Bioassay-guided in vitro study of the antileishmanial and cytotoxic properties of Bixa orellana seed extract

Objective:To investigate the leishmanicidal effect of the Bixa orellana crude seed extract and its fractions against Leishmania amazonensis.Methods:Four main fractions(BO-A,BO-B,BO-C and BO-D)were obtained by exhaustion with solvent with increased polarity from the Bixa orellana crude seed extract and 28 sub-fractions.The antileishmanial activity was evaluated in intracellular amastigotes and the cytotoxicity was assessed in murine intraperitoneal macrophages.Results:The BO-A and BO-B fractions showed a good antileishmanial activity with IC50 values of(12.9±4.1)and(12.4±0.3)μg/mL,respectively.The sub-fractions BO-B1(IC_(50)=(11.8±3.8)μg/mL)and BO-B3[IC_(50)=(13.6±4.7)μg/mL]also proved to have a good leishmanicidal effect.In general,the sub-fractions showed a lower toxicity than the crude extract.A selectivity index of 9 indicated a moderate selectivity of the BO-A,BO-B and BO-C fractions and BO-B1 sub-fraction.Conclusions:Potential of this plant against cutaneous leishmaniasis should be further investigated.

The Cytotoxic Constituents from Marine-derived Streptomyces 3320^(#)

The present work studies the chemical constituents from marine-derived streptomyces 3320^# and their antitumor activities. The n-BuOH extract of the ferment broth of 3320^# was chromatographed on silica gel, Sephadex LH-20, ODS columns and HPLC to separate the compounds with antitoumor activities. Their structures were identified using IR, UV, NMR, MS spectroscopic techniques and compared with published data. The antitumor activities of the isolates were assayed using SRB method and flow cytometry assay, accompanied with the morphological observation of the cells under light micro- scope against mammalian tsFT210 cells. Ten compounds, cyclo-（Ala-Leu） 1, cyclo-（Ala-Ile） 2, cyclo-（Ala-Val） 3, cyclo- （Phe-Pro） 4, cyclo-（Phe-Gly）5, cyclo-（Leu-Pro）6, 1-methyl-1, 2, 3, 4-tetrahydro-β-carboline-3-carboxylic acid 7, N-（4- hydroxyphenethyl） acetamide 8, 4-methyoxy-l-（2-hydroxy） ethylbenzene 9 and uridine 10, were isolated from the ferment broth of streptomyces 3320^# . Among them, compounds 6, 7, 8 and 10 showed potent cytotoxicity against the tsFT210 cell with the IC50 values of 3.6, 7.2, 5.2 and 1.6 mmol L-1, respectively. Compounds 8, 10 also exhibited apoptosis inducing activity under 2.0 mmol L-1. Compounds 6, 7, 8 and 10 are the principle bioactive constituents responsible for the antitumor activities of marine streptomyces 3320^#. Compound 7 was isolated from this species for the first time.

Siderochelins with anti-mycobacterial activity from Amycolatopsis sp. LZ149

Three new compounds, namely siderochelins D （2）, E （3）, and F （4）, together with one known siderochelin A （1）, were isolated from Amycolatopsis sp. LZ149 and elucidated by spectroscopic analyses includinglD- and 2D-NMR and X-ray single crystal diffraction. Compounds 1-3 showed antibacterial activity against Mycobacterium smegmatis.