Two-dimensional NMR studies of marine natural products. 2. Utilization of two-dimensional proton double quantum coherence NMR spectroscopy in natural products structure elucidation on - determination of long-range couplings in plumericin

Martin, Gary E.; Sanduja, Radhika; Alam, Maktoob

doi:10.1021/jo00213a039

Cited by 26 publications

(24 citation statements)

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“…The present work, our previous work [20] and that of Fesik and co-workers [21] have demonstrated the utility of the proton double quantum nmr experiment in structure elucidation and complex proton assignment problems. Corollary information is provided by the combined acquisition of COSY and RCOSY spectra although both of these experiments have shortcomings when highly congested spectral regions must be interpreted, a difficulty circumvented by the proton double quantum experiment.…”

Section: "supporting

confidence: 62%

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ChemInform Abstract: Two‐Dimensional NMR Studies of Marine Natural Products. Part 4. Isolation of the Cembranoid Diterpene Jeunicin from the Mollusc Planaxis sulcatus: Assignment of the Proton and Carbon NMR Spectra by Two‐Dimensional Techniques.

Sanduja¹,

Linz²,

Alam³

et al. 1986

Chemischer Informationsdienst

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Numerous cembranoic diterpenes have been isolated from marine gorgonians and terrestrial plants. There have, however, been only a few reports of the isolation and identification of these interesting compounds from higher animal sources. The isolation of the oxo‐bridged cembranoid diterpene jeunicin from the mollusc Planaxis sulcatus is reported. A comparative discussion of the utility of COSY, homonuclear RELAY (relayed COSY) and proton double quantum coherence techniques is presented, the latter successfully establishing the identities of all of the proton resonances. Acquisition of a two‐dimensional proton‐carbon chemical shift correlation spectrum provided the means of unequivocally establishing 13C resonance assignments.

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Section: "supporting

confidence: 62%

“…The data was collwted as 512 X 2K blocks of data using the pulse sequence shown in Figure 2 using the 32 step phase cycle as previously reported [20,34]. The data was collwted as 512 X 2K blocks of data using the pulse sequence shown in Figure 2 using the 32 step phase cycle as previously reported [20,34].…”

Section: "mentioning

confidence: 97%

ChemInform Abstract: Two‐Dimensional NMR Studies of Marine Natural Products. Part 4. Isolation of the Cembranoid Diterpene Jeunicin from the Mollusc Planaxis sulcatus: Assignment of the Proton and Carbon NMR Spectra by Two‐Dimensional Techniques.

Sanduja¹,

Linz²,

Alam³

et al. 1986

Chemischer Informationsdienst

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“…methanol/CH 2 Cl 2 ) concentrated the activity in the dichloromethane fraction (IC 12 ϭ380 mg/ml). Chromatographic purification of this fraction led to the isolation of a known iridoid lactone, plumericin (1), 11) responsible for the DNA damaging activity of the extract. The activity observed was relatively weak, with an IC 12 value of 70 mg/ml for the RS321 yeast strain.…”

Section: Resultsmentioning

confidence: 99%

A Bioactive Spirolactone Iridoid and Triterpenoids from Himatanthus sucuuba.

