Two new monoterpenoid indole alkaloids from Tabernaemontana divaricata

Two new monoterpenoid indole alkaloids, tabervarines A (1) and B (2), along with seven known monoterpenoid indole alkaloids, were isolated from the methanol extract of the twigs and leaves of Tabernaemontana divaricata. The structures including the absolute configurations of the new alkaloids were elucidated based on MS, NMR, and ECD calculation. The in vitro cytotoxic activities of the isolated alkaloids against several human cancer cell lines were also evaluated.     

Cytotoxic monoterpenoid indole alkaloids isolated from the barks of Voacanga africana Staph.

A new monoterpenoid indole alkaloid compound (1) and six known monoterpenoid indole alkaloids compounds (2–7) were isolated from the barks of Voacanga africana Staph. The structures were established by spectral analysis as ibogamine-16-carboxylic acid,17,20-didehydro-5,6-dioxo-10-methoxy-methyl ester (1), voacamine (2), vobasine (3), voacangine (4), voacristine (5), 19-epi-voacristine (6) and 19-epi-heyneanine (7). Compound 1 was confirmed by X-ray crystallographic analysis. All of the isolated compounds were evaluated for cytotoxicity against five cell lines (HEPG-2, A375, MDA-MB-231, SH-SY5Y, CT26). Among them, compounds 2 and 6 displayed significant inhibitory activities, compounds 3, 4 and 5 showed moderate inhibitory activities, while compounds 1 and 7 showed no inhibitory activities against the five cell lines.     

Fluevirines E and F,two new alkaloids from Flueggea virosa

Abstract

Two new alkaloids, fluevirines E (1) and F (2), along with six known Securinega alkaloids, were isolated from the methanol extract of the twigs and leaves of Flueggea virosa. The structures and absolute configurations of the new compounds were elucidated by means of MS, NMR, and ECD analyses. Compound 1 is a new dimeric indole alkaloid while 2 is a new securinega-type alkaloid. The in vitro cytotoxic activities of the isolated alkaloids against several human cancer cell lines and their acetylcholinesterase inhibitory activity were also evaluated.     

New pyridocarbazole alkaloids from Strychnos nitida

Phytochemical investigation of Strychnos nitida has led to the isolation of three new racemic pyridocarbazole alkaloids, (±)-stritidas A-C (1–3) and three known monoterpenoid indole alkaloids (4–6). Compounds 2 and 3 represent the first examples of pyridocarbazole alkaloids featuring an N-2-hydroxyethyl moiety. Their structures were determined by combined spectroscopic data (MS, UV, IR and NMR) and chemical methods.     

A New Lycopodine-type Alkaloid from Lycopodium japonicum

A new lycopodine-type alkaloid, 12β-hydroxy-acetylfawcettiine N-oxide (1), together with seven known analogues, acetyllycoposerramine M (2), lycopodine (3), lycoclavine (4), diphaladine A (5), lycoposerramine K (6), 11β-hydroxy-12-epilycodoline (7) and fawcettiine (8), were isolated from Lycopodium japonicum. Their structures were established by mass spectrometry and 1D and 2D NMR techniques. The isolated alkaloids were assayed for their inhibition activities against acetylcholinesterase, but no inhibitory activities for the compounds were detected.     

Two new Lycopodium alkaloids from Phlegmariurus phlegmaria (L.) Holub

Two new Lycopodium alkaloids, 4β-hydroxynankakurine B (1) and Δ^13,N,N_α-methylphlegmarine-N_β-oxide (2), together with three known analogues, lycoposerramine E (3), nankakurine B (4) and lobscurinol (5), were isolated from Phlegmariurus phlegmaria. Their structures were established by mass spectrometry and 1D and 2D NMR techniques.     

A new denudatine type C20-diterpenoid alkaloid from Aconitum sinchiangense W. T. Wang

A new denudatine-type C₂₀-diterpenoid alkaloid, designated as sinchianine (1), together with eight known diterpenoid alkaloids, 12-acetyl-12-epi-napelline (2), 12-epi-napelline (3), neoline (4), talatisamine (5), 14-O-acetylsenbusine A (6) and benzoylaconine (7), songorine (8) and aconitine (9), were isolated from the whole herb of Aconitum sinchiangense W. T. Wang. Their structures were elucidated on the basis of extensive spectroscopic analyses (NMR and HR-ESI-MS) and comparison with data reported in the literature.     

