine coupled via 'Y' belts to a nominal IIOV direct current generator was used for the combustion studies. Absolute calibration for this system was not available and the efficiency of the generator could not be determined . Nominal electrical output was determined by measuring the current and voltage on standard panel meters. Maximum electrical output was obtained at 2500 rpm as measured on ~ he diesel motor fly-wheel by a mechanical counter.
TABLE I PHYSICAL AND CHEMICAL CHARACTERISTICS OF COMBUSTIBLE OILS
Fuel
Die sci oi l l!
Coconut oil h
Peanut oil C
Cocohol d
Elhanol
C" C-
" C "
Average molccuhu weight
2 10
6H5
H95
242
46
Carbon chain average
Carbon chain average
Carbon chain average
SolidificHlion poin. C°C)
- 20 '0 - 10
2Ll '0 26
0.0 5
- 5 10 .5
· 117
2
Soiling po int Viscosit)' at JO°C Calnriric valut.-
C°C) (ccnllpaisc) .(MJ/L)
200 '0 )00 3.7 38.2
Decomposes 53 35.6
Decomposes 70 36. 1
270 '0 310 3.8 33.2
79 1.0 23 .. 1
From coconut oil and ethanol
Calculalcd (rom the siandard heat of combustion
54
COCONUT OIL
Unrefined coconut oil was made available by Island Industries and refined coconut oil by Fiji Foods. Both materials were clear liquids above 26°C. On standing at temperatures below 26°C for the refined coconut oil and below 24°C for unrefined oil, both liquids became cloudy with the increased formation of solid particles. On maintafning the liquid in the temperature range 20-24°C, the amount of solid particles increased and sellled to the bottom of the container. Below 20°C for all samples of coconut oil, soPd crystals were slowly formed and all the liquid solldillea .
COCONUT OIL - DIESEL OIL MIXTURES
Coconut oil was mixed with diesel oil in proportions between 10% and 90% by volume. In all cases, the solution became cloudy when maintained at temperatures below 20°C. Maintaining the coconut oil-diesel oil mixtures at 15°C solidified the coconut oil component of the mixture. Admixture with petroleum diesel fuel did appear to increase the time required to form solid particles of coconut oil, but did not substantially reduce the temperature at which a clear solution could be maintained indefinitely .
COCOHOL
Heating coconut oil with an ex~ess of ethano. in the prestnce of a catalyst will convert the "fally acid" section of the coconut oil molecule to the ethyl ester with glycerol being formed as a byproduct. The most favourable conditions for this reaction are presently' under active investi~ation but conversion in excess of 95% can be obtained based upon unreacted coconut oil. As with
cuconut oil Itsell, lile ethyl esters from coconut oil are a mixture of chemical compounds for which we will use the name "Cocohol" Predominant in the mixture is the ethyl ester of lauric acid. This has been used as a basis (Cox and Pilcher, 1970) in deducing the physical and chemical characteristics of Cocohol shown in Table I, wrth visco~ity values being experimental measurements.
RESULTS AND DISCUSSION COMBUSTION CHARACTERISTICS OF COCONUT OIL AND COCONUT OIL
DIESEL OIL MIXTURE The main difficulty. in the combustion of
coconut oil is associated with the high solidification point of the oil. The presence of solid particles within the coconut oil fuel rapidly formed an impervious film which completely clogged the fuel filter and led to the engine being starved for fuel. To avoid this problem whenever coconut oil was being used as a fuel, it was pre-heated to 30°C when the ambient temperature was less than this .
All problems in the fuel system with coconut oil arose during th. winter months when the ambient temperature was less than 25°C. No difficulty ~as experienced in starting the engine when cold by hand cranking using coconut oil as fuel. The engine started and ran with ,imilar visual and audio characteristics as obtained with diesel fuel. The fuel consumption was determined as a function of electrical load as shown in Table 2. It was found that the maximum output available irom the system was less with coconut oil than with diesel oil. This is largely due to a decrease in the rpm. available from the motor at a loading of' approximately 60% of the rated motor output. With the system available for this study, a greater output could not be obtained at a lower engine speed.
