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Ayurveda (the science of life) is one of the branches of Vedas. It is regarded as upaveda of Atharva Veda. It is a steam of knowledge coming down from generation to generation since eternity parallel to Vedic literature which is why its emergence has been said to be from the creator (Brahman) himself prior to the creation. It is taken as eternal because nobody knows when it was not there. In Ayurveda, food is considered to affect the mind as well as the body. By understanding how to prepare foods best suited to our minds and bodies, we can utilize nutrition as a source of healing. Food is the most essential to sustain a good life and the same food if consumed inappropriately becomes the root cause of many diseases. So, proper knowledge about food and its importance should be known by all human beings to have better benefits from it.

A key intermediate, S-(−)-3-benzoylthio-2-methylpropanoic acid (1) was made in high optical purity by the lipase-catalyzed stereoselective esterification of racemic 1 with methanol in an organic solvent system. Among various lipases evaluated, Amano P-30 lipase from Pseudomonas sp. efficiently catalyzed the esterification of 1 to yield R-(+) methyl ester and unreacted S-(−) 1. A reaction yield of 40 mol% and an optical purity of 97.2% were obtained for compound 1 at a substrate concentration of 0.1 m (22 mg/ml). Lipase P-30 was immobilized on Accurel polypropylene (PP) and the immobilized enzyme was reused (23 cycles) in the esterification reaction without loss of enzyme acitivity, productivity or optical purity. Among various solvents evaluated, toluene was found to be the most suitable organic solvent and methanol was the best alcohol for the esterification of racemic 1 by immobilized lipase. Substrate concentrations as high as 1.0 m were used in the esterification reaction. When the temperature was increased from 28° C to 60° C, the reaction time required for the esterification of 0.1 m substrate decreased from 16 h to 2 h. On increasing the methanol to substrate molar ratio from 1:1 to 4:1, the rate of esterification decreased. A lipase fermentation using Pseudomonas sp. ATCC 21 808 was developed. In the batch-fermentation process, 56 units/ml of extracellular lipase activity was obtained. A fed-batch process using soybean oil gave a significant increase in the lipase activity (126 units/ml). Crude lipase recovered from the filtrate by ethanol precipitation and immobilized on Accurel PP was also effective: S-(−) compound 1 was obtained in 35 mol% yield and 95% optical purity.

Several microbial cultures were screened for the ability to catalyse the reduction of N-(4-(1-oxo-2-chloroacetyl ethyl) phenyl methane sulfonamide (1). The chiral intermediate (+)N-(4-(1-hydroxy-2-chloroethyl) phenyl methane sulfonamide (2) was prepared by the stereoselective microbial reduction of the parent ketone 1. Compound 2 is a potential chiral intermediate for synthesis of 4-(2-isopropylamino-1-hydroxyethyl) phenyl methanesulfonanilide (d-sotalol), a beta-receptor antagonist. Microorganisms from the genera Rhodococcus, Nocardia, and Hansenula reduced 1 to 2. A reaction yield of >50% and optical purities of >90% were obtained. The best strain (H.polymorpha ATCC 26012) effectively reduced compound 1 to compound 2 in 95% reaction yield and 99% optical purity. Compound 2 (8.2 g) was isolated from a 3-1 preparative batch in 68% overall yield. Isolated compound 2 had a specific rotation of +20° (CH2Cl2, C-1), an optical purity of 99.5%, and a chemical purity of 97% as analyzed by gas chromatography and HPLC. The nuclear magnetic resonance and mass spectra of compound 2 prepared by bioreduction and a standard chemical sample of 2 were virtually identical. Cell extracts of H. polymorpha in the presence of glucose dehydrogenase, glucose and nicotinamide adenine dinucleotide (NAD +) catalyzed the reduction of 1 to 2 with 98% reaction yield and resulted in an optical purity of 99.4%.