Wood

Lee

Vaisberg

et al. 2001

CHEMICAL & PHARMACEUTICAL BULLETIN

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Himatanthus sucuuba, SPRUCE (M. ARG.) WOODSON (Apocynaceae) ("Bellaco-Caspi"), a tree from the Amazon rain forest, has received much attention in the literature for the treatment of various ailments, although the ethnobotanical information is somewhat contradictory. For example, in Perú, an infusion from the stem bark has been used as wound-healing agent, for the treatment of tumors, boils and swellings, against arthritis, as a vermifuge laxative, 1) and as hallucinogen.2) In Brazil, on the other hand, the dried bark is alleged to have anti-ulcer and aphrodisiac activities whereas the latex is used as an antitumor agent.3) The Caboclos in the Amazon use the dried stem bark for its analgesic and anti-tussive activities. 4) In Colombia, the root is said to be very poisonous. 5)The toxicity of the reproductive system and teratogenic potential of the stem bark have been investigated. 6) Recently, two lichen depsides found in the bark of H. sucuuba, have shown inhibition against monoamine oxidase-B.7) The in vivo cicatrizant activity of H. sucuuba has been investigated by our group. Although, in an initial experiment, an extract of the bark of H. sucuuba showed significant cicatrizant activity, this result could not be reproduced in subsequent runs.8) An acute toxicity screening-after i.p. administration of 0.1 to 1 mg of extract per gram of mouse weight-determined that H. sucuuba was non-toxic in this range.As part of our systematic search for potential anti-cancer agents from plants, 9) an extract of the bark of H. sucuuba underwent a mechanism-based bioassay fractionation. Our assay uses engineered yeasts which lack the RAD52 DNA repair pathway, one of the three major DNA repair pathways that have been defined in yeast, and may also lack the gene for topoisomerase I.10) An extract which inhibits these yeast mutants to a greater extent than it inhibits the wild-type strain RS188N is thus expected to contain agents which induce DNA damage. Results and DiscussionThe ethanolic extract of the bark of H. sucuuba [IC 12 ϭ 4000 mg/ml (RS321)] was partitioned between hexane and 80% aq. methanol, resulting in enhanced activity in the latter fraction. Further partitioning (60% aq. methanol/CH 2 Cl 2 ) concentrated the activity in the dichloromethane fraction (IC 12 ϭ380 mg/ml). Chromatographic purification of this fraction led to the isolation of a known iridoid lactone, plumericin (1), 11) responsible for the DNA damaging activity of the extract. The activity observed was relatively weak, with an IC 12 value of 70 mg/ml for the RS321 yeast strain. For comparison purposes, the known active agent streptonigrin 12) has an IC 12 value of 0.65 mg/ml against RS321. Compound 1 is a known antifungal which has been isolated previously from H. sucuuba 7) and other Himatanthus species.13)The non-polar (hexane) fraction was investigated for its in vitro differential cytotoxic activity using various cancer cell lines (H460, ME180, DU145, MCF-7, HT29). The resulting 50% growth inhibition (GI 50 ) values were greater than the control (BA...

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“…Moreover it is convenient to consider zero-quantum coherence as a rotating monopole, single-quantum coherence as a dipole, and double-quantum coherence as a quadrupole and so on, so that ZQC may be expected to be relatively insensitive to the phases of the applied pulses, thereby allowing a simpler 4-step cycle to be used in comparison to the 32-step time-consuming phase cycling procedure required in the HDQC experiment (ref. 25,26). The ZQC spectrum of strychnine is shown in Fig.…”

Section: Improved Hzqc Methodsmentioning

confidence: 99%

2D Multiple-Quantum Spectroscopy

Rahman

1989

One and Two Dimensional NMR Spectroscopy

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Two-dimensional NMR studies of marine natural products. 2. Utilization of two-dimensional proton double quantum coherence NMR spectroscopy in natural products structure elucidation on - determination of long-range couplings in plumericin

Cited by 26 publications

References 0 publications

ChemInform Abstract: Two‐Dimensional NMR Studies of Marine Natural Products. Part 4. Isolation of the Cembranoid Diterpene Jeunicin from the Mollusc Planaxis sulcatus: Assignment of the Proton and Carbon NMR Spectra by Two‐Dimensional Techniques.

ChemInform Abstract: Two‐Dimensional NMR Studies of Marine Natural Products. Part 4. Isolation of the Cembranoid Diterpene Jeunicin from the Mollusc Planaxis sulcatus: Assignment of the Proton and Carbon NMR Spectra by Two‐Dimensional Techniques.

A Bioactive Spirolactone Iridoid and Triterpenoids from Himatanthus sucuuba.

2D Multiple-Quantum Spectroscopy

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