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Cryptospirolepine is the most structurally complex alkaloid discovered and characterized thus far from any Cryptolepis specie. Characterization of several degradants of the original, sealed NMR sample a decade after the initial report called the validity of the originally proposed structure in question. We now report the development of improved, homodecoupled variants of the 1,1- and 1,n-ADEQUATE (HD-ADEQUATE) NMR experiments; utilization of these techniques was critical to successfully resolving long-standing structural questions associated with crytospirolepine.

Identification of degradants of pharmaceuticals is a necessary challenge of the drug development process following the subjection of candidate molecules to a variety of physico-chemical stresses. It would be desirable to be able to conduct such studies on a minimal amount of material. As a prototypical study, the isolation and identification of degradants of a sample of the complex indoloquinoline alkaloid, cryptospirolepine, was undertaken after prolonged storage in DMSO solution using a combination of cryogenic NMR probe technology and CASE (Computer-Assisted Structure Elucidation) programs. None of the starting alkaloid remained after storage; a chromatogram of the DMSO solution demonstrated the presence of >25 components in the mixture. The two most abundant degradation products were identified as the known alkaloid cryptolepinone (∼35%) and an unprecedented rearrangement product, DP-2, (∼16%).

A direct comparison of the spectral data for synthetic 2-methyl-6,7-dimethoxy-3'-methoxy-4'-hydroxyoxobenzylisoquinoline iodide (1) and its positional isomer 2-methyl-6,7-dimethoxy-3'-hydroxy-4'-methoxyoxobenzylisoquinoline iodide (2) with the data obtained for the oxobenzylisoquinoline alkaloid thalprzewalskiinone revealed that the original structural assignment of the alkaloid as 1 was in error. These results mandate the revision of structure of thalprzewalskiinone to 2-methyl-6,7-dimethoxy-3'-hydroxy-4'-methoxyoxobenzylisoquinoline iodide (2).

The USP Sub com mit tee on Natural Prod ucts was formed in the summer of 1995. Its principal charge was to explore the feasibility and advisability of establishing standards (monographs) for botanical dietary suppiements. This paper describes the work of the Committee over the past five years, in cluding the development of a proto typic botanical monograph, limit tests, marker sub stances, refer ence stan dards, botani al ex racts, botanical dos age forms and publication with in Pharma copeial Forumana the USP24/NF (2000). Thirty-ninemonographs featuring twenty-one botanicals considered as dietary sup piements were developed by the Sub committee over this period. The paper coneludes with men tion of the new Dietary Sup pie ments: Bo tani cals Expert Commit tee that was elected at the 2000 Quinquennial Meeting, and with the proposed plan of action that this com mittee has adopted for the next five yoars.

The nmr analysis of a mixture of cryptolepinone and it's 5(N)-oxide in a 1.5:1 ratio is discussed. The differentiation of the resonances of the two similar compounds, and elucidation of the unknown 5(N)-oxide relied primarily on IDR-GHSQC-TOCSY data in conjunction with ROESY, GHSQC, and GHMBC experiments.

Direct and long-range 1H–15N correlations for cryptolepinone and its N5-oxide as a mixture in DMSO-d6 were determined using a combination of 1H–15N GHSQC and GHMBC experiments. The 15N chemical shifts of cryptolepinone in the mixture were comparable to those reported previously for a pure sample of the alkaloid. Following N-oxidation, the N-5 resonance shifted from 103.4 ppm in cryptolepinone to 188.1 ppm (+84.7 ppm) in the N5-oxide. The N-10 resonance is also shifted from 111.4 ppm downfield by +23.9 ppm to 135.3 ppm in the N-oxide. The downfield shift observed for N-10 is attributed to a transfer of electronic effects via the intervening C-5a—C-10a carbon–carbon double bond in a manner comparable to that observed for fully aromatic diazines and their corresponding N-oxides, although the shift of N-10 is in the opposite direction of that observed for diazine systems and their N-oxides. The downfield shift of N-10 is consistent with the calculated partial charges at N-10 before and after oxidation, which are identical in sense with the partial charges at N-5, the actual site of oxidation, although much smaller in magnitude. © 1999 John Wiley & Sons, Ltd.