A chiral compound [4R-[4α,6s(E)]]-6-[4,4-bis(4-fluorophenyl)-3-(1-methyl-1H-tetrazol-5-yl)-1,3-butadienyl]-tetrahydro-4-hydroxy-2H-pyran-2-one (R-(+)-1) was prepared by the lipase-catalysed stereoselective acetylation of racemic 1 in an organic solvent. Chiral R-(+)-1 is a hydroxymethyl glutaryl coenzyme A (HMG CoA) reductase inhibitor and a potential anticholesterol drug candidate. Among various lipases evaluated, lipase PS-30 from Pseudomonas species efficiently catalysed acetylation of the undesired enantiomer of racemic 1 to yield the S-(−)-acetylated product 2 and unreacted desired R-(+)-1. A reaction yield of 48 mol% and an optical purity of 98% were obtained for R-(+)-1 when the reaction was conducted in toluence as solvent in the presence of isopropenyl acetate as acyl donor. Lipase PS-30 was immobilized on Accurel polypropylene (PP) and the immobilized enzyme was reused (five cycles) in the acetylation reaction without loss of enzyme activity, productivity, or optical purity of the R-(+)-1. The enzymatic acetylation process was scaled-up to 501 and a 640-l volume (preparative batches) at a substrate concentration of 4 g/l. R-(+)–1 was recovered from the preparative batches in 68–71% recovery yield with 98.5% gas chromatography homogeneity index and 98.5% optical purity. The S-(−) acetate 2 produced by the acetylation reaction was enzymatically hydrolysed by lipase PS-30 in a biphasic system to prepare the corresponding S-(−)-1.

A key chiral intermediate lactol(3)[3aS (3aα,4α,7α,7aα)]-hexahydro-4,7-epoxy-isobenzofuran-1 (3H)-one was prepared for the total synthesis of a new thromboxane antagonist. The stereoselective hydrolysis of (exo,exo)-7-oxabicyclo[2.2.1]heptane-2,3-dimethanol, diacetate ester (1) to the corresponding chiral monoacetate ester (2) was carried out with lipases, among which Amano P-30 lipase from Pseudomonas sp. was most effective since it gave the desired enantiomer of monoacetate ester. A yield of 75 mol% and optical purity of >99% was obtained when the reaction was conducted in a biphasic system with 10% toluene at 5 g/l of the substrate. Lipase P-30 was immobilized on Accurel polypropylene (PP) and the immobilized enzyme was reused (five cycles) without loss of enzyme activity, productivity or optical purity. The reaction process was scaled-up to 80 1 (400 g substrate) and monoacetate (2) was isolated in 80 mol% yield with 99.3% optical purity as determined by chiral HPLC and nuclear magnetic resonance (NMR) analysis. A gas chromatography of 99.5% and specific rotation, [α]D of -7.6° was obtained. The chiral monoacetate ester (2) was oxidized to its corresponding aldehyde and subsequently hydrolyzed to give lactol (3).

A key intermediate (S(−) 2-cyclohexyl-1,3-propanediol monoacetate) was made with high optical purity for the total synthesis of a new angiotensin converting enzyme inhibitor, Fosinopril. The stereoselective hydrolysis of 2-cyclohexyl-1,3-propanediol diacetate (I) and 2-phenyl-1,3-propanediol diacetate (II) was carried out with lipases. Among various lipases evaluated, only porcine pancreatic lipase (PPL) and Chromobacterium viscosum lipase demonstrated efficient conversion and gave the desired enantiomer of monoacetate. In aqueous solution, the desired S(−) monoacetate exhibited an optical purity of 65%–80% (30%–60% enantiomeric excess [e.e.]). However, when the same reactions were conducted in a biphasic system, the product S(−) monoacetate exhibited an optical purity of 99%–100% (98%–100% e.e.). The high purity product was achieved with 65 mol% yield at 1% substrate concentration. Among various solvents evaluated in biphasic systems, efficient hydrolysis was achieved in toluene, cyclohexane, and trichloro-trifluoroethane. The crude PPL was partially purified and two lipase fractions (A and B) were identified. Lipases A and B had a molecular mass of 38 000 and 40 000 daltons, respectively, and both were found to catalyze the hydrolysis of I and II to the appropriate monoacetate in a biphasic system.

The reactions of niobium and tantalum pentaethoxides withtrans-cinnamic acid (HCA) and dihydrocinnamic acid (HDCA) were carried out in different stoichiometric ratios. The complexes of the type M(OEt)5−n(CA)n and M(OEt)5−n(DCA)n, (n=1, 2 or 3 and M=Nb or Ta) were obtained.

