Triterpenoids from the seedpods of Holarrhena curtisii King and Gamble

Two new hydroperoxy pentacyclic triterpenoids, 3β-hydroxy-11α-hydroperoxyolean-12-en-28-oic acid (1) and 3β-hydroxy-11α-hydroperoxyursan-12-en-28-oic acid (2), together with nine known triterpenoids, squalene (3), β-amyrin acetate (4), α-amyrin acetate (5), lupeol acetate (6), lupeol (7), lanosta-7,24-dien-3β-ol (8), cycloeucalenol (9), oleanolic acid (11) and ursolic acid (12), a known phytosterol, 24-methylenepollinastanol (10), and two known flavanols, (–)-catechin (13) and (–)-gallocatechin (14), were isolated from the methanolic extract of the fresh seedpods of Holarrhena curtisii. Their structures were determined by spectroscopic analysis (one and two dimensional nuclear magnetic resonance, high resolution electrospray ionization mass spectrometry and attenuated total reflectance-Fourier transform infrared spectroscopy). All compounds (except squalene) were evaluated for their in vitro α-glucosidase inhibitory activity. Compounds 1, 2, 11 and 12, which had a pentacyclic triterpenoid acid skeleton, showed a strong in vitro α-glucosidase inhibitory activity compared to that of the standard control, acarbose.     

Phytochemical and chemotaxonomic study on Dictamnus angustifolius G. Don ex Sweet (Rutaceae)

A phytochemical investigation of Dictamnus angustifolius led to the isolation of 14 compounds, including six furoquinoline alkaloids (1–6), two sesquiterpenoids (7, 8) and six flavonoids (9–14). The structures of these compounds were identified by spectroscopic methods and a comparison of their data with those reported in the literature. This is the first report of three furoquinoline alkaloids 1–3 and six flavonoids 9–14 from the genus Dictamnus and the first isolation of compounds 4–8 from D. angustifolius. The chemotaxonomic significance of furoquinoline alkaloids and sesquiterpenoids has also been summarized.     

Chemical constituents from Cynanchum paniculatum (Bunge) Kitag

Twenty-nine compounds, including five acetophenone derivatives (1–5), three phenanthroindolizidine alkaloids (12–14), seven pentacyclic triterpenoids (15–21) and five C₂₁ steroidal sapogenins (22–26), were isolated from the root of Cynanchum paniculatum (Bunge) Kitag. Their structures were determined by spectroscopic methods and comparison with reported data. Moreover, the chemotaxonomic relationships were also discussed. As a result, acetophenone derivatives, pentacyclic triterpenoids and C₂₁ pregnane sapogenins can be recognized as chemotaxonomic markers for Cynanchum genus, and C. paniculatum has close relationships with some species of genus Cynanchum.     

Sesquiterpenoids from Saussurea laniceps and their chemotaxonomic significance

Twenty-five sesquiterpenoids including seventeen guaiane-type sesquiterpenoids and glucose glycosides (1–17), six eudesmane-type sesquiterpenoids (18–23), and two germacrane-type sesquiterpenoids (24 and 25) were isolated from the aerial parts of Saussurea laniceps Hand.-Mazz. Their structures were elucidated by spectroscopic methods and comparison with previously reported spectral data. Among them, compounds (6 and 8) are new, and seven compounds (2, 9, 12, 18–19, 22–23) are reported for the first time from the genus Saussurea. This paper deals with the isolation, structural elucidation and chemotaxonomic significance of these sesquiterpenoids from S. laniceps.     

Chemical constituents from the roots of Elephantopus scaber L.

A chemical investigation of the roots of Elephantopus scaber L. led to the isolation of thirteen compounds, including four sesquiterpenoids (5, 6, 7, 8), two phenols (1, 2), three triterpenoids (9, 10, 11), two caffeoylquinic acids (3, 4), one alkaloid (12), and one sterol (13). Among these molecules, compound 2 (2-butenoic acid, 3-methyl-[4-(1,5-dimethyl-4-hexenyl)-3-hydroxyphenyl] methyl ester) was identified for the first time from this species, while compounds 1 (curcuphenol) and 12 (patriscabratine) were isolated for the first time from the genus Elephantopus.     

