Objectives: The stratum corneum (SC) remains an obstacle to the passage of drugs applied topically. Several investigations have focused on enhancing the penetration of drugs through the SC by integrating permeation enhancers (PE) into the drug formulation. Terpenes are among the PE utilized in formulations and are categorized by the regulatory bodies as generally recognized as safe (GRAS). This study aimed to comparatively analyze the skin permeation enhancing effect of terpenes on lipophilic drugs. Methods: The present study reviewed the effects of terpenes on the permeation of lipophilic small-molecule drugs through the skin using original research published between 2000 - 2022 retrieved from PubMed®. The search phrase used was (lipophilic drug) AND (terpene) AND (permeation enhancer). Results: Terpenes increase the percutaneous permeation of lipophilic small molecule drugs by 1.06 – 256.80-fold. Linear correlation analysis of terpenes’ cLog P with enhancement ratio (ER) revealed moderate and strong positive correlations in pig skin (r = 0.21) and mouse skin (r = 0.27), and rat skin (r = 0.41) and human skin (r = 0.67), respectively. Drug cLog P is a poor (r = -0.06) predictor of permeation enhancement. Terpenes with cLog P higher than 2.40 had ER greater than 10. Higher ERs (>30) were recorded for nerolidol, carvacrol, borneol, terpineol, limonene, menthone, pulegone, and menthol among the terpene-chemical penetration enhancers. Conclusion cLog P of terpene-based chemical permeation enhancers (CPE) is strongly correlated with ER of lipophilic drugs across human skin. Non-polar groups in terpenes and hydrogen bond interactions by terpenes with SC lipid enhance cutaneous drug penetration of lipophilic drugs.
Terpenes ; Skin

OBJECTIVES: This study investigated the optimal combination of 3-component photoinitiation system, consisting of CQ, p-octyloxy-phenyl-phenyl iodonium hexafluoroantimonate (OPPI), and 2-dimethylaminoethyl methacrylate (DMAEMA) to increase the degree of conversion of resin monomers, and analyze the effect of the ratio of the photoinitiator to the co-initiator. MATERIALS AND METHODS: Each photoinitiators (CQ and OPP) and co-initiator (DMAEMA) were mixed in three levels with 0.2 wt.% (low concentration, L), 1.0 wt.% (medium concentration, M), and 2.0 wt.% (high concentration, H). A total of nine groups using the Taguchi method were tested according to the following proportion of components in the photoinitiator system: LLL, LMM, LHH, MLM, MMH, MHL, HLH, HML, HHM. Each monomer was polymerized using a quartz-tungsten-halogen curing unit (Demetron 400, USA) for 5, 20, 40, 60, 300 sec and the degree of conversion (DC) was determined at each exposure time using FTIR. RESULTS: Significant differences were found for DC values in groups. MMH group and HHM group exhibited greater initial DC than the others. No significant difference was found with the ratio of the photoinitiators (CQ, OPPI) to the co-initiator (DMAEMA). The concentrations of CQ didn't affect the DC values, but those of OPPI did strongly. CONCLUSIONS: MMH and HHM groups seem to be best ones to get increased DC. MMH group is indicated for bright, translucent color and HHM group is good for dark, opaque colored-resin.
Ethylamines ; Methacrylates ; Polymers ; Terpenes

In this study, the antifungal activities of limonene against Trichophyton rubrum were evaluated via broth microdilution and vapor contact assays. In both assays, limonene was shown to exert a potent antifungal effect against T. rubrum. The volatile vapor of limonene at concentrations above 1 microl/800 ml air space strongly inhibited the growth of T. rubrum. The MIC value was 0.5% v/v in the broth microdilution assay. The antifungal activity of limonene against T. rubrum was characterized as a fungicidal effect.
Cyclohexenes ; Terpenes ; Trichophyton

Terpenes are the largest group of natural products and contain the widest assortment of structural types. Terpene cyclization is also the most complex reaction found in nature. For a long time, terpenoids with diverse structures have attracted natural product chemists to explore their biosynthesis mechanism. Such a large number of terpene skeletons are catalyzed by enzymes called terpene synthase. Sesquiterpene synthase is a kind of terpene synthase, which can catalyze the cyclization of linear precursor farnesyl pyrophosphate(FPP) to sesquiterpene skeletons. Sesquiterpene synthase cyclize a single precursor FPP into many sesquiterpene skeletons. With the continuous discovery of sesquiterpene synthase, the cyclization mechanism of sesquiterpene synthase has been studied deeply. In recent years, with the development and improvement of isotope labeling of substrate FPP and structural analysis of sesquiterpene synthase, the structure and cyclization mechanism of sesquiterpene synthase have been studied more systematically and accurately. In this review, we reviewed the progress of the research methods on the mechanism of sesquiterpene cyclization by substrate isotope labeling and protein structure, as well as the summary and prospect of sesquiterpene synthase research.
Cyclization ; Sesquiterpenes ; Terpenes

