Insight into carbohydrate metabolism, protein quantification and mineral regulation in wheat (Triticum aestivum L.) by the action of green synthesized silver nanoparticles (AgNPs) against heat stress

In the present investigation, the role of GS-AgNPs treatment in wheat plants was carried out in reducing heat stress with the aim of facilitating scientists on this topic. The effect of GS-AgNPs against heat stress has rarely been deliberated in wheat plants, and only a few studies have been established earlier in this scenario. This work illustrated the effect of GS-AgNPs on the regulation of carbohydrates metabolism, SOD, proteins, crude fibers, and minerals changes in wheat plants. Data were analysed using PCA analysis, correlation parameters, and normal probability distribution in PAST 3 software. The results indicated that heat stress alone caused severe changes in carbohydrates metabolism, SOD, proteins, crude fibers, and minerals immediately so that plants could not recover without foreign stabilizers such as GS-AgNPs. The application of GS-AgNPs increases the flux of carbohydrates metabolism, SOD, and proteins, including HSPs, crude fibers, and minerals, in wheat plants to reduce the effect of heat stress. The 50 mg/l concentration of GS-AgNPs has shown an increase in carbohydrates metabolism and SOD activity, while crude fibres have shown a significant enhancement at 100 mg/l of GS-AgNPs. The crude and true proteins were also shown pronounced increase in treatment to a concentration of 50 mg/l of GS-AgNPs. GS-AgNPs stimulated HSP production; most importantly, smHSP production was observed in the present results with other HSPs in wheat plants treated with a 50 mg/l concentration of GS-AgNPs. The mineral distribution was also regulated by the respective treatment of GS-AgNPs, and the highest amounts of Ca, P and Fe were found to be highest in wheat under heat stress. In general, we computed the expected model based on GS-AgNPs on the genes/factors that respond to heat stress and their potential role in mitigating heat stress in wheat. In addition, we discussed the prospective signalling pathway triggered by GS-AgNPs in wheat against heat stress. In the future, this work might be helpful in distinguishing the genetic variation due to GS-AgNPs in promoting tolerance in wheat against heat stress.Communicated by Ramaswamy H. Sarma.

Sono-Microwave Assisted Chlorine free and Ionic Liquid (SMACIL) extraction of cellulose from Urtica dioica: A benign to green approach

The extraction of cellulose using eco-friendly solvents has been gaining significant attention for a couple of decades. This study investigated the impact of benign and green solvents on the extraction, thermal stability, mechanical properties, and crystallinity of cellulose extracted from Urtica dioica (Stinging nettle) using a Sono-Microwave Assisted Chlorine free and Ionic Liquid (SMACIL) extraction technique. In this regard, the stalks were undergone through pre chemical treatment before starting bleaching them with hydrogen peroxide (HPO) and 1-butyl-3-methylimidazolium acetate (BMIM-Ac) having different mole ratios (5, 7.5, and 10) to expose cellulose. The Urtica dioica cellulose (UDC) was characterized using FTIR, tensile testing, FESEM, XRD, and TGA. The fibrillation and lumen can be seen in SEM images that confirm the extraction of cellulose. The results showed that the BMIM-Ac-10 gives the maximum cellulose yield (88 %) than other compositions. Moreover, the cellulose extracted using BMIM-Ac-10 has high mechanical strength which makes it a potential constituent for various applications in the field of materials science. These results have significant implications for the development of sustainable and efficient processes for the extraction of cellulose.

Integrated multi-omic analysis reveals the cytokinin and sucrose metabolism-mediated regulation of flavone glycoside biosynthesis by MeJA exposure in Ficus pandurata Hance

Ficus pandurata Hance (FPH) holds a rich history as a traditional Chinese botanical remedy, utilized both as a culinary condiment and a medicinal intervention for diverse ailments. This study focuses on enhancing FPH's therapeutic potential by subjecting it to exogenous methyl jasmonate (MeJA) treatment, a strategy aimed at elevating the levels of active constituents to align with clinical and commercial requirements. Employing metabolomics, the impact of MeJA treatment on the lipid and flavonoid profiles of FPH leaves was investigated, revealing a marked increase in flavone glycosides, a subset of flavonoids. Investigation into the regulatory mechanism governing flavone glycoside biosynthesis uncovered elevated expression of structural genes associated with flavonoid production in response to MeJA exposure. Global endogenous hormone analysis pinpointed the selective activation of JA and cytokinin biosynthesis following MeJA treatment. Through a comprehensive integration of transcriptomic and metabolomic data, the cooperative stimulation of glucosyltransferase activity, alongside the JA and cytokinin signaling pathways, orchestrated by MeJA were explored. Furthermore, genes linked to sucrose metabolism exhibited heightened expression, concomitant with a noteworthy surge in antioxidant activity subsequent to MeJA treatment. These findings validate the augmentation of FPH leaf antioxidant capacity through MeJA intervention, while also offering profound insights into the regulatory role of MeJA in flavone glycoside biosynthesis, mediated by the interplay between cytokinin and sucrose metabolism pathways.