TABLE 2 RATES OF CONSUMPTION (ml/hour)
Electrical load No load
Dicsel oil 4H6
Coconul.,Eil 5)7
Cocohol ;0
Cocohol/cthlUlOl ll
5HI
654
Dh.tillatc or the rC. Lctulll mixture
Cocohol: ClhiHlOI = 6:4: IlUl dhlllh:tJ
2009 Wails max . o utput
3
HOO Wall 21511 W." electrical loud c1CCIrIl:al load
~79 1017
745 1125'
7M I09H
92.1 1.1S.1
The output thermal efficiency as tabulated in I 3 was calculated using the calorific values ra�:bl�.I, originally derived frqm data listed by
of owhung et a!. (1942). All the. energy of the heat
Ch b stion is not available within Internal com b�stion engines, but the comparative data is
cOI�consisten!. The "net" columns of Table 3 were· se
btained by subtracting the fuel consumption o. h no electrical load on the system from the Wit
ured with the quoted electrical load. Of meas . . . · lieance , IS the decrease In the output thermal s�f.\ncy of coconut oil at the high engine e IdC�
ng This is most likely due to a decrease in the loa I . . f . efficiency of combustion 0 coconut 011 at the h· her fuel injection rates. ThiS has prevIOusly �g
postulated as arising from decreasing inj��tiOn characteristics of the high viscosity fuel (Galloway and Ward, 1980).
It was further noted that the back bleeding characteristics of the injector w.as almost zero with the high viSCOSity coconut 011 when compared with a value 30 ml per hour with petroleum diesel fuel in the same injector system. Back bleeding of fuel from the injector is required for sealing the jet between fuel injections. Continual leakage.of the high viscosity fuel from the injector may be one of the factors contributing to carbonization of the injector jet as reported by other workers (Galloway and Ward, 1980; Bruwer, 1980).
COMBUSTION CHARACTERISTICS OF
COCOHOL AND COCOHOL-ETHANOL
MIXTURE
The majority of the fuel tests with Cocohol shown in Tables 2 and 3 were done with the
TABLE 3 OUTPUT THERMAL EFFIC IENCY No load
Electrical load (MJ/hour)
(jro)<Oll
Diesel oil IH.6 J2.4
Coconut oil 19.7 .1.1.1
Cocoho�" 19.4 JI.H
Cocohol/clhllnol ,. 19.7 .1.1.M
DiSliliatc of the reaction mixture
55
undistilled reaction product, from which excess ethanol had been removed by heating the liquid to 100°C and condensing the ethanol. Some of the tests were done with the clear liquid obtained by distillation of the Cocohol at 10 cm water pressure at a temperature up to 250°C. No �ignificant difference was obtained between the distilled and undistilled Cocohol.
The engine started readily by hand cranking with Cocohol and ran at all loads with the absence of smoke in the exhaust:The Cocohol could be left indefinitely in the fuel as no solidification or
separation occurred during the tests. Coco hoi mixed readily with both coconut oil and diesel and was used to rinse the fuel system whenever tests were done with coconut oil.
In a series of runs, the Cocohol-ethanol reaction mixture was used as fuel. The mixture contained 40% unreacted ethanol by volume. No difficulty was experienced in starting the engine by hand cranking. However, with no load on the electrical OUtpUt from the test system, the diesel engine ran very unevenly. With a small load of800 watis electrical OUtput, the engine again ran roughly and the thermal efficiency of the fuel was poor. Increasing the electrical output to the maximum available from the system, the efficiency of the engine increased to be compatible y;ith that from diesel fuel. Under full load, the running characteristics of the mo:or were not noticeably different from that with diesel fuel. The anti-knock characteristics of ethanol that are attractive in spark ignition engines are detrimental
HOO Wall 2150 Wall (M:I/kw hour) (MJ/kw hour)
Nell' Grn!'o� Net!
9.2 IH.7 9.4
9.2 19.9 10.4
7.7 17.0 7.0
9.H IH.4 9.5
'Cocohol: ethanol;;: 6:4; not distilled; calorific \'otluc ;;: 29.J MJ/ L
Calculated by SUbtracting the no luai.l spc:cirlc fucl consumption
4
56
to diesel combustion . The combustion delay is increased. especially at light loading. lead ing to the rougher running. At 40% ethanol. the fuel is not miscible with petroleum die,el fuel and ,eparation occurred within the fuel syste.m. The separated phases produced "slimy" films which presented fuel f'ilter problems.
