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.
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 was shown to have an empirical formula of C34H24N4O 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. One portion of the structure of cryptospirolepine [2] may be biogenetically derived from cryptolepine [1],Cryptolepis sanguinolenta (Lindl.) Schlechter (Asclepiadaceae), a shrub indigenous to West Africa, has long been employed by Ghanaian traditional healers in the treatment of various fevers, including malaria (1). A root decoction has been used in the clinical therapy both of malaria and of urinary and upper respiratory tract infections by Oku Ampofo at the Centre for Scientific Research into Plant Medicine in Ghana since 1974 (1). The indoloquinoline alkaloid cryptolepine (5-methyl-5H-indolo-[3,2-¿}quinoline) [1] was first isolated from extracts of the roots of Cryptolepis triangularis N. E.Br., a species native to the Belgian Congo, by Clinquart in 1929 (2). Shortly thereafter, the alkaloid was again isolated from the same species by Delvaux (3). Quite paradoxically, cryptolepine had been synthesized some 20 years prior by Fichter and coworkers (4-6). Cryptolepine was isolated from a Nigerian sample of Cr. sanguinolenta in 1951 by Gellert et al. (7). Almost 30 years later, the alkaloid was isolated from a
The Dietary Supplements Information Expert Committee (DSI-EC) of the United States Pharmacopeial Convention (USP) reviews the safety of dietary supplements and dietary supplement ingredients for the purpose of determining whether they should be admitted as quality monographs into the United States Pharmacopeia and National Formulary (USP-NF). The United States Food and Drug Administration (FDA) has enforcement authority to pursue a misbranding action in those instances where a dietary supplement product indicates that it conforms to USP standards but fails to so conform. Recently DSI-EC undertook a safety evaluation of spirulina, a widely used dietary ingredient. DSI-EC reviewed information from human clinical trials, animal studies, and regulatory and pharmacopeial sources and analyzed 31 adverse event reports regarding spirulina to assess potential health concerns. At the conclusion of this review, DSI-EC assigned a Class A safety rating for Spirulina maxima and S. platensis, thereby permitting the admission of quality monographs for these dietary supplement ingredients in USP-NF. DSI-EC continually monitors reports concerning the safety of dietary supplements and dietary supplement ingredients for which USP dietary supplement monographs are developed. The DSI-EC may revisit the safety classification of spirulina as new information on this dietary ingredient becomes available.
An HPLC single-laboratory validation was performed for the detection and quantification of the 11 major cannabinoids in most cannabis varieties, namely, cannabidiolic acid (CBDA), cannabigerolic acid (CBGA), cannabigerol (CBG), cannabidiol (CBD), tetrahydrocannabivarin (THCV), cannabinol (CBN), Δ9-trans-tetrahydrocannabinol (Δ9-THC), Δ8-trans-tetrahydrocannabinol (Δ8-THC), cannabicyclol (CBL), cannabichromene (CBC), and Δ9-tetrahydrocannabinolic acid-A (THCAA). The analysis was carried out on the biomass and extracts of these varieties. Methanol-chloroform (9:1, v/v) was used for extraction, 4-androstene-3,17-dione was used as the internal standard, and separation was achieved in 22.2 min on a C18 column using a two- step gradient elution. The method was validated for the 11 cannabinoids. The concentration-response relationship of the method indicated a linear relationship between the concentration and peak area with r2 values of >0.99 for all 11 cannabinoids. Method accuracy was determined through a spike study, and recovery ranged from 89.7 to 105.5% with an RSD of 0.19 to 6.32% for CBDA, CBD, THCV, CBN, Δ9-THC, CBL, CBC, and THCAA; recovery was 84.7, 84.2, and 67.7% for the minor constituents, CBGA, CBG, and Δ8-THC, respectively, with an RSD of 2.58 to 4.96%. The validated method is simple, sensitive, and reproducible and is therefore suitable for the detection and quantification of these cannabinoids in different types of cannabis plant materials.
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.
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