Clinical Utility of N-Terminal Prohormone B-Type Natriuretic Peptide Levels in Patients of Type 2 Diabetes Mellitus with Heart Failure

Objective: To evaluate the effect of type 2 diabetes mellitus on plasma N-terminal prohormone B-type natriuretic peptide levels in patients with heart failure and correlate it with glycosylated haemoglobin levels. Study Design: Comparative cross-sectional study. Place and Duration of Study: Department of Chemical Pathology in collaboration with the Department of Cardiology,Combined Military Hospital, Multan Pakistan, from Feb to Sep 2021. Methodology: We assayed plasma NT-pro BNP levels in 194 individuals with established heart failure, (98 non-diabetics, and 96 patients with diabetes). Plasma NT-pro BNP levels were compared between groups in addition, the correlation of glycosylated haemoglobin with plasma NT-pro BNP levels was explored. Results: The mean plasma NT-pro BNP values were higher in patients with diabetes (15826.08 ±8143.434pg/mL) than in nondiabetics (12534.06±6323.92pg/mL) with a p-value 0.02. When NT-pro BNP was compared there was no significant found difference between the non-diabetic group and the Controlled Diabetes-Group (p-value 0 .882), but it was significantly higher in the Uncontrolled Diabetes-Group (p-value<0.001). A moderate positive association was found between NT-pro BNP and glycosylated haemoglobin (r=0.541, p-value<0.001). Conclusion: Although obesity has an inverse relation with plasma natriuretic peptides level and most patients with diabetes are overweight, the plasma NT-pro BNP is still a very informative tool and holds its significance as a diagnostic and prognosis marker in diabetic patients with heart failure.

Synthesis of a 2D copper(II)-carboxylate framework having ultrafast adsorption of organic dyes

Two-dimensional (2D) coordination polymers are very interesting materials for their attractive applications. A novel 2D metal-organic framework (MOF) was derived from copper(II) and amino benzoic acid under both room temperature and solvothermal reaction conditions using different solvents. From both of the synthesis methods, an identical MOF was crystalized with monoclinic crystal system having P2₁/c space group. Hirshfeld surface analysis is carried out to explore the non-covalent interactions obtained from single crystal XRD investigation in terms of percentage contribution of each interatomic contact involved in packing of molecules into MOF structure. The microstructure analysis and surface morphology studies revealed the 2D layered regular pattern of rhombus disks of ~5 μm thickness throng together via clustering of these rhombic shaped flakes as flowers (ranging 50-100 μm in size) having uniform elemental composition. This 2D MOF efficiently adsorbed organic dyes (methylene blue, methyl orange, and methyl red) from their aqueous solutions. The 2D copper-carboxylate framework (1.2 g/L) exhibited high adsorption rates for organic dyes (0.15-0.19 mM), and >90% of these dyes could be captured as soon as they are exposed to MOF suspension (1 min) in each case. The dye removal efficiency is credited to synergy among structure, ionic strength, shapes and dimensions of dyes with respect to MOF structure. The microstructure of MOF along with electronic interactions like electrostatic, hydrogen bonding, π-π interactions and coordination to open metal sites, might contribute to the ultrafast dye adsorption process by MOF. The adsorption phenomenon is spontaneous and followed the pseudo-second order kinetic mechanism. DFT calculations revealed important electronic parameters of the dyes and model MOF systems, and novel insights with respect to possible dye-MOF interactions. The MOF remained quite stable during the dye adsorption and was regenerated easily for the successful subsequent use.