New triterpenoids from Leonurus japonicus (Lamiaceae)

Three new triterpenoids (1, 4, and 5), together with 17 known analogues, were isolated from the ethyl acetate soluble portion of the EtOH extract of Leonurus japonicus Houtt. Their structures were determined by spectroscopic analysis. All known triterpenoids were isolated from the genus Leonurus for the first time. Among them, triterpenoids 2–3, 9–12, and 16–20 were first isolated from the family Lamiaceae. Furthermore, the cycloartane, taraxastane, ursane, lupane, euphane, and dammarane types are reported here for the first time from the genus Leonurus.     

Chemical constituents from Laggera pterodonta

A phytochemical investigation on the aerial parts of Laggera pterodonta resulted in the isolation and identification of fourteen compounds, including six sesquiterpenoids (1–6), five flavonoids (7–11), one lignan (12), and two pyrrole alkaloids (13, 14). Among them, compounds 1–3, 7–9, and 11 are the characteristic class of secondary metabolites of L. pterodonta. Compounds 4 and 5 were firstly isolated from L. pterodonta and this is the first report of the presence of compounds 6, 10, and 12 from the genus Laggera. Pyrrole alkaloids 13 and 14 may serve as potential chemotaxonomic markers for L. pterodonta and could be used to distinguish among species of Compositae.     

Anticomplement triterpenoids from the roots of Ilex asprella

Five new (1–5) and twenty-eight known (6–33) triterpenoids were isolated from the roots of Ilex asprella. The structures of the new compounds were elucidated by the detailed spectral analysis. The ursane and oleanane triterpenoids were found to show anticomplement activity with some structure-activity relationships. Several triterpenoids (1–3, 6–7) exhibited potent anticomplement activity with the CH₅₀ and AP₅₀ values of 0.058–0.131 mg/mL and 0.080–0.444 mg/mL, respectively. It was found that caffeoyl group could enhance activity remarkably, followed by coumaroyl and feruloyl group. The 28-carboxyl group was also important to anticomplement activity for the triterpenoids. However, the triterpenoids with lactone ring (4, 9–14) exhibited weak activity and triterpenoid glycosides (5, 23–33) showed no inhibition. The targets of several bioactive triterpenoids in complement activation cascade were identified as well.     

Nitric oxide inhibitory constituents from Siegesbeckia pubescens

Two new sesquiterpenoids (1 and 2) and a new ent-pimarane type diterpenoid (3), together with eighteen known compounds (4–21), were isolated from the whole plants of Siegesbeckia pubescens. The structures of the new compounds were determined on the basis of 1D-, 2D NMR and HRESIMS data. All compounds were evaluated for their inhibitory effects on LPS-induced nitric oxide production in RAW 264.7 macrophages. Of these, highly oxygenated germacrane type sesquiterpenoids (1–2 and 13–14) showed significant inhibitory effects with IC₅₀ values ranging from 3.9 to 16.8 μM.     

Constituents from the pseudofruits of Hovenia dulcis and their chemotaxonomic significance

Sixteen compounds, including six flavonoids (1–6), one lignan (7), three megastigmanes (8–10), three triterpenoids (11–13), and three benzoic acid derivatives (14–16) were isolated and structurally elucidated from the pseudo-fruits of Hovenia dulcis. Their structures were analyzed by NMR spectroscopic and data comparison. Among them, compounds 4, 7–11, 13, 15, and 16 were isolated from the Hovenia genus for the first time. The chemotaxonomic significance of the isolates was also described, which revealed a relationship between H. dulcis and H. acerbar as well as other species belonging to the Rhamnaceae family.     

New eudesmane sesquiterpenes from Alpinia oxyphylla and determination of their inhibitory effects on microglia

The fruits of Alpinia oxyphylla are used as healthcare products for the protection on neurons and prevention of dementia. Two new noreudesmane sesquiterpenoids, (5R,7S,10S)-5-hydroxy-13-noreudesma-3-en-2,11-dione (1) and (10R)-13-noreudesma-4,6-dien-3,11-dione (2), and a new eudesmane sesquiterpenoid, (5S,8R,10R)-2-oxoeudesma-3,7(11)-dien-12,8-olide (3), as well as 12 known sesquiterpenoids, were isolated from the fruits of A. oxyphylla. The structures of the new compounds (1–3) were elucidated on the basis of spectroscopic data and circular dichroism experiments. All isolates were evaluated their neuroprotective potential by inhibitory assay on nitric oxide (NO) and tumor necrosis factor-α (TNF-α) production in lipopolysaccharide (LPS)-induced mouse microglia BV-2 cells.     

Sesquiterpenoids and flavonoids from Pteris multifida Poir.

