Chemical Studies On The Anti-Inflammatory N-Butanol Extract Of Clerodendranthus Spicatus

Clerodendranthus spicatus(Thunb.) belongs to Lamiaceae family distributed in Southeast Asia. It was used as an herbal tea for treatment of kidney disease for centuries in Dai medicine with the trivial name "Yanuomiao". In previous study, we confirmed that the n-butanol extracts shows good anti-inflammatory activity. Further chemical investigation has led to 16 compounds isolated from the n-butanol extracts through multiple column chromatography including HPLC, sephadex-LH20 etc.. Structures of the two novel compounds were determined to be clerodendranthuslactone (SC-8), and clerodendranthone (SC-17) based on HRMS, 1D-&2D-NMR and IR spectrum analyses respectively. Other 14 isolated compounds were identified as 6-hydroxy-2H-pyran-3-carb-aldehyde (SC-1), protocatechuic acid methyl ester (SC-2), protocatechuic aldehyde (SC-3), protocatechuic acid (SC-4), oresbiusin A (SC-5), trans-vosmarinic methyl ester (SC-7),7,8-dihydroxy-3-methyl-isochromanone (SC-11),3,4-dihydroxy-benzoethylic methyl ester (SC-12),3,4,-methoxy benzoethylic methyl ester (SC-13),3,4-dihydroxy-phenyl-lactic acid (SC-14),trans-rosmarinic ethyl ester (SC-18), benzoic acid (SC-20), bicyclo[3.3.0] octa-1 (5),3,7-triene-2,6-dione (SC-21),3-hydroxy-2-pyrone (SC-22) by comparison of MS, NMR data with literatures or analyses of 2D-NMR data. Chemical structures identification of four fractions was succeeded by spectral analysis including HPLC-DAD, HPLC-MS,1D-&2D-NMR methods. The results showed that SC-X1 contain a pair of isomers, cis-rosmarinic methyl ester(SC-6):trans-rosmarinic methyl ester(SC-7) (about 1:1);SC-X2 contain a pair of isomers, cis-rosmarinic acid (SC-9):trans-rosmarinic acid (SC-10) (about 1:10); SC-X3 contained a pair of isomers, protocatechuic aldehyde (SC-3):2,5-hydroxy-benzaldehyde(19) (about 7.6:1,); SC-X4 contained n-butyl 3,4-dihydroxy-phenyl-lactate (SC-15): 3-hydroxy-γ-butyrolactone (SC-16)(about 10:7). Compounds SC-1, SC-2, SC-5, SC-6, SC-9, SC-11, SC-12, SC-13, SC-14,SC-15,SC-16, SC-19, SC-21, SC-22 were identified from the plant of C.spicatusiox the first time. Compounds SC-19,SC-21,SC-22 were found in natural resources for the first time. These compounds showed good structure diversity which could be further studied in pharmacodynamics and pharmacokinetics.