Nanoparticles: Synthesis, Morphophysiological Effects, and Proteomic Responses of Crop Plants

Plant cells are frequently challenged with a wide range of adverse environmental conditions that restrict plant growth and limit the productivity of agricultural crops. Rapid development of nanotechnology and unsystematic discharge of metal containing nanoparticles (NPs) into the environment pose a serious threat to the ecological receptors including plants. Engineered nanoparticles are synthesized by physical, chemical, biological, or hybrid methods. In addition, volcanic eruption, mechanical grinding of earthquake-generating faults in Earth's crust, ocean spray, and ultrafine cosmic dust are the natural source of NPs in the atmosphere. Untying the nature of plant interactions with NPs is fundamental for assessing their uptake and distribution, as well as evaluating phytotoxicity. Modern mass spectrometry-based proteomic techniques allow precise identification of low abundant proteins, protein-protein interactions, and in-depth analyses of cellular signaling networks. The present review highlights current understanding of plant responses to NPs exploiting high-throughput proteomics techniques. Synthesis of NPs, their morphophysiological effects on crops, and applications of proteomic techniques, are discussed in details to comprehend the underlying mechanism of NPs stress acclimation.

Effect of excess Fluoride consumption on Urine-Serum Fluorides, Dental state and Thyroid Hormones among children in “Talab Sarai” Punjab Pakistan

190 children aged 7-18 years from an endemic fluorotic village “Talab Sarai (n = 130) and a non-fluorotic, control, village “Ottawa” (n = 60) were selected for comparison. Children were examined for fluoride (F-) concentration in drinking water, urine, and serum as well as Dental fluorosis (DF) and thyroid hormone levels. The mean concentration of water fluoride (WF) in the sample group was 6.23 mg/L, urine fluoride (UF) 3.38 mg/L, and serum fluoride (SF) 0.21 mg/L, while DF was 93.07%. Significant elevations (P = 0.000) in the concentration of all these four variables were observed in sample group children as compared to control. Mean Free Tetra-iodothyronine (FT4), Free Tri-iodothyronine (FT3) and Thyroid Stimulating Hormone (TSH) concentrations in the sample group were 16.64pmol/L, 5.57 pmol /L and 4.41 mlU/L, respectively. No marked difference in FT4 (P = 0.1) was noted, while significant elevations in FT3 and TSH (P = 0.000) were found in the sample relative to the control group. 80% of the children displayed clear thyroid hormonal derangements, with 36.92% having high TSH and 43.07% with FT3 and FT4 disorders. A moderate to strong correlation among WF, UF, SF and DF (r = 0.94, 0.60, 0.60, 0.72) and a very strong correlation between WF and TSH (r = 0.9) were observed. Our results suggest that excess F- level that is four times greater than the “safe limit” is not only increasing fluoride concentration in body fluids but is also affecting thyroid hormones in 4 out of 5 children which could lead to abnormal physical and mental growth in later developmental stages.

Correlation of Water Fluoride with Body Fluids, Dental Fluorosis and FT4, FT3 –TSH Disruption among Children in an Endemic Fluorosis area in Pakistan

In the present study 134 children were studied for comparison and correlation between an endemic fluorotic village Rukh Mudke (RM), n = 74, and a non-fluorotic village Ottawa (OTW), n = 60. The children were aged between 7-18 years and selected for the estimation of fluoride in their household water, body fluids (urine-serum), dental fluorosis and thyroid hormones (Free tri-iodothyronine (FT3) free tetra iodothyronine (FT4) and thyroid stimulating hormone (TSH) respectively. Mean concentration of water fluoride in subjects of RM was 4.6 ×106 ng/L, urine fluoride 2.59 ×106 ng/L, serum fluoride 6.0 ×104 and dental fluorosis 90.5% respectively. Significant elevation (P = 0.000) in the concentration of three out of these four variables (P < 0.01) was observed (except in serum fluoride) in subjects of RM compared to those in the control group (OTW). Mean FT4, FT3 and TSH concentrations in RM subjects was 18.3 pmol/L, 5.06 pmol/L and 3.2 mlU/L respectively. No marked difference in FT4 and FT3 (P = 0.17 and P = 0.7) was found compared to the control (OTW) group, while significant elevation in TSH (P < 0.05) was found in. 22% of the children in the RM group, portrayed well defined thyroid hormonal aberrations. A negative correlation between water fluoride - FT4 (r = - 0.24); a strong positive between water, urine, serum, dental fluorosis and TSH (r = 0.94, 0.87, 0.88, 0.74 and 0.8) and moderate correlation between water fluoride - FT3 (r = 0.52) was observed. Results of this study indicate that the fluoride intoxication through drinking water is not only increasing fluoride level in body fluids and deteriorating teeth but also destroying thyroid function in a large number of children.