4-dehydroxyepisarcovagine A,a new steroidal alkaloid from Sarcococca pruniformis Lindl.

A new steroidal alkaloid, 4-dehydroxyepisarcovagine A (1), along with seven known alkaloids, sarcovagine D (2), sarcovagenine C (3), epoxysarcovagenine D (4), Pachysamine L (5), Pachysamine E (6), sarcovagine A (7) and sarcovagine B (8), was isolated from the roots and stems of Sarcococca pruniformis Lindl. The structure of compound 1 was elucidated by means of spectroscopic analysis.     

Indole alkaloids from leaves and stems of <Emphasis Type="Italic">Hunteria zeylanica</Emphasis>

Investigation of the leaves and stems of Hunteria zeylanica resulted in the isolation of one new indole alkaloid, 11-hydroxyrhazimanine (1), and nine known analogs 2–10. Their structures were determined by 1D and 2D NMR analyses. Decarbomethoxydihydrogambirtannin (2), dihydroantirhine (3), and 3-oxomehranine (4) were isolated from Hunteria genus for the first time.     

Two new monoterpenoid indole alkaloids from Alstonia rostrata

Two new indole alkaloids, winphyllines A (1) and B (4), along with four known alkaloids, N_b-demethylechitamine (2), 17-O-acetylnorechitamine (3), 12-methoxyechitamidine (5), and N(4)-demethylastogustine (6), were isolated from the methanol extract of the twigs of Alstonia rostrata. The structures of 1 and 4 were elucidated by means of HRMS and NMR spectroscopic methods. The in vitro cytotoxic activity of the isolated alkaloids against several human cancer cell lines was evaluated.     

New pyrazinoquinazoline alkaloids Isolated from a culture of Stenotrophomonas maltophilia QB-77

Two new pyrazinoquinazoline alkaloids, epi-fiscalin D (1) and epi-fiscalin E (2), as well as three known analogues, norquinadoline A (3), quinadoline A (4), and fiscalin C (5), were isolated from ethyl acetate extract of the fermentation broth of Stentrophomonas maltophilia QB-77. The structures of new compounds were elucidated on the basis of extensive spectroscopic data analysis including UV, HRESIMS, and 1D and 2D NMR experiments. All the isolated compounds were tested for their in vitro cytotoxicity against five human cancer cell lines (SMMC-7721, MCF-7, HL-60, SW480, and A-549) and antibacterial activities against Bacillus subtilis, Escherichia coli, and Staphylococcus aureus.     

Bioactive isoquinoline alkaloids from Cissampelos pareira†

The phytochemical and biological investigation of Cissampelos pareira leads to the isolation of one new isoquinoline alkaloid (7) along with six known isoquinoline alkaloids, namely, magnoflorine (1), magnocurarine (2), cissamine (3), curine (4), hayatinine (5) and cycleanine (6). Magnoflorine (1) and magnocurarine (2) were isolated for the first time from C. pareira. A new, rapid, simple and sensitive UPLC method was developed for simultaneous quantification of five pure compounds (1–5). Seasonal variation study revealed higher content of these compounds during the rainy season. The chloroform (CPCF) and n-butanol (CPBF) fractions showed cytotoxic efficacy against KB cells. Among pure compounds, hayatinine (5) was found to be most active against KB and A549, while, cycleanine (6) against KB cells.     

Furofuran lignans and alkaloids from Clinacanthus nutans

One new furofuran lignan 2-methoxy-9β-hydroxydiasesamin (1), and four analogues (2–5), together with eight alkaloids (6–13), were isolated from the ethanol extract of the aerial part of Clinacanthus nutans. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. All the compounds were isolated from the genus of Clinacanthus for the first time. In addition, lignans isolated from C. nutans was reported for the first time. Compound 1 exhibited modest activity against three human tumor cell lines Hela, MCF-7, and A549, with IC₅₀ values of 68.55, 60.00, and 59.17 μM, respectively.     

Two new β-carboline alkaloids from the roots of Gypsophila oldhamiana

Phytochemical investigation of the roots of Gypsophila oldhamiana afforded two new β-carboline alkaloids, oldhamiaines A and B (1 and 2), along with a known analogue (3). Their structures were elucidated by using spectroscopic and chemical methods. This is the first report of β-carboline alkaloids in the genus Gypsophila.     

