Chemical characteristics of the sesquiterpenes and diterpenes from Lauraceae family and their multifaceted health benefits: A review

Lauraceae is a large family with significant economic and medicinal value. Bioactive ingredients from Lauraceae plants have contributed greatly to medicines, food nutrients and fine chemical products. In recent years, quite a few sesquiterpenes and diterpenes with unique structures have been achieved from Lauraceae and their potential benefits are embodied in a wide range of health areas. To our knowledge, there is no review to summarizes these constituents and their biological effects systematically. This current work aims to classify and ascribe the structural types and bioactivities of the identified sesquiterpenes and diterpenes. Herein, a total of 362 sesquiterpenes and 69 diterpenes were comprehensively complied. The various bioactivities could be recognized as cytotoxicity, anti-proliferation and/or anti-apoptosis, anti-inflammation, anti-oxidation, anti-bacterium, etc. This updated data could serve as a catalysis of these sesquiterpenes and diterpenes for the future medical and industrial applications.

Preparation, characterization, and biological activity of Cinnamomum cassia essential oil nano-emulsion

To solve the problems of low bioavailability and unstable properties of Cinnamomum cassia Essential oil (CCEO), encapsulation technology was introduced as an effective means to improve its shortcomings. In this study, Cinnamomum cassia Essential oil nano-emulsion (CCEO-NE) was successfully synthesized by the oil-in-water method and characterized by standard analytical methods, including dynamic light scattering (DLS), Scanning electron microscopy (SEM), and Transmission electron microscopy (TEM). The results show that the synthesized CCEO is spherical, smooth in surface, and uniform in shape, with an average particle size of 221.8 ± 1.95 nm, which is amorphous. In this experiment, by simulating the digestion of CCEO-NE in the gastrointestinal tract, it was found that CCEO-NE was undigested in the oral cavity, mainly in the stomach, followed by the small intestine. By understanding the digestion of CCEO-NE, we can improve the potential of CCEO bioavailability in food and drug applications. In addition, through the study of ABTS and DPPH free radicals by CCEO and CCEO-NE, it was found that the antioxidant activity of CCEO-NE was more potent than that of CCEO. When the concentration of CCEO-NE and CCEO is 400 μg/mL, the DPPH free radical scavenging rate is 92.03 ± 0.548% and 80.46 ± 5.811%, respectively. In comparison, ABTS free radical scavenging rate is 90.35 ± 0.480% and 98.44 ± 0.170% when the concentration of CCEO- NE, and CCEO is 75 μg/mL, respectively. The antibacterial test shows that CCEO-NE can inhibit both Gram-positive and Gram-negative bacteria. Among them, CCEO-NE has a stronger antibacterial ability than CCEO, and the maximum inhibition zone diameter of CCEO can reach 15 mm, while that of CCEO-NE can reach 18 mm. Meanwhile, SEM and TEM showed that CCEO-NE treatment destroyed the ultrastructure of bacteria. Generally speaking, we know the situation of CCEO in the gastrointestinal tract. CCEO-NE has more potent antioxidant and antibacterial ability than CCEO. Our research results show that whey protein is an effective packaging strategy that can improve the effectiveness, stability, and even bioavailability of CCEO in various applications, including food and health care industries.

Highly oxygenated isoryanodane diterpenoids from the leaves of Cinnamomum cassia and their immunomodulatory activities