An indolo[3,2-b]quinoline alkaloid bearing an N-methyl substituent at N5, and an oxygen moiety at the 11-position has been variously described as both cryptolepinone and 11-hydroxycryptolepine by independent research groups. The structure of this alkaloid is unequivocally confirmed as the former, cryptolepinone, with substantial changes in double bond isomerization relative to that which would be required if it were indeed the latter. The structure of the alkaloid was confirmed by, total assignment of the 1H, 13C, and 15N nmr spectra at natural abundance using 3 mm micro inverse nmr probe technology at 400 and 500 MHz.

The isolation and structure determination of cryptomisrine, a novel indolo[3,2-b]quinoline dimeric alkaloid obtained from extracts of the roots of the Ghanaian medicinal plant Cryptolepis sanguinolenta is reported. The structure determination was made via a consideration of the spectral data, including uv, ir, nmr, and mass spectra. In particular, one-dimensional proton/carbon nmr, one-dimensional nOe difference nmr, and a series of homonuclear (COSY) and inverse-detected heteronuclear two-dimensional (HMQC, HMBC) experiments were utilized, as well as high resolution FABMS. Cryptomisrine is most unusual in that its two monomeric parts apparently exist in such a C2 symmetric environment that only one set of proton and carbon nmr resonances are observed. Cryptomisrine is the first example of a dimeric indolo-[3,2-b]quinoline alkaloid to have been isolated from nature.

The roots of the indigenous West African shrub Cryptolepis sanguinolenta have proved to be a rich source of indoloquinoline alkaloids. To date, all of the alkaloids isolated have been analogs of indolo[3, 2-b]quinoline. We now wish to report examples of two new indoloquinoline alkaloids which differ in the fusion of the indole and quinoline rings. The first, cryptosanguinolentine, is an angular indolo[3, 2-c]quinoline. The second, cryptotackieine, is a linear indolo[2, 3-b]quinoline system. Both of these families of alkaloids are without precedent from C. sanguinolenta. The structures of both were established through the extensive use of inverse-detected micro nmr methods.

Cryptolepis sanguinolenta (Lindl.) Schlechter (Asclepiadaceae), a shrub indigenous to West Africa, has been employed by traditional healers in the treatment of various fevers, including malaria. Column chromatography of the alkaloid fraction obtained from a defatted ethanolic extract of the roots of the plant afforded the previously characterized alkaloids cryptolepine, quindoline and cryptospirolepine. Continued extensive column chromatography, followed by preparative high-performance liquid chromatography, resulted in the isolation of nine new alkaloids, including approximately 100 μg of a novel indoloquinoline-β-carboline dimeric alkaloid, cryptolepicarboline. The structure was elucidated through the use of a combination of spectroscopic techniques which included UV, Fourier transform, electron impact mass spectrometry, and 500 MHz NMR spectroscopy. NMR data included 1D 1H and 13C reference spectra, the latter recorded in 40 μl of DMSO-d6 using a new Varian heteronuclear Nano-probe and in 140 μl of DMSO-d6 using a Nalorac carbon-optimized microprobe. These 13C NMR spectra allow the first direct comparison of these two probe formats. Homonuclear 2D NMR data acquired included both COSY and ROESY spectra. The homonuclear 2D experiments were variously performed in both a homonuclear Nano-probe and micro-inverse detection probes. Heteronuclear shift correlation experiments included HMQC, HMBC and IDR (inverted direct response)-HMQC-TOCSY spectra, which were uniformly performed using a 500 MHz Nalorac micro inverse-detection probe.

