The most important category of fatty nonionic surfactants are synthesized by the oxyalkylation Synthesis and evaluation of some surface active agents from long chain fatty amine

This study continues our series of synthesis of surface active agents containing heterocyclic moiety. NHeptadecanoyl- 3-(4-oxo-4H-benzo[d][1,3]oxazin-2-yl)- acrylamide (4) was used as a new starting material to synthesize propenoxylated nonionic surface active agents having heterocycles such as (thiazole, triazole, benzoxazine, quinazoline, triazine, and oxazine). The structures of the prepared compounds were elucidated by using spectroscopic tools (IR, 1H NMR and Mass spectroscopy). Physical properties such as surface and interfacial tension, cloud point, foaming height, wetting time, emulsification power and critical micelle concentration (CMC) were determined. Antimicrobial and biodegradability properties were also screened. It was found that the produced novel groups of nonionic surface active agents have pronounced surface properties and good antimicrobial activities.


INTRODUCTION
The most important category of fatty nonionic surfactants are synthesized by the oxyalkylation

Synthesis and evaluation of some surface active agents from long chain fatty amine
By A.M. F. Eissa Chemistry Department, Faculty of Science, Benha University, Egypt.ref_at@hotmail.com(with ethylene oxide and propylene oxide) of organic compounds containing active hydrogen in the presence of a base (Sallary, et al., 1997), acid as well as untraditional catalysts (Pegiadou, et al., 2001).These compounds fulfill the following requirements: a-Presence of long chain hydrocarbon (C 12 -C 18 ) that acts as amphiphilic part.b-Presence of active hydrogen atoms (NH, NH 2 , SH, OH and COOH) in the molecule which are able to propyloxylate (Amin, et al., 2004;Lagerman, et al., 1994) to produce the hydrophobic part in a correct hydrophilichydrophobic balance (Pegiadou, et al., 2000) It has recently been reported that surfactants containing heterocyclic moiety have bactericidal and antifungal activities as well as industrial importance (Amin, et al., 2004;Yassin, et al., 1994).2-Substituted benzoxazolinone as well as their corresponding quinazoline derivatives have been reported to exhibit biological activities such as antipyretic, antiinflammatory, anticancer and antimitotic agents (Wasfy, et al.,1995).
Herien, as a part of our program (Eissa et al., 2006;Amin, et al., 2004;Amin, et al., 2003;Eissa, 2006) on the synthesis and characterization of different types of surface active agents, this manuscript describes the synthesis of a novel group of nonionic surface active agents containing heterocyclic moieties from low cost fatty amine (heptadecylamine)

MATERIALS AND METHODS
Melting points are uncorrected.IR spectra in KBr were measured on a Pye-Uncam SP-1000 infrared spectrophotometer on a KBr disk or nujol.The 1 H NMR spectra were obtained on a Varian EM-390-60 MHz spectrometer in DMSO as the solvent.Tetramethylsilane TMS served as an internal reference and chemical shifts are expressed as d (ppm).Mass spectra were recorded on a GC/MS Finning-MAT.Microanalyses were preformed by the Micro analytical Unit at Cairo University.All the compounds gave satisfactory elemental analyses.Thin layer chromatography (TLC) was carried out on silica gel (MN-Kieselgel G., 0.2 mm thickness) and the plates were scanned under 254 nm ultraviolet light.Antimicrobial and antifungal activity tests were carried out by the microbiology Lab., Faculty of Science, Benha University, Egypt.

General procedure for preparation of Schiff bases 8a,b
A mixture of 4 (0.01 mole) and the corresponding aldehydes (0.01 mole) in ethanol (25 ml) was treated with concentrated HCl (0.5 ml) and refluxed for 2 h.The reaction mixture after cooling was filtered and recrystallized from ethanol to give 8a and 8b.

