Dehydroepiandrosterone - Wikipedia

High resolution MSn and 1H NMR analyses showed unequivocally that the CYP82Y1 reaction product derived from N-methylcanadine was 1-hydroxy-N-methylcanadine. Since none of the three CYP82 candidates accepted canadine as a substrate, and because neither CYP82X1 nor CYP82X2 acted on N-methylcanadine, the conversion of N-methylcanadine to 1-hydroxyl-N-methylcanadine by CYP82Y1 clearly represents the first committed step in noscapine biosynthesis and appears crucial to further elaboration of further pathway by other enzymes. CYP82X1 and CYP82X2 are likely responsible for cleavage of the N7/C8 bridge and hydroxylation of the C13 position. 1-Hydroxylation of N-methylcanadine distinguishes the biosynthesis of noscapine and narcotoline in opium poppy from the formation of other phthalideisoquinoline alkaloids, such as hydrastine and bicuculline which are found mostly in plants outside of the genus Papaver and lack a C4′ hydroxyl or methoxyl moiety. Should downstream enzymes in opium poppy depend on the C1 hydroxylation of N-methylcanadine in order to catalyze subsequent ring opening and lactone bridge conversions, the biosynthesis of compounds such as hydrastine and bicuculline might involve relatively unrelated genes. It will be interesting to determine whether homologs of CYP82Y1 and genomic clusters of phthalideisoquinoline alkaloid biosynthetic genes occur in plants such as goldenseal (Hydrastis canadensis) and Corydalis chaerophylla, which accumulate hydrastine and bicuculline, respectively. Interestingly, the C4′ methoxyl group contributes to the potent pharmacological properties of noscapine compared with other phthalideisoquinolines.

BERBERINE PowerPoint PPT Presentations ..

Figure ‎6.102-‎6.103‎6.104The structure of hydrastine,berberine and canadine.
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Goldenseal Rich in alkaloids berberine, hydrastine Potential ..

A major unresolved aspect of noscapine biosynthesis concerns the transformation of the protoberberine to the secoberbine backbone as a component in the ultimate formation of the phthalideisoquinoline scaffold. On structural grounds, secoberbine alkaloids, such as macrantaline and macrantoridine, were considered as possible intermediates between a protoberberine precursor, such as scoulerine or 1-methoxyscoulerine, and noscapine (). An alternative proposal involves the stereospecific N-methylation of scoulerine followed by multistage oxidation to egenine, which is further oxidized to phthalideisoquinoline alkaloids, such as bicuculline (). A protoberberine, such as scoulerine, has also been hypothesized to potentially undergo N-methylation and C8 oxidation to the secoberbine macrantaldehyde, which could be reduced to macrantaline or oxidized to macrantoridine (). Theoretically, macrantaldehyde could undergo oxidation to narcotinehemiacetal (). As such, a hypothetical scheme for noscapine biosynthesis in opium poppy was proposed whereby N-methylcanadine is hydroxylated at C1 and possibly O-methylated to form 1-methoxy-N-methylcanadine (). Oxidation of 1-methoxy-N-methylcanadine at C8 was seen as the entry point to the formation of a secoberbine intermediate, such as macrantaldehyde. The drawback of this hypothesis is the lack of empirical evidence for the occurrence of secoberbine alkaloids in opium poppy. Most known secoberbine alkaloids have been isolated from different Papaver species such as Papaver pseudo-oriental, Papaver armeiacum, and Papaver fugax (Sariyar 2002). However, the proposed pathway extrapolated from the partial physiological characterization of a putative noscapine biosynthetic gene cluster supports the natural occurrence of secoberbine alkaloids in opium poppy (). The individual suppression of transcript levels for six of ten clustered genes using VIGS was interpreted to suggest a biosynthetic route involving an initial ring opening (i.e., cleavage of the berberine bridge) on N-methylcanadine catalyzed by either CYP82X1 or CYP82Y1 and yielding a secoberbine intermediate. CYP82X2 was proposed to then catalyze hydroxylation at the C3 position, yielding a derivative of this secoberbine intermediate. The two schemes agree on the involvement of an enzymatic product derived from N-methylcanadine as the entry point to unidentified secoberbine intermediates in noscapine biosynthesis.