Proteomic Analysis of the Effect of Inorganic and Organic Chemicals on Silver Nanoparticles in Wheat

Production and utilization of nanoparticles (NPs) are increasing due to their positive and stimulating effects on biological systems. Silver (Ag) NPs improve seed germination, photosynthetic efficiency, plant growth, and antimicrobial activities. In this study, the effects of chemo-blended Ag NPs on wheat were investigated using the gel-free/label-free proteomic technique. Morphological analysis revealed that chemo-blended Ag NPs resulted in the increase of shoot length, shoot fresh weight, root length, and root fresh weight. Proteomic analysis indicated that proteins related to photosynthesis and protein synthesis were increased, while glycolysis, signaling, and cell wall related proteins were decreased. Proteins related to redox and mitochondrial electron transport chain were also decreased. Glycolysis associated proteins such as glyceraldehyde-3-phosphate dehydrogenase increased as well as decreased, while phosphoenol pyruvate carboxylase was decreased. Antioxidant enzyme activities such as superoxide dismutase, catalase, and peroxidase were promoted in response to the chemo-blended Ag NPs. These results suggested that chemo-blended Ag NPs promoted plant growth and development through regulation of energy metabolism by suppression of glycolysis. Number of grains/spike, 100-grains weight, and yield of wheat were stimulated with chemo-blended Ag NPs. Morphological study of next generational wheat plants depicted normal growth, and no toxic effects were observed. Therefore, morphological, proteomic, yield, and next generation results revealed that chemo-blended Ag NPs may promote plant growth and development through alteration in plant metabolism.

In vitro germination and biochemical profiling of citrus reticulata in response to green synthesised zinc and copper nanoparticles

Green synthesis of nanoparticles by using plants is an emerging class of nanobiotechnology. It revolutionizes all the fields of nanobiotechnology by synthesizing chemical‐free nanoparticles for various purposes. In the present study, zinc and copper nanoparticles were synthesized by using the white leaves of Allium cepa and further characterized through Zeta analyzer and Scanning electron microscopy. Zeta analyzer elucidated that zinc nanoparticles ranged from 8‐32 nm while copper nanoparticles ranged from 15‐30 nm. Scanning electron microscopy clarified that zinc nanoparticles were irregular while copper nanoparticles were spherical in shape. The effects of green synthesized nanoparticles were evaluated on the germination frequency and biochemical parameters of plant tissues. The nucellus tissues were inoculated on Murashige and Skoog (MS) medium augmented with 30 µg/ml suspension of zinc and copper nanoparticles. Green synthesized nanoparticles enhanced the in vitro germination parameters because of their low toxicity and high efficacy. Significant results were obtained for germination parameters in response to the applications of zinc nanoparticles as compared to copper nanoparticles. These nanoparticles could also induce stress in plantlets by manipulating the endogenous mechanism as a result various defence compounds are produced which have potential in treating various human ailments. Copper nanoparticles showed higher toxicity as compared to zinc nanoparticles and triggered the production of antioxidative enzymes and non‐ enzymatic compounds.

Proteomic and physiological analyses of wheat seeds exposed to copper and iron nanoparticles

To elucidate the role of Cu and Fe NPs on the yield of wheat varieties, a gel-free proteomic technique was used. NPs were synthesized and characterized through zeta potential, EDX, and SEM. Spike length, number of grains per spike, and 1000 grain weight were increased in wheat varieties treated with 25ppm Cu and Fe NPs. On treatment with 25ppm Cu and Fe NPs, a total of 58, 121, and 25 proteins were changed in abundance in wheat seeds of galaxy-13, Pakistan-13, and NARC-11, respectively. In galaxy-13, exposure to Cu NPs increased proteins involved in starch degradation and glycolysis. Furthermore, the number of proteins related to starch degradation, glycolysis, and tricarboxylic acid cycle was increased in galaxy-13 on Fe NPs exposure. Proteins related to glycolysis and the tricarboxylic acid cycle was increased in Pakistan-13 and NARC-11 by Fe NPs exposure. The sugar content and SOD activity was increased in wheat seeds treated with Cu and Fe NPs. The Cu content was increased at 25ppm Cu NPs exposure in seeds of wheat varieties. These results suggest that Cu NPs improved stress tolerance in wheat varieties by mediating the process of starch degradation, glycolysis, and tricarboxylic acid cycle through NPs uptake.

