A new flavan named 4α, 5-dimethoxy-8-formyl-7-hydroxy-6-methylflavan (1) was isolated from Sinacalia tangutica. Its structure was determined using spectroscopic methods and X-ray diffraction experiments. A new flavan named 4α, 5-dimethoxy-8-formyl-7-hydroxy-6-methylflavan (1) was isolated from Sinacalia tangutica. Its structure was determined using spectroscopic methods and X-ray diffraction experiments.