The structure of a new indolobenzazepine alkaloid, homocryptolepinone, isolated from extracts of the roots of the indigenous Ghanaian medicinal plant Cryptolepis sanguinolenta, is reported. The structure was determined using mass spectrometric, one-dimensional nOe difference nmr, and inverse-detected two-dimensional nmr experiments which included HMQC, IDR-(Inverted Direct Response)-HMQC-TOCSY, and HMBC experiments. The structure of homocryptolepinone is significant in that it may provide insight into the biogenesis of the benzpyrrolizinobenzazepine portion of the structure of the complex spiro nona-cyclic alkaloid cryptospirolepine previously isolated in these laboratories from C. sanguinolenta, and which has no precedent in alkaloid chemistry.

From the alkaloidal fractions of the West African plant Cryptolepis sanguinolenta (Asclepiadaceae), two alkaloids were purified: one was identified as the known indoloquinoline alkaloid cryptolepine [1]. A second, novel alkaloid has shown to have an empirical formula of C 34 H 24 N 4 O based on exact mass measurement. Through the concerted application of a series of homonuclear and inverse-detected 2D nmr experiments, the structure of the second alkaloid was established as a spiro-nonacyclic alkaloid, cryptospirolepine

The reisolation of the indoloquinoline alkaloid quindoline (also known as norcryptolepine) from Cryptolepis sanguinolenta is reported. The structure was unequivocally confirmed by two-dimensional nmr methods; the proton and carbon spectra were assigned for the first time. Because of congestion in the proton spectrum HMQC-TOCSY was used as an alternative to the more familiar COSY experiment. In addition to establishing proton-proton connectivities, HMQC-TOCSY affords the added benefit of providing, in an indirect sense, connectivity information between protonated carbons.

The relatively rare alkaloid cryptolepine, 5-methyl-5H-indolo[3,2-b]quinoline, was isolated from Cryptolepis sanguinolenta (Lindl.) Schlecter (Asclepiadaceae). Unequivocal proton and carbon nmr assignments in dimethyl sulfoxide are reported based on two-dimensional nmr methods, including COSY, inverse-detected direct (HMQC), and long-range (HMBC) correlations. Several of the assignments were confirmed using one-dimensional SIMBA spectra - a new, selective, one-dimensional analogue of the proton-detected long-range heteronuclear shift correlation experiment (HMBC). The SIMBA experiment was also used in an attempt to observe a two-bond coupling from the H11 proton to C10a at several optimizations.

A novel β-hydroxychalcone, galiposin (1), was isolated from the bark of Galipea granulosa. The structure of galiposin was established via spectroscopic analysis, including high resolution one- and two-dimensional nuclear magnetic resonance spectrometry, as well as mass spectroscopy.

This manuscript reviews the history and pharmacognosy of ergot, and describes the isolation/preparation, chemistry, pharmacodynamics, and pharmacotherapeutics of the major ergot alkaloids and their derivatives. A brief discussion of the hallucinogenic properties of lysergic acid diethylamide is also featured. An abbreviated form of the material found in this paper is presented in a 4-hour didactic format to third-professional year PharmD students as part of their study of vascular migraine headaches, Parkinson's disease, and naturally occurring hallucinogens/hallucinogen derivatives in the modular course offering Neurology/Psychiatry.

The development of USP botanical dietary supplement monographs by the Subcommittee on Natural Products (1995-2000) and the Dietary Supplements-Botanicals Committee of Experts (2000-2005) of the USP is described in this review. Featured details include the USP as an organization, focusing upon its history, mission, and publication of the United States Pharmacopeia-National Formulary (USP-NF); the formulation and composition of botanical dietary supplement monographs and related general chapters, as well as appropriate admission criteria; and a summary of the accomplishments of the Committees (1995-2005).

A novel chromone, granulosin (1), has been isolated from the bark of Galipea granulosa. The extract of the bark, as well as granulosin (1), exhibited lethality in the brine shrimp test. The structure of granulosin (1) as 2-propyl-7,8-(methylenedioxy)chromone was established via spectroscopic analysis.