Gel-free/label-free proteomic analysis of wheat shoot in stress tolerant varieties under iron nanoparticles exposure

Iron nanoparticles (Fe NPs) have stimulatory effects on the germination ratio and plant growth of wheat. To elucidate the effects of Fe NPs on shoot of drought tolerant Pakistan-13 and salt tolerant NARC-11, a gel-free/label-free proteomic technique was used. The weights/lengths of seedling, shoot, and root of wheat varieties were increased on 5ppm Fe NPs exposure. The number of proteins related to photosynthesis and protein metabolism was decreased and increased in drought tolerant variety and salt tolerant variety, respectively, treated with Fe NPs compared to untreated plants. Differentially changed proteins in drought tolerant variety and salt tolerant variety were mainly related to photosynthesis. Out of photosynthesis related proteins, light reaction was enhanced in salt tolerant variety compared to drought tolerant variety on Fe NPs exposure. The abundance of ribulose bisphosphate carboxylase/oxygenase small chain in drought tolerant variety was higher than that in salt tolerant variety; however, in salt tolerant variety, it was increased 3 fold by Fe NPs exposure compared to untreated plant. These results suggest that Fe NPs improve the growth of wheat seedling, which might be associated with the increase of protein abundance in photosynthesis in salt tolerant variety.

Quantitative proteomic analysis of post-flooding recovery in soybean root exposed to aluminum oxide nanoparticles

Aluminum oxide nanoparticles (Al2O3 NPs) are used in various commercial and agricultural products. Soybean exhibits severe reduction in growth under flooding condition. To examine the effects of Al2O3 NPs on the recovery of soybean from flooding, proteomic analysis was performed. Survival percentage and weight/length of root including hypocotyl were improved after 2 and 4days of flooding with 50ppm Al2O3 NPs leading to recovery as compared to flooding. A total of 211 common proteins were changed in abundance during the recovery period after treatment without or with Al2O3 NPs. These proteins were related to protein synthesis, stress, cell wall, and signaling. Among the identified stress-related proteins, S-adenosyl-l-methionine dependent methyltransferases were recovered from flooding with Al2O3 NPs. Hierarchical clustering divided the identified proteins into three clusters. Cluster II exhibited the greatest change in proteins related to protein synthesis, transport, and development during the recovery from flooding with Al2O3 NPs. However, activity of enolase remained unchanged during flooding leading to subsequent recovery with Al2O3 NPs. These results suggest that S-adenosyl-l-methionine dependent methyltransferases and enolase might be involved in mediating recovery responses by Al2O3 NPs.

BIOLOGICAL SIGNIFICANCE

This study highlighted the role of Al2O3 NPs in recovery of soybean seedlings from flooding stress using gel-free proteomic technique. The key findings of this study are as follows: (i) survival percentage was enhanced at 50ppm Al2O3 NPs during the recovery stage; (ii) seedling weight and weight/length of root including hypocotyl improved at 50ppm Al2O3 NPs during the period of recovery; (iii) protein synthesis and stress related proteins were increased on recovery after flooding without or with Al2O3 NPs; (iv) the abundance of S-adenosyl-l-methionine dependent methyltransferases recovered from flooding with Al2O3 NPs; (v) glycolysis related proteins amplified under flooding with Al2O3 NPs; (vi) enolase enzyme remained unchanged during flooding leading to subsequent recovery from flooding with Al2O3 NPs. Collectively, these results suggest that S-adenosyl-l-methionine dependent methyltransferases and enolase are involved in response to flooding with Al2O3 NPs and might be helpful in recovery from flooding stress.

