Lakshman Nilantha

Lakshman Nilantha
University of Ruhuna · Department of Food Science and Technology

BSc-Agri (Ruhuna-Sri Lanka) MSc(Peradeniya-Sri Lanka) MSc (Ryukyus-Japan) PhD (Kagoshima-Japan)

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197
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Introduction
Food chemistry, Bio Chemistry, Enzymes, structures of bio compounds, Product development technology, Biotechnology

Publications

Publications (197)
Article
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In the title compound, C21H17N3O2, the triazole ring system is inclined at dihedral angles of 4.14 (18) and 69.24 (11)° with the naphthalene ring system and phenyl ring, respectively. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds into double columns propagating along the b-axis direction.
Article
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The asymmetric unit of the title compound, C34H28ClN3O3S, contains two independent mol­ecules (A and B). They differ essentially in the orientation of the 4-meth­oxy­phenyl ring with respect to the pyridine ring of the quinoline moiety; this dihedral angle is 37.01 (18)° in mol­ecule A but only 7.06 (17)° in mol­ecule B. In both mol­ecules, the cyc...
Article
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In the title di­spiro compound, C32H26ClN3O2, the cyclo­hexa­none ring of the iso­quinoline unit has a distorted envelope conformation, with the methyl­ene C atom adjacent to the spiro C atom as the flap. The central 1-methyl­pyrrolidine ring has an envelope conformation with the N atom as the flap. The mean planes of the indolin-2-one ring system,...
Article
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The schemes and chemical names are corrected in three related papers: Vishnupriya, Suresh, Bharkavi et al. [Acta Cryst. (2014), E70, o968–o969], Vishnupriya, Suresh, Gunasekaran et al. [Acta Cryst. (2014), E70, o978], and Vishnupriya, Suresh, Sakthi et al. [Acta Cryst. (2014), E70, o1120–o1121].
Article
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In the title compound C22H18BrN3, the cyclo­pentane ring adopts an envelope conformation with the central methyl­ene C atom as the flap. The dihedral angles between the central pyridine ring and the pendant benzyl and and bromo­benzene rings are 82.65 (1) and 47.23 (1)°, respectively. In the crystal, inversion dimers linked by pairs of N—H⋯Nn (n =...
Article
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The title compound, C23H21N3, comprises a 2-amino-3-cyano­pyridine ring fused with a cyclo­pentane ring. The later adopts an envelope conformation with the central methyl­ene C atom as the flap. The benzyl and and p-tolyl rings are inclined to one another by 56.18 (15)°, and to the pyridine ring by 81.87 (14) and 47.60 (11)°, respectively. In the c...
Article
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In the title compound, C30H27ClN4O, the central pyrrolidine ring adopts an envelope conformation with the methyl­ene C atom being the flap. The quinoxaline and indane rings are each essentially planar, with r.m.s. deviations of 0.027 (1) and 0.0417 (1) Å, respectively. The pyrrolidine ring forms dihedral angles of 88.25 (1) and 83.76 (1)° with the...
Article
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In the title compounds, C24H22BrN3, (I), and C24H22ClN3, (II), the 2-amino­pyridine ring is fused with a cyclo­heptane ring, which adopts a half-chair conformation. The planes of the phenyl and benzene rings are inclined to that of the central pyridine ring [r.m.s. deviations = 0.0083 (1) and 0.0093 (1) Å for (I) and (II), respectively] by 62.47 (1...
Article
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The title compound, C25H25N3O, comprises a 2-amino­pyridine ring fused with a cyclo­heptane ring, which adopts a chair conformation. The central pyridine ring (r.m.s. deviation = 0.013 Å) carries three substituents, viz. a benzyl­amino group, a meth­oxy­phenyl ring and a carbo­nitrile group. The N atom of the carbo­nitrile group is significantly di...
Article
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In the title compound, C25H23Cl2N3, the cyclo­octene ring adopts a twist chair–chair conformation. The dihedral angles between the central pyridine ring (r.m.s. deviation = 0.013 Å) and the pendant chloro­benzene and benzyl rings are 78.07 (11) and 87.47 (12)°, respectively. No directional inter­actions could be identified in the crystal and the pa...
Article
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The mol­ecules of the two isotypic title compounds, C25H24BrN3, (I), and C25H24FN3, (II), comprise a 2-imino­pyridine ring fused with a cyclo­octane ring. In (I), the cyclo­octane ring adopts a twisted chair–chair conformation, while in (II), this ring adopts a twisted boat–chair conformation. The dihedral angles between the planes of the pyridine...
Article
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In the title compound, C27H19N3O, the dihedral angles between the plane of the pyridine ring and those of the indole (r.m.s. deviation = 0.018 Å), phenyl and meth­oxy­benzene substituents are 33.60 (6), 25.28 (7) and 49.31 (7)°, respectively. The N atom of the carbo­nitrile group is significantly displaced [0.288 (2) Å] from the plane of the pyridi...
Article