A total of twelve highly oxygenated isoryanodane (also known as cinncassiol D-type) diterpenoids including nine undescribed ones, named cinnacassins A-I, were isolated from the leaves of Cinnamomum cassia. Their chemical structures were elucidated by extensive spectrometric and spectroscopic techniques including HRESIMS, 1D and 2D NMR, single-crystal X-ray diffraction analysis, calculated ¹³C-NMR DP4+ analysis, and chemical methods. The absolute configuration of cinnacassin A was unambiguously delineated by single-crystal X-ray diffraction analysis. Cinnacassin H represents the first example of 16-O-glucosylated isoryanodane diterpenoid, and cinnacassin I is the first isoryanod-13(18)-ene diterpenoid. The relationship of the configuration C-18 and the chemical shifts of H₂-19 and C-20 in the 19-hydroxy-isoryanodane diterpenoids was discussed, and the 18S-configuration of three known 19-hydroxy-isoryanodane diterpenoids, cinncassiol D₁, 19-O-β-D-glucopyranosyl-cinncassiol D₁, and cinncassiol D₃ was assigned. All the isolated isoryanodane diterpenoids were evaluated for their immunomodulatory effects in vitro, and cinnacassin A and cinncassiol D₁ enhanced the proliferation of Con A-induced murine T cells with enhancement rates ranging from 17.9% to 45.4%, which were more potent than the positive control, thymosin α1. In addition, cinncassiol D₁ significantly promoted the proliferation of LPS-induced murine B cells with an enhancement rate up to 116.1%, two-fold more potent than thymosin α1 at a concentration of 1.5625 μM.

Aromatic and Aliphatic Apiuronides from the Bark of Cinnamomum cassia

Cinnamomum cassia Presl (Cinnamon) has been widely cultivated in the tropical or subtropical areas, such as Yunnan, Fujian, Guandong, and Hainan in China, as well as India, Vietnam, Thailand, and Malaysia. Four new glycosides bearing apiuronic acid (1, 4, 6, and 7) and their sodium or potassium salts (2, 3, and 5), together with 31 known compounds, were isolated from a hot water extract of the bark of C. cassia via repeated chromatography. The structures of the new compounds (1-7) were determined by NMR, IR, MS, and ICP-AES data and by acid hydrolysis and sugar analysis. This is the first report of the presence of apiuronic acid glycosides. Some of the isolates were evaluated for their analgesic effects on a neuropathic pain animal model induced by paclitaxel. Cinnzeylanol (8), cinnacaside (9), kelampayoside A (10), and syringaresinol (11) showed analgesic effects against paclitaxel-induced cold allodynia.

The Total Synthesis of Diquinane-Containing Natural Products

Diquinane or bicyclo[3.3.0]octane is a conspicuous structural unit existing in the carbo-frameworks of a wide range of natural products such as alkaloids and terpenoids. These diquinane-containing molecules not merely exhibit intriguing architectures, but also showcase a broad spectrum of significant bioactivities, which draw widespread attention from the global synthetic community. During the past decade, with an aim to accomplish the total syntheses of such specified cornucopias of natural products, a variety of elegant strategies for construction of the diquinane ring system have been disclosed. In this Minireview, the achievements on this subject in the timeline from 2010 to June 2020 are demonstrated and it is discussed how the diquinane unit is strategically forged in the context of the specific target structure. In addition, impacts of the selected works to the field of natural product total synthesis is highlighted and the particular outlook of diquinane-containing natural product synthesis is provided.

Metabolomic profiling and comparison of major cinnamon species using UHPLC-HRMS

The metabolomic profiles of four major species of cinnamon (Cinnamomum verum, C. burmannii, C. loureiroi, and C. cassia) were investigated by ultra-high-performance liquid chromatography-high-resolution mass spectrometry (UHPLC-HRMS). Thirty-six metabolites were tentatively characterized, belonging to various compound groups such as phenolic glycosides, flavan-3-ols, phenolic acids, terpenes, alkaloids, and aldehydes. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) on the HRMS data matrix resulted in a clear separation of the four cinnamon species. Coumarin, cinnamaldehyde, methoxycinnamaldehyde, cinnamoyl-methoxyphenyl acetate, proanthocyanidins, and other components varied among the four species. Such variations were used to develop a step-by-step strategy for differentiating the four cinnamon species based on their levels of pre-selected components. This study suggests a significant variation in the phytochemical compositions of different cinnamon species, which have a direct influence on cinnamon's health benefit potentials. Graphical Abstract.

