Assessment of morphological and genetic variability through genic microsatellite markers for essential oil in Sandalwood (Santalum album L.).

Sandalwood (Santalum album L; family Santalaceae) is a highly significant aromatic oil yielding tree. It is valued for two important traits, heartwood and essential oil obtained from the heartwood. This study was proposed to assess the morphological and genetic variability of sandalwood accessions. For this, genotypes were randomly selected (n = 177) from the 14 populations from three states in southern India. The total heartwood oil content and quality was estimated by UV method and GC-MS. Total 14 oil-specific genic SSR markers were procured to evaluate the genetic diversity among the sandalwood accessions. Total core size, heartwood content, and oil of S. album ranged from 4.4 to 19.1 cm; 0.0 to 17.3 cm; and 0.0 to 5.96% with covariance 27.61, 85.25, and 73.12% followed by mean 9.74, 3.77, and 2.71, respectively. Genetic diversity estimates were highly polymorphic in terms of Na 7.28, Ne 5.89, He 8.0 PIC 0.891, with little Ho, and F-0.922. AMOVA revealed that minimal genetic variation among populations and highest variation was found among individuals with Nm (58.4). The UPGMA reveals the cluster favored the grouping pattern by the PCA analysis. Structure and PCA analysis clustered the entire populations into two major groups with F ST 0.046 in which population of Kerala and Karnataka were pure and Telangana accessions were found admixtures. No significant correlation (r 2 = 0.23, P = 0.00) was observed between heartwood oil and genetic structures. A high degree of transferability of genic markers would facilitate the assessment of novel genotypes for future tree improvement and conservation of Sandalwood populations.

A convenient synthesis of novel pyranosyl homo-C-nucleosides and their antidiabetic activities.

A series of pyranosyl homo-C-nucleosides have been synthesized by reaction of butenonyl C-glycosides (5a-5j, and 8) and cyanoacetamide in presence of t-BuOK followed by further modifications. The reaction proceeds by Michael addition of cyanoacetamide to the butenonyl C-glycosides and subsequent dehydrative cyclization and oxidative aromatization to give glycosylmethyl pyridones (6a-6j, 7a-7j, 9, and 10). The glycosylmethyl pyridones (6a-6e) on reaction with POCl(3) under reflux gave respective glycosylmethyl pyridines (11a-11e and 12a-12e) in good yields. The synthesized compounds were screened for their in vitro α-glucosidase, glucose-6-phosphatase and glycogen phosphorylase inhibitory activities. One of the pyridylmethyl homo-C-nucleoside, compound 11d, displayed 52% inhibition of glucose-6-phosphatase as compared to the standard drug sodium orthovanadate while compound 12a showed a significant antihyperglycemic effect of 17.1% in the diabetic rats as compared to the standard drug metformin.

Application of butenonyl-C-glucosides in the synthesis of pyrazolinyl-, aminopyrimidinyl- and biphenyl methyl-ß-D-C-glucopyranosides.

An access to different glycohybrids involving nucleophilic addition of N- and C-nucleophiles to the butenonyl glycosides followed by cyclization and subsequent reactions is reported. In the present communication, three different prototypes, ß-D-glucopyranosylmethyl pyrazolines, ß-D-glucopyranosylmethyl pyrimidines and ß-D-glucopyranosylmethyl biphenyls, were prepared in moderate to good yields.

Synthesis and molecular docking studies of 1-phenyl-4-glycosyl-dihydropyridines as potent antileishmanial agents.

A series of 1-phenyl-4-glycosyl-dihydropyridines (4-17 and 19-21) were prepared by the one pot multicomponent reaction of glcosyl aldehyde, beta-keto compounds and aniline or substituted aniline in the presence of TBAHS as catalyst. The compounds were screened in vitro and in vivo for their antileishmanial activities. Most of the compounds exhibited moderate to good activity against amastigotes and promastigotes of Leishmania donovani. The compounds 4, 11, 12, 13, and 17 exhibited potent in vivo activity with selectivity index (SI) values 7.43-18.93. Molecular docking studies with these compounds revealed L. donovani PTR1 as the possible target to show antileishmanial activities.

Application of Huisgen (3+2) cycloaddition reaction: synthesis of 1-(2,3-dihydrobenzofuran-2-yl-methyl [1,2,3]-triazoles and their antitubercular evaluations.

1,4-Disubstituted-1,2,3-triazoles (3-27) have been synthesized by [3+2] cycloaddition of different 2-(azidomethyl)-dihydronaptho(benzo)furans (2a, 2b, 2c and 2d) with different alkynes. All the compounds were screened for antitubercular activity against Mycobacterium tuberculosis H37Rv. Compounds 2a, 7, 9, 12 and 14 exhibited antitubercular activities with MIC ranging from 12.5 to 3.12 microg/ml.

Synthetic studies in butenonyl C-glycosides: Preparation of polyfunctional alkanonyl glycosides and their enzyme inhibitory activity.

A simple synthesis of phenyl butenoyl C-glycosides has been achieved by Aldol condensation of peracetylated glycosyl acetones with aromatic aldehydes followed by deacetylation with methanolic NaOMe. The selected butenoyl C-glycosides on conjugate addition of diethyl malonate resulted in polyfunctional alkanonyl glycosides in good yields. The butenoyl C- and alkanoyl C-glycosides were evaluated for their alpha-glucosidase, glucose-6-phosphatse and glycogen phosphorylase enzyme inhibitory activities in vitro. Three of the synthesized (3, 5 and 9) showed potent enzyme inhibitory activities as compared to standard drugs. Compounds 3, 5 and 9 were evaluated in vivo too displaying significant activity as compared to standard drugs acarbose and metformin.

Aldol reaction of beta-C-glycosylic ketones: synthesis of C-(E)-cinnamoyl glycosylic compounds as precursors for new biologically active C-glycosides.

A series of beta-C-glycosylic ketones were prepared starting from d-glucose, d-xylose, d-mannose, and cellobiose. The beta-C-glycosylic ketones on aldol condensation with different aromatic aldehydes in the presence of a suitable organocatalyst led to the formation of respective C-(E)-cinnamoyl glycosides stereoselectively in good yields as precursors for the synthesis of biologically active compounds.