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The title compound, C25H24ClN3, comprises a 2-imino­pyridine ring fused with a cyclo­octane ring, which adopts a twist boat–chair conformation. In the crystal, C—H⋯N inter­actions form R2²(14) ring motifs and mol­ecules are further connected by weak C—H⋯π inter­actions. The resulting supra­molecular structure is a two-dimensional framework parallel...
Article
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The asymmetric unit of the title compound, C21H15Cl2N5O4, contains two independent mol­ecules (A and B) having similar conformations. The amine (NH2) group forms an intra­molecular hydrogen bond with the benzoyl group, giving an S(6) ring motif in both mol­ecules. The central six-membered rings adopt sofa conformations and the imidazole rings are p...
Article
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In the title compound, C26H16ClN3, the dihedral angles between the central pyridine ring and the pendant phenyl, chloro­benzene and indole rings are 18.52 (12), 48.97 (11) and 21.20 (10)°, respectively. An intra­molecular C—H⋯Nc (c = cyanide) hydrogen bond occurs. In the crystal, inversion dimers linked by pairs of N—H⋯Nc hydrogen bonds generate R2...
Article
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In the title compound, C24H14BrN3S, the dihedral angles between the planes of the pyridine ring and the pendant thio­phene ring, the indole ring system (r.m.s. deviation = 0.022 Å) and the bromo­benzene ring are 9.37 (17), 21.90 (12) and 69.01 (15)°, respectively. The approximate coplanarity of the central ring and the indole ring system is support...
Article
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In the title compound, C19H19FN2O, the cyclo­octene ring adopts a twisted boat–chair conformation. The dihedral angle between the plane of the fluorophenyl substituent and that of the pyridine ring is 76.39 (8)°. The F and ortho-H atoms of the fluoro­benzene ring are disordered, with occupancy factors of 0.226 (5) and 0.774 (5). In the crystal, no...
Article
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In the title compound, C22H18BrN5O4, the central six-membered ring, derived from 1,4-di­hydro­pyridine, adopts a distorted boat conformation with a puckering amplitude of 0.197 (3) Å, the imidazole ring adopts a twisted conformation with a puckering amplitude of 0.113 (3) Å, and the oxindole moiety is planar with an r.m.s. deviation of 0.0125 Å. Tw...
Article
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In the title compound, C20H22N2O2, the central pyridine ring forms a dihedral angle of 76.32 (8)° with the pseudo-axial benzene ring. The cyclo­octane ring adopts a twisted boat chair conformation. In the crystal, weak inter­molecular C—H⋯π inter­actions between inversion-related mol­ecules result in the formation of linear double chains along the...
Article
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In the title compound C21H17N5O4·C2H6OS, the central six-membered ring derived from 1,4-di­hydro­pyridine adopts a distorted boat conformation with a small puckering amplitude of 0.127 (3) Å. The sums of bond angles around the pyridine N atom [358.7 (2)°] and the other imidazolidine N atom [60 (2)°] indicate that these atoms are in sp² hybridizatio...
Article
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The asymmetric unit of the title compound, C19H16N2O5S, contains four independent mol­ecules (A, B, C and D), with two mol­ecules (B and D) displaying disorder in their methyl­sulfanyl groups [occupancy ratios of 0.797 (11):0.203 (11) and 0.85 (2):0.15 (2)]. The nitro groups are twisted slightly out of the planes of the 2-pyrroline rings to which t...
Article
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The asymmetric unit of the title compound, C26H25ClN2O3, contains two independent mol­ecules (A and B). The conformation of the two mol­ecules differs essentially in the dihedral angle involving the two benzene rings. They are inclined to one another by 52.47 (10) in A and by 31.75 (11)° in B. In both mol­ecules, the six-membered piperidin-3-one ri...
Article
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In the title compound, C19H16N2O6S, the pyrrolidine ring adopts a twisted conformation with puckering parameters q2 = 0.088 (3) Å and Φ2 = 61.5 (14)°. The cyclo­pentane ring adopts a twisted conformation with puckering parameters q2 = 0.099 (2) Å and Φ2 = 242.8 (14)°. A weak intra­molecular O—H⋯O inter­action occurs. In the crystal, pairs of C—H⋯O...
Article
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In the title compound, C18H14N2O5, the pyrrolidine ring adopts a shallow envelope conformation, with the C atom bearing the OH group (and remote from the N atom) displaced by 0.257 (2) Å from the other atoms. The cyclo­pentane ring has a twisted conformation about the C—C bond bearing one =O and one —OH grouping. The dihedral angle between the five...
Article
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In the title compound, C27H28N2O3, each of the pyrrolidine rings adopts a twisted conformation, as does the cyclo­pentane ring. The indane ring has an r.m.s deviation of 0.0693 Å. The dihedral angle between the mean plane of the pyrrolizine ring and indane system is 82.58 (1)°. The piperidine ring has the methyl substituent in an equatorial positio...
Article
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In the title compound, C31H30N4O, the central pyrrolidine ring adopts an envelope conformation with the methyl­ene C atom being the flap. The quinoxaline and indane rings are each planar, having r.m.s. deviations of 0.030 and 0.050 Å, respectively. The pyrrolidine ring mean plane forms dihedral angles of 88.25 (1) and 83.76 (1)° with the quinoxalin...
