Cytotoxicity of Triterpenoid Alkaloids from Buxus microphylla against Human Tumor Cell Lines.

Shi-Tou Bai,Ming-Hua Qiu,Guo-Lei Zhu,Jian-Chao Chen,Mu-Yuan Yu,Jin-Run Dong,Xing-Rong Peng,Luo-Sheng Wan

doi:10.3390/molecules21091125

Abstract

Three new triterpenoid alkaloids, namely buxmicrophyllines P–R (1–3), were isolated from the twigs and leaves of Buxus microphylla. Their structures were elucidated on the basis of NMR and MS spectroscopic analyses. Structurally, compounds 1–3 belong to the 9,10-cycloartane type alkaloids. In addition, compound 3 exhibited moderate cytotoxic activities in vitro against HL-60, SMMC-7221, A-549, MCF-7, and SW480 cell lines (with IC50 values ranging from 4.51 to 15.58 μM).

Highlights

Extraction and IsolationThe chopped, dried plant material of B. microphylla (10.0 kg) was extracted three times with acetone (20 L) at room temperature, seven days each time
AAbbssttrraacctt:: TThhrreeee nneeww ttrriitteerrppeennooiidd aallkkaallooiiddss, nnaammeellyy bbuuxxmmiiccrroopphhyylllliinneess PP––RR ((11––33)), wweerree iissoollaatteedd ffrroomm tthhee ttwwiiggss aanndd lleeaavveessooffBBuuxxuussmmicircorpohpyhlylall.aT. hTehierisrtrsutrcutuctruesrews ewreereeluecliudcaitdeadteodnothnethbaesbisaosifsNoMf NRManRdaMndS MspSecstpreocstcroopscicopaincaalnyaselyss. eSst.ruStcrtuucrtaullrya,llcyo, cmopmopuonudnsd1s–13–3bebleolnogngtotoththee99,1,100-c-cyyccloloaarrtatanneettyyppeeaallkkaallooiiddss
The filtrate was concentrated under reduced pressure to yield a residue (500 g), which was further suspended in 0.001 N HCl and partitioned with ethyl

Summary

Extraction and Isolation

The chopped, dried plant material of B. microphylla (10.0 kg) was extracted three times with acetone (20 L) at room temperature, seven days each time. The filtrate was concentrated under reduced pressure to yield a residue (500 g), which was further suspended in 0.001 N HCl and partitioned with ethyl. The filtrate was concentrated under reduced pressure to yield a residue (500 g), which was further suspended in 0.001 N HCl and partitioned with ethyl acetate (EtOAc). The aqueous layer was alkalinized to pH 10.0 with 2 N NaOH followed by exhaustive extraction with CHCl3. The CHCl3-soluble fraction (120 g) was chromatographed on a silica gel column, eluted with CHCl3–MeOH (100:0, 50:1, 20:1, 10:1, 2:1) to give five fractions, A1–A5. Fraction A4 (12 g) was subjected to further silica gel column chromatography using petroleum ether–EtOAc–diethylamine (20:1:1, 10:1:1, 5:1:1, 2:1:1), to yield 1 (20 mg), 2 (4 mg), 3 (5 mg).

Cytotoxicity Assay

Findings

Conclusions