A single test engine was used for all thL measurements reponcd here. The major dimcully. experienced was blockage of the fuel filler aher coconut oil had been used in the initial series of tests . II proved very dimcull to nush coconut oil COl)'lpletely from the fuel system with petroleum diesel fuel. After Coeohol became available . this was successful in removing all coconut oil and then diesel oil readily mixed with the Cocohol. The cyclinder was insp'ected after approximately 50 hours of test rnns . No abnormal deposits were apparent and mechanical repairs of any type were not necessary.
ECONOMICS
A comprehensive review of the coconut . . industry has been recently completed in Fiji but this is not available at present. The international market has been characterized by large nuctua~ tions in the value of vegetable oil. In the case of coconut oil . the income to Fiji from exponing the oil varied from 25 centsl L in 1970. to a low 15 centsl Lin' 1972. reaching a peak of 70 centsl Lin 1974 and again in 1979 on a yearly average. Current expon prices are similar to the 1977 and 1978 average of 45 cents l L. By comparison. the current 1980 landed cost of diesel fuel in Fiji is 23 centsl L. II would appear that present production of coconut oil in Fiji has the potential to supply the energy re4uirements of 20% of current automobile diesel fuel requirements. This might be expected to fuel all automotive fuel requirements in an emergency situation. Based upon a return to the primary producers equivalent to than now received. the cost to the consumer would be similar to the current retail cost of petroleum fuel.
The discussion above represents the least cost for petroleum fuel and the maximum return for coconut oil. both with respect to input or export at the major pon ' of Suva. Thc cost of fuel is increased by wholesale distribution costs within the Region. while the return from coconut oil is
s
decreased by costs in bringing the oil (or copra) to the point of export. It is likely that individual studies would show that coconut oil is currently a more economical fuel at a number of locations in the South Pacific Region .
I n convening coconut oil and ethanol to Cocohol approximately 3% of the calorific value of the reactants is released as heat during the reaction. This is more than sufficient to heat the reaction mixture to the boiling point of ethanol. Approximately 3% of the calorific value of the ethanol is required to heat the initial reaction mixture from room temperature . It is not necessary to boil the ethanol. only to keep the reacting mixture hot. so that \he conversion of coconut oil to Cocohol occurs at a faster rate. The most economical fuel is not 100% Cocohol but will consist ofa homogenou'ssolution of Coco hoi. coconut oil. ethanol and glycerol. This will be formulated with regard to the key parameters of a viscosity compatible to tpat of petroleum diesel fuel. The liquid must remain homogenous at minimum ambient temperatures in the South Pacific. This fuel could be produced with industrial plant currently available in the South Pacific for processing coconut oil at an energy cost of approximate ly 5% of that of the coconut oil and ethanol.
The economics for inclusion of ethanol into the fuel formulation are dependent upon the cost of production of ethanol. Currently it is estimated that this can be produced from sugar cane or cassava at a cost of 50 cents l L within Fiji . Using the calorific value from Table I. this is an energy cost of 2. 14 centsl MJ of energy. At costs of 22.4 cents l L for diesel oil and 45 centsl L for coconut oil. the corresponding energy costs are 0.59 cents and 1.26 centsl MJ of energy for diesel oil and coconut oil. respectively. Both petroleum fuel and coconut oil are more economical fuels than ethano l. Ethanol must be subsidised as a fuel alongside the landed cost of petroleum fuels at present and for the immediate future .
Incorporation of ethanol into a fuel with coconut oil decreases the cost effectiveness of the fuel relative to both petroleum fuel and coconut oil itself. Formation of ethanol with coconut oil will enable the production of substantial amounts of a locally produced fuel with technical characteristics which have the promise of being compatible to petroleum diesel fuel itself. This
fuel could be lIsed iii unmodified diesel engines with less subsidy per energy unit than is required for the incorporation of ethanol into the fuel of petrol engines.
REFERENCES
Bruwer J .J . (1980) Sunnower fuel as reported in Londbounuus Agricultural News, June.
Chowhung, D.H.; S.N. Mukerji; J .S. Aggarwal , and L.c. Verman (1942) Indian vegetable oils for diesel . engines. Gas and Oil Power, 80·85 .
57
Cox J .D. and G. Pilcher (1980) Thermochemistry 0/ Organil' and Organometallic COlllpoinds, Academic Press.
