The 13C-NMR chemical shifts of 112 sterols (4-demethyl-, 4-monomethyl-, and 4, 4-dimethylsterols) and triterpene alcohols, most of which are the naturally occurring ones, are listed and a number of methods for signal assignment are explained. The utility of 13C-NMR spectral analysis for the structure elucidation of these compounds is discussed.
Investigation of pyrolysis characteristics of saturated mono-, di- and triglycerides by thermogravimetry (TG) and derivative thermogravimetry (DTG) was conducted. 1) The TG and DTG curves of mono-, di- and triglycerides showed similar patterns when the glyceride groups was the same in all cases. However, different patterns were obtained when a different glyceride group was used in each case. The differences were remarkable at temperatures at which the rate of weight reduction was maximum during pyrolysis under a stream of nitrogen : about 300°C in the case of monoglyceride, and about 420°C in the case of triglyceride. For diglyceride, two maximum rates were observed in the temperature range from 350 to 400°C. 2) The initial or final temperature of the pyrolysis of mono-, di- and triglycerides having the same acyl group increased in the order of monoglyceride, diglyceride and triglyceride. In the pyrolysis of mono- and diglycerides, temperatures at initial and 75% pyrolysis increased with acyl carbon number. However, this tendency was not apparent in pyrolysis of triglyceride.
The extraction of carotenes from crude palm oil pretreated with phosphoric acid carried out using various adsorbents. Adsorption experiments were conducted at 50°C for 1 h using 20.0 g of the oil and 13 g of an adsorbent. Alumina, silica gel, activated clay (abbreviated as clay), alumina gel-clay and silica gel-clay of various mixing ratio (1 : 11 : 4) were used as the adsorbents. Adsorbed carotenes were released by a 20% acetic acid heptane solution at 80°C for 30 min. Carotene content was determined as β-carotene by spectrophotometry. The amount of adsorbed carotene per unit weight of adsorbent was greatest (ca. 3.5 mg/g adsorbent) in the case of clay and became progressively less in the order of silica gel-clay and alumina gel-clay. An increase in the mixing ratio of clay favored carotene adsorption in all cases. No carotene was adsorbed on either alumina or silica gel. In the case of alumina gel-clay, carotene recovery based on the amount of adsorbed carotene increased with decrease in the mixing ratio of clay. The highest value was 41%. In the case of silica gel-clay, no relationship could be detected between carotene recovery and the mixing ratio. Carotene recovery was ca. 7% in all cases. Carotene adsorbed on the clay could not be released under the present experimental conditions. Replacement of heptane with ethanol in the releasing system enhanced the recovery of carotene adsorbed on alumina gel-clay and silica gel-clay but both chloroform and benzene when used instead failed to do so. When acetic acid was substituted by KOH ethanol solution, benzene was effective for recovery of the carotene adsorbed on alumina gel-clay. Modification of the present releasing system did not improve the recovery of carotene adsorbed on the clay. X-ray diffraction patterns of the adsorbents changed according to the adsorption procedure used.
A series of crown ethers (12- to 21-membered) and various alkanoic acids with long hydrocarbon chains were examined as carriers for the active and competitive transport of alkaline earth metal cations (Mg2+, Ca2+, and Ba2+) in a chloroform liquid membrane system. The transport of all cations except Mg2+ was efficiently carried out, on the condition that a mixture of crown ether and alkanoic acid was used. This confirms the cooperative action of these two compounds as carriers. Transport efficiency was found to depend greatly on the structure of alkanoic acid and to a slight extent on the ring size of crown ether. Of the alkanoic acids examined, 2-bromododecanoic acid was the most efficient co-carrier. Unsubstituted alkanoic acids (C8C18) combined with dicyclohexano-18-crown-6 or 21-crown-7 were found to transport Ba2+ exclusively in the competitive system.