Terpenoids and Their Biological Activities from Cinnamomum: A Review

Cinnamomum is a genus of the family Lauraceae, which has been recognized worldwide as an important genus due to its beneficial uses. A great deal of research on its phytochemistry and pharmacological effects has been conducted. It is noteworthy that terpenoids are the characteristic of Cinnamomum due to the peculiar structures and significant biological effects. For a more in-depth study and the better use of Cinnamomum plants in the future, the chemical structures and biological effects of terpenoids obtained from Cinnamomum were summarized in the present study. To date, a total of 181 terpenoids with various skeletons have been isolated from Cinnamomum. These compounds have been demonstrated to play an important role in immunomodulatory, anti-inflammatory, antimicrobial, antioxidant, and anticancer activities. However, studies on the bioactive components from Cinnamomum plants have only focused on a dozen species. Hence, further studies on the potential pharmacological effects need to be conducted in the future.

Cassiabudanols A and B, Immunostimulative Diterpenoids with a Cassiabudane Carbon Skeleton Featuring a 3-Oxatetracyclo[6.6.1.02,6.010,14]pentadecane Scaffold from Cassia Buds

Two novel diterpenoids, cassiabudanols A (1) and B (2), were isolated from cassia buds. Their structures were determined by comprehensive spectroscopic analysis and single-crystal X-ray diffraction. Compounds 1 and 2 possess an unprecedented 11,14- cyclo-8,14:12,13-di- seco-isoryanodane (cassiabudane) carbon skeleton featuring a unique 3-oxatetracyclo[6.6.1.0^2,6.0^10,14]pentadecane bridged system, and their biosynthetic pathways are proposed. Compounds 1 and 2 exhibited significant immunostimulative activity, and the mode of action of 2 involves upregulating CD4⁺ and CD8⁺ T cells and downregulating Tregs.

Diterpenoids with Immunosuppressive Activities from Cinnamomum cassia

Three new diterpenoids with unprecedented carbon skeletons, cinncassiols F (1) and G (2) and 16-O-β-D-glucopyranosyl-19-deoxycinncassiol G (3), a new isoryanodane diterpenoid, 18-hydroxyperseanol (4), six known isoryanodane diterpenoids, 5-10, and a known ryanodane diterpenoid, 11, were isolated from the stem bark of Cinnamomum cassia. Compound 1 possesses an 11,13:12,13-diepoxy-6,11-epoxy:12,13-disecoisoryanodane diterpenoid skeleton bearing ketal and hemiketal functionalities, whereas compounds 2 and 3 feature an 11,12-secoisoryanodane diterpenoid skeleton with an 11,6-lactone moiety. The structures of the four new diterpenoids, 1-4, and their absolute configurations were established using HRESIMS, NMR, ECD, single-crystal X-ray diffraction, and chemical methods. Compounds 2 and 11 significantly inhibited the proliferation of murine T cells induced by ConA.

Wilsonols A-L, megastigmane sesquiterpenoids from the leaves of Cinnamomum wilsonii

Twelve new megastigmane sesquiterpenoids, wilsonols A-L (1-12), were isolated from the leaves of Cinnamomum wilsonii, along with seven known analogues (13-19). The structures of compounds 1-12 were established by spectroscopic analyses. The absolute configurations of 1-5 were determined by single-crystal X-ray diffraction analysis with Cu Kα irradiation, and the absolute configurations of 6-12 were determined by the modified Mosher's method. Compounds 1-9 and 13-19 were evaluated for in vitro cytotoxicity against five human cancer cell lines, HL-60, SMMC-7721, A-549, MCF-7, and SW-480, and compared against the Beas-2B immortalized (noncancerous) human bronchial epithelial cell line. Compound 13 exhibited IC50 values ranging from 2.5 to 12 μM and selectivity indices of >10 against SMMC-7721, A-549, and MCF-7 cell lines. Selected compounds were evaluated for in vitro immunomodulatory activity.