The aporphine alkaloids (+)-isocorydine, (-)-3-hydroxynuciferine, and 3-hydroxy-6a,7-dehydronuciferine were isolated from the alkaloid fraction of an ethanol extract of the leaves of Ocotea brenesii Standley. Although (+)-isocorydine has been isolated from extracts of several Ocotea species previously, this is the first reported isolation of (-)-3-hydroxynuciferine and 3-hydroxy-6a,7-dehydronuciferine from this genus. Finally, to our knowledge, this is the first reported isolation of (-)-3-hydroxynuciferine from nature, although the compound was previously synthesized from nuciferine. In addition, it is only the second reported isolation of 3-hydroxy-6a,7-dehydronuciferine from a higher plant.

Long-range 1 H- 15 N GHMQC spectra afford a viable means of beginning to incorporate 15 N into strategies to elucidate the structures of potentially novel alkaloids. Long-range 1 H- 15 N heteronuclear shift correlation using a variant of the gradient-enhanced HMQC pulse sequence is demonstrated at 15 N natural abundance using the indoloquinoline alkaloid cryptolepine.

Fractionation and chromatography of the ethanolic extract of the roots of Thalictrum angustifolium L. (Ranunculaceae) afforded five alkaloids: noroxyhydrastinine (1), O-methylthalicberine (2), berberine iodide (3), jatrorrhizine iodide (4), magnoflorine iodide (5). In addition, one simple aromatic compound, methyl-4-hydroxybenzoate (6), was also isolated. These compounds were identified via comparison of their spectral data with authentic compounds or spectra available within our laboratory. This is the first reported isolation of these compounds from this species.

In the search for antiprotozoal compounds from natural sources, Triclisia patens displayed activity against L. donovani promastigotes (IC(50) = 1.5 microg/mL) and T. b. brucei blood stream trypomastigote forms (IC(50) = 31.25 microg/mL). In addition, a total of 20 bisbenzylisoquinoline alkaloids were screened for antileishmanial and antitrypanosomal activity in vitro. Fangchinoline (IC(50) = 0.39 microM) was found to be as active as the standard pentamidine against Leishmania donovani promastigotes. Phaeanthine was three-fold more active (IC(50) = 2.41 microM; 1.5 microg/mL) than the standard drug Pentostam against L. donovani amastigotes, but at this concentration was toxic to murine macrophages. In contrast, cocsoline (IC(50) = 12.3 microM; 6.76 microg/mL) was as active as Pentostam, and was not toxic to macrophages at this concentration. Thalisopidine showed the strongest activity (IC(50) = 1.14 microM) against Trypanosoma brucei brucei blood stream form trypomastigotes, but was less active than pentamidine.

A novel tetrahydroprotoberberine-aporphine dimeric alkaloid, (-)-thalibealine (1), was isolated from the roots of Thalictrum wangiii, and its structure established via spectroscopic analysis. Three other alkaloids were isolated, including the benzyltetrahydroisoquinoline-aporphine dimer (+)-thalmelatidine, the aporphine (+)-magnoflorine, and the protoberberine berberine. This is the first reported isolation of a tetrahydroprotoberberine-aporphine dimer from nature, as well as the first reported isolation of constituents from Thalictrum wangii.

Four flavonoids 5,7,4′-trihydroxy-3,3′-dimethoxyflavone (3′,3′-di-O-methylquercetin) (1), 5,4′-dihydroxy-3,7-dimethoxyflavone (kumatakenin) (2), 5,4′-dihydroxy-6,7,8,-trimethoxyflavone (xanthomicrol) (3) and 5,7,4′-trihydroxy-3,6,3′-trimethoxyflavone (jaceidine) (4) were isolated and identified from the Jordanian Varthemia iphionoides. They have not previously been reported in this genus. The aqueous alkaline solution of these compounds showed little or no activity against the bacteria Staphylococcus aureus, Bacillus cereus and Salmonella typhimurium. Compound 2 was active against the fungi Fusarium solani and Candida tropicalis while compounds 1 and 3 were much more active against F. solani, Aspergillus parasiticus and C. tropicalis.

