Eriophyoid mites from Eastern India: description of three new species (Acari: Prostigmata: Eriophyoidea).[Pubmed: 27395518]

Three new eriophyoid mite species, namely Dichopelmus puncti n. sp. (Eriophyidae) from cogan grass, Imperata cylindrica (Poaceae); Calacarus kalyaniensis n. sp. (Eriophyidae) from Siam weed, Chromolaena odorata (Asteraceae) and Neorhynacus bidhanae n. sp. (Diptilomiopidae) from Croton caudatus (Euphorbiaceae), are described and illustrated from West Bengal, India. The new species are vagrants on the leaves of their respective host plants with no visible damage observed. Keys to the known species of Dichopelmus and Neorhynacus are provided along with a checklist of eriophyoid mites species present in West Bengal.

New Cytotoxic Tigliane Diterpenoids from Croton caudatus.[Pubmed: 27002392]

Three new tigliane-type diterpenoids were isolated from the methanolic extract of the twigs and leaves of Croton caudatus, trivially named crotusins A-C (1-3). The structures of compounds 1-3 were elucidated on the basis of extensive spectral methods. These new compounds were highly oxygenated and heavily substituted. Cytotoxic activity against five human tumor cell lines was assessed for compounds 1-3 of which compound 3 showed significant inhibitory activity with IC50 values ranging from 0.49 to 4.19 µM against these cells, while crotusins A and B exhibited moderate activity.

Diterpenoids from the twigs and leaves of Croton caudatus var. tomentosus.[Pubmed: 26475984]

One new 9,10-seco-abietane derivative, crotontomentosin A (1), four new abietane-type diterpenoids, crotontomentosins B-E (2-5), one new ent-halimane-type diterpenoid, crotontomentosin F (6), along with five known diterpenoids (7-11) and one known sesquiterpenoid (12) were obtained from the twigs and leaves of Croton caudatus Geisel. var. tomentosus Hook. The structures of the compounds were established on the basis of extensive spectroscopic data. Compounds 1-4 and 11 exhibited moderate to weak inhibitory activity against the proliferation of the Hela, Hep G2, MDA-MB-231, or A549 cell lines selectively.

Protective effect of Croton caudatus Geisel leaf extract against experimental visceral leishmaniasis induces proinflammatory cytokines in vitro and in vivo.[Pubmed: 25655407]

In the present state of overwhelming emergence of drug-unresponsive phenotypes of Leishmania donovani and persistent severe toxicity in conventional anti-leishmanial therapy, in search for novel leads, the aim of this study has been fixed to identify the active extract(s) of Croton caudatus Geisel. var. tomentosus Hook effective against the parasitic protozoans in vitro and in vivo. C. caudatus Geisel. is often used by Chakma and Hmar community, the local tribes of north-east India for medicinal and veterinary purposes. Among the five semi-purified extracts tested, C. caudatus leaves, extracted in hexane and subsequently semi-purified in a column packed with silica gel (70-130 µM; mesh size 60 A°) using ethyl acetate-hexane solvent (9:1), was found to be the most effective growth inhibitor (JDHex) against the Leishmania promastigotes and amastigotes. JDHex significantly altered the biochemical parameters (protein, lipid and carbohydrates) in promastigotes followed by the morphological changes, DNA condensation and subsequent apoptosis in L. donovani. In consequent steps, it has been also proved that JDHex reduced the replication of intracellular amastigotes with concomitant release of nitric oxide and pro-inflammatory cytokines, IL-12 and TNF-α in vitro. Significantly, the 50% inhibitory concentration of JDHex was estimated much lower against the intracellular amastigotes (2.5 µg/mL) in comparison to promastigotes (10 µg/mL). JDHex was also found efficient in reducing parasite burden in spleen and liver when treated in vivo and increased the intracellular IFN-γ and decreased the IL-10 in CD4+ T cells in splenocytes of orally treated animals. The results of this study support the importance in exploration of novel anti-leishmanial leads from C. caudatus Geisel. var. tomentosus Hook. against the L. donovani (MHOM/IN/83/AG83) infection. Partial chemical characterization of JDHex revealed the presence of terpenoids. However, the further chemical investigation of JDHex is warranted.

Flavonoids from the stems of Croton caudatus Geisel. var. tomentosus Hook.[Pubmed: 20335965]

A new flavone, named crotoncaudatin (1), was isolated from the stems of Croton caudatus Geisel. var. tomentosus Hook., together with nine known analogues: 3,5,6,7,8,3',4'-heptamethoxyflavone (2), tangeretin (3), nobiletin (4), 5,6,7,4'-tetramethoxy-flavone (5), sinensetin (6), kaempferol (7), tiliroside (8), kaempferol-3-O-rutinoside (9) and rutin (10). The structures of the above compounds were established by a combination of spectroscopic methods, including HR-ESI-MS, 1H-NMR, 13C-NMR, HMQC and HMBC spectra. All compounds were isolated from and identified in this species for the first time and compounds 1-6 are new for the genus Croton.

Molecular authentication of the traditional dai medicinal plant Croton caudatus.[Pubmed: 17516330]

Croton caudatus is an important species in Dai folk medicine. Some other Croton species, in particular, C. kongensis, C. cascarilloides, C. crassifolius, C. lachnocarpus and C. olivaceus are often marketed as C. caudatus, and thus, the therapeutic effects of C. caudatus are not achieved. The respective morphological features of the plants are similar, and they are not easy to distinguish morphologically from each other. In an attempt to find a method for discriminating among these species, we compared their nuclear ribosomal DNA internal transcribed spacer (ITS) region. Species-specific probes were derived from the ITS region of these species for species identification. This method provides effective and accurate identification of C. caudatus.