An Overview of Synthesis of Indole Alkaloids and Biological Activities of Secondary Metabolites Isolated from Hyrtios Species.

Marine sponges are a rich source of more than 50% of marine natural compounds that have been isolated from marine organisms. This review article is focused on the importance of biologically active and pharmaceutically important secondary metabolites extracted from one of the important classes of marine sponge Hyrtios sp. This review also deals with reported synthetic routes of some indole alkaloids extracted from the marine sponge Hyrtios sp. A range of bioactivities displayed by indole-based alkaloids is described.

Trimethyl[3-methyl-1-(o-tolenesulfonyl)indol-2-ylmethyl]ammonium iodide and benzyl[3-bromo-1-(phenylsulfonyl)indol-2-ylmethyl]tolylamine.

The title compounds, C(20)H(25)N(2)O(2)S(+).I(-), (I), and C(29)H(25)BrN(2)O(2)S, (II), respectively, both crystallize in space group P-1. The pyrrole ring subtends an angle with the sulfonyl group of 33.6 degrees in (I) and 21.5 degrees in (II). The phenyl ring of the sulfonyl substituent makes a dihedral angle with the best plane of the indole moiety of 81.6 degrees in (I) and 67.2 degrees in (II). The lengthening or shortening of the C-N bond distances in both compounds is due to the electron-withdrawing character of the phenylsulfonyl group. The S atoms are in distorted tetrahedral configurations. The molecular structures are stabilized by C-H.O and C-H.I interactions in (I), and by C-H.O and C-H.N interactions in (II).

Diethyl [3-[beta-(2,4-dichlorophenyl)vinyl]-N-(phenylsulfonyl)indol-2-ylmethyl]phosphonate and diethyl [3-[beta-(4-bromophenyl)vinyl]-N-(phenylsulfonyl)indol-2-ylmethyl]phosphonate.

The title compounds, C(27)H(26)Cl(2)NO(5)PS, (I), and C(27)H(27)BrNO(5)PS, (II), respectively, crystallize in the centrosymmetric space group P2(1)/n with one molecule in the asymmetric unit in each case. The dihedral angle between the benzene and pyrrole rings is 2.1 (1) degrees in (I) and 0.9 (2) degrees in (II). The phenylsulfonyl group is orthogonal to the halophenyl moiety, with a dihedral angle of 82.0 (1) degrees in (I) and 78.7 (2) degrees in (II). In both compounds, the molecular structures and packing are stabilized by C-H...O and C-H...halogen interactions. The intermolecular hydrogen bonds in (I) form cyclic dimers with graph-set descriptors R(2)(1)(10) and R(2)(2)(8) about a 2(1) axis, and those in (II) form a C(2)(2)(20) chain.

Ethyl beta-[2-[4-(dimethylamino)phenyliminomethyl]-1-(phenylsulfonyl)indol-3-yl]acrylate.

The title compound, C(28)H(27)N(3)O(4)S, crystallizes in the centrosymmetric space group P2(1)/n, with one molecule in the asymmetric unit. In the indole ring, the dihedral angle between the fused rings is 3.6 (1) degrees. The phenyl ring of the sulfonyl substituent makes a dihedral angle of 79.2 (1) degrees with the best plane of the indole moiety. The phenyl ring of the dimethylaminophenyl group is orthogonal to the phenyl ring of the phenylsulfonyl group. The dihedral angle formed by the weighted least-squares planes through the pyrrole ring and the phenyl ring of the dimethylaminophenyl group is 7.8 (1) degrees. The molecular structure is stabilized by C-H.O and C-H.N interactions.

N-Methyl-N-(1-phenylsulfonylindol-2-ylmethyl)aniline.

In the title compound, 2-[(methylphenylamino)methyl]-1-(phenylsulfonyl)indole, C22H20N2O2S, the indole system is not strictly planar and the dihedral angle between the fused rings is 2.7 (1) degrees. The angles around the S atom of the sulfonyl substituent deviate significantly from the ideal value for tetrahedral geometry. The pyramidalization at the indole N atom is very small. Of the two C-H...O interactions, one influences the orientation of indole with respect to the sulfonyl group and the other determines the orientation of the phenyl bound to sulfonyl. The phenyl ring of the sulfonyl substituent makes a dihedral angle of 89.6 (1) degrees with the best plane of the indole. The molecular packing is stabilized by C-H...pi and C-H...O hydrogen bonds.