General procedure for preparation of 9a,b
Thioglycillic acid (0.01 mol) was added to a solution of Schiff base 8a,b (0.01 mol) in dry acetone .The reaction mixture was refluxed for 3 h.A solid product was obtained after cooling to give the adduct 9a and 9b which was crystallized from ethanol.

Conversion of the prepared compounds (4, 16) to nonionic surfactants (17a-c -31a-c)
They were prepared by the addition of n moles of propylene oxide (n = 5, 10, 15) to one mol of suitable product using KOH as catalyst.A completed description of the procedure is given in (Morgos, et al., 1983).The amount of propylene oxide which was reacted and the average degree of propenoxylation were determined through the increment in mass of the reaction mixture (increase in weight of the mixture after the addition of propylene oxide is the average amount of propenoxylation) and also, by the 1 H NMR protons and these products were confirmed by spectroscopic methods.The addition of propylene oxide gave a mixture of propenoxylated products whose structures were confirmed by IR and 1 H NMR spectra.IR spectra showed two broad bands at 1100 and 950 cm -1 characteristic for C-O-C ether linkage of polypropenoxy chain and 1 H NMR spectra showed the protons of propenoxy groups ␦= 3.2-3.7 (m, -CH 2 CH(CH 3 )-O)-.

Determination of the performance properties.
Surface and interfacial tension were measured with a Du-Nouy tensiometer (Findly, 1963) (Kruss, Type 8451) using aqueous solution of surfactants (0.1 wt %) at room temperature (25 o C) Cloud point was determined by gradually heating a surfactant solution (1.0 wt %) in a temperature controlled bath, and recording the temperature at which the clear, or nearly clear solutions become definitely turbid.The reproducibility of this temperature was checked by cooling the solutions until they become clear again (Wiel, et al., 1963).
Wetting time was determined by immersing a sample of cotton fabric in 1.0 wt % aqueous solution of surfactants (Draves, et al., 1931) Foaming properties were measured according to (El-Sukkary, et al., 1987).In this procedure a 25 ml solution (1.0 wt %) was shaken vigorously for 10 seconds in a 100 ml graduated cylinder with a glass stopper at 25 °C.The solution was allowed to stand for 30 seconds, and then, the foam height was measured.
Emulsification stability was prepared from 10 ml of a 20 mmol.aqueous solution of surfactant and 5 ml of toluene at 40 °C.Emulsion stability was determined as the time which took 9 ml of the aqueous layer to separate from the emulsion counting from the cession of shaking (Takeshi, H, 1970).

Biodegradability
Biodegradability was evaluated by surface tension measurements which were taken each day, on each sample during the degradation test.

Biological activity
The antimicrobial activities of the synthesized surfactants were determined in vitro using the hole plate and filter paper disc method (Rosen, 1989).Compounds were dissolved in 10% acetone at different concentrations (125, 250, 500 µg/ml).Agar plates were inoculated uniformly from fresh broth culture of Gram +ve, Gram -ve bacteria and fungi.The disks were incubated at 28 °C for 24 h, and the formed inhibition zones were measured in mm.
Reaction of 4 was used as target compound for the synthesis of different types of condensed and noncondensed heterocyclic compounds (c.f.Scheme 2).

Conversion of the prepared compounds (4-16) to nonionic surfactants (17a-c-30a-c)
Generally, for compounds acting as nonionic surface active agents two requirments are needed.The first one is that the hydrogen containing group present should be active enough to react with alkylene oxide and the second is that the molecular weight should be suitable to become an amphiphilic molecule with the suitable hydrophilic-lipophilic balance (Wasfy, et al., 1996).Reaction of all synthesized compounds (4-16) with different moles (n) of propylene oxide (where n = 5, 10, 15) in the presence of KOH as catalyst gave the corresponding propenoxylated products (17a-c to 31a-c), respectively.The reaction conditions are illustrated in Table 1.Scheme 3 shows the propenoxylation of compounds 5 and 6 as examples.