Penicindopene A,a new indole diterpene from the deep-sea fungus Penicillium sp. YPCMAC1

A new indole diterpene, named penicindopene A (1), together with seven known compounds (2?–?8), was isolated from the deep-sea fungus Penicillium sp. YPCMAC1. The structure of penicindopene A was elucidated by extensive spectroscopic analyses (1?D and 2?D NMR, and HRESIMS data), in addition to the ECD calculations for the assignments of its absolute configuration. Penicindopene A represented the first example of indole diterpenes possessing a 3-hydroxyl-2-indolone moiety, and it exhibited moderate cytotoxicities against A549 and HeLa cell lines with IC₅₀ values of 15.2 and 20.5?µM, respectively.     

New furocarbazole alkaloids from Lonicera quinquelocularis

Two new furocarbazole alkaloids, 3-formyl-6,7-dimethoxy-furo[1,2]carbazole (1) and methyl-6,7-dimethoxy-furo[1,2]carbazole-3-carboxylate (2), along with two known carbazole alkaloids, 3-formyl-2-hydroxy-7-methoxycarbazole (3) and methyl 2,7-dimethoxycarbazole-3-carboxylate (4) were isolated from the ethyl acetate soluble fraction of Lonicera quinquelocularis. Their structures were established on the basis of spectroscopic analysis.     

Isolation and structure determination of a new diketopiperazine dimer from marine-derived fungus Aspergillus sp. SF-5280

A new diketopiperazine dimer designated as SF5280-415 (1) was isolated from an EtOAc extract of the marine-derived fungus Aspergillus sp. SF-5280 by various chromatographic methods. The structure of 1 was mainly determined by analysis of the NMR spectroscopic data and MS data, along with Marfey’s method. This compound is a new diastereoisomer of known bispyrrolidinoindoline diketopiperazine alkaloid WIN 64745, which possesses unique architecture biosynthetically derived from an indole oxidation reaction of tryptophan.     

New alkaloids from <Emphasis Type="Italic">Casimiroa edulis</Emphasis> fruits and their pharmacological activity

The extract of Casimiroa edulis was investigated for antihypertensive activity. The ethanol and total alkaloids (in chloroform) extracts were found to have antihypertensive properties at doses of 500 and 200 mg/kg, respectively. Four quinolinone alkaloids were isolated and identified as: 2-(2′-hydroxy-4′-methoxyphenyl)-5,8-dimethoxy-3-propyl-1H-quinolin-4-one (1), 5,8-dimethoxy-2-(3′-methoxyphenyl)-3-propyl-1H-quinolin-4-one (2), 5,8-dimethoxy-2-(3′,4′-dimethoxyphenyl)-3-propyl-1H-quinolin-4-one (3), and 5,6-dimethoxy-2-(2′,5′,6′-trimethoxyphenyl)-1H-quinolin-4-one (4). Interestingly, compounds 1, 2, and 3 were found to be new alkaloids. The four isolated alkaloids showed antihypertensive activity at doses of 50, 100, 200, and 300 mg/kg, respectively. Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 473–476, September–October, 2007.     

Two new alkaloids from Melodinus hemsleyanus Diels

Two new monoterpenoid indole alkaloids, named 14,15-dihydro-14β,15β-epoxy-10-hydroxyscandine (1) and 15α-hydroxy-meloscandonine (2), together with 12 known compounds, were isolated from the aerial parts of Melodinus hemsleyanus Diels. The structures of 1 and 2 were elucidated on the bases of 1D and 2D NMR spectra and MS. Two new compounds were evaluated for their PTP1B and Drak2 inhibitory effects, and inactivity.     

12α-hydroxy-N-demethyl-sauroxine,a lycodane type alkaloid from Phlegmariurus saururus

Abstract

12α-hydroxy-N-demethyl-sauroxine (1), another new Lycopodium alkaloid from the Lycodane group, was isolated from Phlegmariurus saururus (Lam.) B. Øllg. (Lycopodiaceae). Elucidation of the chemical structure and relative stereochemistry were stated by spectroscopic data and chemical correlation. In addition, the inhibitory activity on acetylcholinesterase for 1 was determined as well as for N-methyllycodine (2), a derivative with the same nucleus, previously identified in P. saururus (IC₅₀ = 33.8?±?0.8?μM and 547.5?±?0.5?μM, respectively) and N-demethylsauroxine (3) whose inhibition in the actual conditions was better than the previously informed.