The synthesis and characterization of the complexes from the reactions of trichloro(cyclopentadienyl)titanium(IV) with 1,5-diarylthiocarbazones (aryl=phenyl,o-tolyl,o-chlorophenyl,p-tolyl,p-chlorophenyl, or 3,5-dimethylphenyl) are reported. They are of the types CpTi(HDz)Cl2 and CpTi(HDz)2Cl (Cp=cyclopentadienyl, HDz−=the mono-anion of a 1,5-diarylthiocarbazone, H2Dz). The compounds are nonelectrolytes in dimethylformamide (DMF). In solid state, the far i.r. spectra of CpTi(HDz)Cl2 indicate the complexes to be dimeric, involving Cl-bridges.

Reactions of Aluminium isopropoxide with monofunctional bidentateSchiff bases, such as salicylidene-o-toluidine, salicylidene-p-toluidine, 2-hydroxy-1-naphthylmethylidene-p-toluidine and 2-hydroxy-1-naphthylmethylidene-p-toluidine in different stoichiometric ratios have yielded products of the type Al(OPr i)2(SB), Al(OPr i)(SB)2, and Al(SB)3 (whereSB − is the anion of the correspondingSchiff base,SBH). Bifunctional tetradentateSchiff bases in 1∶1 and 2∶3 molar ratios [Al(OPr i)3:SBH2] yielded insoluble derivatives of the type Al(OPr i)SB and Al2(SB)3 (whereSB − represents the anion of theSchiff baseSBH2 andSBH2=bis-salicylaldehyde-o-phenylene-diamine or bis-salicylaldehyde-p-phenylenediamine). The newSchiff base derivatives have been characterized by elemental analyses, infrared spectroscopy and molecular weight determinations.

Procedures for the purification of an aldehyde dehydrogenase from extracts of the obligate methylotroph, Methylomonas methylovora are described. The purified enzyme is homogeneous as judged from polyacrylamide gel electrophoresis. In the presence of an artificial electron acceptor (phenazine methosulfate), the purified enzyme catalyzes the oxidation of straight chain aldehydes (C1--C10 tested), aromatic aldehydes (benzaldehyde, salicylaldehyde), glyoxylate, and glyceraldehyde. Biological electron acceptors such as NAD+, NADP+, FAD, FMN, pyridoxal phosphate, and cytochrome c cannot act as electron carriers. The activity of the enzyme is inhibited by sulfhydryl agents [p-chloromercuribenzoate, N-ethylmaleimide and 5,5-dithiobis (2-nitrobenzoic acid)], cuprous chloride, and ferrour nitrate. The molecular weight of the enzyme as estimated by gel filtration is approximately 45000 and the subunit size determined by sodium dodecyl sulfate-gel electrophoresis is approximately 23000. The purified enzyme is light brown and has an absorption peak at 410 nm. Reduction of enzyme with sodium dithionite or aldehyde substrate resulted in the appearance of peaks at 523 nm and 552nm. These results suggest that the enzyme is a hemoprotein. There was no evidence that flavins were present as prosthetic group. The amino acid composition of the enzyme is also presented.

Niobium(V) and tantalum(V) pentaethoxides react with monofunctional benzoyl hydrazones (BHy) in refluxing benzene to give products of the type, M(OEt)5−n(BHy)n (where M=Nb or Ta and n=1, 2 or 3). The complexes have been characterised on the basis of elemental analysis, spectral (i.r. and n.m.r.) and molecular weight data.

Dichlorobis(cyclopentadienyl)titanium(IV), Cp2TiCI2, reacts with bidentate Schiff bases such as salicylideneaniline, salicylidene-o-toluidine, salicylidene-m-toluidine, salicylidene-p-toluidine and 2-hydroxy-l-naphthyl

Zirconium(IV)Schiff base derivatives have been synthesised by reacting zirconium isopropoxide with monofunctional bidentateSchiff bases in different stoichiometric ratios. The resulting derivatives of the type Zr(O-Isopr)3(SB) and Zr(O-Isopr)2(SB)2, whereSB− is the anion of the correspondingSchiff baseSBH, have been isolated in almost quantitative yields. Their molecular weights have been determined ebullioscopically and their ir spectra recorded.

Oximate complexes of bis(cyclopentadienyl)zirconium(IV) chloride (Cp2ZrCl2 ) having the general formulae Cp2Zr(Ox), Cp2Zr(OxH)Cl and Cp2Zr(OxH)2 [where OxH2 = RC6H4C(OH)R′: NOH, R = H, Me, R′= H, Me, Et, n-Pr; PhC: N(OH)CH(OH)Ph and R″C : N(OH)N(OH): CR″, R″ = H, Me and Ph] have been synthesized by reacting bis(cyclopentadienyl)zirconium(IV) chloride with the appropriate oxime in tetrahydrofuran in the presence of triethylamine at room temperature. The complexes have been characterized by their elemental analysis, i.r. and electronic spectra, molecular weight determination, electrical conductance and magnetic measurements.