Cruz, I.E. (1980) Studies on the utilization of indigenous fuels at Ihe University of the Philippines, J. Eng. Ed/lc. in South Eost Asia 10 (1),97· 100.
Galloway, D.J. and J. F. Ward (1980) Compre. hensive testing of modern compression ignition engines in extended operation on vegetable oil. Nawral Philosophy Research Repof/ No . ~4, James Cook University of North Queenslnnd.
6
58
AryJpropanoids from Myristica castaneifolia (Myristicaceae)
Sadaquat Ali,A,B Roger W. ReadB,C and Subramaniam SotheeswaranA
A Chemistry Depanment. School of Pure and Applied Sciences, UniversilY of !he Sou III Pacific, Suva. Fiji. B School of Chemistry, Universily of New South Wales, P.O. Box I, KensinglOn N.S.W. 2033, Australia.
C Aulllor 10 whom correspondence should be addressed.
Abstract. The dichloromelhane extract of the combined bark and heanwood of Myristica
castanei/olia A. Gray (Myristicaceae) has yielded a new arylalkanone, named caslanone (I), two structurally related, open chain arylalkanones, (2) and (3), and three benzofuranoid
neolignans (4) - (6). The known antibacterial activity of the neolignans accounts for the
antidiarrhoeal propeny of M. castanei/olia.
Introduction Myristica castanei/olia A. Gray, of the family Myristicaceae, is commonly known in Fijian as
"Kaudamu" or "Fiji Nutmeg". A preparation made from the scrapings of the stem of M.
castanei/olia is used to treat diarrhoea in the South Pacific.' The heanwood is also a durable
limber lhat turns dark red in colour when CUI and is used in the manufacture of furniture. In
this paper, the dichloromethane extractives from the bark and hcanwood are reponed for the
first time. One new arylalkanone, named casta none (I), two other structurally related
arylalkanones, (2) and (3), and three neolignans, (4) - (6), have been isolated.
Results and Discussion
The dichloromethane extracts of the bark and timber of M. casIanei/olia were separated by
silica gel vacuum liquid chromatography (VLC) followed by radial chromatography or
preparative thin layer chromatography on silica gel. Six arylpropanoids were isolated: a new
benzopyranone (castanone) (1), two arylalkanones, viz, compound (2)2 and malabaricone A
(3),2,3 that have been isolated previously from other Myristica species, and three more
widesp(ead neolignans (4).4.6 (5)4.7.8 and (6).5-7.9
The structure of the new compound (I) was clearly related to those of arylalkanones
(2) arid CU . . Its molecular formula was established by microanalysis and mass spectrometry to
be C23H2603 (M+, mJz 350.1885). Its I H n.m.r. and infrared spectra showed the presence of
a conjugated carbonyl group (V max 1660 cm-I), a hydrogen-bonded hydroxyl group (vm3x
3520-3300 cm-I; 012.57, s, IH, exchang�ble with 020), an olefinic proton (0 6.10, s, IH).
and an enol ether (vmax 1635 cm-I). The IH and I3C n.m.r. spectra were consistent with the
presence of an unsymmetrically 1,2,3-trisubstituted benzene residue with substituent groups
similar to those found in (2) and (3). For example. the aromatic carbon signals at 0 106.9
(CH). 108.4 (eH), 110.6 (e), 135.1 (eH), 156.8 (C) and 160.8 (eH) were in close
agreement with those reported2 for 2-methoxy-6-hydroxytetradecanoylbenzene, viz, 0 101.34 .
(C3), 110.04 (e5), 111.43 (el), 135.80 (e4), 161.43 (e2) and 164.85 (e6). There also
appeared carbon signals due to a vinylogous ester group with substitution adjacent to the ether
oxygen (0 111.2, eH; 171.3, 183.7,2 x quaterna� e) that were reminiscent of the carbon
signals in 2-methylbenzopyran-4-oneIO (0 116 .6 (e3), 166.3 (e2), 178.0 (e4». The
chromone srructure (I) in which a -(eH2)ge6HS was attached at position 2 was consistent
with these features and satisfied the remaining data, including the presence of a significant
fragment ion in the mass spectrum at mlz 189. ehromone (7), a major component of the
secretions from the secretary hairs of azalea lace bug, S(ephani(is pyrioides, also gave a base
peak at mlz 189 in its mass spectrum. I I The ion was not identified but it could be attributable
to any one of Ihe structures (8a-c), derived through unusual scission y to the chromone ring of
Ihe two molecules.