Surface active properties
The study of the surface active properties of the oxypropylated compounds has been done in an aqueous solution (1wt %, pH = 7) at 25 °C.The results are listed in Table 2.

Surface and interfacial tension
The surface and interfacial tension of the prepared compounds are shown in Table 2.It can be observed that the new nonionic surfactants have pronounced surface activity.In general, the surface and interfacial tensions increase with an increasing molecular weight of the hydrophilic moiety (Eissa et al., 2003).The data given in Table 2 shows that the values of surface and interfacial tension are increased with the increasing number of propylene oxide units added to the molecule.

Cloud point
A very important factor in making the most efficient use of nonionic surfactants in an aqueous system, at different temperatures, is a property known as cloud point.The data shows that the cloud points increased with an increasing number of propenoxy groups per hydrophobic molecule.The cloud points of the prepared surfactants were recorded in Table 2 and reflect the fact that it can be used over a wide range of temperatures.

Wetting time
All the prepared compounds showed a decrease in wetting time with an increase in the number of propylene oxide units in the molecule.The products are thus very effective as wetting agents and they can find a wide application in house hold detergents (Eissa, 1995).A; Antimicrobial activity of tested compounds; the width of the zone of inhibition indicates the potency of antimicrobial activity, (-) no antimicrobial activity, (+) weak activity with diameter equal to (0.5-0.7cm), (++) moderate activity with the diameter zone equal to (1.0-1.2cm),(+++) marked activity with the diameter zone equal to (1.6-1.8cm).MIC; Minimum inhibition concentration in µg/ml.
increases with an increase in the propylene oxide units per molecule of surfactant.The low foaming power could have an application in dyeing auxiliary industry (Somaya, et al., 1998).

Emulsion stability
Studies are still being carried out on the utilization of surfactants in emulsions formulation which are of immense importance for technological development.It was proved that the prepared surfactants exhibit good emulsifying properties.Emulsion stability increases with a decrease in the number of propylene oxide units.The results recorded that all synthesized nonionic compounds exhibit good emulsification time and these results might lead to the application of the surfactants of choice in the formulation of pesticides and cosmetics .

Biodegradability
The trend of degradation in river die-away tests was followed by the surface tension measurements.The results are given in Table 3.The rate of degradation of these compounds depended on the size of the molecule; a bulky molecule diffuses difficulty through the cell membrane, and its degradation is more difficult.This means that molecules with a low proportion of propylene oxide are more degradable than those containing a higher proportion.

Biological activity
As show in Table 4 most of the synthesized surfactants have remarkable antimicrobial activity towards the selected bacteria and fungi.The presence of heterocyclic moiety in the prepared nonionic surfactant molecule revealed an increase in the biological activity.It is therefore clear that these surfactants were effective and inhibited the growth of all tested microorganisms.

CONCLUSION
It can be concluded that all the prepared nonionic surfactants which containing heterocyclic moieties have a double functions as antimicrobial and surface active agents with good emulsifying and wetting properties.They can have applications in the non edible media such as insecticides, pesticides, drugs, cosmetics and house hold detergents.

AKNOWLDGMENTS
Origin of cultures: Botany Department, Faculty of Science, Benha University, Egypt.

-16 were
propenoxylated at any active hydrogen (OH, NH, SH, NH 2 and COOH) to give products from

17a-c to 31a-c, respectively
.SYNTHESIS AND EVALUATION OF SOME SURFACE ACTIVE AGENTS FROM LONG CHAIN FATTY AMINE

Table 2 Surface properties of nonionic compounds.
a) Error was: surface and interfacial tensions = ± 0.1 dynes/cm; cloud point = ± 1 o C; foam height = ± 2 mm; wetting time = ± 1 sec; emulsion = ± 1 min b) n in the number of propylene oxide added to the chosen compound SYNTHESIS AND EVALUATION OF SOME SURFACE ACTIVE AGENTS FROM LONG CHAIN FATTY AMINE