Does D-Carnitine exist?

Answer from top 10 papers

D-Carnitine, an enantiomer of the naturally occurring L-carnitine, does exist. L-carnitine is a compound involved in the metabolism of fatty acids in living organisms. While the L-form is biologically active and naturally occurring, the D-form can also be synthesized, although it is not produced in vivo and is considered biologically inactive in terms of fatty acid metabolism. The existence of D-carnitine is acknowledged in the context of stereoisomers, similar to the stereoisomers of picrasidine Y synthesized from tartaric acid (Salama, 2021).
Interestingly, the presence of D-carnitine is not directly discussed in the provided papers, which focus on various other naturally occurring compounds and their applications or effects. For instance, the papers discuss the synthesis and applications of β-carboline alkaloids (Salama, 2021), hydronopylformamides derivatives (Suwa et al., 2013), and the use of progenitor cells for cardiac repair (Thuong et al., 2016), among others. None of these papers directly address the existence of D-carnitine.
In summary, while D-carnitine is not a focus of the provided papers, its existence is implied through the general understanding of stereoisomers in chemistry. The papers provided do not offer direct information on D-carnitine, but they do illustrate the breadth of research on naturally occurring compounds and their synthetic analogs (Salama, 2021; Suwa et al., 2013; Thuong et al., 2016).

Source Papers

Efficacy of Disinfectants against Naturally Occurring and Artificially Cultivated Bacteria

Naturally occurring bacteria, is exist in nature, and is never cultivated on conventional culture medium. We evaluated the efficacy of disinfectants against naturally occurring bacteria in in-use cotton balls soaked in 0.02% benzalkonium chloride solution which had been used to disinfect the genital area by patients undergoing self-catheterization at home and the same bacteria subcultured on nutrient broth (artificially cultivated bacteria). The colony forming units (CFU) of naturally occurring bacteria such as Serratia marcescens, Alcaligenes xylosoxidans, and Burkholderia cepacia were not decreased after 48 h exposure to 0.025-0.1% benzalkonium chloride solution, but the same strains subcultured on nutrient broth were killed within only 10 min exposure to 0.025-0.1% benzalkonium chloride solution. In addition, the CFU of these three kinds of naturally occurring bacteria were not decreased after 48 h exposure to 0.02% chlorhexidine gluconate solution, but the same strains subcultured on nutrient broth were killed within 2 h exposure to chlorhexidine gluconate solution. The result showed that disinfectant efficacy differed markedly against naturally occurring and artificially cultivated bacteria. Therefore, it is preferable to use the naturally occurring bacteria not only artificially cultivated bacteria when examining disinfectant efficacy.

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Open Access
Naturally Occurring Triploidy in Cannabis

Polyploidy is a significant evolutionary process in plants that involves the duplication of genomic content and has been recognized as a key mechanism driving plant diversification and adaptation. In natural populations, polyploids frequently arise from unreduced gametes, which subsequently fuse with reduced or unreduced gametes, resulting in triploid or tetraploid offspring, respectively. Cannabis sativa L. is a diploid species, but recent work using artificially induced polyploidy has demonstrated its potential advantages in an agricultural setting. Further, recent work has identified that some elite clonal cultivars, vis. Mac1, are triploid, with no indication that they were artificially produced. The current study was conducted to determine if polyploidy is a naturally occurring phenomenon in cannabis and to estimate the frequency of this phenomenon across populations. To do this, the presence of natural triploid individuals was evaluated in 13 seedling populations of cannabis using a flow cytometry analysis. Among the examined populations, natural triploids were identified in 10 groups with an average frequency of approximately 0.5%. The highest frequency of natural triploids was observed in a self-pollinated population at 2.3%. This research demonstrates that polyploidy is a naturally occurring event in cannabis and triploids are present at an average of approximately 0.5%, or 1 in 200 plants. These data shed light on the natural variation in ploidy within cannabis populations and contribute valuable insights to the understanding of cannabis genetics and breeding practices.

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Open Access
The Naturally Occurring Compound Garcinia Indica Selectively Impairs the Reconsolidation of a Cocaine-Associated Memory.

