Nyasicoside

J Basic Clin Physiol Pharmacol. 2016 Nov 1;27(6):659-66.

Antithrombotic and cytotoxic activities of four Bangladeshi plants and PASS prediction of their isolated compounds.[Pubmed: 27371821]

This study aims to investigate whether tested organic extracts possess antithrombotic properties with minimal or no toxicity and to predict the activity of some of their isolated compounds.
METHODS AND RESULTS:
An in vitro thrombolytic model was used to check the clot lysis effect of four Bangladeshi herbal extracts viz., roots ofCurculigo recurvataW.T. Aiton (Satipata), leaf ofAmorphophallus bulbiferRoxb. (Olkachu), leaf ofPhyllanthus sikkimensisMuell. Arg., and whole plant ofThunbergia grandifloraRoxb. (Nillata) using streptokinase as a positive control and water as a negative control. Cytotoxicity was screened by brine shrimp lethality bioassay using vincristine sulfate as positive control. In silico prediction of activity spectra for substances (PASS) prediction was applied for phytoconstituents, namely, Nyasicoside, glucomannan, grandifloric acid, serine, and alanine. Using an in vitro thrombolytic model,C. recurvata,A. bulbifer,P. sikkimensis, andT. grandiflorashowed 28.10±1.64%, 42.47±1.96%, 32.86±1.92%, and 25.51±1.67% of clot lysis, respectively. Reference drug streptokinase exhibited 75.00±3.04% clot lysis. Examined herbs showed significant (p<0.001) percentage (%) of clot lysis compared to negative control. In brine shrimp cytotoxic assay,C. recurvata,A. bulbifer,P. sikkimensis, andT. grandiflorashowed LC50values 210.64±3.44, 98.51±1.47, 187.29±2.01, and 386.43±3.02 μg/mL, respectively, with reference to vincristine sulfate (LC500.76±0.04). PASS predicted that examined phytoconstituents have a wide range of biological activity.
CONCLUSIONS:
Through our study it was found thatA. bulbiferandP. sikkimensiscould be considered as very promising and beneficial thrombolytic agents.

J Nat Prod. 1999 May;62(5):734-9.

Three novel constituents from curculigo capitulata and revision of C-2 stereochemistry in nyasicoside.[Pubmed: 10346957]

METHODS AND RESULTS:
Continuing study of the constituents of the rhizomes of Curculigo capitulata provided three novel compounds, including two norlignan glucosides, curcapicycloside (2) and (1S,2R)-O-methylNyasicoside (3), and a phenanthrofuran, curcapital (9). The former two compounds were characterized as their tetra-O-methyl derivatives. Compound 2 possesses a glucosyl-fused skeleton with 1R,2R configuration. Biogenetic consideration led to a revision of the previously assigned 2S configuration of Nyasicoside (1) to 2R, which was confirmed by NOE studies of the acetonide of its tetra-O-methyl derivative. The 2R configuration in tetra-O-methyl-1-O-methyl curculigine (7a) and isocurculigine (8a) was also established by chemical correlation of the former with (1R, 2R)-tetra-O-methyl-1-O-methylNyasicoside (10a).
CONCLUSIONS:
Curcapital (9) represents the first natural product having a phenanthro[9,10, b]furan skeleton.