Phytochemical constituents were isolated from the fruits of Acanthopanax chiisanensis by repeated column chromatography. Their structures were identified as beta-sitosterol (1), daucosterol (2), sesamin (3), chiisanogenin (4), and 22alpha-hydroxy chiisanogenin (5) by spectroscopic analysis (MS, 1H-, and 13C-NMR). Compounds 1 - 5 were isolated for the first time from the fruits of A. chiisanensis.
Eleutherococcus* ; Araliaceae ; Chromatography ; Fruit* ; Terpenes*

To investigate the chemical constituents of Saussurea deltoidea, 10 compounds were isolated from the title plant by various chromatography methods such as silica gel, RP-18 silica gel, Sephadex LH-20 column chromatography, HPLC, et al. Their structures were elucidated by spectral analysis. Five isoprenoids and Five phenylpropanoids were isolated and elucidated as (3R, 6R, 7E) -3-hydroxy-4, 7-megastigmadien-9-one (1), (3S, 5R, 6S, 7E) -5, 6-epoxy-3-hydroxy-7-megastigmen-9-one (2), 3-hydroxy-beta-damascone (3), S-(+) -dehydrovomifoliol (4), megastigman-5-ene-3beta, 9R-diol (5), coniferaldehyde (6), beta-hydroxypropiovanillone (7), 3-hydroxy-1-(4-hydroxy-3, 5-dimethoxyphenyl) -1-propanone (8), dihydrosyringenin (9), 4-[(1S) -3-hydroxy-1-methoxypropyl]-2, 6-dimenthoxyphenol (10). All the compounds were isolated from S. deltoidea for the first time.
Saussurea ; chemistry ; Terpenes ; isolation & purification

Syringa plants are of important value in ornamental, economic and medical fields. The terpenoids in Syringa plants mainly include iridoids, sesquiterpenoids, and triterpenoids, most showing activities such as cardioprotective, neuroprotective, hypoglycemic, anti-flu virus, anti-bacterial, anti-inflammatory, and anti-oxidation effects. Among the above active compounds, sesquiterpenoids have attracted increasing attention. In this review, the phytochemical and pharmacological activities of Syringa terpenoids were summarized in order to provide an overview for further research and development of Syringa plants.
Phytochemicals ; Sesquiterpenes ; Syringa ; Terpenes ; Triterpenes

The chemical composition of the leaves of Artemisia annua L. has been investigated Besides artemisinine, an antimalarial compound - six other terpenes such as amyrinacetate, artemisinic acid, a-amyrine, b-sitosterol, stigmasterol and arteanuine have been found. Their structures were identified by spectroscopic methods
Terpenes ; chemistry ; Plants, Medicinal ; Medicine, Traditional

Genome mining for the search and discovery of two new globin-like enzymes, TriB fromFusarium poae and TutaA from Schizophyllum commne, are involved in the synthesis of two linear terpenes tricinonoic acid (1) and 2-butenedioic acid (3). Both in vivo heterologous biosynthesis and in vitro biochemical assays showed that these two enzymes catalyzed the C-C double bond cleavage of a cyclic sesquiterpene precursor (-)-germacrene D (7) and a linear diterpene backbone schizostain (2), respectively. Our work presents an unusual formation mechanism of linear terpenes from fungi and expands the functional skills of globin-like enzymes in the synthesis of terpene compounds.
Terpenes/chemistry* ; Alkyl and Aryl Transferases ; Globins ; Diterpenes

The terpenoids in Pogostemon cablin have complex structures and abundant pharmacological effects. Patchouli alcohol(PA) and pogostone(PO) have a high medicinal value by virtue of anti-tumor, anti-inflammatory, antibacterial, antioxidant, and other biological activities. Due to the low content of terpenoid metabolites in P. cablin, the study of biosynthesis and metabolism regulation can provide a biosynthetic basis for obtaining high-content terpenoids. In this study, key enzyme genes in biosynthesis, transcription factors in metabolism regulation, spatio-temporal expression of terpene synthase were reviewed, aiming to provide a reference for the development, protection, and utilization of P. cablin resources.
Pogostemon/genetics* ; Terpenes ; Transcription Factors/genetics*