- Benzylisoquinoline alkaloid biosynthesis.

Three CYP families have been implicated in BIA metabolism (). Whereas several enzymes in the CYP80 and CYP719 families have been shown to catalyze aromatic hydroxylation and inter- and intramolecular C-O and C-C coupling reactions involved in 1-benzylisoquinoline, protoberberine, aporphine, bisbenzylisoquinoline, and morphinan alkaloid biosynthesis, only two members in the CYP82 family have been functionally characterized: CYP82N4 catalyzes aliphatic hydroxylation at C14 of N-methylcanadine and N-methylstylopine, resulting in tautomerization to allocryptopine and protopine, respectively (), whereas CYP82N2v2 from E. californica catalyzes aliphatic hydroxylation at C6 of protopine and allocryptopine leading to intramolecular rearrangement to the benzo[c]phenenthridine scaffold (). CYP82Y1 displays considerable sequence identity with CYP82N4 (53%) and CYP82N2v2 (44%) and, similar to CYP82N4, also accepted only N-methylcanadine and N-methylstylopine as substrates. In contrast, CYP82Y1 and CYP82N4 catalyze regiospecific hydroxylation at C1 and C14, respectively. Also, CYP82N4 converted both N-methylstylopine and N-methylcanadine at similar rates (), whereas PsCYP82Y1 converted N-methylcanadine with greater efficiency than N-methylstylopine. Alterations in the residues responsible for substrate recognition and alkaloid binding might be attributed to differences in substrate preference and oxidation activity among CYP82 variants. In contrast with the KPIAPXXXPH substrate recognition site motif of enzymes in the CYP719 family, CYP82Y1, CYP82X1, and CYP82X2 contain a distinct YPA(G/S)XXX(E/D)R domain and a conserved Gly-370 residue. However, whereas the residues specific for alkaloid binding in N-methylstylopine 14-hydroxylase (CYP82N4) () are Ile and Leu, the corresponding residues in CYP82Y1 are Leu and Ser (). CYP82N2v2 was relatively promiscuous with protopine alkaloid substrates, including protopine, allocryptopine, 13-oxoprotopine, and corycavine (). Other substituted quaternary protoberberine alkaloids beyond N-methylcanadine and N-methylstylopine could also serve as substrates for CYP82Y1 and CYP82N4, although such reactions might not be physiologically relevant. A narrow substrate range is common among CYPs involved in the biosynthesis of BIAs (–) and other plant-specialized metabolites. For example, CYP82G1 from tobacco (N. tabacum), which catalyzes the final step in the biosynthesis of common homoterpene volatiles, displays substrate specificity for (E,E)-geranyllinalool and its C15 analog (E)-nerolidol (), and CYP82C2 and CYP82C4 from mouse ear cress (A. thaliana) show substrate specificity for 8-methoxypsoralen ().

Literature References: Isoln of naturally occurring l-b-form from Hydrastis canadensis L., Ranunculaceae together with berberine and canadine
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5 Amazing Health Benefits of Berberine

