Three new flavonoids, quercetin-3-O-6-[methyl-(S)-3-hydroxy-3-methylglutaroyl(1→6]-β-d-glucopyranoside (1), kaempferol-3-O-[methyl-(S)-3-hydroxy-3-methylglutaroyl(1→6)]-β-d-glucopyranoside (2), and quercetin-3-O-6-[(E)-4-methoxy-5-methylhexa-2,4-dienoatyl(1→6)]-β-d-glucopyranoside (3), and two new alkaloids, 5-dehydroxymethyl-pyrrolemarumine 4″-O-α-l-rhamnopyranoside (4) and N1-methyl-N2-((4-O-α-l-rhamnopyranoside)benzyl) oxalamide (5), together with 45 known compounds (6-50) were isolated from the leaves of Moringa oleifera Lam. Among those compounds, 1-octacosanol (50), a straight-chain 28-carbon alcohol, exhibited good activity against diphenoxylate-induced constipation in mice, which is obtained as a laxative constituent from the plant for the first time. In order to have an accurate understanding of the content of compound 50, a quantification with gas chromatography-tandem mass spectrometry (GC-MS/MS) was carried out. The anti-inflammatory and α-glucosidase inhibitory activity of some compounds also was assessed.