The substance from M. castaneifolia was thus identified as 5-hydroxy-2-phenyloctyl-(4H)-
benzopyran-4-one (I). II has been named casta none and is reponed here for the first time.
The biogenetic origin of castanone is unclear but most likely involves an aryl propanoid
residue, extended at e-2 by acetate or malonate units and subsequently cyclised. The co-
occurrence of castanone with arylalkanones (2) and (3) and neolignans (4)-(6) confirms this
belief.
59
60
-Tho .remaining substances differed from the arylalkanones in their chromatographic
behaviour and spectroscopic propenies. Neolignan (4) is strikingly active in a bioassay
against the larvae of Hombyx mori,7 and neolignan (6) has significant antibacterial activity
against Srreprococci:u murans.l2 Biological activities of lignans also cover a broad range l3
including antitumour, antimitotic and antiviral properties. The antidiarrhoeal property of the
South Pacific M. casranei/olia may therefore be attributed to the presence of the lignans.
Funhennore, in our hands arylalkanone (3) was found to undergo ready oxidation to a brown
pigment when absorbed on to silica gel and exposed to air and light. The nature of the
oxidation products could not be deternlined but this behaviour may contribute to the colour of
the timber of the furniture made from M. ca.rraneifolia. The durability of the timber froin the
plant may also be due to the antibacterial neolignans present in it.
Experimental
Melting points were determined on a Kofler hot stage apparatus and are uncorrected. Infrared
spectra were recorded with an Hitachi EPI ·G2 grating spectrophotometer or a Perkin· Elmer
model 298 spectrophotometer. Ultraviolet spectra were recorded with a Carey 17 recording
spectrophotometer on methanol solutions. Proton n.m.r. spectra were measured with a
Bruker CXP300 instrument operating al ~(){} MHz while 13C n.m.r. spectra were determined
using a Bruker AM500 instrument operaling al 125.(\ MHz. Carbon assignments were made
by use of DEPT (Distortion less Enhancement by Polarisation Transfer) experiments. Vacuum
liquid cilromalography (VLC) was carried out on Merck silica gel type 60 while analytical and
preparative thin layer chromatography ulilized silica gel GF254. T.l.c. plates were visualized
either by u~e of an ultraviolet light or by spraying with .an ethanolic solution of
phosphomolybdic acid . Radial chromatography \Vas performed with a Harrison Research
Chromatotron model 7924 preparative centrifugal thin·layer chromatograph.
Plant Material
Myrisrica casraneifolia used in this investigation was collected from Colo·i·Suva tropical
forest, Fiji, in June 1989. The plant was iden tilied and authe nticated by Mr S. Vodonaivalu of
the University of the South Pacific, and a voucher specimen (no. F64/!/4) is kept in the
Herbarium of the Institute of Natural Resources . Universit y of the South Pacific, Suva, Fiji .
Extr:acti_on .and Isolation The dried. powdered bark and heartwood (1.0 kg) of M. castaneifolia was extracted with
dichloromethane (4 L) for 3 d using a Soxhlet apparatus. The extract (ca. 4.5 g) was
separated by VLC o� silica gel by elution with a dichloromethane-ethyl acetate gradiant to yield
in order, fractions A (750 mg), B (510 mg), C (420 mg) and D (310 mg).
Radial chromatography of fraction A (9: I, dichloromethane-ethyl acetate) and
subsequent recrystallization of the components gave the following compounds.
