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Two new flavonoids, 2',4',6',2,3,4-hexamethoxychalcone (1) and 5-hydroxy-7,2',5'-trimethoxyflavone (2) together with a known flavone glycoside, echioidinin 5-O-beta-D-glucopyranoside (3) were isolated from the whole plant of Andrographis neesiana, and the structures were elucidated by electrospray ionization tandem mass spectrometry (ESI-MS/MS) and one- and two-dimensional (1D- and 2D)-NMR spectral studies including 1H-1H correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC), heteronuclear multiple bond connectivity (HMBC) and nuclear Overhauser enhancement spectroscopy (NOESY) experiments.

A new sesquiterpene lactone, 5-isopropyl-3-methyl-2,4,7-trimethoxy-8,1-naphthalene carbolactone (1) together with a known naphthoquinone, 8-formyl-7-hydroxy-5-isopropyl-2-methoxy-3-methyl-1,4-naphthoquinone (2) were isolated from the root bark of Bombax malabaricum. The structures of these two compounds were established by extensive one- and two-dimensional (1D- and 2D)-NMR spectral studies.

Two new flavonoids, 5, 7, 2', 5'-tetramethoxyflavanone (1) and 5-hydroxy-7, 2'-dimethoxyflavone (2), together with two known flavones, skullcapflavone I (3) and echioidin (4) were isolated from the whole plant of Andrographis rothii. The structures of the new compounds were established by extensive one- and two-dimensional (1D- and 2D-) NMR spectral studies.