Chemical modification of soybean lipoxygenase (LG) by N-acyloxysuccinimides (1) and the enzyme reaction of free linolic acid in a hexane-water biphasic system were studied. Non-modified LG showed no enzyme activity in the Biphasic system due to denaturation of the enzyme. However, modified LG gave enzyme activity in the order of CN=8>6>4>2 [CN : carbon number of the acyl group in (1)]. That is, activity in the biphasic system increased with increasing the additional hydrophobicity of LG by modification. The stability of modified LG in the biphasic system was in the order of CN=2>4>6>8. This may possible be due to conformational change in the enzyme by modification. The products were determined by HPLC and GC-MS.
A study of the effects of the copolymerization ratio and polymerization degree of sodium styrenesulfonate-sodium methacrylate copolymers, P (NaSS-NaMAA), on the removal efficiency and redeposition of Fe2O3 particulate soil in hard water, at pH 10, 30°C, to obtain a phosphate builder substitute was carried out. The ζ-potentials of Fe2O3 particles from soiled nylon fabric in washing liquor were measured by microelectrophoresis to investigate the electric potential effects of the builder on particulate soil removal. Removal efficiency and redeposition of particles were found to be influenced more by electrokinetic phenomena than chelating action under alkaline washing conditions such as dilute concentration of P (NaSS-NaMAA), 50100 ppm water hardness. Thus P (NaSS-NaMAA), a multivalent polyelectrolyte, removes soil primarily through electric and steric barrier effects. The polymerization degree of P (NaSS-NaMAA) noted to be a more important factor than the copolymerization ratio. The optimum P (Nass-MaAA) having the copolymerization ratio of 3 : 7, and a molecular weight of 1.5×104, showed a builder effects far superior to STP in solution containing a surfactant such as DBS or APE.
A study was made of lipase-catalyzed transesterification between tri-n-butyrin (1) and aliphatic primary alcohols (2) (ROH : R=C6H13C11H23) in substrates to give the corresponding n-alkyl butyrates. Six out of thirteen lipases (C.c. : Candida cylindracea, P.f. : Pseudomonas fluorescens P.s. : Pseudomonas sp., P.c. : Penicillium cyclopium, P.r. : Penicillium requeforti and P.p. : Porcine pancreas) showed good reactivity. The addition of water increased and optimum rates were observed at 1.0, 0.8 and 0.4 vol% of water added for C.c., P.f. and P.s., P.p., and P.c. and P.r., respectively [in (1) containing 2 M (2), lipase=20 mg/mL-sub]. The lipases were classified into three types according to the manner in which they were affected by water. The reactivity of (2) was confirmed by the lipases, i.e., C8C10 and C9 alcohols gave maximum rates for C.c., P.f. and P.s., respectively. No significant change in rate could be detected for P.c., P.r., or P.p. lipase. Optimum rates were observed at 90, 60, 50 and 30 for P.f. and P.s., P.p., and P.c., C.c., and P.r. lipases, respectively. The addition of butyric acid caused no significant change in the rates. The thermal stability of Pseudomonas lipase in (1) was also examined.
This paper describes the synthesis of pheromones and jasmonoids from acrylaldehyde diethyl acetal (1). The synthetic route is shown in Scheme-1. The radical addition reaction of aldehyde with (1) was carried out with benzoyl peroxide as the initiator in N2 atomosphere. γ-Oxoaldehyde acetal [(6), (7), (8), (9)] was obtained as the major product by this reaction. cis-12-Nonadecen-9-one (14) was synthesized from 1, 1-diethoxy-4-oxododecanal (11) prepared from (7), by Wittig reaction in 62% yield. Similarly, cis-13-icosen-1O-one (15) and cis-5-undecen-2-one (16) were prepared from γ-oxoaldehyde in 6062% yield. Methyl jasmonate (18) and cis-jasmone (19) were synthesized from 2- (cis-2-pentenyl) -2-cyclopentenone (17) prepared from 4-oxo-cis-7-decenal (10), according to the published method. γ-Jasmolactone (21) was prepared from 1, 1-diethoxy-cis-7-decen-4-ol (20) by Jones oxidation in 88% yield.