(i) 5-Hydroxy-2-(8-phenyloctyl)-(4H)-benzopyran-4-one (named castanone) (1),
pale yellow needles (8.0 mg, 0.0008%), m.p. 88-90°C (1:2, dichloromethane-hexane)
(Found: C, 78.9; H, 7.4; mlz 350.1883. C2)H260) requires C, 78.9; H, 7.4%; mlz
350.1882). Vmax (KBr) 3520-3300, 1660, 1635 em·l. Amax (MeOH) (log E) 232 (4.30), 252
sh (2.03), 325 nm (3.10); Amax (-OH/MeOH) 232, 252 sll, 362 nm. IH n.m.L I) (CDCI.3) . I
1.33, br s, 8H, (H3'h - (H6'h; 1.57-I.7S, m, 4H, (H2'h and (HTh; 2.60, t, J·8.0 Hz, (HI'h and (H8'h; 6.10, s, H3; 6.72, d, J 8.0 Hz, H6; 6.86, d, J 8.0 Hz, H8; 7.16-7.29, m,
5H, H2" - H6"; 7.48-7.SI, m, H7; 12.S7, s, OH (exchangeable with D20). 13C n.m.r. I)
(COCi) 26.8, 29.0,29.2 (2C), 29.3, 31.4. C2' - C7'; 34.3, 36.0, CI' and C8'; 106.9, C8;
108.4, C6; 110.6, C4a; 111.2, C3; 12S.6. C4": 12X3 , C2" and C6"; 128.4, C3" and.CS";
135.1, C7; 142.8, CI"; 156.8, C8a; 160.R. C5: 17U, C2; 183.7, C4. mlz 3S0 (M, 48%),
189 (100), 176 (40), 91 (40).
(ii) lrans-2,3-Oihydro-7 -melhox y-2 -( 3.4-mel hy lenediox yphen yl)-3-melhy 1-S-( I-CE)
propenyl)benzofuran (4), while needles (9.0 mg, 0.O(X)9%) m.p. 95-96°C, [alD +S4.6° (Iit.4
m.p. 92.0-92.SoC, [alD +60.7°; li\.5 m.p. 91-92°C).
Radial chromatography of fraction B (I :4, dichloromethane-elhyl acetate) and
subsequent recrystallization of the major component from dichloromethane-hexane gave 1-(2,6-dihydroxyphenyl)-tetradecan-I-one (2) as pale yellow needles (11.0 mg, 0.0011 %) m.p.
95-98°C 2 9 I-92°C).
61
62
Radial chromatography of fraelioll C (I : I. dichloromelhane-elhyl acelale) and
subsequent recryslallizalion of Ihe major compollenl from dichloromelhane-hexane gave 1-
(2.6-dihydroxyphenyl)-9-phenylnonan-I-one (3) as pale yellow needles (10.0 mg. 0.00 I 0%)
m.p . 79-S2°C (lir).9 SI-S2°C).
Preparalive tl.c . of fraclion D (2:3. dichloromerhane-erhyl ace rare) and subsequenr
recrysLallization of the major components gave Ihe following compounds.
(i) Irans-2.3- Dihydro-7 -merhoxy-2-(3.4-dimelhox yphenyl)-3-merhyl-5-( I-(E)-
propenyl)benzofuran (5). while crysrals (25.0 mg. 0 .0025%) m.p. 115°C. [aID -3.0° (c
0.112. CHCI) (IiI.? m.p. 119.5-120.5°C; litH m.p . III-112°C. [aID -3 .6°) .
(ii) crallS-2.3-Dih ydro-7 -melhoxy-2-( 4-hydroxy-3-melhoxyphen y 1)-3-merhy 1-.5-( 1-
(E)-propenyl)benzofuran (6). colourless cryslals ( 10.5 mg. 0 .00 I 0%) m.p . 136-137°C
(lilI14-1 WC5; 133-134~C7; 133°c9).
Acknowledgments
The aurhors wish ro Ihank Mrs H.E.R. Slellder alld Dr J.J. Brophy for Iheir assislance in
acquiring n.m.T. and mass spec Ira. One of us (S.A.) Ihanks Ihe Univcrsily of rhe Sourh
Pacific for a posrgraduale srudenlship and sludy leave. The suppon of Ihe Nelwork for Ihe
Chemislry of Biologically Imponanl Naluml Prod ucls. an aCli vily of Ihe lnlcrnalional
Developmenl Program of Auslralian Universilies and Colleges. for funds for a research visir
by S.A . 10 the University of New South Wales is gratefully acknowledged ,
(
(
[c
Arylpropanoids
OH 0
6(CH)-Q' I " _
"" OH
(3)
(h)
(')
(5)
,�)
(Sb)
(2)
R' R'
-CII,-Cfl) ell) ell, II
63
OR'
OR'
(Sc)
Arylpropanoids [rom MyriJlica caJtaneifalia A. Gray (�Iyri<licaccae) by Ali, Read and SolhecswOr:ln