Phytochemical research of Pteris multifida Poir. led to the isolation of fifteen compounds, including six flavonoids (1–6) and nine sesquiterpenoids (7–15). Their structures were characterized by NMR, MS, ORD and CD data. Compounds kaempferol 3-O-α-L-rhamnoside-7-O-β-D-glucoside (1), myricetin 3-O-β-D-glucoside (2), kaempferol 3-O-β-D-glucoside (4), luteolin-7-O-β-D-rutinoside (5), quercetin-3-O-α-L-rhamnopyranoside (6), (2S,3S)-12-hydroxypterosin Q (7), (2S,3S)-pterosin Q (8), 2-hydroxypterosin C (9) and (2S)-12-hydroxypterosin A (10) were first isolated from P. multifida, and compounds 1–2 and 10 were first isolated from the family Pteridaceae. Furthermore, the chemotaxonomic significance of the isolates was discussed.     

A new methoxylated flavone from Lonicera hypoglauca and its chemotaxonomic significance

Phytochemical investigation of the stems and leaves of Lonicera hypoglauca Miq. led to the isolation of one novel methoxylated flavone, acunminatin (7,2′,4′-trihydroxyl-5,5′- methoxyflavone) (1), and fourteen known compounds (2–15), including six flavonoids (mearnsetin 2, kaempferol 3, acacetin 4, 5,7,3′,4′-tetramethoxyflavone 5, tricin 6, and 5,7,3′,4′,5′-pentamethoxyflavone 7), two coumarins (umbelliferone 8 and scopoletin 9), two phenylpropanoids (trans-ferulic acid 10 and chlorogenic acid 11), two iridoid glycosides (loganin 12 and sweroside 13), and two triterpenoids (uvaol 14 and ursolic acid 15). The structures of the compounds were identified by spectroscopic analysis and by comparing their spectral data with those reported in the literature. Five of these compounds (1, 2, 4, 5, and 7) were isolated from the L. genus for the first time, and compounds 6–8 and 14–15 were isolated for the first time from L. hypoglauca. The chemotaxonomic significance of the isolated compounds in the L. genus and the Caprifoliaceae family are discussed herein.     

Chemical constituents from Cyclocarya paliurus (Batal.) Iljinsk

A novel triterpenoid, cyclocarioside K, together with fifteen known compounds, including seven triterpenoids (2–8), five flavonoids (9–13), three phenolic derivatives (14–16), was obtained from the leaves of Cyclocarya paliurus (Batal.) Iljinsk (Juglandaceae). Their structures were elucidated by spectroscopic methods, including two-dimensional NMR experiments (HSQC DEPT and HMBC). The chemotaxonomic relationships were also discussed. As a result, 3, 4-secodammarane triterpenoids and kaempferol glycosides may represent phytochemical fingerprints for C. paliurus, and C. paliurus has close relationships with other species of Juglandaceae.     

Phytochemical investigation of Eremostachys moluccelloides Bunge (Lamiaceae)

Phytochemical investigation of the aerial parts of Eremostachys moluccelloides Bunge led to the identification of a new diterpene, 2β,14-dihydroxy −11-formyl- 12-carboxy-13-des-isopropyl-13-hydroxymethyl-abieta-8,11,13- triene- 16(17)- lactone (1), along with the known compounds 12, 18-dicarboxy-14-hydroxy-13-des -isopropyl-13-hydroxymethyl- abieta-8,11,13-triene-16(17)-lactone (2), 5-hydroxy-3′,4′,7-trimethoxyflavone (3), 5-hydroxy-4’,7-dimethoxyflavone (4), luteolin-7-O-β-glucoside (5), verbascoside (6), luteolin 7-O-(6″-O-β-D-apiofuranosyl) -β-D-glucopyranoside (7), chlorogenic acid (8), echinacoside (9), apigenin-7-O-β-D-glucoside (10), p-coumaric acid (11), vanillic acid (12), apigenin-7-O-(6″-E-p-coumaroyl)-β-D-glucopyranoside (13), apigenin-7-O-(3″,6″-E-p-dicoumaroyl)-β-glucoside (14), lamalbide (15), 6β-hydroxy-7-epi-loganin (16), phloyoside II (17) The structures were elucidated on the basis of 1D and 2D NMR spectroscopy, UV, MS and by comparison with compounds previously reported in the literature. Compounds 1–4, 8, 9, 11, 12, 14 have not been reported previously from any species within the genus Eremostachys. Compounds 1–14, 17 were obtained from this species for the first time. The chemotaxonomic significance of the isolated compounds is discussed.     

