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A novel isoflavan-4-ol (pumilanol), ( re l)-3β-(2′-hydroxy-4′,5′-methylenedioxyphenyl)-6-methoxy-4α,7-dihydroxybenzo-3,4-dihydropyran ( 1 ) and two known flavonoids, tephrinone ( 2 ) and rotenone ( 3 ) together with lupeol and stigmasterol were isolated from the roots of Tephrosia pumila (Fabaceae) from a collection made in Andhra Pradesh, India. The structures of the compounds were determined by MS, 1D and 2D-NMR spectral analysis. Pumilanol ( 1 ) exhibited significant antiprotozoal activity against T. b. rhodensiense , T. cruzi and L. donovani with IC 50 of 3.7, 3.35 and 17.2 μg/mL, respectively, but displayed high toxicity towards L-6 (IC 50 of 17.12 μg/mL) rat skeletal myoblasts.

A benzil, calophione A, 1-(6′-Hydroxy-1′,3′-benzodioxol-5′-yl)-2-(6″-hydroxy-2″-isopropenyl-2″,3″-dihydro-benzofuran-5″-yl)-ethane-1,2-dione and three coumestan derivatives, tephcalostan B, C and D were isolated from the roots of Tephrosia calophylla. Their structures were deduced from spectroscopic data, including 2D NMR 1 H– 1 H COSY and 13 C– 1 H COSY experiments. Compounds were evaluated for cytotoxicity against RAW (mouse macrophage cells) and HT-29 (colon cancer cells) cancer cell lines and antiprotozoal activity against various parasitic protozoa. Calophione A exhibited significant cytotoxicity with IC 50 of 5.00 (RAW) and 2.90 μM (HT-29), respectively.

A new 2′,6′-dimethoxy-4′,5′-(2″,2″-dimethyl)-pyranochalcone (1) and three known flavanones, namely 5-hydroxy-7-methoxy-8-(3,3-dimethylallyl)-flavanone (methyl glabranin) (2), 5,7-dimethoxy-8-(3,3-dimethylallyl)-flavanone (candinone) (3) and 5- O-methyl obovatin (pongachin) (4), have been isolated from the chloroform extract of the roots of Tephrosia pulcherrima. The flavonoids were fully characterized by detailed 1D- and 2D-NMR spectroscopic investigations. The pyranochalcone 1 showed significant antimicrobial activity when tested against a series of micro-organisms.