Genetic divergence for high-molecular weight glutenin subunits (HMW-GS) in indigenous landraces and commercial cultivars of bread wheat of Pakistan

Wheat flour quality is an important consideration in the breeding and development of new cultivars. A strong association between high-molecular weight glutenin subunits (HMW-GS) and bread making quality has resulted in the widespread utilization of HMW-GS in wheat breeding. In this study, we analyzed 242 lines of wheat, including landraces from the provinces of Punjab and Baluchistan, as well as the commercial varieties of Pakistan, to determine allelic variation in the Glu-A1, Glu-B1, and Glu-D1 loci encoding HMW-GS. Higher genetic diversity was observed for HMW-GS in landraces from Baluchistan, followed by landraces collected from Punjab and then commercial varieties. Rare and uncommon subunits were observed in Glu-B1, whereas Glu-A1 was less polymorphic. However, Glu-B1 was the highest contributor to overall diversity (78%), with a total of 31 rare alleles, followed by Glu-D1 (20%) with the high quality 5+10 allele and other variants. Commercial cultivars possessed favorable alleles, potentially from indirect selection for wheat flour quality by the breeders; however, this indirect selection has decreased the pedigree base of commercial cultivars. The allelic combinations, including 2*, 5+10, and 17+18, showing high quality scores were frequent among landraces, indicating their usefulness in future crop improvement and breeding programs.

Development of a liquid chromatographic method based on ultraviolet-visible and electrospray ionization mass spectrometric detection for the identification of nitrocatechols and related tracers in biomass burning atmospheric organic aerosol

RATIONALE

Studying the chemical composition of biomass burning aerosol (BBA) is very important in order to assess their impact on the climate and the biosphere. In the present study, we focus on the characterization of some newly recognized biomass burning aerosol tracers including methyl nitrocatechols, nitroguaiacols and 4-nitrocatechol, but also on nitrophenols, methyl nitrophenols and nitrosalicylic acids, using liquid chromatography tandem mass spectrometry.

METHODS

For the purpose of their separation and detection in atmospheric aerosol, a new chromatographic method was initially developed based on reversed-phase chromatography coupled with ultraviolet/visible (UV/Vis) detection. The method was afterwards transferred to a liquid chromatography/electrospray ionization linear ion trap mass spectrometry (LC/ESI-LITMS) system in order to identify the targeted analytes in winter aerosol from the city of Maribor, Slovenia, using their chromatographic retention times and characteristic (-)ESI product ion (MS(2) ) spectra.

RESULTS

The fragmentation patterns of analytes obtained with LITMS are presented. Additional nitro-aromatic compounds (m/z 168 and 182) closely related to the targeted nitrocatechols and nitroguaiacols were detected in the aerosol. According to their MS(2) spectra these compounds could be attributed to methyl homologues of methyl nitrocatechols and nitroguaiacols.

CONCLUSIONS

The proposed LC/MS method results in a better separation and specificity for the targeted analytes. Several nitro-aromatic compounds were detected in urban BBA. The LC/MS peak intensity of the newly detected methyl nitrocatechols and nitroguaiacols is comparable to that of the methyl nitrocatechols, which also qualifies them as suitable molecular tracers for secondary biomass burning aerosol.

Mass spectrometric characterization of isomeric terpenoic acids from the oxidation of α-pinene, β-pinene, d-limonene, and Δ3-carene in fine forest aerosol

In this study, we present liquid chromatographic and mass spectral data for predominant terpenoic acids formed through oxidation of α-pinene, β-pinene, d-limonene, and Δ(3)-carene that occur in fine forest aerosol from K-puszta, Hungary, a rural site with coniferous vegetation. Characterization of these secondary organic aerosol tracers in fine ambient aerosol is important because it allows one to gain information on monoterpene precursors and source processes such as oxidation and aging processes. The mass spectral data were obtained using electrospray ionization in the negative ion mode, accurate mass measurements, and linear ion trap tandem mass spectrometric experiments. Emphasis is given to the mass spectrometric differentiation of isobaric terpenoic acids, such as, e.g. the molecular weight (MW) 186 terpenoic acids, cis-pinic, cis-caric, homoterpenylic, ketolimononic, and limonic acids. Other targeted isobaric terpenoic acids are the MW 184 terpenoic acids, cis-pinonic and cis-caronic acids, and the MW 204 tricarboxylic acids, 3-methyl-1,2,3-butanetricarboxylic and 3-carboxyheptanedioic acids. Fragmentation pathways are proposed to provide a rational explanation for the observed isomeric differences and/or to support the suggested tentative structures. For the completeness of the data set, data obtained for recently reported lactone-containing terpenoic acids (i.e. terpenylic and terebic acids), related or isobaric compounds (i.e. norpinic acid, diaterpenylic acid acetate, and unknown MW 188 compounds) are also included, the rationale being that other groups working on this topic could use this data compilation as a reference.