Biotransformation of dianabol with the filamentous fungi and β-glucuronidase inhibitory activity of resulting metabolites

Biotransformation of the anabolic steroid dianabol (1) by suspended-cell cultures of the filamentous fungi Cunninghamella elegans and Macrophomina phaseolina was studied. Incubation of 1 with C. elegans yielded five hydroxylated metabolites 2–6, while M. phaseolina transformed compound 1 into polar metabolites 7–11. These metabolites were identified as 6β,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (2), 15α,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (3), 11α,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (4), 6β,12β,17β-trihydroxy-17α-methylandrost-1,4-dien-3-one (5), 6β,15α,17β-trihydroxy-17α-methylandrost-1,4-dien-3-one (6), 17β-hydroxy-17α-methylandrost-1,4-dien-3,6-dione (7), 7β,17β,-dihydroxy-17α-methylandrost-1,4-dien-3-one (8), 15β,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (9), 17β-hydroxy-17α-methylandrost-1,4-dien-3,11-dione (10), and 11β,17β-dihydroxy-17α-methylandrost-1,4-dien-3-one (11). Metabolite 3 was also transformed chemically into diketone 12 and oximes 13, and 14. Compounds 6 and 12–14 were identified as new derivatives of dianabol (1). The structures of all transformed products were deduced on the basis of spectral analyses. Compounds 1–14 were evaluated for β-glucuronidase enzyme inhibitory activity. Compounds 7, 13, and 14 showed a strong inhibition of β-glucuronidase enzyme, with IC₅₀ values between 49.0 and 84.9 μM.     

Cytotoxic triterpene saponins from the stem bark of Kalopanax pictus

Three new compounds, 3β,6β,23-trihydroxyolean-12-en-28-oic acid 3-O-α-l-arabinopyranoside (1), kalopanaxsaponin L (2), and kalopanaxsaponin M (13), as well as eleven known compounds (3–12 and 14), were isolated from the stem bark of Kalopanax pictus. Their structures were determined on the basis of extentive spectroscopic analyses and acid hydrolysis. The cytotoxicity of the compounds was evaluated in three human carcinoma cell lines, including HL-60, HCT-116, and MCF-7. Compounds 1, 5–8, 10, and 11 exhibited significantly cytotoxic activity toward HL-60 cells, with IC₅₀ values ranging from 0.1 to 6.9 μM. Compounds 4–7 and 14 showed significant cytotoxicity against HCT-116 cells, with IC₅₀ values ranging from 0.4 to 9.2 μM. Remarkably, the cytotoxic activities of compounds 5–7 against HCT-116 cells were greater than that of the anticancer chemotherapy drug, mitoxantrone (IC₅₀ = 3.7 μM). Compounds 1, 3, 5, and 14 were cytotoxic toward MCF-7 cells with IC₅₀ values in a range of 7.4–14.5 μM.     

Chemical constituents with ɑ,β-unsaturated carbonyl group from the whole plants of Erigeron breviscapus (Vant.) Hand.-Mazz. (Asteraceae)

Phytochemical characterization of the whole plants of Erigeron breviscapus (Vant.) Hand.-Mazz. Led to the isolation of two indole derivatives (1–2), seven monoterpenoids (3–9), two sesquiterpenoids (10–11), and four pyrone derivatives (12–15). The structures of these compounds were examined with spectroscopic methods, and also by comparing with previously reported spectroscopic data. Among them, ten compounds (1–2, 6–11, 14–15) are reported from Erigeron breviscapus for the first time. In addition, three compounds (2, 8–9) are isolated for the first time from Asteraceae family. On the basis of chemical research, we also described the chemotaxonomic significance of these compounds.     

Phytochemical and chemotaxonomic study on the leaves of Rhododendron amesiae

The phytochemical study of the leaves of Rhododendron amesiae (Ericaceae) led to the isolation and identification of 19 compounds, including six diterpenoids (1–6), six triterpenoids (7–12) and seven flavonoids (13–19). The chemical structures of these compounds were identified by spectroscopic data, as well as by comparison with previously reported data in literature. This is the first systematic study on the chemical constituents of Rhododendron amesiae. All the compounds were isolated from this plant for the first time. Compounds 12, 14 and 15 were first isolated and reported from the genus Rhododendron and the family Ericaceae. Furthermore, the chemotaxonomic significance of these compounds was discussed.