A new flavonoid from heartwood of Caesalpinia sappan Studies on Compounds from Caesaipinia sappan L. Chemical constituents from seeds of Caesalpinia sappan Diterpenoids from seeds of Caesalpinia sappan Study on chemical constituents from heartwood of Caesalpinia sappan Study on chemical constituents from heartwood of Caesalpinia sappan Vasorelaxation effects of homoisoflavonoids from Caesalpinia sappan in  rat thoracic aortic rings