The isolation and identification of aporphinoid alkaloids from two Costa Rican Guatteria species is described. The aporphine alkaloids (−)-anonaine, (+)-isocorydine, (−)-roemerine and the oxoaporphine alkaloid liriodenine were isolated from Guatteria oliviformis while the aporphine alkaloids (−)-anolobine and (−)-roemeroline, along with the oxoaporphine alkaloid O-methylmoschatoline, were isolated from Guatteria tonduzii.

The isolation and identification of six alkaloids from the whole plant of Thalictrum delavayi are described. The alkaloids isolated were the aporphines (+)-isocorydine, (+)-Ieucoxylonine, (+)-ocoteine, and (+)-magnoflorine; the bisbenzylisoquinoline alkaloid (+)-hernandezine; and the phenanthrene alkaloid thalicthuberine.

A novel oxobenzylisoquinoline alkaloid, thalprzewalskiinone (1), was isolated from the roots of Thalictrum przewalskii, and its structure was established via spectroscopic analysis. Five other alkaloids were isolated: the protoberberines pseudocoptisine and berberine, the aporphines (+)-N-methylnantenine and (+)-magnoflorine, and the simple isoquinolone N-methyl-6,7-dimethoxyisoquinolone. Isovanillin was also isolated from this extract.

Quantities of material required for structural analysis were reduced substantially following the introduction of 3 mm microinverse and microdual NMR probes in 1992. We now report the first very low-level results obtainable with a new 1.7 mm submicro-inverse-detection gradient or SMIDG NMR probe. Using this technology at 600 MHz, it was possible to fully characterize an 8% impurity contained in a 0. 55mgr;mol sample of cryptolepine (1) that had been standing in excess of 2 years since its initial isolation. The impurity was unequivocally identified as cryptolepinone (2) through the concerted interpretation of GHSQC, GHMBC, homonuclear TOCSY, and ROESY spectra in conjunction with APCI LC/MS and CID data acquired from a portion of the serial dilution solution used to prepare the NMR sample. Submicro-inverse-detection gradient probes offer the prospect of reducing still further the quantities of sample required for full characterization under favorable circumstances, making rare and potentially novel natural products amenable to structural determination. SMIDG NMR technology is equally applicable to a range of small samples requiring characterization such as isolated impurities from drug substances, isolates from drug degradation studies, and secondary metabolites.

Publisher Summary This chapter discusses the chemistry and pharmacology of the thalictrum alkaloids. Many of these alkaloids have interesting and important pharmacological properties, and a plethora of studies involving the biological evaluation of these compounds have been undertaken and published. The purpose of this work is to review the research that has been published in the last decade. This chapter summarizes the isolation and identification of the alkaloids of Thalictrum cultratum Wall. The plant was collected in Azad Kashmir, Pakistan, and extracts of the whole plant proved to be a uniquely prolific source of benzylisoquinoline-derived alkaloids, including monomers of the aporphine, pavine, phenanthrene, and protoberberine groups, and dimers of the bisbenzylisoquinoline, secobisbenzylisoquinoline, and aporphine-benzylisoquinoline groups. Eighteen bisbenzylisoquinoline alkaloids were isolated, with these compounds belonging to the thalisopine, thalicberine, thalidasine, and thalmine series.

The structure of the isoquinolone alkaloid thalflavine, originally proposed as 1-oxo-2-methyl-5-methoxy-6,7-methylenedioxy-1,2,3,4-tetrahydroisoquinoline, is revised to 1-oxo-2-methyl-5,6-methylenedioxy-7-methoxy-1,2,3,4-tetrahydroisoquinoline, on the basis of synthesis.

The isolation and identification of 12 alkaloids from an extract of the roots of Thalictrum isopyroides is described. The alkaloids isolated are the aporphines ocoteine (thalicmine), thaliporphine, preocoteine, N -methyllaurotetanine, delporphine, isoboldine, N -methylcassythine and magnoflorine, the dehydroaporphine, dehydroocoteine, the oxoaporphine, thalicminine, and the bisbenzylisoquinolines, thaligosinine and thalisopidine.