[Studies on chemical constituents in heartwood of Taxus cuspidata].

OBJECTIVE: To study the chemical constituents in the heartwood of Taxus cuspidata. METHOD: Silica gel column chromatography, preparative HPLC and preparative TLC were used to isolate and purify the chemical constituents; 1H- and 13C-NMR spectroscopic methods were used for structural identification. RESULT: Ten compounds, taxinine (1), taxusin (2), beta-sitosterol (3), 1 beta-hydroxybaccatin I (4), 2alpha, 5alpha, 10beta-triacetoxy-14beta-(2'-methyl) butanoyloxy-4 (20), 11-taxadiene (5), 2alpha, 5alpha, 10beta-triacetoxy-14beta-(2'-methyl-3'-hydroxy-butanoyloxyl-4 (20), 11-taxadiene (yunnanxane) (6), 9alpha, 10beta, 13alpha-triacetoxy-5alpha-cinnamoyltaxa-4 (20), 11-diene (7), 2-deacetoxytaxinine J (8), taxezopidine G (9), 2alpha, 7beta, 9alpha, 10beta, 13alpha-pentaacetoxyl-taxa-4 (20), 11-dien-5-ol (5-decinnamoyltaxinine J) (10), were isolated and identified from the heartwood of T. cuspidata. CONCLUSION: Three taxanes, 1 beta-hydroxybaccatin I (4), 2alpha, 5alpha, 10beta-triacetoxy-14beta-(2'-methyl-3'-hydroxy-butanoyloxy)-4 (20), 11-taxadiene (yunnanxane) (6), and 2alpha, 7beta, 9alpha, 10beta, 13alpha-pentaacetoxyltaxa-4 (20) , 11-dien-5-ol (10), were obtained from this plant for the first time.

Cortex phellodendri Extract Relaxes Airway Smooth Muscle.

Cortex phellodendri is used to reduce fever and remove dampness and toxin. Berberine is an active ingredient of C. phellodendri. Berberine from Argemone ochroleuca can relax airway smooth muscle (ASM); however, whether the nonberberine component of C. phellodendri has similar relaxant action was unclear. An n-butyl alcohol extract of C. phellodendri (NBAECP, nonberberine component) was prepared, which completely inhibits high K(+)- and acetylcholine- (ACH-) induced precontraction of airway smooth muscle in tracheal rings and lung slices from control and asthmatic mice, respectively. The contraction induced by high K(+) was also blocked by nifedipine, a selective blocker of L-type Ca(2+) channels. The ACH-induced contraction was partially inhibited by nifedipine and pyrazole 3, an inhibitor of TRPC3 and STIM/Orai channels. Taken together, our data demonstrate that NBAECP can relax ASM by inhibiting L-type Ca(2+) channels and TRPC3 and/or STIM/Orai channels, suggesting that NBAECP could be developed to a new drug for relieving bronchospasm.

1-deoxypaclitaxel and abeo-taxoids from the seeds of Taxus mairei.

A new paclitaxel derivative and two new 2(3-->20)-abeo-taxoids were isolated from a methanol extract of the seeds of Taxus mairei, and their structures were established as 1-deoxypaclitaxel (1), 7beta,10beta-diacetoxy-2alpha,5alpha,13alpha-trihydroxy-2(3-->20)-abeo-taxa-4(20),11-dien-9-one (2), and 2alpha,13alpha-diacetoxy-10beta-hydroxy-2(3-->20)-abeo-taxa-4(20),6,11-triene-5,9-dione (3) on the basis of spectroscopic data analysis. Taxane 1 is the first example of a paclitaxel analogue with a C-1beta hydrogen substituent. Taxane 3 is an 2(3-->20)-abeo-taxane with a rare C-5 ketone and C-6 double bond.

Two new alkaloidal taxoids from the needles of Taxus canadensis.

Two new taxanes with a dimethylamino group on the C-5 side chain were identified for the first time in the needles of the Canadian yew, Taxus canadensis. Their structures were characterized as 7beta,10beta,13alpha-triacetoxy-5alpha-(3'-dimethylamino-3'-phenylpropanoyl)oxy-2alpha-hydroxy-2(3-->20)abeotaxa-4(20),11-dien-9-one (1) and 2alpha,10beta-diacetoxy-9alpha-hydroxy-5alpha-(3'-dimethylamino-3'-phenylpropanoyl)oxy-3,11-cyclotax-4(20)-en-13-one (2).