Murradiate and murradiol, two structurally unique heterodimers of carbazole-monoterpene and carbazole-phenylethanol from Murraya tetramera

•Two novel heterodimers were isolated from Murraya tetramera.•Murradiate (1) is the first carbazole alkaloid coupled with p-menthane monoterpene.•Murradiol (2) possesses a rare carbazole-phenylethanol dimeric skeleton.•Both compounds exhibited weak inhibition of nitric oxide production in BV-2 microglial cells stimulated with lipopolysaccharide.