Reactions of niobium and tantalum pentaethoxides with ethyl-1-hydroxycyclohexylacetate (HECA), ethyl 2-hydroxy-2-arylpropionate (HEAP) and ethyl 2-hydroxy-2-aryl butyrate (HEAB) lead to compounds of the type [M(OEt)5−n(L)n] (where M=Nb or Ta; n=1, 2 or 3; and L=HECA, HEAP or HEAB). These were characterised by elemental analysis, molecular weight determinations and i.r. and n.m.r. spectral studies. Alcoholysis reactions witht-butanol were also carried out.

Reactions of titanium(IV) isopropoxide with ethyl 1-hydroxycyclohexylacetate, ethyl 2-hydroxy-2-arylpropionate, ethyl 2-hydroxy-2-arylbutyrate and ethyl 2-hydroxy-2-arylhydrocinnamate have been studied in dry benzene in different molar ratios under strictly anhydrous conditions. The Ti(OPr-i)4-nLn type compounds, where L = hydroxy ester and n = 1 to 4, have been isolated and characterised by elemental analysis, molecular weight, i.r. and n.m.r. spectral studies. These products may be distilled unchanged under reduced pressure.

Uranyl(VI) complexes of malonic acid dihydrazide (MDH2) and phthalic acid dihydrazide (PDH2) and the products of their reactions with four β-diketones have been characterised by elemental analysis and by electrical conductance, and spectral (i.r. and electronic) measurements. The MDH2 and PDH2 complexes UO2(L)2(H2O)2 are eight coordinate whereas the macrocyclic UO2(L′)(H2O)2 complexes are six coordinate. In each complex MDH2 and PDH2 act as bidentate liglands having the coordination sites at secondary amide-nitrogen atoms.

The reactions of tetra(isopropoxy)hafniumiso-propanol, Hf(OPri)4 · PriOH with monofunctional bidentate (MH) and bifunctional tridentate (BH2) benzoyl hydrazones (derived from the condensation of benzoyl hydrazine with aldehydes/ ketones) in different molar ratios have been carried out in refluxing benzene. Products of the type, Hf(OPri)4−n(M)n and Hf(OPri)4−2n(B)n (where n=1 to 4) were obtained and characterized on the basis of elemental analyses, electrical conductance measurements, and spectral (infrared, electronic and1H n.m.r.) data.

The synthesis and characterization of the complexes from the reactions of mono(cyclopentadienyl)titanium(IV) chloride (CpTiCl3) with Schiff bases. (obtained by the condensation of aldehyde/ketone withS-methyldithiocarbazate, ) are reported. They are of the type: CpTiCl2(SB). CpTiCl(SB)2 and CpTiCl(SB′) (where [SB]− and [SB′]2− are the anions of the monobasic (SBH) and dibasic (SB′H2) Schiff bases, respectively). The compounds are nonelectrolytes in dimethylformamide. The presence of the cyclopentadienyl group was confirmed from infrared and proton magnetic resonance spectra.

Dichlorobis(methylcyclopentadienyl)titanium(IV) reacts with 1,5-diarylthiocarbazones (aryl=phenyl,p-tolyl,o-chlorophenyl orp-chlorophenyl) in 1∶1 and 1∶2 molar ratios in tetrahydrofuran in the presence of triethylamine, to yield [(MeCp)2Ti(HDz)Cl], [(MeCp)2Ti(Dz)] and [(MeCp)2-Ti(HDz)2] (MeCp=methylcyclopentadienyl; HDz− and Dz2− are the mono- and di-anions of a 1,5-diarylthiocarbazone, H2Dz).S-Methyl-1,5-diphenylthiocarbazone and [(MeCp)2TiCl2] react to give [(MeCp)2Ti(MeDz)Cl] and [(MeCp)2Ti(MeDz)2] (MeDz− represents the mono-anion ofS-methyl-1,5-diphenylthiocarbazone, HMeDz) in an excess of triethylamine. These new derivatives have been characterised on the basis of elemental analyses, magnetic moment, electrical conductance, i.r.,1H n.m.r. and electronic spectral studies.