Article
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In the title compound, C30H28N4O, the central pyrrolidine ring adopts an envelope conformation with the CH2 C atom as the flap. The quinoxaline and indene ring systems are planar, with r.m.s. deviations of 0.0165 and 0.0181 Å, respectively. The pyrrolidine ring mean plane forms dihedral angles of 88.84 (1) and 86.14 (1)° with the quinoxaline and in...
Article
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In the title compound, C37H32F2N2O2, the central six-membered piperidine ring adopts a twisted half-chair conformation, with the N and methyl­ene C atoms deviating by −0.2875 (16) and 0.4965 (15) Å, respectively, from the mean plane defined by the other four atoms. The piperidine connected to the octa­hydro­indolizine ring is in a half-chair confor...
Article
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The title compound, C35H28N4O6S, crystallizes with two mol­ecules in the asymmetric unit. In both mol­ecules, the piperidine ring adopts a shallow-chair conformation, the thia­zole ring adopts a twisted conformation about the Cm—N bond (m = methine) and the pyrrole ring adopts an envelope conformation with the C atom shared with the thia­zole ring...
Article
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In the title compound, C19H14FN3O3, the central pyran ring adopts a boat conformation with the O atom and the quaternary C atom diagonally opposite displaced by 0.068 (1) and 0.075 (1) Å, respectively, above the mean plane defined by the other four ring atoms. The co-planar atoms of the pyran ring and the fluoro­phenyl ring are nearly perpendicular...
Article
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In the title compound, C20H17N3O4, the central pyran ring adopts a boat conformation with the O atom and diagonally opposite C atoms displaced by 0.1171 (1) and 0.1791 (1) Å, respectively, from the mean plane defined by the other four atoms. The coplanar atoms of the pyran ring and the meth­oxy­benzene ring are nearly perpendicular, as evidenced by...
Article
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In the title compound, C39H38N2O4, the pyridinone ring adopts a twisted half-chair conformation with the N atom deviating by 0.3304 (1) and with the methyl­ene C atom adjacent to the octa­hydro­indolizine unit deviating by 0.444 (3) Å from the mean plane defined by the other four atoms. In the octa­hydro­indolizine system, the pyrrolidine ring exhi...
Article
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In the title compound, C22H18FNO3S2, the five-membered thia­zolidine ring is planar (r.m.s. deviation = 0.003 Å) and forms dihedral angles of 70.2 (3), 73.16 (17) and 10.32 (14)° with the cyclo­propane, fluoro­benzene and methyl­thio­benzene rings, respectively. The sum of the bond angles around the thia­zolidine ring N atom (359.6°) indicates sp²...
Article
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In the title E isomer of the racemic compound, C37H32F2N2O2, the pyridinone ring adopts a twisted half-chair conformation with the N atom deviating by −0.355 (3) Å and with the methyl­ene C atom next to octa­hydro­indolizine moiety deviating by 0.415 (3) Å from the mean plane defined by other four atoms. In the octa­hydro­indolizine system, the pyr...
Article
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In the title compound, C25H25ClO2, the C ring adopts a chair conformation, while the B ring approximates a half-chair conformation. The five-membered ring D has a twist con­form­ation on the C—C bond fused with the C ring. Aromatic rings A and E are not coplanar, as evidenced by the dihedral angle of 7.51 (1)°. In the crystal, O—H⋯O hydrogen bonds...
Article
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In the title compound, C37H32Cl2N2O2, the pyridinone ring adopts a twisted half-chair conformation. The fused pyrrolidine and piperidine rings of the octa­hydro­indolizine unit exhibit envelope (with the C atom bound to the C atom bearing the chloro­benzene ring being the flap atom) and chair conformations, respectively. The dihedral angle between...
Article
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In the title compound, C37H34N2O2, the pyridinone ring adopts a half-chair conformation. In the octa­hydro­indolizine fused-ring system, the piperidine ring is in a chair conformation and the pyrrole ring is twisted about the N—C(piperidine) bond. The mol­ecular structure features a weak intra­molecular C—H⋯O inter­action.
Article
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In the title compound, C37H30Cl4N2O2, the pyridinone ring adopts a twisted half-chair conformation. In the octa­hydro­indolizine fused-ring system, the piperidine ring is in a chair conformation and the pyrrole ring is twisted about the C—N bond linking the five- and six-membered rings. The mol­ecular structure features an intra­molecular C—H⋯O int...
Article
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The furan ring in the title compound, C26H17BrN2O2, adopts a twisted envelope conformation. The mol­ecular structure is stabilized by an intra­molecular C—H⋯O inter­action which generates an S(6) ring motif. The crystal packing is stabilized by N—H⋯O and C—H⋯Br inter­actions, generating an R2²(16) ring motif and a C(12) linear chain motif, respecti...