Antibacterial mechanisms of s and herbs: The antibacterial activities of herbs are multi fold and depend upon the phytoconstituents, concentration of phytoconstituents/phytochemicals and bioactive principles and their synergistic as well as antagonistic actions (; ; ; ; ). These phtochemicals include flavonoids, steroids, β-carotene, anthocyanins, anthraquinones, glycosides, coumarins, alkaloids, saponins, tannins, alkaloids, gallic acid and others (; ; ; ; ; ; ; ; ). Various mechanisms of action and antibacterial abilities of herbal remedies relies on their several beneficial properties viz., immunomodulatory nature with enhancement of both humoral and cell mediated immunity as well ameliorating stress and immunosuppression; cytokine regulation; anti-inflammatory, antioxidative and inhibiting pathogens by a variety of pathways (; ; ; ; ). Many herbs have anti-oxidative potential by counteracting s or metaboloites produced during various biochemical pathways (; ; , ; ). A vast number of herbal plants show anti-inflammatory action by selective inhibition of cyclooxygenase-2, 5-lipoxygenase, glutathione S-transferase and thus inhibiting the prostaglandin biosynthesis. Several herbs decreases the production of of inflammatory agents (histamine, bradykinin, serotonin), enhance activity of cortisol and augments bllod circulation which help removing bacterial toxins out of the body (; ). Certain plants contain and carotenoids which have been found to augment both humoral and cell-mediated immune function, thereby reducing risk of infectious by enhancing the antigenic surveillance of the immune system (; ; ; ). Immunomodulation of most of herbal extracts are governed by cytokine regulation as well as anti-inflammatory properties (; ; ; ; ). Certain plants facilitate proliferation of CD4+ T-helper and B type immune cells. Others have been found beneficial in blocking bacterial adherence to different body cells thus help preventing the infection; blocking NF-êB pathway and the motogenic responses in infected cells; causing damage to cell membrane with loss of electrolytes and intracellular contents leading to bacteria death; downregulating the synthesis of LasA protease, LasB elastase and AHL molecules which inhibits the bacterial pathogenesis phenomenon by quorum sensing (; ; ; ; ; ; ; ). Steroidal alkaloids and steroidal lactones present in herbs enhance engulfing activity of macrophages, increases the activity of white blood cells and other immune cells which in turn enhances their antimicrobial potentials (; ; ; ). All these factors decide the ultimate effect on host and pathogens and remedial effects of various herbs. Such mechanisms of actions, nature of phytoconstituents and potential antibacterial role/applications of many well established herbs and s have been briefly enlisted in and depicted in .

Ipecac emetine hydrastis berberine, hydrastine sanguinaria ..

Noscapine is a phthalideisoquinoline alkaloid investigated for its potent pharmacological properties. Although structurally elucidated more than a century ago, the biosynthesis of noscapine has not been established. Radiotracer studies have shown that noscapine is derived from the protoberberine alkaloid (S)-scoulerine and has been proposed to proceed through (S)-N-methylcanadine. However, pathway intermediates involved in the conversion of N-methylcanadine to noscapine have not been identified. We report the isolation and characterization of the cytochrome P-450 CYP82Y1, which catalyzes the 1-hydroxylation of N-methylcanadine to 1-hydroxy-N-methylcanadine. Comparison of transcript and metabolite profiles of eight opium poppy chemotypes revealed four cytochrome P-450s, three from the CYP82 and one from the CYP719 families, that were tightly correlated with noscapine accumulation. Recombinant CYP82Y1 was the only enzyme that accepted (R,S)-N-methylcanadine as a substrate with strict specificity and high affinity. As expected, CYP82Y1 was abundantly expressed in opium poppy stems where noscapine accumulation is highest among plant organs. Suppression of CYP82Y1 using virus-induced gene silencing caused a significant reduction in the levels of noscapine, narcotoline, and a putative downstream secoberbine intermediate and also resulted in increased accumulation of the upstream pathway intermediates scoulerine, tetrahydrocolum-bamine, canadine, and N-methylcanadine. The combined biochemical and physiological data support the 1-hydroxylation of (S)-N-methylcanadine catalyzed by CYP82Y1 as the first committed step in the formation of noscapine in opium poppy.

A PERSPECTIVE ON THE ANTI-INFECTIVE ACTIVITY OF …

The main active constituents are themixture of alkaloids; the main component is morphine. The additional alkaloidsinclude codeine, thebaine, papaverine, narcotine and narceine. Otherconstituents are different organic acids, e.g. meconic acid, fumaric acid,malic acid and succinate acid, sugars, amino acids and water.