Sustained abstinence from cocaine use is frequently compromised by exposure to environmental stimuli that have previously been strongly associated with drug taking. Such cues trigger memories of the effects of the drug, leading to craving and potential relapse. Our work has demonstrated that manipulating cocaine-cue memories by destabilizing them through interfering with the reconsolidation process is one potential therapeutic tool by which to prolong abstinence. Here, we examine the use of the naturally occurring amnestic agent garcinol to manipulate an established cocaine-cue memory. Rats underwent 12 days of cocaine self-administration training during which time active lever presses resulted in an i.v. infusion of cocaine that was paired with a light/tone cue. Next rats underwent lever extinction for 8 days followed by light/tone reactivation and a test of cue-induced cocaine-seeking behavior. Systemic injection of garcinol 30 min after reactivation significantly impaired the reconsolidation of the cocaine-associated cue memory. Further testing revealed that garcinol had no effect on drug-induced cocaine-seeking, but was capable of blocking the initial conditioned reinforcing properties of the cue and prevents the acquisition of a new response. Additional experiments showed that the effects of garcinol are specific to reactivated memories only, temporally constrained, cue-specific, long-lasting, and persist following extended cocaine access. These data provide strong evidence that the naturally occurring compound, garcinol, may be a potentially useful tool to sustain abstinence from drug abuse.

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Open Access
Hydronopylformamides: Modification of the Naturally Occurring Compound (-)-β-Pinene to Produce Insect Repellent Candidates against Blattella germanica.

The development of a novel repellent plays an important role in the integrated control of Blattella germanica. A series of novel hydronopylformamides derivatives were synthesized from a naturally occurring compound (-)-β-pinene. The structures of these hydronopylformamides derivatives were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (1H-NMR and 13C-NMR), and electron impact mass spectrometry (EI-MS). Repellency of these hydronopylformamides derivatives against Blattella germanica was evaluated by the using petri dish arena method. The results showed that four derivatives (compounds 8a, 8b, 8c and 8e) exhibited repellency against Blattella germanica at a concentration of 20 mg/mL. Compound 8a was the most active compound among these derivatives, where the repelling ratios of compound 8a against Blattella germanica were 66.10%, 50.46%, 48.26%, at concentrations of 20 mg/mL, 10 mg/mL, and 5 mg/mL, respectively. In addition, compound 8a showed better repellency than the traditional insect repellent N, N-diethyl-3-methylbenzamide (DEET), which indicated that compound 8a had a good application prospect in the prevention of Blattella germanica. This research hopes to promote the value-added utilization of (-)-β-pinene and the development of novel German cockroach repellents.

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Open Access
Potentiating the Naturally Occurring Process for Repair of Damaged Heart

This article reviews the current progresses in application of both exogenous and endogenous progenitor cells/stem cells for cardiac repair, and the current understanding of the naturally-occurring process for physiological myocyte turnover and possibly cardiac repair. In particular the development of methods for potentiating the naturally-occurring mechanism for substantial repair of pathologically damaged cardiac tissues is discussed. In the last decade, tremendous efforts to identify both exogenous and endogenous progenitor cells/stem cells possessing capacities of differentiating into cardiac lineages have been made for potential cardiac repair. Although many impressive progresses have been made in the application of differently sourced progenitor cells/stem cells, such as embryonic stem cells (ESCs), induced pluripotent stem cell (iPS), bone marrow-derived mesenchymal stem cells (MSCs), skeletal myoblasts (SMs), umbilical cord blood cells (UCBs), residential cardiac stem cells (CSCs), cardiac resident fibroblasts (CRFs), or adipose tissue-derived stem cells (ASCs) for repair of damaged heart, however, inevitable controversies exist concerning: (i) the immune compatibility of the exogenous donor progenitors/stem cells, (ii) the tumorigenicity with ESCs and iPS, and (iii) the efficiency of these exogenous or endogenous progenitors/ stem cells to acquire cardiac lineages to reconstitute the lost cardiac tissues. The recent recognition of some active small molecules that can induce myocardial regeneration to repair damaged heart tissues through enhancing the naturally-occurring cardiac-repair mechanism has offered the hope for clinical translation of the technology. Potentiating the naturally-occurring process for cardiac repair by administration of such small molecules has provided a promising strategy for reconstruction of damaged cardiac tissues after heart infarction. Therefore, this article is in favor of the notion that such small molecules with the activity of manipulating gene expressions in such a way of inducing endogenous stem cells to commit cardiac lineage differentiation and consequently myocardial regeneration may fulfill the dream of substantial repair of damaged heart.

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